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General Discussion => New Physics for Space Technology => Topic started by: rfmwguy on 03/10/2016 02:00 pm

Title: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/10/2016 02:00 pm
This is a thread - Thread 7 in the series - focused on objective analysis of whether the EM Drive (a cavity resonating at microwave frequencies) reported "thrust force" is an experimental artifact or whether it is a real propulsion effect  that can be used for space applications, and if so, in discussing those possible space propulsion applications.

Objective skeptical inquiry is strongly welcome.   Disagreements should be expressed politely, concentrating on the technical, engineering and scientific aspects, instead of focusing on people.   As such, the use of experimental data, mathematics, physics, engineering, drawings, spreadsheets and computer simulations are strongly encouraged, while subjective wordy statements are discouraged. Peer-reviewed information from reputable journals is strongly encouraged.  Please acknowledge the authors and respect copyrights.

Commercial advertisement is discouraged.

In order to minimize bandwidth and  maximize information content, when quoting, one can use an ellipsis (...) to indicate the clipped material.

Only use the embed [img ]http://code when the image is small enough to fit within the page. Anything wider than the width of the page makes the page unreadable as it stretches it (we're working on auto reduction, but different browsers work different ways, etc.)

This link

http://math.typeit.org/

enables typing of mathematical symbols, including differentiation and integration, Greek letters, etc.

--

Links to previous threads:

Thread 1:
http://forum.nasaspaceflight.com/index.php?topic=29276.0

Thread 2:
http://forum.nasaspaceflight.com/index.php?topic=36313.0

Thread 3:
http://forum.nasaspaceflight.com/index.php?topic=37642.0

Thread 4:
http://forum.nasaspaceflight.com/index.php?topic=38203.0

Thread 5:
http://forum.nasaspaceflight.com/index.php?topic=38577.0

Thread 6:
http://forum.nasaspaceflight.com/index.php?topic=39004.0

--

Entry level thread:
http://forum.nasaspaceflight.com/index.php?topic=37438.0

Baseline NSF Article:
http://www.nasaspaceflight.com/2015/04/evaluating-nasas-futuristic-em-drive/

This is the link to the EM Drive wiki that users are encouraged to contribute to, edit for accuracy, and build as a knowledge resource for the EM Drive:

http://emdrive.wiki
http://rfdriven.com

Chris note: Please note all posts need to be useful and worthwhile or they will be removed via moderation. This subject has large interest, with over 3.5 million thread reads and 850,000 article reads. Most people are reading and not posting, so when you post it is in front of a very large audience.

Also, and it should go without saying, amateur experiments are discouraged unless you have gained educated and/or professional advice for safety reasons.

For clarity, the following is an (evolving) chart which attempts to place the "EMDrive" within a larger class of propellantless propulsion concepts. Special thanks to Dr. Jose Rodal.

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=39772.0,3Battach=1113424,3Bimage.pagespeed.ic.g4M4DLR-BO.jpg)

(https://peninkandpaper.files.wordpress.com/2013/09/be-careful-safety-first-sign-s-4115.gif)

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/10/2016 02:04 pm
Welcome to T7, let the conversations continue!
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/10/2016 02:06 pm
Quote
Re: EM Drive Developments - related to space flight applications - Thread 6

Thought about this a lot. Incidental reflections off the side wall don't seem nearly as critical as the endplate reflections. For me, just as in optics, the flatness, thickness and parallel alignment of the endplates is the critical factor.

Of course, I'm 1 DIYer and the beauty of this thing is there is no wrong way to build it; as the right way has not yet been formally disclosed...just hinted at.

It is arguably contrary to present knowledge that <<reflections off the side wall don't seem nearly as critical as the endplate>>.

This can be  shown using the well-known Snell's laws and the coefficients for reflection, as used in microwave engineering for countless applications.

It also runs counter to all the simulations shown in previous EM Drive threads, using:

Meep
Comsol
Feko

The recent analysis using FEKO by Monomorphic being most pertinent in this respect.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/10/2016 02:09 pm
Quote
Re: EM Drive Developments - related to space flight applications - Thread 6

Thought about this a lot. Incidental reflections off the side wall don't seem nearly as critical as the endplate reflections. For me, just as in optics, the flatness, thickness and parallel alignment of the endplates is the critical factor.

Of course, I'm 1 DIYer and the beauty of this thing is there is no wrong way to build it; as the right way has not yet been formally disclosed...just hinted at.

It is incorrect to state that <<reflections off the side wall don't seem nearly as critical as the endplate>>.

This can be trivially shown using the well-known Snell's law and the coefficients for reflection, as used in microwave engineering for countless applications.

It also runs counter to all the simulations shown in previous EM Drive threads, using:

Meep
Comsol
Feko

The recent analysis using FEKO by Monomorphic being most pertinent in this respect.

As I see it, if the end plates are not highly parallel and at a right angle to the frustum length axis, the reflections will walk off toward the widest separation of the end plates and bunch up against the side wall at that point.

It may be possible to put a very slight concave curve into each end plate, which will try to stop the walk off even if the end plates are not highly aligned. Or maybe not.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/10/2016 02:12 pm
Quote
Re: EM Drive Developments - related to space flight applications - Thread 6

Thought about this a lot. Incidental reflections off the side wall don't seem nearly as critical as the endplate reflections. For me, just as in optics, the flatness, thickness and parallel alignment of the endplates is the critical factor.

Of course, I'm 1 DIYer and the beauty of this thing is there is no wrong way to build it; as the right way has not yet been formally disclosed...just hinted at.

It is incorrect to state that <<reflections off the side wall don't seem nearly as critical as the endplate>>.

This can be trivially shown using the well-known Snell's law and the coefficients for reflection, as used in microwave engineering for countless applications.

It also runs counter to all the simulations shown in previous EM Drive threads, using:

Meep
Comsol
Feko

The recent analysis using FEKO by Monomorphic being most pertinent in this respect.

All the sims are done with perfect geometry and alignment. Maybe misalign / non parallel the end plates in the sim and see what is produced?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/10/2016 02:14 pm
Quote
Quote from: Rodal on Today at 01:40 PM
...

It is trivial  to show (with equations routinely used by Aerospace Engineers to design thin shell structures for rockets and spacecraft) that a shell structure made of copper 2 mm thick and 0.2 m length and diameter, would be easy to deform by more than 13 micrometers just by handling.  (Several DIY reported early on that they could change the natural frequency of their EM Drive DIY just by squeezing the EM Drive with their hands).

So, if Shawyer really means that a tolerance of 13 micrometers is necessary, he must have used much thicker (than 2 mm) copper shell structure for the Flight Thruster.

If anything even close to 13 micrometers tolerance is needed, it is easy to show that the thickness of copper used by rfmwguy, SeeShells, Berca,  NASA and others for the EM Drive conical walls are way too thin.

Also, it is well known by Aerospace Engineers for a long time that to provide shell structure stiffness with minimum weight, this can be done with a sandwich wall construction, for example using honeycomb between fascia, for example, such that the metal (aluminum or copper or silver) fascia are thin and such that shear stiffness is provided by the honeycomb and bending stiffness is provided by the distance between the metal (aluminum or copper or silver) fascia in the sandwich wall construction.

If weight savings is not an issue, it should be easier to provide high tolerance for roundness by machining techniques of a thick metal form, than to achieve high tolerance using a very thin metal fascia.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/10/2016 02:16 pm
Quote
Re: EM Drive Developments - related to space flight applications - Thread 6

Thought about this a lot. Incidental reflections off the side wall don't seem nearly as critical as the endplate reflections. For me, just as in optics, the flatness, thickness and parallel alignment of the endplates is the critical factor.

Of course, I'm 1 DIYer and the beauty of this thing is there is no wrong way to build it; as the right way has not yet been formally disclosed...just hinted at.

It is incorrect to state that <<reflections off the side wall don't seem nearly as critical as the endplate>>.

This can be trivially shown using the well-known Snell's law and the coefficients for reflection, as used in microwave engineering for countless applications.
Sidewall deformations are not ideal, but I (just me) am speculating that the fields produced by the alignment of the endplates are more critical than sidewall perfection.

If a sidewall reflection eventually leads to the large plate in a conical scheme, I surmise the large and small plates are what needs to be aligned perfectly. A dented microwave horn will still resonate and radiate, just produce a slightly distorted pattern.

Others are welcome to their own opinions, of course. When it comes to emdrive, I've learned there are few absolutes  ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/10/2016 02:24 pm
Quote
Re: EM Drive Developments - related to space flight applications - Thread 6

Thought about this a lot. Incidental reflections off the side wall don't seem nearly as critical as the endplate reflections. For me, just as in optics, the flatness, thickness and parallel alignment of the endplates is the critical factor.

Of course, I'm 1 DIYer and the beauty of this thing is there is no wrong way to build it; as the right way has not yet been formally disclosed...just hinted at.

It is incorrect to state that <<reflections off the side wall don't seem nearly as critical as the endplate>>.

This can be trivially shown using the well-known Snell's law and the coefficients for reflection, as used in microwave engineering for countless applications.
Sidewall deformations are not ideal, but I (just me) am speculating that the fields produced by the alignment of the endplates are more critical than sidewall perfection.

If a sidewall reflection eventually leads to the large plate in a conical scheme, I surmise the large and small plates are what needs to be aligned perfectly. A dented microwave horn will still resonate and radiate, just produce a slightly distorted pattern.

Others are welcome to their own opinions, of course. When it comes to emdrive, I've learned there are few absolutes  ;)
In your present proposed experiment I understand that you are going with much thicker end plates than the thickness of the copper used for the EM Drive walls.

The thin copper used for your sidewalls is easy to deform out-of-round.

You can perform experiments, if you like, measuring the Q quality of resonance, with EM Drive's made with sidewalls that are not round, to convince yourself that to have a high Q you must have round cross-sections and hence how important it is to have round sidewalls for reflection purposes and hence for high Q.


Alternatively, the effect on Q of having out-of-round sidewalls vs. out-of-flat end plates can be analyzed with numerical methods like Meep, Comsol or FEKO.


*************

Concerning the EM Drive "experiments" this discussion reveals once again how un-rigorous have been the reports on EM Drive experiments up to now:

* Yang has not provided dimensions, we have no idea what is the thickness and dimensions she used

* of institutional reports only NASA has provided full information on dimensions, including thickness
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/10/2016 02:35 pm
I've learned a lot about metal working the past couple of weeks, regarding flatness. If it looks flat...it really isn't.

The 1/8 copper disk (small diameter) looked great from the supplier until I put it on a lapping plate with a backing disk. Progressing from 60 to 2000 grit sandpaper, I was amazed at the material I had to remove to make it close to "flat".

At 2000 grit last night, serious striations are gone but there is still a micron level "unflatness" even after about 4 hours of hand sanding. What this taught me is there is almost no way DIYers can ever achieve perfection in sidewalls. I agree its desirable to maintain shape and symmetry, but I think its best not to worry about it too much. A fully machined and polished frustum is well beyond our budgets. I received a quote for leveling and polishing the small endplate and it was $675  :o
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RERT on 03/10/2016 02:43 pm
TT has reported Roger Shawyer's remarks on required tolerances, but we don't know what Shawyer's goals are.

In other words, if he's trying to make something with extremely high Q (presumably for high thrust) his comments might make sense.

Even if he is right, that doesn't really speak to whether DIY builds can generate measurable thrust with less demanding tolerances.

Maybe TT has more context for RS's remarks which he can share.

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/10/2016 02:51 pm
TT has reported Roger Shawyer's remarks on required tolerances, but we don't know what Shawyer's goals are.

In other words, if he's trying to make something with extremely high Q (presumably for high thrust) his comments might make sense.

Even if he is right, that doesn't really speak to whether DIY builds can generate measurable thrust with less demanding tolerances.

Maybe TT has more context for RS's remarks which he can share.

R.

Roger stated with the tolerance quoted, if should be possible to achieve around 75% of the theoretical max Q and to do it in an affordable manner.

Quote
... If you aim for something like 75% of theoretical Q you will still get viable levels of thrust within a reasonable budget ....


I suggest that someone with a lot more sim model making experience than myself can start to model how far out of parallel the end plates must be to start to get degraded Q and mode.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/10/2016 03:01 pm
...

I suggest that someone with a lot more sim model making experience than myself can start to model how far out of parallel the end plates must be to start to get degraded Q and mode.

The numerical simulations would have to be conducted with much, much finer mesh that used up to now.

The simulations that have been shown in this thread using Meep, and FEKO have a mesh too coarse to accurately show the effect on Q of such tolerance.  The number of nodes is way to small to get close to the tolerances being discussed.   It doesn't appear that this can be really done with the computer resources they have available (certainly they cannot do it to show anything close to the 13 micrometers tolerance being asked by Shawyer).

Still, simulations could show that the side walls are just as important or more important than the end plates, since I really question rfmwguy's assertion regarding that the end plate tolerance is more important than the roundness of the side walls.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/10/2016 03:01 pm
Good to see you back Phil...Yes, I'd love to see the modeling of endplate tolerances...a mm off may drastically change things. Wondering if all feko/meep/comsol models have been assuming perfect parallel plates.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/10/2016 03:02 pm
Thanks for reminding me about the end-plate to end-plate bolts used in Shawyers emdrive. Compressing the frustum is an easy way to tweak the internal dimensions by small fractions. I'm using aluminum plate here to help ad rigidity to the end plates. I think others are using ceramic.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/10/2016 03:19 pm
From my calcs of the internals of the Flight Thruster as below:

BD: 0.2314m
SD: 0.1257m
Len: 0.1386m

the internal area is:  0.137670m^2. Stated mass: 2.92kg

Assuming no flanges and end plates the diameter of the end of the frustum side walls and constant thickness overall, the mass is then:

2mm Copper: 2.46kg
7mm Aluminium: 2.51kg

A 7mm thick end plate and side wall Aluminium Flight Thruster should be fairly stable.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/10/2016 03:29 pm
Thanks for reminding me about the end-plate to end-plate bolts used in Shawyers emdrive. Compressing the frustum is an easy way to tweak the internal dimensions by small fractions. I'm using aluminum plate here to help ad rigidity to the end plates. I think others are using ceramic.

Those external bolts, nuts and attachment flanges are there for a reason.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: zellerium on 03/10/2016 03:50 pm
I designed a frustum that should be able to be made within at least .001 in on an auto lathe. Attached is the drawing for the TE113 mode.
Unfortunately this method get much more pricey for a larger frustum because its turned from a solid piece of Al, but a 9 inch diameter 9 inch tall slug of 6061 should run ~$500 to $600.
 
A few updates I haven't made to these drawings since latest sims:
Aperture size: .875 in by 1.005 in
top radius 1.4 in
bottom radius 4.4 in
waveguide input should be at center, not 1/4 length

Also, I haven't really figured out how to secure the waveguide without welding it in case it needs to be replaced. Anyone have a simple solution?


Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: aero on 03/10/2016 03:56 pm
Good to see you back Phil...Yes, I'd love to see the modeling of endplate tolerances...a mm off may drastically change things. Wondering if all feko/meep/comsol models have been assuming perfect parallel plates.


Yes, all of my meep simulations assume perfect parallel plates.

For a cavity 0.2 m in length, with resolution of 200 gives 1000 voxels per meter. That is one mm resolution and turns out to be a computer challenging but doable resolution. For meep, both cpu cycles and memory requirements preclude directly simulating 10 micron resolution at 2.45 GHz.

Perhaps someone can imagine an effective approximation.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/10/2016 04:02 pm
Thanks for reminding me about the end-plate to end-plate bolts used in Shawyers emdrive. Compressing the frustum is an easy way to tweak the internal dimensions by small fractions. I'm using aluminum plate here to help ad rigidity to the end plates. I think others are using ceramic.

Yes, I'm using ceramic plates <.05um flatness, they provide these very critical build and design points.

Force the endplate flat. The copper 101 O2 free .032" from the factory is better then .3um flat. (best I can measure) When bonded I don't need to do extreme lapping to get high flatness and plus it makes it easier to lap.

Keep deformations to a minimum even during a build from soldering or handling.

They maintain the flatness of the plates during cavity heating.

They make sure the plates stay together via the Quartz rod during tune and maintain parallelism during runs and thermal heating.

Allow the sidewalls expand up and past the small endplate which isn't captured but has a beryllium gasket.

Makes a stiffer overall frustum.

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/10/2016 04:08 pm
I designed a frustum that should be able to be made within at least .001 in on an auto lathe. Attached is the drawing for the TE113 mode.
Unfortunately this method get much more pricey for a larger frustum because its turned from a solid piece of Al, but a 9 inch diameter 9 inch tall slug of 6061 should run ~$500 to $600.
 
A few updates I haven't made to these drawings since latest sims:
Aperture size: .875 in by 1.005 in
top radius 1.4 in
bottom radius 4.4 in
waveguide input should be at center, not 1/4 length

Also, I haven't really figured out how to secure the waveguide without welding it in case it needs to be replaced. Anyone have a simple solution?
Fantastic dwgs! THIS is what I've been looking for and most familiar visual with from back in the day. Guess I've gotta get a student version somehow  ;)

Waveguide launch into the side is quite challenging. Shell might have the answer. Consider this: direct injection of magnetron monopole requires 1 hole and an adapter ring that can be pressure fitted. A 4 point frame would be needed to mount magnetron assembly.

Think it might be easier than a waveguide weld.

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/10/2016 04:22 pm
Perhaps someone can imagine an effective approximation.

I'm pretty sure I can do this in FEKO if I import the misaligned meshes from another program, and then crank up the near field point requests.

How much shall I make the end plates misaligned?  I'm going to try 5 degrees off on the small end plate first.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/10/2016 04:39 pm
I designed a frustum that should be able to be made within at least .001 in on an auto lathe. Attached is the drawing for the TE113 mode.
Unfortunately this method get much more pricey for a larger frustum because its turned from a solid piece of Al, but a 9 inch diameter 9 inch tall slug of 6061 should run ~$500 to $600.
 
A few updates I haven't made to these drawings since latest sims:
Aperture size: .875 in by 1.005 in
top radius 1.4 in
bottom radius 4.4 in
waveguide input should be at center, not 1/4 length

Also, I haven't really figured out how to secure the waveguide without welding it in case it needs to be replaced. Anyone have a simple solution?
Fantastic dwgs! THIS is what I've been looking for and most familiar visual with from back in the day. Guess I've gotta get a student version somehow  ;)

Waveguide launch into the side is quite challenging. Shell might have the answer. Consider this: direct injection of magnetron monopole requires 1 hole and an adapter ring that can be pressure fitted. A 4 point frame would be needed to mount magnetron assembly.

Think it might be easier than a waveguide weld.

If you want to take it apart then a 3/8" or 1/4" mounting plate onto the sidewall of the frustum can be done. Secure it with waveguide weld and mount and slide the waveguide over it and secure it with small screws. Detail work but it can be done and made RF tight.

I liked 1/4 inch Aluminum because it can be hand formed over a mandrel and I used a large hammer and a steel pipe to get it curved.

Shell

Added: Use your fingers.
https://www.sciencedaily.com/releases/2013/09/130916110853.htm
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: X_RaY on 03/10/2016 06:38 pm
@TT
Tolerances of 13µm for a 2.45GHz frustum made of copper???
This would be hard to build and for sure really expensive ;)
Another problem is the thermal expansion coefficient over a few Kelvin is bigger than this!

Example:
L=0,25m (Frustum sidewall length)
a=16.5e-6*Ke-1 (thermal lenght expansion coefficient of copper)
dK=50 degree (temperatur difference)

--->dL=206.25µm

https://forum.nasaspaceflight.com/index.php?topic=39214.msg1470152#msg1470152
https://de.wikipedia.org/wiki/Ausdehnungskoeffizient / https://en.wikipedia.org/wiki/Thermal_expansion

(http://2.bp.blogspot.com/-qHy3-b6v-6g/T9j2X_jMd7I/AAAAAAAAHA0/f1GOWmquYcE/s1600/3-14-expansion.011.png)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/10/2016 07:00 pm
Pardon the large image, but I think it shows relevant information regarding frustum tolerances. The interesting thing here is Random Distortion (0.1) actually has a higher near field power. However, I do not think that is because the distortion makes it more efficient, but that I am not quite center-on TE311, but a little off - and the dimensions of the slightly distorted frustum are closer to center-on TE311.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/10/2016 07:07 pm
I've learned a lot about metal working the past couple of weeks, regarding flatness. If it looks flat...it really isn't.

The 1/8 copper disk (small diameter) looked great from the supplier until I put it on a lapping plate with a backing disk. Progressing from 60 to 2000 grit sandpaper, I was amazed at the material I had to remove to make it close to "flat".

At 2000 grit last night, serious striations are gone but there is still a micron level "unflatness" even after about 4 hours of hand sanding. What this taught me is there is almost no way DIYers can ever achieve perfection in sidewalls. I agree its desirable to maintain shape and symmetry, but I think its best not to worry about it too much. A fully machined and polished frustum is well beyond our budgets. I received a quote for leveling and polishing the small endplate and it was $675  :o

A few threads ago I suggested that electroforming might be the best frustum fabrication technique, and I still think so. Complex wavequide structures are often fabbed this way, and beauty of it is that the final interior finish depends only on the finish of the exterior surface of the form.

The ideal form would be conductive machinable wax, and the plating process is easily a DIY process (jewelers do it quite often in lieu of lost wax casting).

The final frustum would be a reflection (pun intended) of the form, with surface finishes of 2 micron regularly achievable. The wax form would be easily turned on a lathe, and the surface polished by flame or solvent, much like applying a "french polish" to a wooden item in the lathe.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/10/2016 07:21 pm
Pardon the large image, but I think it shows relevant information regarding frustum tolerances. The interesting thing here is Random Distortion (0.1) actually has a higher near field power. However, I do not think that is because the distortion makes it more efficient, but that I am not quite center-on TE311, but a little off - and the dimensions of the slightly distorted frustum are closer to center-on TE311.
Very nice, can you estimate the real value of 0.1 distortion in mm?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: madsci on 03/10/2016 07:23 pm
  Monomorphic,

  If I'm not mistaken you were working on an optical EmDrive:

   https://www.reddit.com/r/EmDrive/comments/3p1atx/optical_em_drive/

  What happened to that project ?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/10/2016 08:07 pm
I've learned a lot about metal working the past couple of weeks, regarding flatness. If it looks flat...it really isn't.

The 1/8 copper disk (small diameter) looked great from the supplier until I put it on a lapping plate with a backing disk. Progressing from 60 to 2000 grit sandpaper, I was amazed at the material I had to remove to make it close to "flat".

At 2000 grit last night, serious striations are gone but there is still a micron level "unflatness" even after about 4 hours of hand sanding. What this taught me is there is almost no way DIYers can ever achieve perfection in sidewalls. I agree its desirable to maintain shape and symmetry, but I think its best not to worry about it too much. A fully machined and polished frustum is well beyond our budgets. I received a quote for leveling and polishing the small endplate and it was $675  :o

A few threads ago I suggested that electroforming might be the best frustum fabrication technique, and I still think so. Complex wavequide structures are often fabbed this way, and beauty of it is that the final interior finish depends only on the finish of the exterior surface of the form.

The ideal form would be conductive machinable wax, and the plating process is easily a DIY process (jewelers do it quite often in lieu of lost wax casting).

The final frustum would be a reflection (pun intended) of the form, with surface finishes of 2 micron regularly achievable. The wax form would be easily turned on a lathe, and the surface polished by flame or solvent, much like applying a "french polish" to a wooden item in the lathe.
This is still interesting to me. Do you have any idea what amount of time it would take to deposit 2 mm of copper on a typical frustum dimension?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/10/2016 08:42 pm
  Monomorphic,

  If I'm not mistaken you were working on an optical EmDrive:

   https://www.reddit.com/r/EmDrive/comments/3p1atx/optical_em_drive/

  What happened to that project ?
The wavelength is much smaller in the optical range and the force predicted by all EM Drive theories should be much, much smaller in the optical range with a small micro-dimensioned  EM Drive.

See:

https://forum.nasaspaceflight.com/index.php?topic=39214.msg1474347#msg1474347


Conversely if instead of using an EM Drive with very small micro dimensions, the plan was to use an EM Drive with dimensions similar to the ones built up to now, the mode shape would be extremely high at optical frequencies, and such very high modes are small amplitude. A FEKO simulation would show this.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RFPlumber on 03/10/2016 08:55 pm
Here’s a story about having tried to publish a paper. The paper describing my null result experiment is now available on Vixra (http://viXra.org/abs/1603.0153). I made a good faith effort to publish it on arXiv.org first, I was even moderately optimistic in the beginning when I knew mostly nothing about the nature of this “wonderful” organization and was still assuming that all it takes to publish there was a single endorsement… Turns out both ArchiveFreedom.org and Vixra.org exist for a good reason. And no, it is not the endorsement step at arXiv which is a concern. It is what happens once the paper has been endorsed and submitted…

…In my case it was reasonably easy to get endorsements; I searched their popular physics category for papers which would be at least marginally related to EmDrive, such as space travel, warp drive, etc. and contacted those authors who had the endorsement privilege. Initially no one replied, but after a week or so I received a notification that I had been endorsed and could now submit my paper. And then a few days later I received another endorsement notification, and then one more. My interpretation of this is that I have been endorsed by at least 3 people. Eventually about 2 weeks later I received a reply from one of my endorsers who happened to be a Professor of Physics at a certain university in California, acknowledging that he has read my paper and found it “interesting and well written". Looking back this has been the high point of this entire publishing effort.  :)
 
Encouraged by all those endorsements I submitted to arXiv. The paper was accepted but then promptly put on hold just 3 hour before going live…  A week later I received a notice from their (anonymous) moderation team asking that before I attempt any future submissions (note the scope here – it is not just for this paper, but for all future submissions of mine) to provide them with a list of my conventional publications and to further clarify my institutional affiliation. And this is where it just struck me, as presumably they consider this information somehow relevant to their decision on whether a particular  paper gets published or not. Well… to me this is just wrong, but it’s their effort, and so I honestly told them that I didn’t have any conventional publications except for 10 or so US patents, and those were all in Computer Science anyway. Ten days later I finally received another e-mail informing me that my submission was removed for lack of having a conventional publication record. Btw, that last e-mail didn’t even have a “sorry to inform you” anywhere in it.

This was definitely an eye-opening experience, and I have got my own strong opinion about this place. Also I do feel for those professional scientists who might depend on it for their careers.

The paper has then been published on Vixra along with a donation to help them keep going. I will update the link on EmDrive Wiki to point to this published version.

The “Acknowledgments” paragraph  in the paper reads:
“The author would like to thank the participants of the “EMDrive Developments” forum at www.nasaspaceflight.com for their constructive and timely feedback while conducting this experiment.”

This concludes the saga.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/10/2016 09:03 pm
Here’s a story about having tried to publish a paper. The paper describing my null result experiment is now available on Vixra (http://viXra.org/abs/1603.0153). I made a good faith effort to publish it on arXiv.org first, I was even moderately optimistic in the beginning when I knew mostly nothing about the nature of this “wonderful” organization and was still assuming that all it takes to publish there was a single endorsement… Turns out both ArchiveFreedom.org and Vixra.org exist for a good reason. And no, it is not the endorsement step at arXiv which is a concern. It is what happens once the paper has been endorsed and submitted…

…In my case it was reasonably easy to get endorsements; I searched their popular physics category for papers which would be at least marginally related to EmDrive, such as space travel, warp drive, etc. and contacted those authors who had the endorsement privilege. Initially no one replied, but after a week or so I received a notification that I had been endorsed and could now submit my paper. And then a few days later I received another endorsement notification, and then one more. My interpretation of this is that I have been endorsed by at least 3 people. Eventually about 2 weeks later I received a reply from one of my endorsers who happened to be a Professor of Physics at a certain university in California, acknowledging that he has read my paper and found it “interesting and well written". Looking back this has been the high point of this entire publishing effort.  :)
 
Encouraged by all those endorsements I submitted to arXiv. The paper was accepted but then promptly put on hold just 3 hour before going live…  A week later I received a notice from their (anonymous) moderation team asking that before I attempt any future submissions (note the scope here – it is not just for this paper, but for all future submissions of mine) to provide them with a list of my conventional publications and to further clarify my institutional affiliation. And this is where it just struck me, as presumably they consider this information somehow relevant to their decision on whether a particular  paper gets published or not. Well… to me this is just wrong, but it’s their effort, and so I honestly told them that I didn’t have any conventional publications except for 10 or so US patents, and those were all in Computer Science anyway. Ten days later I finally received another e-mail informing me that my submission was removed for lack of having a conventional publication record. Btw, that last e-mail didn’t even have a “sorry to inform you” anywhere in it.

This was definitely an eye-opening experience, and I have got my own strong opinion about this place. Also I do feel for those professional scientists who might depend on it for their careers.

The paper has then been published on Vixra along with a donation to help them keep going. I will update the link on EmDrive Wiki to point to this published version.

The “Acknowledgments” paragraph  in the paper reads:
“The author would like to thank the participants of the “EMDrive Developments” forum at www.nasaspaceflight.com for their constructive and timely feedback while conducting this experiment.”

This concludes the saga.

Congratulations again on your excellent test program !

You exhibited the true hallmark of scientific experimentation: a complete lack of bias and reporting the actual results without prejudice.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RFPlumber on 03/10/2016 09:15 pm
Here’s a story about having tried to publish a paper.
...

Congratulations again on your excellent test program !

You exhibited the true hallmark of scientific experimentation: a complete lack of bias and reporting the actual results without prejudice.

Thank you. I honestly wish for there would have been some anomalous force there... At this point I don't think there's any though.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/10/2016 09:20 pm
Pardon the large image, but I think it shows relevant information regarding frustum tolerances. The interesting thing here is Random Distortion (0.1) actually has a higher near field power. However, I do not think that is because the distortion makes it more efficient, but that I am not quite center-on TE311, but a little off - and the dimensions of the slightly distorted frustum are closer to center-on TE311.

Can you please also show:

1) a comparison of theoretical Q (quality of resonance) for the cases shown above

2) comparison: A) random distortion only on the end plates vs.B)  random distortion only on the side conical walls
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/10/2016 09:26 pm
I've learned a lot about metal working the past couple of weeks, regarding flatness. If it looks flat...it really isn't.

The 1/8 copper disk (small diameter) looked great from the supplier until I put it on a lapping plate with a backing disk. Progressing from 60 to 2000 grit sandpaper, I was amazed at the material I had to remove to make it close to "flat".

At 2000 grit last night, serious striations are gone but there is still a micron level "unflatness" even after about 4 hours of hand sanding. What this taught me is there is almost no way DIYers can ever achieve perfection in sidewalls. I agree its desirable to maintain shape and symmetry, but I think its best not to worry about it too much. A fully machined and polished frustum is well beyond our budgets. I received a quote for leveling and polishing the small endplate and it was $675  :o

A few threads ago I suggested that electroforming might be the best frustum fabrication technique, and I still think so. Complex wavequide structures are often fabbed this way, and beauty of it is that the final interior finish depends only on the finish of the exterior surface of the form.

The ideal form would be conductive machinable wax, and the plating process is easily a DIY process (jewelers do it quite often in lieu of lost wax casting).

The final frustum would be a reflection (pun intended) of the form, with surface finishes of 2 micron regularly achievable. The wax form would be easily turned on a lathe, and the surface polished by flame or solvent, much like applying a "french polish" to a wooden item in the lathe.
This is still interesting to me. Do you have any idea what amount of time it would take to deposit 2 mm of copper on a typical frustum dimension?

My own experience with electroforming is that, in general, the lower the current the smoother the finish and of course the slower the deposit. A guesstimate for the "average" frustum would be on the order of 24-48 hours for 2 mm thick walls with 2 micron surface finish. Under tightly controlled conditions, quite a bit faster (perhaps 4-6 hours).
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/10/2016 09:33 pm
  What happened to that project ?

Why build one when you can have two at twice the price? I'm still working on the optical/laser emdrive. Plan on using the same interferometer test rig for both 2.45Ghz and 450nm versions. I'm slowly building/purchasing all the myriad parts for the optical version. The optical version is much more tedious and costly. It all adds up fast and I can only sneak so much $$$ past the spouse each month!
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/10/2016 09:54 pm
Very nice, can you estimate the real value of 0.1 distortion in mm?

It looks like between 1 and 2 mm. Closer to 2.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/10/2016 10:56 pm
(snip)
The “Acknowledgments” paragraph  in the paper reads:
“The author would like to thank the participants of the “EMDrive Developments” forum at www.nasaspaceflight.com for their constructive and timely feedback while conducting this experiment.”

This concludes the saga.
Thanks so much for sharing. Similar story of my own in the conventional book publishing biz. My "adhd" has had me writing family genealogies, fiction and non-fiction books over the past 20 years; that in addition to trade mag publications in electronics...

I sent my first book years ago to several publishers who asked similar things of me...provenance and name recognition is paramount to these "big" publishers. You get around this by ordering advance copies of your own book from them and then peddle it yourself. The system is designed to keep newbies out without "paying" their dues up front so to speak.

Then print on demand happened and so much for the old-school roadblock. They books did reasonably well and I even received offers from publishers afterwards once my amazon numbers started rising. By then, I was off doing something else (making a documentary about one of the books) and had no interest in pursuing book advances or cranking out volumes of literature (helped of course by the ever-present army of ghost writers contracted by the publishers).

Bottom line is, I would have done the same thing you did on your paper...break down the firewall and find other outlets. We have that option nowadays that many an aspiring author didn't have a couple of decades ago. So be it.

Thanks for the story and for our mention in your paper. While you may not have experienced success on your test, you learned a lot and have the satisfaction that the gauntlet can be overcome. Great success story and congrats on your paper. Perhaps we'll hear more from you down the road if you decide to dust off the test gear.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: FattyLumpkin on 03/10/2016 11:13 pm
Seems a shame to put so much time, effort and $$ into these prototypes without providing some protection for the (Q)-quality of the inner surfaces. Any one for evacuating the frustum of air and replacing it with nitrogen? + one could +/- calculate volume changes associated with predicted thermal expansion and pressurize the frustum at X value < ambient in order to mitigate the "balloon effect". Of course thermal expansion of the construction materials: copper, aluminum, silver et al would still be in the running, but oxidation of the surfaces would ostensibly be eliminated.   F L
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: FattyLumpkin on 03/10/2016 11:22 pm
The above attached horn is electroformed and gold plated $895.   About  4"L x 2.39" D.  K band
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: OttO on 03/11/2016 07:32 am
Hi, I do not know if it is useful but to have a good surface quality I think that copper plated glass would be useful for a DIYer. For example a google search for copper plated martini glass is interesting. Frustum for less than 10$ :-)
The copper would be at the exterior of the glass but that would be interesting to weld it to the mirror plates at each end...
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: madsci on 03/11/2016 12:58 pm
  Monomorphic,

  If I'm not mistaken you were working on an optical EmDrive:

   https://www.reddit.com/r/EmDrive/comments/3p1atx/optical_em_drive/

  What happened to that project ?
The wavelength is much smaller in the optical range and the force predicted by all EM Drive theories should be much, much smaller in the optical range with a small micro-dimensioned  EM Drive.

See:

https://forum.nasaspaceflight.com/index.php?topic=39214.msg1474347#msg1474347


Conversely if instead of using an EM Drive with very small micro dimensions, the plan was to use an EM Drive with dimensions similar to the ones built up to now, the mode shape would be extremely high at optical frequencies, and such very high modes are small amplitude. A FEKO simulation would show this.

  Thanks for the answer.
  If I'm not mistaken in Shawyer's theory/formula, the thrust doesn't depend on the wavelength, but it's proportional to:
     -the input power
     -the quality factor Q
  Since the input power is around 12W and Q is in the millions (according to the posts on Reddit), the resulting thrust should be even bigger than the one expected from the 2.45 GHz emdrives.

  Am I missing something here ?

P.S.:
  This is the thread where Q is discussed:

     https://www.reddit.com/r/EmDrive/comments/42uzo7/opticallaser_emdrive_revealed/

The interesting post is this:

Quote
Monomorphic 2 points 1 month ago

I calculated this a few months back. Q would be somewhere around 9,000,000 with the aluminum mirrors. ~70,000,000 with dialectric end mirrors
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/11/2016 01:03 pm
I was able to replicate the "predicted" TE012 in RFPlumber's frustum. The antenna shape is critical in this design to excite this mode. It cannot be replicated with a monopole or dipole antenna in that location.

However, I did not see TE012 at the "actual" frequency of 2.308Ghz.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/11/2016 01:27 pm
NASA Eagleworks Update - FYI only

About a month ago, I alluded to a brief email exchange with a member of NASA's Blue Ribbon Panel. There is no confidential information in it and I will keep that member's name private. Here is the relevant context of the email I received:

"As a member of the blue ribbon review panel, I am not allowed to make any public comments about the status or content of a committee report. Only NASA officials or designated representatives can issue public statements about any findings of the blue ribbon committee. My apology for not being able to state anything else.

Likewise, as a blue ribbon committee member, I am under an agreement not to issue any opinions of the project other than what is contained in the committee report once it has been released. (Until the report is released to the public I cannot make any comments.)"


In effect, this confirms that there is/was a panel and that they cannot mention anything prior to an official NASA release. This is why I stated that rumors would not be posted on NSF nor should they be taken seriously if found elsewhere as the key individuals are not going to pre-release information.

We continue to await details from official channels. In respect to this person's position, no further correspondence was initiated.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/11/2016 01:31 pm
  Monomorphic,

  If I'm not mistaken you were working on an optical EmDrive:

   https://www.reddit.com/r/EmDrive/comments/3p1atx/optical_em_drive/

  What happened to that project ?
The wavelength is much smaller in the optical range and the force predicted by all EM Drive theories should be much, much smaller in the optical range with a small micro-dimensioned  EM Drive.

See:

https://forum.nasaspaceflight.com/index.php?topic=39214.msg1474347#msg1474347


Conversely if instead of using an EM Drive with very small micro dimensions, the plan was to use an EM Drive with dimensions similar to the ones built up to now, the mode shape would be extremely high at optical frequencies, and such very high modes are small amplitude. A FEKO simulation would show this.

  Thanks for the answer.
  If I'm not mistaken in Shawyer's theory/formula, the thrust doesn't depend on the wavelength, but it's proportional to:
     -the input power
     -the quality factor Q
  Since the input power is around 12W and Q is in the millions (according to the posts on Reddit), the resulting thrust should be even bigger than the one expected from the 2.45 GHz emdrives.

  Am I missing something here ?

P.S.:
  This is the thread where Q is discussed:

     https://www.reddit.com/r/EmDrive/comments/42uzo7/opticallaser_emdrive_revealed/

The interesting post is this:

Quote
Monomorphic 2 points 1 month ago

I calculated this a few months back. Q would be somewhere around 9,000,000 with the aluminum mirrors. ~70,000,000 with dialectric end mirrors

In the following post I dealt in detail with the force/InputPower and the Q for a number of theories, including Shawyer's theory:


https://forum.nasaspaceflight.com/index.php?topic=39214.msg1474347#msg1474347

in that post I carefullly showed that the smaller the dimensions of the EM Drive the, smaller the Q, which is a well-known fact.  Furthermore, the smaller the EM Drive the smaller the field density which will translate into much smaller force/InputPower.  Conversely, if you one keeps the field density constant, the electromagnetic field magnitudes will be much greater and exceed electric breakdown  (since for constant density, the smaller the volume, the higher the field magnitude).  Electrical breakdown is a serious constraint in linear accelerators  electromagnetic cavities. It limits the electrical field strength, or gradient, which can be maintained in practice, and so, therefore, the power of such devices. (For many years, the design of cavities has been predicated on a semi-empirical formula known as the Kilpatrick criterion in order to address this problem. )

On the other hand, if the EM drive dimensions are kept comparable to present EM Drives, but a frequency in the optical range is used, the mode shape will be extremely high and it is well known that such high mode shapes are very low amplitude.

Briefly stated: I challenge the assertion that the Q will be 9 to 70 million and that there will be a significant force using optical frequencies.  Using a much higher frequency (in the optical range) is the wrong way to go according to all EM Drive theories, including Shawyer's theory.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: madsci on 03/11/2016 01:44 pm
Briefly stated: I challenge the assertion that the Q will be 9 to 70 million and that there will be a significant force using optical frequencies.  Using a much higher frequency (in the optical range) is the wrong way to go according to all EM Drive theories, including Shawyer's theory.

  Thanks for the detailed response.
  Just to clarify, Monomorphic's optical cavity has macroscopic dimensions (centimeters).

  Can you give an estimation of the order of magnitude of Q for such cavities ?
  Also, what theory/model/formula should be used for such an estimation ?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/11/2016 01:48 pm
I challenge the assertion that the Q will be 9 to 70 million and that there will be a significant force using optical frequencies.  Using a much higher frequency (in the optical range) is the wrong way to go according to all EM Drive theories, including Shawyer's theory.

You're probably right Dr. Rodal.  The optical/laser emdrive isn't theorized to operate according to RF frequency emdrive theories.  It is a separate theory I am working on independently.  That's why I tend not to talk about it much here, as this forum is more geared toward RF frequencies. I've also abandoned that other forum for the most part, so I doubt there will be any updates on the optical emdrive until after the interferometer test rig and my first shawyer-esque emdrive is completed and tested.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/11/2016 01:53 pm
  Can you give an estimation of the order of magnitude of Q for such cavities ?
  Also, what theory/model/formula should be used for such an estimation ?

This is what I used to estimate Q in an optical cavity.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/11/2016 01:57 pm
I was able to replicate the "predicted" TE012 in RFPlumber's frustum. The antenna shape is critical in this design to excite this mode. It cannot be replicated with a monopole or dipole antenna in that location.

However, I did not see TE012 at the "actual" frequency of 2.308Ghz.

Very nice work monomorphic to question everything and examine all the frustum builds. Very smart.

If your FEKO calculations (your modeling has been outstanding so far) are correct, being off by 15MHz with his narrow band solid state amp would put him into a area where there was no mode of excitement and no energy being put into the frustum.
https://drive.google.com/folderview?id=0B3jbXEyEMvU8RmZGNk9pVF9GRk0&usp=drive_web
 
Good questions arise.

Shell

PS: I also think RFPlumber did a outstanding job at compiling and presenting his data and my comments are not in any way meant to take away from his DYI build or test, but I'm being a little like monomorphic here and question everything and look at everything.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/11/2016 02:25 pm
Hoping RFP will take another stab at it with all the interesting post-test analysis  8)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/11/2016 02:43 pm
I second Shells sentiment. We're not trying to tear anyone down and sincerely appreciate RFPlumbers work.

This is RFPlumber's second run listed in the paper. Same deal as before. Paper says he "verified its resonance modes with a scalar network analyzer."  So what we could be seeing here may be related to our previous discussions on tolerances. I'm simulating a perfect frustum, while RFP is measuring the modes in a crude frustum. Would be interesting to see the interior of the frustum. Is solder protruding like the exterior and changing the geometry?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RonM on 03/11/2016 03:01 pm
I challenge the assertion that the Q will be 9 to 70 million and that there will be a significant force using optical frequencies.  Using a much higher frequency (in the optical range) is the wrong way to go according to all EM Drive theories, including Shawyer's theory.

You're probably right Dr. Rodal.  The optical/laser emdrive isn't theorized to operate according to RF frequency emdrive theories.  It is a separate theory I am working on independently.  That's why I tend not to talk about it much here, as this forum is more geared toward RF frequencies. I've also abandoned that other forum for the most part, so I doubt there will be any updates on the optical emdrive until after the interferometer test rig and my first shawyer-esque emdrive is completed and tested.

Since there isn't an accepted theory on EM drives, I think it is great that you are trying optical frequencies. I expect that you will not see any thrust, but we'll never know unless you give it a try. Data is needed to prove or disprove EM drives and a wide variety of experiments helps.

Keep up the good work.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/11/2016 03:43 pm
Briefly stated: I challenge the assertion that the Q will be 9 to 70 million and that there will be a significant force using optical frequencies.  Using a much higher frequency (in the optical range) is the wrong way to go according to all EM Drive theories, including Shawyer's theory.

  Thanks for the detailed response.
  Just to clarify, Monomorphic's optical cavity has macroscopic dimensions (centimeters).

  Can you give an estimation of the order of magnitude of Q for such cavities ?
  Also, what theory/model/formula should be used for such an estimation ?


1) Monomorphic stated that his proposed optical EM Drive is not based on any existing EM Drive theory, including Shawyer's "theory" :

You're probably right Dr. Rodal.  The optical/laser emdrive isn't theorized to operate according to RF frequency emdrive theories.  It is a separate theory I am working on independently.  That's why I tend not to talk about it much here, as this forum is more geared toward RF frequencies. I've also abandoned that other forum for the most part, so I doubt there will be any updates on the optical emdrive until after the interferometer test rig and my first shawyer-esque emdrive is completed and tested.

2) You ask about the Q for an EM Drive of similar dimensions as the ones tested up to now, but with an optical rather than a radio frequency excitation.

I have addressed the formulas involved in the aforementioned post

https://forum.nasaspaceflight.com/index.php?topic=39214.msg1474347#msg1474347,

but let me address this physically here.

There is a huge dissonance between what has transpired in the last few pages of these threads and this question about a "Q" for such an optical EM Drive:

* on one hand we have TheTraveller (https://forum.nasaspaceflight.com/index.php?topic=39004.msg1502215#msg1502215) posting that Shawyer is stating that a tolerance 10 times the skin depth, or at 2.45 GHz,  10* 1.32 micrometers = 13 micrometers is needed to get 75% (https://forum.nasaspaceflight.com/index.php?topic=39772.msg1502318#msg1502318 ) of the theoretical Q at radio frequencies ~ 2.45 GHz, which have a free space wavelength of ~ 0.1224 m = 122 mm = 122,364 micrometers

So TheTraveller is stating that Shawyer is saying that the tolerance required is ~ 13 micrometers / 122,364 micrometers = 1/9413, about 1/10,000 of the wavelength.

At optical frequencies, of 500 THz, about 200,000 times greater frequency than 2.45 GHz, this means a tolerance requirement of 13/200,000 micrometers = 6.5*10^(-11) m = 65 picometers

So that you understand what this means: the picometre's length is of an order such that its application is almost entirely confined to particle physics and quantum physics. Atoms are between 62 and 520 pm in diameter, and the typical length of a carbon-carbon single bond is 154 pm.

Now, imagine that if to get 75% of theoretical Q at optical frequencies with an EM Drive of similar dimensions as presently tested, a tolerance equal to an atom's diameter, you will begin to understand the absurdity of getting anywhere close to such resonance in an actual device.  It would be practically impossible. 

The situation is worse: Monomorphic has accepted that he is aiming for a tolerance of only 1 mm.  There is no way that a resonance is going to be achieved at optical frequencies that have a wavelength 200,000 times smaller than the frequencies of a typical EM Drive.

There is no way that you are going to have reflection and resonance, with well-formed standing waves with a tolerance of only 1 mm at optical frequencies.

How can one have resonance in a cavity having 1 mm tolerance, with an optical wavelength of 0.0006 mm ???


Also think about the absurdity of discussing resonant mode shapes at such frequencies:  we are discussing mode shape TM212 for NASA's experiment at ~2 GHz and TE012 or TE013 for Shawer and Yang's experiments.  You would be discussing mode shapes with m and p orders of magnitude higher (m,n,p where TEmnp).

We have Monomorphic arguing whether RFMPlumber excited a very low frequency mode shape in his experiment.  Then, we cannot really simultaneously argue for the possibility of exciting optical mode shapes in an EM Drive of similar dimensions ???

I was able to replicate the "predicted" TE012 in RFPlumber's frustum. The antenna shape is critical in this design to excite this mode. It cannot be replicated with a monopole or dipole antenna in that location.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1104124;image)

However, I did not see TE012 at the "actual" frequency of 2.308Ghz.

...

Since there isn't an accepted theory on EM drives, I think it is great that you are trying optical frequencies. I expect that you will not see any thrust, but we'll never know unless you give it a try. Data is needed to prove or disprove EM drives and a wide variety of experiments helps.

Keep up the good work.
Sorry, but there is complete dissonance in these latest pages  ???

A resonant frequency mode shape with m=thousand or hundreds of thousands ???????

A Q in the millions with an optical EM Drive cm long and 1 mm tolerance ?????

Q resonance in a cavity having 1 mm tolerance, with an optical wavelength of 0.0006 mm ?????

*****

A laser inside a copper cavity that is cm long does not mean that you are going to get a resonance with "m" (in TEmnp) in the dozens of thousands and a Q in the millions.

If people are discussing whether a given mode shape was excited with cm wavelength at 2.45 GHz, what makes one think that they are going to be able to excite any significant resonance amplitude at optical frequencies?



 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/11/2016 04:00 pm
Latest email from Roger:

Hi Phil

... The Horizon programme will be transmitted in the UK at 20:00 on Wed 23 March. It is called Project Greenglow the search for gravity control.

Not sure how much reference to EmDrive there will be after it was reviewed by USAF and UK MOD.

Best regards

Roger
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/11/2016 04:15 pm
How can one have resonance in a cavity having 1 mm tolerance, with an optical wavelength of 0.0006 mm ???[/b]

The 1mm tolerance is for the 2.45Ghz emdrive Dr. Rodal (though I hope to do better than that!). An optical emdrive would use optomechanical mounts to achieve MUCH higher tolerances (um). Optomechanical mounts are also very expensive. End plates are also purchased laboratory grade concave convex mirrors. It's a whole different beast... which is why I prefer not to talk about it here until after the TE311 Shawyer-esque build is completed. It's confusing as details are being mixed between the two.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RonM on 03/11/2016 04:15 pm
...

Since there isn't an accepted theory on EM drives, I think it is great that you are trying optical frequencies. I expect that you will not see any thrust, but we'll never know unless you give it a try. Data is needed to prove or disprove EM drives and a wide variety of experiments helps.

Keep up the good work.
Sorry, but there is complete dissonance in these latest pages  ???

A resonant frequency mode shape with m=thousand or hundreds of thousands ???????

A Q in the millions with an optical EM Drive cm long and 1 mm tolerance ?????

*****

A laser inside a cavity that is cm long does not mean that you are going to get a resonance with m in the dozens of thousand and a Q in the millions

I've read page after page about resonant frequency mode shapes and while it is fascinating, does it really have anything to do with anomalous force in EM drives? One would think so if the anomalous force is anything other than unaccounted thermal effects. Then again, there may be something truly unusual going on here. Probably not, but the DIY experimenters here feel that it is worth their time and effort.

Monomorphic has a theory to test and it won't hurt anything to give it a shot.

Although, it would be a good idea to share the theory before building the device. Save time and effort if there are any issues with the theory.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/11/2016 04:16 pm
Briefly stated: I challenge the assertion that the Q will be 9 to 70 million and that there will be a significant force using optical frequencies.  Using a much higher frequency (in the optical range) is the wrong way to go according to all EM Drive theories, including Shawyer's theory.

  Thanks for the detailed response.
  Just to clarify, Monomorphic's optical cavity has macroscopic dimensions (centimeters).

  Can you give an estimation of the order of magnitude of Q for such cavities ?
  Also, what theory/model/formula should be used for such an estimation ?


1) Monomorphic stated that his proposed optical EM Drive is not based on any existing EM Drive theory, including Shawyer's theory "theory" :

You're probably right Dr. Rodal.  The optical/laser emdrive isn't theorized to operate according to RF frequency emdrive theories.  It is a separate theory I am working on independently.  That's why I tend not to talk about it much here, as this forum is more geared toward RF frequencies. I've also abandoned that other forum for the most part, so I doubt there will be any updates on the optical emdrive until after the interferometer test rig and my first shawyer-esque emdrive is completed and tested.

2) You ask about the Q for an EM Drive of similar dimensions as the ones tested up to now, but with an optical rather than a radio frequency excitation.

I have addressed the formulas involved in the aforementioned post

https://forum.nasaspaceflight.com/index.php?topic=39214.msg1474347#msg1474347,

but let me address this physically here.

There is a huge dissonance between what has transpired in the last few pages of these threads and this question about a "Q" for such an optical EM Drive:

* on one hand we have TheTraveller (https://forum.nasaspaceflight.com/index.php?topic=39004.msg1502215#msg1502215) posting that Shawyer is stating that a tolerance 10 times the skin depth, or at 2.45 GHz,  10* 1.32 micrometers = 13 micrometers is needed to get 75% (https://forum.nasaspaceflight.com/index.php?topic=39772.msg1502318#msg1502318 ) of the theoretical Q at radio frequencies ~ 2.45 GHz, which have a free space wavelength of ~ 0.1224 m = 122 mm = 122,364 micrometers

So TheTraveller is stating that Shawyer is saying that the tolerance required is ~ 13 micrometers / 122,364 micrometers = 1/9413, about 1/10,000 of the wavelength.

At optical frequencies, of 500 THz, about 200,000 times greater frequency than 2.45 GHz, this means a tolerance requirement of 13/200,000 micrometers = 6.5*10^(-11) m = 65 picometers

So that you understand what this means: the picometre's length is of an order such that its application is almost entirely confined to particle physics and quantum physics. Atoms are between 62 and 520 pm in diameter, and the typical length of a carbon-carbon single bond is 154 pm.

Now, imagine that if to get 75% of theoretical Q, a tolerance equal to an atom's diameter, you will begin to understand the absurdity of getting anywhere close to such resonance in an actual device.  It would be practically impossible. 

The situation is worse: Monomorphic has accepted that he is aiming for a tolerance of only 1 mm.  There is no way that a resonance is going to be achieved at optical frequencies that have a wavelength 200,000 times smaller than the frequencies of a typical EM Drive.

Also think about the absurdity of discussing resonant mode shapes at such frequencies:  we are discussing mode shape TM212 for NASA's experiment at ~2 GHz and TE012 or TE013 for Shawer and Yang's experiments.  You would be discussing mode shapes with m and p orders of magnitude higher (m,n,p where TEmnp).

How can we have rfmwguy and seeshells encouraging Monomorphic arguing whether RFMPlumber excited a very low frequency mode shape in his experiment and simultaneously argue for the possibility of exciting optical mode shapes in an EM Drive of similar dimensions.

Sorry, but there is complete dissonance in these latest pages  ???


My discussion is about the validity of a test and the possible error in a test with a frustum in the microwave mode, not monomorphic's testing of a optical cavity.

Consider these points.

I wondered when RFPlumber's test when he first ran his tests he deformed the large plate from heating.

I also wondered how a TE012 mode could provide the thermal profile on the large plate to warp it. It didn't match his COMSOL sim of a TE012.

Looking at the simulation of RFPlumbers done by monomorphic it just made sense that if he was off in the frequency that it would show up in the area of the highly modified loop antennas as a thermal profile and warp the endplate just like the FEKO image.

TT's spreadsheet doesn't show resonance and FEKO doesn't and I'm not sure if aero ran it in meep, so maybe could you run your numbers to see? Your maths calculated the mode frequencies agreeing with Frank Davis's COMSOL to a very high degree.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/11/2016 04:24 pm
...

Since there isn't an accepted theory on EM drives, I think it is great that you are trying optical frequencies. I expect that you will not see any thrust, but we'll never know unless you give it a try. Data is needed to prove or disprove EM drives and a wide variety of experiments helps.

Keep up the good work.
Sorry, but there is complete dissonance in these latest pages  ???

A resonant frequency mode shape with m=thousand or hundreds of thousands ???????

A Q in the millions with an optical EM Drive cm long and 1 mm tolerance ?????

*****

A laser inside a cavity that is cm long does not mean that you are going to get a resonance with m in the dozens of thousand and a Q in the millions

I've read page after page about resonant frequency mode shapes and while it is fascinating, does it really have anything to do with anomalous force in EM drives? One would think so if the anomalous force is anything other than unaccounted thermal effects. Then again, there may be something truly unusual going on here. Probably not, but the DIY experimenters here feel that it is worth their time and effort.
..

I answered a question I was asked about the Q quality of resonance for such a contraption, quoting somebody stating that the Q would be in 9 to 70 million for an EM Drive with similar dimensions as presently tested, but with optical rather than radio frequencies. The tolerance was quoted as ~ 1mm. That doesn't make sense.

Resonance of 9 to 70 million Q in a cavity that is cm long having 1 mm tolerance, with an optical wavelength of 0.0006 mm


If you can argue how can it make sense to have a Q of 9 to 70 millions with such a contraption, I am all ears. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RonM on 03/11/2016 04:34 pm
...

Since there isn't an accepted theory on EM drives, I think it is great that you are trying optical frequencies. I expect that you will not see any thrust, but we'll never know unless you give it a try. Data is needed to prove or disprove EM drives and a wide variety of experiments helps.

Keep up the good work.
Sorry, but there is complete dissonance in these latest pages  ???

A resonant frequency mode shape with m=thousand or hundreds of thousands ???????

A Q in the millions with an optical EM Drive cm long and 1 mm tolerance ?????

*****

A laser inside a cavity that is cm long does not mean that you are going to get a resonance with m in the dozens of thousand and a Q in the millions

I've read page after page about resonant frequency mode shapes and while it is fascinating, does it really have anything to do with anomalous force in EM drives? One would think so if the anomalous force is anything other than unaccounted thermal effects. Then again, there may be something truly unusual going on here. Probably not, but the DIY experimenters here feel that it is worth their time and effort.
..

I answered a question I was asked about the Q quality of resonance for such a contraption, quoting somebody stating that the Q would be in 9 to 70 million. That doesn't make sense.

If you can argue how can it make sense to have a Q of 9 to 70 millions with such a contraption, I am all ears.

I don't think a Q in the millions makes sense. Without seeing Monomorphic's theory we don't know the rational of the optical test, so we have to wait until the test is complete.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/11/2016 04:40 pm
If one googles "optical cavity" one can readily find arXiv and Nature articles on optical nanocavities ( (*)

(https://upload.wikimedia.org/wikipedia/commons/thumb/0/02/Glass_nanoparticle_suspended_in_an_optical_cavity.png/220px-Glass_nanoparticle_suspended_in_an_optical_cavity.png)

an arrangement of mirrors
that forms a standing wave cavity resonator for light waves)
having high Q's > 10^5:  what is being discussed here is an EM Drive copper cavity that is  several centimeters long at optical frequencies, with 1 mm tolerance being able to have a Q >9 million.  Such optical nanocavities not relevant to the discussion of a several cm long copper cavity with mm tolerance.


_____

(*) or even what are considered "large" optical cavities: those larger than 4 μm
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: madsci on 03/11/2016 05:08 pm

The situation is worse: Monomorphic has accepted that he is aiming for a tolerance of only 1 mm.  There is no way that a resonance is going to be achieved at optical frequencies that have a wavelength 200,000 times smaller than the frequencies of a typical EM Drive.

There is no way that you are going to have reflection and resonance, with well-formed standing waves with a tolerance of only 1 mm at optical frequencies.

How can one have resonance in a cavity having 1 mm tolerance, with an optical wavelength of 0.0006 mm ???



  As far as I understand, Monomorphic stated that his microwave frustum will have a tolerance (better than) 1mm, not the optical one.
  Most likely, the optical one will have optically aligned mirrors.
  Optical cavities can easily have Q of several millions, see:

     https://www.rp-photonics.com/q_factor.html

  Therefore, if we are to take Shawyer's theory as guide, it makes total sense that the thrust of an optical system with:
   -input power ~ 10W
   -quality factor > 1e6
will be easily measurable.

  Like RonM, I too think that the optical EmDrive is a legitimate path to explore, at least in light of what we know so far.
  Of course, there might be other arguments against an optical EmDrive, in this case, let's hear them.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/11/2016 05:09 pm
what is being discussed here is an EM Drive copper cavity that is  several centimeters long at optical frequencies, with 1 mm tolerance being able to have a Q >9 million.

We are getting details of the 2.45Ghz and optical build confused. There are two separate builds.

The optical emdrive is all glass, either vapor deposited aluminum or a super mirror dialectric.

The Shawyer inspired version is the one where 1mm (though hopefully better) tolerances are expected. It is copper and 18.4 cm in length - 2.45Ghz.

Both builds would utilize the same interferometer test rig (as shown).
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/11/2016 05:14 pm

The situation is worse: Monomorphic has accepted that he is aiming for a tolerance of only 1 mm.  There is no way that a resonance is going to be achieved at optical frequencies that have a wavelength 200,000 times smaller than the frequencies of a typical EM Drive.

There is no way that you are going to have reflection and resonance, with well-formed standing waves with a tolerance of only 1 mm at optical frequencies.

How can one have resonance in a cavity having 1 mm tolerance, with an optical wavelength of 0.0006 mm ???



  As far as I understand, Monomorphic stated that his microwave frustum will have a tolerance (better than) 1mm, not the optical one.
  Most likely, the optical one will have optically aligned mirrors.
  Optical cavities can easily have Q of several millions, see:

     https://www.rp-photonics.com/q_factor.html

  Therefore, if we are to take Shawyer's theory as guide, it makes total sense that the thrust of an optical system with:
   -input power ~ 10W
   -quality factor > 1e6
will be easily measurable.

  Like RonM, I too think that the optical EmDrive is a legitimate path to explore, at least in light of what we know so far.
  Of course, there might be other arguments against an optical EmDrive, in this case, let's hear them.

In your prior questions you had commingled Shawyer's EM Drive with an optical cavity.  From your description, I was addressing an EM Drive made of copper, same shape and dimensions as presently tested, but instead excited at optical frequencies.

I think that this may have been lost to many readers, as I was asked by you the question referring to whether Shawyer's theory considers the wavelength.

It is important for the readers to understand that an optical cavity uses optical mirrors at both ends.  It is important for the readers to understand that the mode shape resonance is not due to a frustum of a cone shape, and it is not related to mode shapes in Shawyer's EM Drive.


Quote
Therefore, if we are to take Shawyer's theory as guide, it makes total sense that the thrust of an optical system with:
   -input power ~ 10W
   -quality factor > 1e6
will be easily measurable.

You are taking Shawyer's theory as a guide ?????

The resonance mode shapes have nothing to do with each other,  apples and oranges.

These are typical optical cavities:

(https://upload.wikimedia.org/wikipedia/commons/c/ca/Optical-cavity1.png)

it is misleading to be confusing such an optical cavity with an EM Drive:

(http://www.nasaspaceflight.com/wp-content/uploads/2015/04/2015-04-19-005958-350x236.jpg)

(http://ayuba.fr/images/emdrive/TE012_from_Frustum_modes_overview_2A.png)

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/11/2016 05:24 pm
Actually, you can create a concave-convex optical cavity in the shape of a frustum. In fact, the cavity length (5cm) is dictated by which concave and convex mirrors are available for purchase at specific diameter and radii.

As pointed out by Dr. Rodal, the huge difference is the modes in an optical cavity will be much higher order.

NOTE: Side walls are also mirrored, they are only shown clear here so you can see the interior of the frustum.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/11/2016 05:29 pm
Actually, you can create a concave-convex optical cavity in the shape of a frustum. In fact, the cavity length (5cm) is dictated by which concave and convex mirrors are available for purchase at specific radii.

As pointed out by Dr. Rodal, the huge difference is the modes in an optical cavity will be much higher order.
Thanks for the picture and the discussion.

Does this have side-walls ? if so, what material is used for the side walls?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/11/2016 05:31 pm
Does this have side-walls ? if so, what material is used for the side walls?

I updated my post. The side walls are shown clear here so we can see the interior. They would be of the same material as the end-plate mirrors. Glass and vapor deposited aluminum or dialectric mirror.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: madsci on 03/11/2016 06:01 pm
It is important for the readers to understand that an optical cavity uses optical mirrors at both ends.  It is important for the readers to understand that the mode shape resonance is not due to a frustum of a cone shape, and it is not related to mode shapes in Shawyer's EM Drive.

  Actually, as Monomorphic says, his optical cavity is a frustum of a cone:

Actually, you can create a concave-convex optical cavity in the shape of a frustum. In fact, the cavity length (5cm) is dictated by which concave and convex mirrors are available for purchase at specific diameter and radii.

  But I agree with you (Rodal) that the resonance modes will be very different in an optical EmDrive compared to those in a microwave one.

  So, if I understand correctly, you're saying that one cannot measure thrust with an optical EmDrive because the optical resonance modes are of much higher order than the ones Shawyer specified ?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/11/2016 06:28 pm
Latest email from Roger:

Hi Phil

... The Horizon programme will be transmitted in the UK at 20:00 on Wed 23 March. It is called Project Greenglow the search for gravity control.

Not sure how much reference to EmDrive there will be after it was reviewed by USAF and UK MOD.

Best regards

Roger
Tangential on Greenglow: http://forteana-blog.blogspot.com/2015/05/project-greenglow.html
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/11/2016 07:12 pm
Dr. Rodal,

I am still curious to what you see as a resonate mode with your Mathcad or Wolfram on RFPlumbers dimentions and frequency in his cavity.
https://drive.google.com/folderview?id=0B3jbXEyEMvU8RmZGNk9pVF9GRk0&usp=drive_web

It would be a good data point to a intriguing question.


Thanks

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/11/2016 07:18 pm
Dr. Rodal,

I am still curious to what you see as a resonate mode with your Mathcad or Wolfram on RFPlumbers dimentions and frequency in his cavity.
https://drive.google.com/folderview?id=0B3jbXEyEMvU8RmZGNk9pVF9GRk0&usp=drive_web

It would be a good data point to a intriguing question.


Thanks

Shell

What are the dimensions and material?

Flat Ends? Yes _   No _

Interior Small End Diameter:
 
Interior Big End Diameter:

Interior Distance between Flat Ends (measured along axis of axisymmetry, perpendicular to the flat ends):

Cavity metal:

Thickness of cavity's metal:

Were the dimensions of the frustum actually measured? 

(A file reads:

D_big: 264 mm
D_small: 162 mm
L_center: 196 mm

but I don't know whether those are interior or exterior dimensions)

When arguing about a small difference in natural frequency it is important to accurately know what are the actual dimensions of  what was tested ...
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RFPlumber on 03/11/2016 07:49 pm
...
Consider these points.

I wondered when RFPlumber's test when he first ran his tests he deformed the large plate from heating.

I also wondered how a TE012 mode could provide the thermal profile on the large plate to warp it. It didn't match his COMSOL sim of a TE012.

...

Shell, I noticed you keep mentioning that the large plate in my tests has been deformed from heating, I am not sure what makes you think so. I recall the exchange when someone asked whether the end plates on my frustum were flat or warped and I measured it and replied that they were maybe 1 mm warped in the center. My assumption back then was that the question referred to the quality of construction, and not to any deformation caused by the actual test. And my reply was also with an implicit assumption that this 1mm warping has been there from the start, and it was not the result of RF heating. I doubt one can cause any real warping on the plates with only 30W of energy (where a portion of it is then further leaking out as plain RF).

Also, if I were to get any non-trivial amount of induction heating inside the frustum, I would have most likely witnessed "thrust" from all the hot air escaping through the gaps around side walls. It is possible that some of the thermal force I am attributing to the RF amplifier hot plate air convection could be coming from said hot air escaping from the frustum, but again, 30W is hardly enough to make any lasting deformation on the 0.5mm copper plates.

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/11/2016 07:52 pm
Dr. Rodal,

I am still curious to what you see as a resonate mode with your Mathcad or Wolfram on RFPlumbers dimentions and frequency in his cavity.
https://drive.google.com/folderview?id=0B3jbXEyEMvU8RmZGNk9pVF9GRk0&usp=drive_web

It would be a good data point to a intriguing question.


Thanks

Shell

What are the dimensions and material?

Flat Ends? Yes X   No _

Interior Small End Diameter:
 
Interior Big End Diameter:

Interior Distance between Flat Ends (measured along axis of axisymmetry, perpendicular to the flat ends):

Cavity metal: Believe it was Aluminum

Thickness of cavity's metal:

Were the dimensions of the frustum actually measured? 

(A file reads:

D_big: 264 mm
D_small: 162 mm
L_center: 196 mm

but I don't know whether those are interior or exterior dimensions)

I would hope these are the interior measurements but he doesn't state that. Although the 15MHz difference in what monomorphic reported as resonance is quite large compared to the walls measured on the outside. Run them both. 

When arguing about a small difference in natural frequency it is important to accurately know what are the actual dimensions of  what was tested ...

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: X_RaY on 03/11/2016 07:53 pm
Dr. Rodal,

I am still curious to what you see as a resonate mode with your Mathcad or Wolfram on RFPlumbers dimentions and frequency in his cavity.
https://drive.google.com/folderview?id=0B3jbXEyEMvU8RmZGNk9pVF9GRk0&usp=drive_web

It would be a good data point to a intriguing question.


Thanks

Shell

What are the dimensions and material?

Flat Ends? Yes _   No _

Interior Small End Diameter:
 
Interior Big End Diameter:

Interior Distance between Flat Ends (measured along axis of axisymmetry, perpendicular to the flat ends):

Cavity metal:

Thickness of cavity's metal:

Were the dimensions of the frustum actually measured? 

(A file reads:

D_big: 264 mm
D_small: 162 mm
L_center: 196 mm

but I don't know whether those are interior or exterior dimensions)

When arguing about a small difference in natural frequency it is important to accurately know what are the actual dimensions of  what was tested ...
I come to the same conclusion for TE012 using flat end plates.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/11/2016 07:56 pm
Cavity metal: Believe it was Aluminum

It was copper.  0.5mm thick
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/11/2016 08:01 pm
I come to the same conclusion for TE012 using flat end plates.

X-RaY, what dimensions does your spreadsheet say are the best dimensions for TE311 @ precisely 2.45Ghz?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: X_RaY on 03/11/2016 08:04 pm
I come to the same conclusion for TE012 using flat end plates.

X-RaY, what dimensions does your spreadsheet say are the best dimensions for TE311 @ precisely 2.45Ghz?

A lot of different dimensions ;)
Please give me two them, I will calculate the missing one.

This is a simple calculation of the resonant frequency nothing else, it tells nothing about possible thrust!
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: A_M_Swallow on 03/11/2016 08:05 pm
Latest email from Roger:

Hi Phil

... The Horizon programme will be transmitted in the UK at 20:00 on Wed 23 March. It is called Project Greenglow the search for gravity control.

Not sure how much reference to EmDrive there will be after it was reviewed by USAF and UK MOD.

Best regards

Roger

Project Greenglow is a name I have not heard in a decade.

Engines for alien spaceships. UFO (Unidentified Flying Objects) research.

EMDrive research is sufficiently controversial I suggest that publicly we stay away from a group that are even more controversial. Although if EMDrives can be made to work the Greenglow people may be willing to fly using them.

edit:spelling and grammar
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/11/2016 08:10 pm
Please give me two them, I will calculate the missing one.

Big end radius: 11
Small end radius: 5.75
Height: ?

Thanks!
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/11/2016 08:11 pm
...
Consider these points.

I wondered when RFPlumber's test when he first ran his tests he deformed the large plate from heating.

I also wondered how a TE012 mode could provide the thermal profile on the large plate to warp it. It didn't match his COMSOL sim of a TE012.

...

Shell, I noticed you keep mentioning that the large plate in my tests has been deformed from heating, I am not sure what makes you think so. I recall the exchange when someone asked whether the end plates on my frustum were flat or warped and I measured it and replied that they were maybe 1 mm warped in the center. My assumption back then was that the question referred to the quality of construction, and not to any deformation caused by the actual test. And my reply was also with an implicit assumption that this 1mm warping has been there from the start, and it was not the result of RF heating. I doubt one can cause any real warping on the plates with only 30W of energy (where a portion of it is then further leaking out as plain RF).

Also, if I were to get any non-trivial amount of induction heating inside the frustum, I would have most likely witnessed "thrust" from all the hot air escaping through the gaps around side walls. It is possible that some of the thermal force I am attributing to the RF amplifier hot plate air convection could be coming from said hot air escaping from the frustum, but again, 30W is hardly enough to make any lasting deformation on the 0.5mm copper plates.



RFPlumber, thanks for dropping in and providing some input. I find this open question intriguing why the differences in calculated resonance and modes between FEKO and Comsol. Digging through the search here on the site I found where you talked about the warped plates and it seems they were only off by a small amount.

Were the measurements inside or outside of the frustum?

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/11/2016 08:22 pm
Latest email from Roger:

Hi Phil

... The Horizon programme will be transmitted in the UK at 20:00 on Wed 23 March. It is called Project Greenglow the search for gravity control.

Not sure how much reference to EmDrive there will be after it was reviewed by USAF and UK MOD.

Best regards

Roger

Project Greenglow is a name I have not heard in a decade.

Engines for alien spaceships. UFO (Unidentified Flying Objects) research.

EMDrive research is sufficiently controversial I suggest that we publicly say away from a group that are even more controversial. Although if EMDrives can be made to work the Greenglow people may be willing to fly using them.

Good point.  See this for example:

Quote
"I find it rather peculiar that they've done this," said Bob Park from the American Physical Society, in reaction to the BAe Systems admission. "One can only conclude that at the higher levels of these organisations there are people who don't have a very sound grounding in fundamental physics."

BBC News
Monday, 27 March, 2000, 23:34 GMT 00:34 UK
Gravity research gets off the ground


http://news.bbc.co.uk/2/hi/sci/tech/692968.stm

Robert L. Park is Professor of Physics and former chairman of the Department of Physics at the University of Maryland. He also directs the Washington Office of the American Physical Society.

Park obtained his Ph.D. in physics at Brown University in 1964.

Park, Robert L. (2002). Voodoo science: the road from foolishness to fraud. Oxford [Oxfordshire]: Oxford University Press. ISBN 0-19-860443-2.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/11/2016 08:47 pm
2.7" for TE311.
Note this is an approximation only!

Sorry, my dimensions are in cm. I only work in metric! teehee

Frequency: 2.45Ghz
Big end radius: 11cm
Small end radius: 5.75cm
Height: cm?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/11/2016 08:54 pm
These are typical optical cavities:

(https://upload.wikimedia.org/wikipedia/commons/c/ca/Optical-cavity1.png)

it is misleading to be confusing such an optical cavity with an EM Drive:

(http://www.nasaspaceflight.com/wp-content/uploads/2015/04/2015-04-19-005958-350x236.jpg)

The concave-convex optical model is, as I understand it, the end plate configuration of the Demonstrator and Flight Thruster EmDrives. With both Rs at the vertex of the cone / frustum

I suggest the confocal arrangement would help to eliminate most end plate alignment issues. Rs of both end plates would be very large, maybe 50x to 100x length. Very shallow concave curve in each end plate.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/11/2016 09:00 pm
EMDrive speculation to the year 2035 - An interesting and perhaps accurate prognostication on EMDrive development for entertainment and diversion only (love the 2035 entry):

(snip)

2032: Emdrive applications trickle down to civilian and terrestrial uses. Sophisticated 3D nagivation and spacial awareness technologies allow for cars to be fitted with Emdrive thrusters for vertical lift- the first true example of a 'hover car'. The Emdrive however still loses thrust with acceleration, and so hydrogen thrusters provide lateral propulsion, as per Shawyer's original demonstrator vehicle design from 2009.

Late 2032: Planetary Resources launches a staging post to lie at the Lagrangian point between Earth and the Moon; the beginning of a space station that will serve mining vessels performing operations on Near Earth Asteroids. Future vessels will be built on Earth and sent to the Lagrangian station with materials to expand the station itself (largely through additive manufacturing).

2034: On behalf of all on Earth, the first human steps foot on Mars. Due to huge improvements over the past twenty years to the efficiency and thrust potential of the Emdrive, his/her trip has been a relatively short one. On top of this, the Emdrive has made it possible to transport large amounts of equipment and materials into Earth orbit and ultimately onto the Mars-bound craft, making it capable of also carrying the necessary starter-kit for a colony, with the knowledge that whoever stays there will have the ability to return to Earth in a brief time period. Humanity, thanks to the Emdrive, is now a multi-planet species.

2035: The physicist Sean Carroll upgrades his view of the Emdrive's thrust from 'impossible' to being 'improbable'.

Original posting: http://tinyurl.com/jbjyexd from a friendly, open-minded subreddit about 9 months ago ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/11/2016 09:06 pm
Radius=8.835cm
theta 30.7199°

Radius? I just need the height (in cm). This is a flat-end frustum. Want to see how it compares to what I found.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: X_RaY on 03/11/2016 09:10 pm
Radius 8.835cm*2=17.67cm

Radius? I just need the height (in cm). This is a flat-end frustum. Want to see how it compares to what I found.
SORRY I meant the height!  17.67cm
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: tchernik on 03/11/2016 09:18 pm
The disappointment simply comes from unrealistic expectations about the speed of the experiments and the validation process required to change opinions. People seemed to expect we would see hyper-strong Emdrives in a short while, while all replications have been showing very tenuous forces at best.

Which would still be a very big deal, because we should be seeing none at all or just those caused by a equivalent photon rocket.

This is still a highly speculative and controversial potential physical phenomenon, which hasn't left the stage of experimental anomaly reported by a few.

It needs a lot of work of many people, working on improving the experiments, models and ruling out sources of error, to finally enter into the stage of "somewhat verified phenomenon".

And that can take a lot of time, with its related frustrations, enduring mocking criticisms and mustering the required perseverance from the part of those actually doing experiments and measuring something.

I have resigned myself to the very likely fact that, in the best of worlds, we won't ever see a flying car out of this, but that we might eventually see some revolutionary propellentless satellites or probes treading the Solar System in 20 or 30 years, after this finally gets out of the NASA TRL or anything equivalent in other space agencies.

Which would be completely fine and actually, an astounding result.

Or simply, nothing will come out of it, except the amusement of discussing what-ifs.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/11/2016 09:19 pm

The situation is worse: Monomorphic has accepted that he is aiming for a tolerance of only 1 mm.  There is no way that a resonance is going to be achieved at optical frequencies that have a wavelength 200,000 times smaller than the frequencies of a typical EM Drive.

There is no way that you are going to have reflection and resonance, with well-formed standing waves with a tolerance of only 1 mm at optical frequencies.

How can one have resonance in a cavity having 1 mm tolerance, with an optical wavelength of 0.0006 mm ???



  As far as I understand, Monomorphic stated that his microwave frustum will have a tolerance (better than) 1mm, not the optical one.
  Most likely, the optical one will have optically aligned mirrors.
  Optical cavities can easily have Q of several millions, see:

     https://www.rp-photonics.com/q_factor.html

  Therefore, if we are to take Shawyer's theory as guide, it makes total sense that the thrust of an optical system with:
   -input power ~ 10W
   -quality factor > 1e6
will be easily measurable.

  Like RonM, I too think that the optical EmDrive is a legitimate path to explore, at least in light of what we know so far.
  Of course, there might be other arguments against an optical EmDrive, in this case, let's hear them.

Which brings up the fascinating fact that the Q of a standard, say 6 inch long, HeNe (helium neon) laser tube is infinitely high, because the cavity exhibits gain, not loss. So back to ammonia filled frustums with maser gain?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/11/2016 09:25 pm
Actually, you can create a concave-convex optical cavity in the shape of a frustum. In fact, the cavity length (5cm) is dictated by which concave and convex mirrors are available for purchase at specific diameter and radii.

As pointed out by Dr. Rodal, the huge difference is the modes in an optical cavity will be much higher order.

NOTE: Side walls are also mirrored, they are only shown clear here so you can see the interior of the frustum.

In fact, from the historical perspective, this is why the laser was not actually built until 1960, when it could easily have been done as early as the 1920's. Everyone ASSUMED that standing wave resonance would be required in the optical cavity, but that is obviously not so.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/11/2016 09:32 pm
...
Consider these points.

I wondered when RFPlumber's test when he first ran his tests he deformed the large plate from heating.

I also wondered how a TE012 mode could provide the thermal profile on the large plate to warp it. It didn't match his COMSOL sim of a TE012.

...

Shell, I noticed you keep mentioning that the large plate in my tests has been deformed from heating, I am not sure what makes you think so. I recall the exchange when someone asked whether the end plates on my frustum were flat or warped and I measured it and replied that they were maybe 1 mm warped in the center. My assumption back then was that the question referred to the quality of construction, and not to any deformation caused by the actual test. And my reply was also with an implicit assumption that this 1mm warping has been there from the start, and it was not the result of RF heating. I doubt one can cause any real warping on the plates with only 30W of energy (where a portion of it is then further leaking out as plain RF).

Also, if I were to get any non-trivial amount of induction heating inside the frustum, I would have most likely witnessed "thrust" from all the hot air escaping through the gaps around side walls. It is possible that some of the thermal force I am attributing to the RF amplifier hot plate air convection could be coming from said hot air escaping from the frustum, but again, 30W is hardly enough to make any lasting deformation on the 0.5mm copper plates.

For perspective, the average hobbyist soldering iron is about 30 watts.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/11/2016 09:36 pm
Cavity metal: Believe it was Aluminum

It was copper.  0.5mm thick

For perspective, 0.5mm is about 0.020 inch, or about the thickness of 4 sheets of typing paper.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/11/2016 10:17 pm
Actually, you can create a concave-convex optical cavity in the shape of a frustum. In fact, the cavity length (5cm) is dictated by which concave and convex mirrors are available for purchase at specific radii.

As pointed out by Dr. Rodal, the huge difference is the modes in an optical cavity will be much higher order.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1104186;image)
Thanks for the picture and the discussion.

Does this have side-walls ? if so, what material is used for the side walls?


I updated my post. The side walls are shown clear here so we can see the interior. They would be of the same material as the end-plate mirrors. Glass and vapor deposited aluminum or dialectric mirror.

At optical frequencies, I don't think that one needs the side walls, and actually the side walls will be detrimental to the effect being pursued.


Quote
The optical resonator is sometimes referred to as an "optical cavity", but this is a misnomer: lasers use open resonators as opposed to the literal cavity that would be employed at microwave frequencies in a maser. The resonator typically consists of two mirrors between which a coherent beam of light travels in both directions, reflecting back on itself so that an average photon will pass through the gain medium repeatedly before it is emitted from the output aperture or lost to diffraction or absorption. If the gain (amplification) in the medium is larger than the resonator losses, then the power of the recirculating light can rise exponentially.

At optical frequencies, your side walls are never going to be accurately straight and parallel to the optical ray and they are never going to be sufficiently smooth.  They don't serve any useful function and worse, they are detrimental.  It would be better not to have anything that can either reflect or refract the optical rays on the conical sides.  Better leave it open. (Of course, do wear eye protection).

SUGGESTION: Test it both A) with sidewalls and B) WITHOUT side walls


(https://upload.wikimedia.org/wikipedia/commons/thumb/4/4b/Laser_DSC09088.JPG/250px-Laser_DSC09088.JPG)

(https://upload.wikimedia.org/wikipedia/commons/c/ca/Optical-cavity1.png)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: FattyLumpkin on 03/11/2016 11:41 pm
Dr. Rodal, would minimal arc (concave) in the large reflector be beneficial? The mirrors below might do well?  FL
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SteveD on 03/12/2016 01:29 am
Actually, you can create a concave-convex optical cavity in the shape of a frustum. In fact, the cavity length (5cm) is dictated by which concave and convex mirrors are available for purchase at specific radii.

As pointed out by Dr. Rodal, the huge difference is the modes in an optical cavity will be much higher order.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1104186;image)
Thanks for the picture and the discussion.

Does this have side-walls ? if so, what material is used for the side walls?


I updated my post. The side walls are shown clear here so we can see the interior. They would be of the same material as the end-plate mirrors. Glass and vapor deposited aluminum or dialectric mirror.

I don't think that one needs the side walls, and actually the side walls will be detrimental to the effect being pursued.


Quote
The optical resonator is sometimes referred to as an "optical cavity", but this is a misnomer: lasers use open resonators as opposed to the literal cavity that would be employed at microwave frequencies in a maser. The resonator typically consists of two mirrors between which a coherent beam of light travels in both directions, reflecting back on itself so that an average photon will pass through the gain medium repeatedly before it is emitted from the output aperture or lost to diffraction or absorption. If the gain (amplification) in the medium is larger than the resonator losses, then the power of the recirculating light can rise exponentially.

At optical frequencies, your side walls are never going to be accurately straight and parallel to the optical ray and they are never going to be sufficiently smooth.  They don't serve any useful function and worse, they are detrimental.  It would be better not to have anything that can either reflect or refract the optical rays on the conical sides.  Better leave it open.

SUGGESTION: Test it both A) with sidewalls and B) WITHOUT side walls


Bae, in his photonic laser thruster research, found that putting a gain media in the resonance cavity will cause the resonance to become highly resilient to misalignment of the reflectors (he had an Oh Sh*t moment when he held one of the mirrors in his hand and the thing remained in resonance).  I'm not sure what adding a solid gain medium would do for an EMDrive, but it might be worth a shot to see if it can alleviate the need for extremely precise alignments. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/12/2016 01:49 am
Dr. Rodal, would minimal arc (concave) in the large reflector be beneficial? The mirrors below might do well?  FL

Telescope mirror coating would need to be 10x skin depth thickness. 1x skin depth for Aluminium at 2,450MHz is 1.66um.

http://chemandy.com/calculators/skin-effect-calculator.htm

Rf penetrates 5x skin depth. So the mirror coating needs to be at least 16.6um thick and pin hole free..

Next issue is the end plates (mirrors) need to be in very good, continuous around the rim, electrical contact with the side walls to stop Rf leaks and potential arcing. Not an easy job but could maybe work if the Alum or Silver coating were thick enough.

BTW I once hand ground & polished telescope mirrors, so know them well.

Interesting though is using 2 in a long confocal arrangement might reduce the amount of eddy current losses in the side walls and if so, increase Q quote a bit. Or not?

The shorter the focal length, the higher the phase distortion introduced upon each reflection.

Phil
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RFPlumber on 03/12/2016 02:00 am
...
Were the measurements inside or outside of the frustum?


The dimensions are supposed to be for the inside diameters, and w.r.t. COMSOL simulations this is definitely the case (as COMSOL does not even require wall thickness). The actual frustum was measured with a tape measure where the error is easily on the order of (at least) +-0.5mm, so even though I was measuring the inside dimension, for a 0.5 mm wall it almost does not matter...

Simulated sensitivity of the resonance frequency to the change in diameter (at either end) was about 5 MHz per mm give or take.

P.S. Hanging around as I am very curious to see how the next experimenter is going about convincing herself/himself and others that the observed force is not the result of hot air.  :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RotoSequence on 03/12/2016 02:30 am
P.S. Hanging around as I am very curious to see how the next experimenter is going about convincing herself/himself and others that the observed force is not the result of hot air.  :)

Have you considered re-testing your experiment? Using FEKO, Monomorphic believes that your setup was ~15 Mhz off of establishing any mode shape, but would achieve the targeted resonance mode at 2.323 GHz. (http://forum.nasaspaceflight.com/index.php?topic=39772.msg1502671#msg1502671)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/12/2016 02:40 am
Dr. Rodal, would minimal arc (concave) in the large reflector be beneficial? The mirrors below might do well?  FL

Telescope mirror coating would need to be 10x skin depth thickness. 1x skin depth for Aluminium at 2,450MHz is 1.66um.

http://chemandy.com/calculators/skin-effect-calculator.htm

Rf penetrates 5x skin depth. So the mirror coating needs to be at least 16.6um thick and pin hole free..

Next issue is the end plates (mirrors) need to be in very good, continuous around the rim, electrical contact with the side walls to stop Rf leaks and potential arcing. Not an easy job but could maybe work if the Alum or Silver coating were thick enough.

BTW I once hand ground & polished telescope mirrors, so know them well.

Interesting though is using 2 in a long confocal arrangement might reduce the amount of eddy current losses in the side walls and if so, increase Q quote a bit. Or not?

The shorter the focal length, the higher the phase distortion introduced upon each reflection.

Phil

Phil, I don't know where you get your "mirror coating would need to be 10x skin depth thickness", or "Rf penetrates 5x skin depth". Skin depth is an engineering convenience, and nothing else, based on 1/e, ( inverse natural logarithm) of energy depletion of an electromagnetic wave in a conductor. In other words, the wave rapidly depletes within the conductor to the point that its field strength becomes effectively negligable.

Dielectic mirrors required for (example , Helium Neon) laser gain most definitely violate the conditions you state. Can you provide some source of confirmation for your declaration?

And "The shorter the focal length, the higher the phase distortion introduced upon each reflection" isn't quite necessarily true, but you're treading into quantum mechanics territory with that statement. At distances less than a wavelength, true. At distances greater, not. This is why recent advances in optics (optical, x-ray, ultrasonic, and others) that "violate" the Raleigh limit are of interest.

Are they Emdrive applicable? No one knows; that's why we're all here. But I beg you to not make unsubstantiated statements without at least a modicum of verifiable reference.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/12/2016 03:52 am
Actually, you can create a concave-convex optical cavity in the shape of a frustum. In fact, the cavity length (5cm) is dictated by which concave and convex mirrors are available for purchase at specific radii.

As pointed out by Dr. Rodal, the huge difference is the modes in an optical cavity will be much higher order.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1104186;image)
Thanks for the picture and the discussion.

Does this have side-walls ? if so, what material is used for the side walls?


I updated my post. The side walls are shown clear here so we can see the interior. They would be of the same material as the end-plate mirrors. Glass and vapor deposited aluminum or dialectric mirror.

I don't think that one needs the side walls, and actually the side walls will be detrimental to the effect being pursued.


Quote
The optical resonator is sometimes referred to as an "optical cavity", but this is a misnomer: lasers use open resonators as opposed to the literal cavity that would be employed at microwave frequencies in a maser. The resonator typically consists of two mirrors between which a coherent beam of light travels in both directions, reflecting back on itself so that an average photon will pass through the gain medium repeatedly before it is emitted from the output aperture or lost to diffraction or absorption. If the gain (amplification) in the medium is larger than the resonator losses, then the power of the recirculating light can rise exponentially.

At optical frequencies, your side walls are never going to be accurately straight and parallel to the optical ray and they are never going to be sufficiently smooth.  They don't serve any useful function and worse, they are detrimental.  It would be better not to have anything that can either reflect or refract the optical rays on the conical sides.  Better leave it open.

SUGGESTION: Test it both A) with sidewalls and B) WITHOUT side walls


Bae, in his photonic laser thruster research, found that putting a gain media in the resonance cavity will cause the resonance to become highly resilient to misalignment of the reflectors (he had an Oh Sh*t moment when he held one of the mirrors in his hand and the thing remained in resonance).  I'm not sure what adding a solid gain medium would do for an EMDrive, but it might be worth a shot to see if it can alleviate the need for extremely precise alignments.

Whoa, whoa, whoa!!! I thought this thread was about investigating whether Roger Shawyer's claims were physically realizable? To whit, an easily obtainable microwave oven magnetron, when launched into a "closed" resonant cavity, will develop thrust in reference to its environment, due to reaction against fields which can be incorporated within known Einstein/Newton physics? And as the Q increases, so does the thrust. Period.

Again, why has no one TUNED THE SOURCE TO THE FRUSTUM??? Rather than spend EONS TRYING TO TRIM COPPER TO MATCH A RESONANT CAVITY TO AN UNMATCHABLE MICROWAVE SOURCE???
 
Some experiments and theories are getting way out of bounds, me thinks. Optical replications of an effect that has NEVER been replicated in its original configuration are beyond pointless.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SteveD on 03/12/2016 04:20 am
Whoa, whoa, whoa!!! I thought this thread was about investigating whether Roger Shawyer's claims were physically realizable? To whit, an easily obtainable microwave oven magnetron, when launched into a "closed" resonant cavity, will develop thrust in reference to its environment, due to reaction against fields which can be incorporated within known Einstein/Newton physics? And as the Q increases, so does the thrust. Period.

Again, why has no one TUNED THE SOURCE TO THE FRUSTUM??? Rather than spend EONS TRYING TO TRIM COPPER TO MATCH A RESONANT CAVITY TO AN UNMATCHABLE MICROWAVE SOURCE???
 
Some experiments and theories are getting way out of bounds, me thinks. Optical replications of an effect that has NEVER been replicated in its original configuration are beyond pointless.

TheTraveller is running tests with a tuneable rf source and has mentioned initially positive results (8 mN I believe, plus some interesting subsequent observations).  The hackaday EMDrive team is also using a tuneable source.  Shell . . . actually is working on the extremely tight tolerances need to tune the frustum to the source and think the random fluctuation from the magnetron might have something to do with the effect.  I'm not really sure what rfmwguy is up to.  I've heard about attempting to work in brass or to utilize some non-standard shape. 

As for an optical EmDrive, I think there are people out there that would find it easier to believe the effect existed if it involved lasers and not microwave emitters.   
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/12/2016 05:01 am
Actually, you can create a concave-convex optical cavity in the shape of a frustum. In fact, the cavity length (5cm) is dictated by which concave and convex mirrors are available for purchase at specific radii.

As pointed out by Dr. Rodal, the huge difference is the modes in an optical cavity will be much higher order.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1104186;image)
Thanks for the picture and the discussion.

Does this have side-walls ? if so, what material is used for the side walls?


I updated my post. The side walls are shown clear here so we can see the interior. They would be of the same material as the end-plate mirrors. Glass and vapor deposited aluminum or dialectric mirror.

I don't think that one needs the side walls, and actually the side walls will be detrimental to the effect being pursued.


Quote
The optical resonator is sometimes referred to as an "optical cavity", but this is a misnomer: lasers use open resonators as opposed to the literal cavity that would be employed at microwave frequencies in a maser. The resonator typically consists of two mirrors between which a coherent beam of light travels in both directions, reflecting back on itself so that an average photon will pass through the gain medium repeatedly before it is emitted from the output aperture or lost to diffraction or absorption. If the gain (amplification) in the medium is larger than the resonator losses, then the power of the recirculating light can rise exponentially.

At optical frequencies, your side walls are never going to be accurately straight and parallel to the optical ray and they are never going to be sufficiently smooth.  They don't serve any useful function and worse, they are detrimental.  It would be better not to have anything that can either reflect or refract the optical rays on the conical sides.  Better leave it open.

SUGGESTION: Test it both A) with sidewalls and B) WITHOUT side walls


Bae, in his photonic laser thruster research, found that putting a gain media in the resonance cavity will cause the resonance to become highly resilient to misalignment of the reflectors (he had an Oh Sh*t moment when he held one of the mirrors in his hand and the thing remained in resonance).  I'm not sure what adding a solid gain medium would do for an EMDrive, but it might be worth a shot to see if it can alleviate the need for extremely precise alignments.

Whoa, whoa, whoa!!! I thought this thread was about investigating whether Roger Shawyer's claims were physically realizable? To whit, an easily obtainable microwave oven magnetron, when launched into a "closed" resonant cavity, will develop thrust in reference to its environment, due to reaction against fields which can be incorporated within known Einstein/Newton physics? And as the Q increases, so does the thrust. Period.

Again, why has no one TUNED THE SOURCE TO THE FRUSTUM??? Rather than spend EONS TRYING TO TRIM COPPER TO MATCH A RESONANT CAVITY TO AN UNMATCHABLE MICROWAVE SOURCE???
 
Some experiments and theories are getting way out of bounds, me thinks. Optical replications of an effect that has NEVER been replicated in its original configuration are beyond pointless.


Again, why has no one TUNED THE SOURCE TO THE FRUSTUM??? Rather than spend EONS TRYING TO TRIM COPPER TO MATCH A RESONANT CAVITY TO AN UNMATCHABLE MICROWAVE SOURCE???


You need to look at the other side of the same coin. You can do as you say and tune the incoming RF to the frustum or you can tune the frustum to the RF source.

If the RF source is an oven magnetron with a nasty power supply that causes the RF to be scattered all over a 30-50MHz bandwidth you stabilize it.

Everyone thinks that a magnetron is a widely spewing RF source with no real Fo but fail to realize that's because of three things that home makers of microwave ovens don't want to add into the cost of a microwave oven. It's also true that making the RF out of a magnetron   jittery helps to cook food.

Magnetrons are used in the Semiconductor industry and are high power, highly stable RF sources.

*The Power supply on a oven microwave is designed to output a 50% duty cycle to the magnetron and the voltage is not regulated. Causing jitter of the magnetron output signal.

*The cooling system of fins/fan just barely keeps the magnetron from overheating causing frequency drifting.

*The magnetron heater will cause sputtering if left on during operation.

If you address these issues with a magnetron power supply that removes these problems you will be left with a high power stable RF source. I've done that.

You then design the frustum to be tuned to the incoming RF and even when heating is observed in the frustum leading to thermal expansion you compensate for it. I've done that.

Tests up to now have been done at low power or the results that have been seen at high powered magnetrons lead to either a RF source so low as to not be able to take the system out of a error bar or using a RF magnetron source that splatters all over and heats up the frustum causing it to detune from any mode of operation.

This is cut and pasted from another site and should carry some weight in answering your question.

I was the very first builder to remove the magnetron off the frustum in a separate area that was shielded.
I am the only builder to use a Carbon Fiber Composite beam negating any issues of beam expansion from heat.
I was the only builder who said from the start that you needed a common ground system called a star ground to keep ground loops under control and also one of the first to talk about Lorentz issues and address them.
I was one of the first to detail out the thermal ballooning issues and provide a solution.
I was the first to redesign the power supply in for the magnetron to eliminate splattering and therefor excess heating.
I was the first to design waveguides into the frustum, antennas can cause issues.
I was the first to take a balance beam to measure not only pressure but using the same DUT and test stand measure acceleration.
I am the only one to design a frustum that negates the thermal expansion copper issues.
I am the only one to add ceramic plates to keep endplates from warping from thermal heat.
I'm the only one to thermally cool the magnetron to keep it from frequency drifting form heat.

Added: I also designed a fully enclosed frustum that vents any air jets away from the frustum causing measurement issues.

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Tcarey on 03/12/2016 05:05 am
Actually, you can create a concave-convex optical cavity in the shape of a frustum. In fact, the cavity length (5cm) is dictated by which concave and convex mirrors are available for purchase at specific radii.

As pointed out by Dr. Rodal, the huge difference is the modes in an optical cavity will be much higher order.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1104186;image)
Thanks for the picture and the discussion.

Does this have side-walls ? if so, what material is used for the side walls?


I updated my post. The side walls are shown clear here so we can see the interior. They would be of the same material as the end-plate mirrors. Glass and vapor deposited aluminum or dialectric mirror.

At optical frequencies, I don't think that one needs the side walls, and actually the side walls will be detrimental to the effect being pursued.


Quote
The optical resonator is sometimes referred to as an "optical cavity", but this is a misnomer: lasers use open resonators as opposed to the literal cavity that would be employed at microwave frequencies in a maser. The resonator typically consists of two mirrors between which a coherent beam of light travels in both directions, reflecting back on itself so that an average photon will pass through the gain medium repeatedly before it is emitted from the output aperture or lost to diffraction or absorption. If the gain (amplification) in the medium is larger than the resonator losses, then the power of the recirculating light can rise exponentially.

At optical frequencies, your side walls are never going to be accurately straight and parallel to the optical ray and they are never going to be sufficiently smooth.  They don't serve any useful function and worse, they are detrimental.  It would be better not to have anything that can either reflect or refract the optical rays on the conical sides.  Better leave it open. (Of course, do wear eye protection).

SUGGESTION: Test it both A) with sidewalls and B) WITHOUT side walls


(https://upload.wikimedia.org/wikipedia/commons/thumb/4/4b/Laser_DSC09088.JPG/250px-Laser_DSC09088.JPG)

(https://upload.wikimedia.org/wikipedia/commons/c/ca/Optical-cavity1.png)

This subject of an optical frustrum has me wondering about several things.

First, how would you inject light into the frustrum? I imagine that would require a hole in one of the end plates which would reduce the Q.

Second, if the end plates are optically flat and optically parallel wouldn't the light be reflected back to the input hole? If the injection beam is not perfectly collimated then it will spread out as it bounces back and forth so at some number of reflections it will impinge the frustrum sidewalls. That will of course happen because of imperfections in the mirrors and the alignment.

There was a comment about laser's having an infinite Q. I can't grasp that. Lasers have a continuous input of energy. If they had an infinite Q they would never put out any light at all.




 





Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/12/2016 07:15 am
First, how would you inject light into the frustum? I imagine that would require a hole in one of the end plates which would reduce the Q.

I've only found a few ways to inject laser light into a frustum-shaped optical cavity and have the beam remain stable as it bounces between end-plates. One of the methods requires the side walls.

The best method, of course, would be to generate the photons in the frustum itself - by filling the frustum with a gain medium, such as CO2 and N2, or HeNe, and attaching a cathode and anode. Though I'm not sure how well high voltage electrical discharges work in mirrored cavities!
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/12/2016 12:29 pm
Phil, I don't know where you get your "mirror coating would need to be 10x skin depth thickness", or "Rf penetrates 5x skin depth". Skin depth is an engineering convenience, and nothing else, based on 1/e, ( inverse natural logarithm) of energy depletion of an electromagnetic wave in a conductor. In other words, the wave rapidly depletes within the conductor to the point that its field strength becomes effectively negligable.

http://daycounter.com/Calculators/SkinEffect/Skin-Effect-Calculator.phtml
Quote
Skin depth is defined as the distance below the surface where the current density has fallen to 1/e or 37% of its value at the surface.

To get close to 100% reduction in current density below the surface density requires 5x skin depth and not the ~37% at 1x skin depth penetration.

In engineering terms this 1st ~37% drop is referred to as a 1 TC decline and to get full effect requires 5x. As it is for cavity fill and discharge time as it is for cap and inductors as it is for skin depth penetration.

Then assuming errors in the surface smoothness and possible surface pits, needs 10x to make an old engineers gut sleep well at night.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/12/2016 12:31 pm
P.S. Hanging around as I am very curious to see how the next experimenter is going about convincing herself/himself and others that the observed force is not the result of hot air.  :)

Careful there. Your bias is starting to show.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/12/2016 01:09 pm
Here is a simple excel calculator to show how many reflections will occur from each end plate, depending on unloaded cavity Q 5 TC time, Rf freq and number of 1/2 resonant waves in the cavity.

Example attached shows that for a TXXX3 resonant mode at 2.45 GHZ with a unloaded cavity Q of 86.2k, there would be 45,731 reflection from each end plate, for every cycle of Rf input, until the Rf energy is totally thermalised or converted into an externally usable force over 27.998usec. Which is a good life time for 1 cycle of 2.45GHz input Rf energy.

45,731 reflections from each end plate is a lot to keep perfectly aligned and for them to not walk off to a wider separation point. Of course the end plate alignment also affects cavity Q as it affects wall losses.

At least now we have a way to calc how many reflection will occur from each end plate if we get the cavity built perfect to 10x skin depth accuracy or better.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/12/2016 02:05 pm
SORRY I meant the height!  17.67cm

Okay thanks. I was wondering why is was so short! Looks like you have TE311, albeit not as strong as the TE311 I was able to locate by simulating large numbers of frustum dimensions.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: X_RaY on 03/12/2016 03:13 pm
SORRY I meant the height!  17.67cm

Okay thanks. I was wondering why is was so short! Looks like you have TE311, albeit not as strong as the TE311 I was able to locate by simulating large numbers of frustum dimensions.
https://forum.nasaspaceflight.com/index.php?topic=39214.msg1473268#msg1473268  ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/12/2016 05:24 pm
X-RaY, out of curiosity, does your spreadsheet indicate that TE211 is possible with a frustum length of ~18cm? End-plate radius can be arbitrary. I've been trying to find larger dimensions that resonate at that mode, as the one I found was only ~12cm in length.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SteveD on 03/12/2016 05:39 pm
Here is a simple excel calculator to show how many reflections will occur from each end plate, depending on unloaded cavity Q 5 TC time, Rf freq and number of 1/2 resonant waves in the cavity.

Example attached shows that for a TXXX3 resonant mode at 2.45 GHZ with a unloaded cavity Q of 86.2k, there would be 45,731 reflection from each end plate, for every cycle of Rf input, until the Rf energy is totally thermalised or converted into an externally usable force over 27.998usec. Which is a good life time for 1 cycle of 2.45GHz input Rf energy.

45,731 reflections from each end plate is a lot to keep perfectly aligned and for them to not walk off to a wider separation point. Of course the end plate alignment also affects cavity Q as it affects wall losses.

At least now we have a way to calc how many reflection will occur from each end plate if we get the cavity built perfect to 10x skin depth accuracy or better.

Urm, I don't suppose anybody can hack a simulator to check this to see if bounces off the sidewalls cause one endplate to undergo more bounces than the other.  While CoM says it shouldn't matter, it would be nice to have the data to make sure nothing odd is going on.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: X_RaY on 03/12/2016 05:52 pm
X-RaY, out of curiosity, does your spreadsheet indicate that TE211 is possible with a frustum length of ~18cm? End-plate radius can be arbitrary. I've been trying to find larger dimensions that resonate at that mode, as the one I found was only ~12cm in length.
[email protected]≈2.45GHz
Small Diameter=99mm
Big Diameter=149mm
Center Length=180mm
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: aero on 03/12/2016 07:35 pm
@ Dr. Rodal,

You may have already explained this but I can't rely on memory.

It is difficult to find Drude model parameters for metals and I am looking for Silver. Plus, data that I do find is not guaranteed to compare to DeltaMass's detailed derivation for copper.

Is it fair to simply multiply CU conductivity I'm using from DeltaMass by the ratio silver-conductivity divided by copper-conductivity where I use silver and copper conductivities from a published source?

My source gives conductivities, Ag = 62.1 and CU = 58.5

aero
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/12/2016 08:55 pm
@ Dr. Rodal,

You may have already explained this but I can't rely on memory.

It is difficult to find Drude model parameters for metals and I am looking for Silver. Plus, data that I do find is not guaranteed to compare to DeltaMass's detailed derivation for copper.

Is it fair to simply multiply CU conductivity I'm using from DeltaMass by the ratio silver-conductivity divided by copper-conductivity where I use silver and copper conductivities from a published source?

My source gives conductivities, Ag = 62.1 and CU = 58.5

aero

Please refresh my mind

A) (preferably) by linking to my messages where I provided the Meep input for copper (I can't find them) or
B) otherwise by giving me the actual Meep input you use for copper properties

Thanks
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/12/2016 09:24 pm
@ Dr. Rodal,

You may have already explained this but I can't rely on memory.

It is difficult to find Drude model parameters for metals and I am looking for Silver. Plus, data that I do find is not guaranteed to compare to DeltaMass's detailed derivation for copper.

Is it fair to simply multiply CU conductivity I'm using from DeltaMass by the ratio silver-conductivity divided by copper-conductivity where I use silver and copper conductivities from a published source?

My source gives conductivities, Ag = 62.1 and CU = 58.5

aero

Please refresh my mind

A) (preferably) by linking to my messages where I provided the Meep input for copper (I can't find them) or
B) otherwise by giving me the actual Meep input you use for copper properties

Thanks
This what you're looking for?
https://forum.nasaspaceflight.com/index.php?topic=38577.msg1451836#msg1451836

Scroll down for more info.

Back to building.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: aero on 03/12/2016 11:04 pm
@ Dr. Rodal,

You may have already explained this but I can't rely on memory.

It is difficult to find Drude model parameters for metals and I am looking for Silver. Plus, data that I do find is not guaranteed to compare to DeltaMass's detailed derivation for copper.

Is it fair to simply multiply CU conductivity I'm using from DeltaMass by the ratio silver-conductivity divided by copper-conductivity where I use silver and copper conductivities from a published source?

My source gives conductivities, Ag = 62.1 and CU = 58.5

aero

Please refresh my mind

A) (preferably) by linking to my messages where I provided the Meep input for copper (I can't find them) or
B) otherwise by giving me the actual Meep input you use for copper properties

Thanks

I have these:

Rodal's explaination of how to ratio conductivity.
http://forum.nasaspaceflight.com/index.php?topic=38577.msg1453093#msg1453093  (http://forum.nasaspaceflight.com/index.php?topic=38577.msg1453093#msg1453093)or better -
http://forum.nasaspaceflight.com/index.php?topic=38577.msg1453316#msg1453316  (http://forum.nasaspaceflight.com/index.php?topic=38577.msg1453316#msg1453316)and one following
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/13/2016 12:40 am
Optical polishing almost done. Before and after pics of small endplate of NSF-1701A
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: aero on 03/13/2016 12:47 am
Hmm  - Before and after? or after and before  :D
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/13/2016 01:35 am
After and before...from top to bottom  :D
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/13/2016 01:49 am
Optical polishing almost done. Before and after pics of small endplate of NSF-1701A

Very nice work!!!
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: zen-in on 03/13/2016 03:01 am
Optical polishing almost done. Before and after pics of small endplate of NSF-1701A

Nice polishing job.   You can use it as a faux bronze age mirror.   I did something similar a few weeks ago.   The brass disk (before and after) is the cover plate for a diesel engine water pump.   Instead of buying a replacement I machined it flat then polished it.  Later I found 2 new cover plates in a locker.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: CW on 03/13/2016 07:27 am
I can see 4 atoms sticking out of the surface. Will it be precise enough to cause the Shawyer effect?  ;D
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/13/2016 12:05 pm
http://www.bbc.co.uk/programmes/b0752f85

Quote
Project Greenglow - The Quest for Gravity Control
Horizon, 2015-2016

This is the story of an extraordinary scientific adventure - the attempt to control gravity. For centuries, the precise workings of gravity have confounded the greatest scientific minds - from Newton to Faraday and Einstein - and the idea of controlling gravity has been seen as little more than a fanciful dream. Yet in the mid 1990s, UK defence manufacturer BAE Systems began a ground-breaking project code-named 'Greenglow', which set about turning science fiction into reality. On the other side of the Atlantic, Nasa was simultaneously running its own Breakthrough Propulsion Physics Project. It was concerned with potential space applications of new physics, including concepts like 'faster-than-light travel' and 'warp drives'.

Looking into the past and projecting into the future, Horizon explores science's long-standing obsession with the idea of gravity control. It looks at recent breakthroughs in the search for loopholes in conventional physics and examines how the groundwork carried out by Project Greenglow has helped change our understanding of the universe. Gravity control may sound like science fiction, but the research that began with Project Greenglow is very much on-going, and the dream of flying cars and journeys to the stars no longer seems quite so distant.

The program segment will probably be geo blocked outside the UK. Do trust it will make the jump to open access YouTube.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/13/2016 12:41 pm
Optical polishing almost done. Before and after pics of small endplate of NSF-1701A

Dave, is the thin concentric dark ring at the copper perimeter a groove for the side-walls to sit in?

Looks like your new copper is much thicker than 1mm.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/13/2016 01:30 pm
It is a rough cut solder channel a mil or so deep. The cone will be formed and seam soldered then put into the channel. The disk will sit on a hotplate and full of reflowed solder, basically, a liquid moat of silver solder. The hotplate gets turned off and hopefully a uniform solder seal occurs. Slow temp changes should maintain flatness.

I've not done this before, thought I'd try something new for the fun of it.

Also, the disk is 1/8 inch thick. The large end will be the same. Figured warping would be minimal and I don't have to mess with gluing thin copper on a batting material. Expansion coefficients of different materials can be a problem at times.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/13/2016 01:37 pm
Optical polishing almost done. Before and after pics of small endplate of NSF-1701A

Nice polishing job.   You can use it as a faux bronze age mirror.   I did something similar a few weeks ago.   The brass disk (before and after) is the cover plate for a diesel engine water pump.   Instead of buying a replacement I machined it flat then polished it.  Later I found 2 new cover plates in a locker.
Very nice. I meant to video the process, but got lazy. Copper is a weird metal, its softness really trashes tools and fine grit sandpaper. Found the best polish is 9, 3 and 1 micron diamond polish available in a syringe.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/13/2016 01:53 pm
It is a rough cut solder channel a mil or so deep.
I hope you accounted for that 1mm in your side walls!   ;D
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/13/2016 02:05 pm
Yes, the cone is not cut yet. I'll oversize it then use the lapping plate to sand the cone down to a precise measurement between top and bottom plates. I have some ideas to frequency tune magnetron to match to whatever final resonance will be. Size of frustum will be fixed but think I have the mag fine tuning solution worked out.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/13/2016 03:23 pm
Yes, the cone is not cut yet.

What thickness copper side walls? The 1/8 or sticking with 1mm?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/13/2016 04:24 pm
Yes, the cone is not cut yet.

What thickness copper side walls? The 1/8 or sticking with 1mm?
1mm sidewalls. Was going to to spin thicker copper but no spinners responded with decent prices. A fully funded institutional project could spin then polish. A user here also suggested a lost wax pocess.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: zen-in on 03/13/2016 04:56 pm
Yes, the cone is not cut yet.

What thickness copper side walls? The 1/8 or sticking with 1mm?
1mm sidewalls. Was going to to spin thicker copper but no spinners responded with decent prices. A fully funded institutional project could spin then polish. A user here also suggested a lost wax pocess.

Spinning is your best option.   Copper is not amenible to the lost wax casting process.  It does not liquify well in the presence of Oxygen.  The outer surface converts to cupric oxide.    Copper is cast in a vacuum, using graphite molds.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/13/2016 06:10 pm
Yes, the cone is not cut yet.

What thickness copper side walls? The 1/8 or sticking with 1mm?
1mm sidewalls. Was going to to spin thicker copper but no spinners responded with decent prices. A fully funded institutional project could spin then polish. A user here also suggested a lost wax pocess.

It is not going to be possible to have a high Q (quality of resonance) close to theoretical with 1 mm walls: very compliant (the opposite of stiff).  For a length of 0.26 meters and diameter of 0.28 meters, a 1 mm wall thickness is easy to deform out of shape just by applying hand pressure, and hence difficult to maintain geometrical tolerance.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/13/2016 06:36 pm
Yes, the cone is not cut yet.

What thickness copper side walls? The 1/8 or sticking with 1mm?
1mm sidewalls. Was going to to spin thicker copper but no spinners responded with decent prices. A fully funded institutional project could spin then polish. A user here also suggested a lost wax pocess.

It is not going to be possible to have a high Q (quality of resonance) close to theoretical with 1 mm walls: very compliant (the opposite of stiff).  For a length of 0.26 meters and diameter of 0.28 meters, a 1 mm wall thickness is easy to deform out of shape just by applying hand pressure, and hence difficult to maintain geometrical tolerance.

I hope you don't mind me adding my .02 cents on a 1mm or .039" copper wall. Once the endplates are secured by soldering you could literally stand on the frustum, I did. That's not the biggest issue we face in deforming, it's the thermal aspect of deformation that is the Q killer.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: meberbs on 03/13/2016 07:06 pm
Here is a simple excel calculator to show how many reflections will occur from each end plate, depending on unloaded cavity Q 5 TC time, Rf freq and number of 1/2 resonant waves in the cavity.

Example attached shows that for a TXXX3 resonant mode at 2.45 GHZ with a unloaded cavity Q of 86.2k, there would be 45,731 reflection from each end plate, for every cycle of Rf input, until the Rf energy is totally thermalised or converted into an externally usable force over 27.998usec. Which is a good life time for 1 cycle of 2.45GHz input Rf energy.

45,731 reflections from each end plate is a lot to keep perfectly aligned and for them to not walk off to a wider separation point. Of course the end plate alignment also affects cavity Q as it affects wall losses.

At least now we have a way to calc how many reflection will occur from each end plate if we get the cavity built perfect to 10x skin depth accuracy or better.

Urm, I don't suppose anybody can hack a simulator to check this to see if bounces off the sidewalls cause one endplate to undergo more bounces than the other.  While CoM says it shouldn't matter, it would be nice to have the data to make sure nothing odd is going on.

"Number of bounces" has limited meaning in this context. It only makes sense when thinking about individual photons, and that does not provide useful insight to a resonator like this. For a 2 mirrors situation, you can calculate number of photons per time hitting each mirror easily, but the interactions with the side walls make such calculations less direct and meaningful.

The existence of individual photons is a quantum mechanical effect, and is not noticeable at macro scale/energies except when there is something such as the photoelectric effect where the energy delivered to a single electron needs to be a certain value to cause the effect. To give an idea, 1 Joule of energy is equivalent to over 600000000000000000000000 photons at 2.5 GHz (that is 23 zeros, I would use scientific notation but I want to emphasize this is a ridiculously huge number). You would need over 68 billion Terabytes of memory to have just one bit dedicated to each of those photons. Additionally since photons are overlapping quantum mechanical particles, it is literally meaningless and impossible to follow the path of any one photon.

Inside a frustum resonator, the fields are effectively the result of photons traveling in multiple directions where the fields are partially cancelling, generating the interesting patterns for different modes. I don't believe there is any way to easily reconstruct what different directions are underlying the patterns, if that even is a meaningful concept. Energy is being exchanged between the fields and the currents and charge distributions in the walls. Energy is lost as heat when the currents encounter resistance. This happens throughout the walls as a function of current density and is not directly tied to any discrete photon. Q under the definition being used here describes how quickly this energy turns into heat averaged over a cycle.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/13/2016 09:01 pm
"Number of bounces" has limited meaning in this context....

Put an E field sensor through one end plate plus a lot of attenuation so it doesn't add significant load to the cavity.

Set up to measure the unloaded cavity Q and the number of positive peak events in the E field during 5 TCs of the cavity discharge time.

Fill the cavity with resonant Rf.

Stop the Rf input just as the Rf crosses zero.

Measure the time until the E field probe says there is no more Rf energy inside the cavity. Should be 5x TC.

Count the number of E field positive peak events during the 5 x TC time period (should occur at the rate of the Rf resonant freq). Should be the indicated end plate reflection count number.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/13/2016 09:23 pm
Yes, the cone is not cut yet

If you still plan on exciting using the maggie antenna inserted in the middle of one end plate, expect to excite TM113 and not TE013 (same guide wavelength), which would require the antenna inserted through the side wall at one of the 3 peak E field locations.

Maybe one of the FEKO guys can model your build and antenna placement so you get the best cone end plate to end plate length to match resonance at your excitation freq and you understand what the TM113 mode fields should look like.

Best of luck.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/13/2016 09:37 pm
"Number of bounces" has limited meaning in this context....

Put an E field sensor through one end plate plus a lot of attenuation so it doesn't add significant load to the cavity.

Set up to measure the unloaded cavity Q and the number of positive peak events in the E field during 5 TCs of the cavity discharge time.

Fill the cavity with resonant Rf.

Stop the Rf input just as the Rf crosses zero.

Measure the time until the E field probe says there is no more Rf energy inside the cavity. Should be 5x TC.

Count the number of E field positive peak events during the 5 x TC time period (should occur at the rate of the Rf resonant freq). Should be the indicated end plate reflection count number.

What the heck is this constant of 5 you keep using? It first reared it's head when you claimed that a wall thickness of 5 skin depths would yield zero field. Which isn't true. The strength is down to (off the top of my head) about 0.7%, (curiously close to 0.707?) but NOT zero.

It's similar to radioisotope half-lives. The radiation just gets statistically very small, until it's effectively negligable. Making arbitrary statements about what is or is not negligable while studying an unknown and unproved effect (the Emdrive) is...odd. IMHO.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/13/2016 09:44 pm
Yes, the cone is not cut yet.

What thickness copper side walls? The 1/8 or sticking with 1mm?
1mm sidewalls. Was going to to spin thicker copper but no spinners responded with decent prices. A fully funded institutional project could spin then polish. A user here also suggested a lost wax pocess.

Dave, if you're referring to electroforming as a lost wax process, it is not. The form is often reusable, and needn't be made of wax. It just seems to me that machinable wax would be an easy and inexpensive material for the DIY community, with access to a lathe, to fabricate an accurate frustum with excellent surface finish.

If you're referring to some comment I missed regarding actual lost wax casting, my apologies. I agree that lost wax casting (as in pouring molten copper) of a frustum would be an exercise in futility for the DIY group. Brass or bronze could work, though, if you were willing to do quite a bit of post casting finishing.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/13/2016 09:50 pm
"Number of bounces" has limited meaning in this context....

Put an E field sensor through one end plate plus a lot of attenuation so it doesn't add significant load to the cavity.

Set up to measure the unloaded cavity Q and the number of positive peak events in the E field during 5 TCs of the cavity discharge time.

Fill the cavity with resonant Rf.

Stop the Rf input just as the Rf crosses zero.

Measure the time until the E field probe says there is no more Rf energy inside the cavity. Should be 5x TC.

Count the number of E field positive peak events during the 5 x TC time period (should occur at the rate of the Rf resonant freq). Should be the indicated end plate reflection count number.

What the heck is this constant of 5 you keep using? It first reared it's head when you claimed that a wall thickness of 5 skin depths would yield zero field. Which isn't true. The strength is down to (off the top of my head) about 0.7%, (curiously close to 0.707?) but NOT zero.

It's similar to radioisotope half-lives. The radiation just gets statistically very small, until it's effectively negligable. Making arbitrary statements about what is or is not negligable while studying an unknown and unproved effect (the Emdrive) is...odd. IMHO.

At 1x skin depth the surface current density is down to approx 37% or 1/e. Takes 5x skin depth to reduce it to approx 100%.

For a resonant cavity 1x TC is unloaded Q / (2 × Pi × freq resonant). Takes 5x that time to fully fill or discharge the cavity. 1x TC time will discharge the cavity to 1/e or ~37%.

Please see my earlier post:
http://forum.nasaspaceflight.com/index.php?topic=39772.msg1502999#msg1502999
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/13/2016 10:03 pm
Yes, the cone is not cut yet.

What thickness copper side walls? The 1/8 or sticking with 1mm?
1mm sidewalls. Was going to to spin thicker copper but no spinners responded with decent prices. A fully funded institutional project could spin then polish. A user here also suggested a lost wax pocess.

It is not going to be possible to have a high Q (quality of resonance) close to theoretical with 1 mm walls: very compliant (the opposite of stiff).  For a length of 0.26 meters and diameter of 0.28 meters, a 1 mm wall thickness is easy to deform out of shape just by applying hand pressure, and hence difficult to maintain geometrical tolerance.

I hope you don't mind me adding my .02 cents on a 1mm or .039" copper wall. Once the endplates are secured by soldering you could literally stand on the frustum, I did. That's not the biggest issue we face in deforming, it's the thermal aspect of deformation that is the Q killer.

Shell

Perhaps what I wrote was not readily understandable, so I will try to explain it further.   The issue I was concerned with is the issue of tolerance that DIY people should use.  TheTraveller quoted Shawyer as invoking a tolerance of 13 micrometers (which to me is way too stringent for 2.45 GHz microwaves with a free-space wavelength of 0.122 m).  On the other hand, it appears that rfmwguy and SeeShells have a much, much loser tolerance.

With a shell structure that is 1 mm thick but 0.28 m diameter and 0.26 m long the issue is deformation, not strength.

Stiffness is not the same thing as strength.

Strength is the highest stress that a structure can carry before it fails (it can be defined as permanent deformation  (*) for a tough material or fracture for a brittle material).
On the other hand, stiffness is the ratio of strain (change in length per unit original length) to stress, or the ratio of deformation by force.

A structure can be strong but not stiff enough for a given application.

The issue with the quality of resonance is not at all anything to do with strength.

When you say:

Quote
Once the endplates are secured by soldering you could literally stand on the frustum, I did.

you may be able to determine just by standing on it is whether you exceeded the strength of the structure, certainly if it fractures, or perhaps if it permanently deforms and the permanent deformation is large enough to be perceived.

To check the stiffness, you would need to be able to apply a load (stand on it) and simultaneously measure the deformation while the load is being applied.   This is usually done with universal testers (either mechanical, screw-driven, or servo-hydraulic testers).

 For elastic deformation, the structure will return to its original shape once you unload from it.

The concern is that the Q quality of deformation will be affected by deformations of the order of a mm.

There is a huge dissonance between TheTraveller writing that Shawyer is asking for a tolerance of 13 micrometers in order to achieve a Q close to theoretical and on the other hand, saying that all the tolerance needed is whether one can observe deformation of truncated cone just by standing on it.

I don't think that you would be able to determine an elastic deformation of a mm just by standing on it (you would need to have mirrors and an incredible vision to be able to tell a mm deformation !!! ). (*)


So what is needed here is to quantify stiffness: to quantify deformation of the structure. Even when looking for permanent deformation, since the expected permanent deformation is of the order of a mm (the wall thickness) (**) standing on the truncated cone may not be an accurate way to determine it..

And what is needed is for DIY experimenters to agree on a tolerance: there is a huge gap between the 13 micrometer tolerance invoked by TheTraveller/Shawyer and on the other hand invoking that if one can stand on the truncated cone, that is good enough.

_____

(*) Actually, one does not need to really stand on the structure to be able to figure out the deformation of a cylinder that is 0.26 m long by 0.28 m diameter with a wall thickness of only 1 mm .  One can readily use the theory of elasticity for thin shells to figure the deformation of cylindrical shell under load  :).  The problem, though, is what is the boundary condition fixing the end plates to the cylindrical section: is it simply supported (appropriate for thin end plates) or is it cantilevered ends  (which would be appropriate for very thick end plates). 

(**)  The "standing on the cone" structure did serve as a test that you did not reach snap-through permanent buckling, but permanent deformation of the order of thickness (mm) was still certainly possible.

The Q of the truncated cone will be affected by deformations much smaller than something like the snap-through buckling permanent deformation shown in this picture :

(http://www.ma.man.ac.uk/~mheil/MATTHIAS/GIF/LR5FullTube.gif)

It would be good for DIY to agree on a tolerance that may not be as extreme as the 13 micrometers invoked by TheTraveller/Shawyer, but yet is not as loose as "standing on it"
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/13/2016 10:08 pm
Yes, the cone is not cut yet.

What thickness copper side walls? The 1/8 or sticking with 1mm?
1mm sidewalls. Was going to to spin thicker copper but no spinners responded with decent prices. A fully funded institutional project could spin then polish. A user here also suggested a lost wax pocess.

Dave, if you're referring to electroforming as a lost wax process, it is not. The form is often reusable, and needn't be made of wax. It just seems to me that machinable wax would be an easy and inexpensive material for the DIY community, with access to a lathe, to fabricate an accurate frustum with excellent surface finish.

If you're referring to some comment I missed regarding actual lost wax casting, my apologies. I agree that lost wax casting (as in pouring molten copper) of a frustum would be an exercise in futility for the DIY group. Brass or bronze could work, though, if you were willing to do quite a bit of post casting finishing.
Yes, electroforming using wax that can be melted and drained out of the rf insertion port. Sorry, just reminded me of lost wax which is molten metal.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/13/2016 11:16 pm
Yes, the cone is not cut yet.

What thickness copper side walls? The 1/8 or sticking with 1mm?
1mm sidewalls. Was going to to spin thicker copper but no spinners responded with decent prices. A fully funded institutional project could spin then polish. A user here also suggested a lost wax pocess.

It is not going to be possible to have a high Q (quality of resonance) close to theoretical with 1 mm walls: very compliant (the opposite of stiff).  For a length of 0.26 meters and diameter of 0.28 meters, a 1 mm wall thickness is easy to deform out of shape just by applying hand pressure, and hence difficult to maintain geometrical tolerance.

I hope you don't mind me adding my .02 cents on a 1mm or .039" copper wall. Once the endplates are secured by soldering you could literally stand on the frustum, I did. That's not the biggest issue we face in deforming, it's the thermal aspect of deformation that is the Q killer.

Shell

Perhaps what I wrote was not readily understandable, so I will try to explain it further. 

Stiffness is not the same thing as strength.

Strength is the highest stress that a structure can carry before it fails (it can be defined as permanent deformation for a tough material like steel or fracture for a brittle material like a ceramic).
On the other hand, stiffness is the ratio of strain (change in length per unit original length) to stress. 

The issue with the quality of resonance is not at all anything to do with strength.

When you say:

Quote
Once the endplates are secured by soldering you could literally stand on the frustum, I did.

all you may be able to determine is whether you exceeded the strength of the structure, certainly if it fractures, or perhaps if it permanently deforms and the permanent deformation is large enough to be perceived.

To check the stiffness, you would need to be able to apply a load (stand on it) and simultaneously measure the deformation while the load is being applied.  For elastic deformation, the structure will practically instantaneously return to its original shape once you unload from it.

In this case, one can readily show that the Q quality of deformation will be severely affected by deformations of the order a mm. 

I don't think that you would be able to determine an elastic deformation of a mm just by standing on it (you would need to have mirrors and an incredible vision to be able to tell a mm deformation !!! ).

And one does not need to really stand on the structure to be able to figure out the deformation of a cylinder that is 0.26 m long by 0.28 m diameter with a wall thickness of only 1 mm .  One can readily use the theory of elasticity for thin shells to figure the deformation of the truncated cone under load  :).

So what is needed here is to quantify stiffness: to quantify deformation of the structure.  Even when looking for permanent deformation, since the expected permanent deformation is of the order of a mm (the wall thickness) (*) standing on the truncated cone may not be an accurate way to determine it.

_____

(*)  The "standing on the cone" structure did serve as a test that you did not reach snap=through permanent buckling, but permanent deformation of the order of thickness (mm) was still certainly possible.

Are we talking about two different things Dr. Rodal? The Young's modulus verses thermal expansion coefficient of copper. If your talking about copper being changed from the pressures of a hand in the copper frustum you would have to exert.

Longitudinal stress = Force(F)/Cross sectional area (A) = F/A
Longitudinal strain = Extension(e)/Original length (Lo) = e/Lo
(E) = [F/A]/[e/Lo] = FLo/eA

Copper=120 Gpa (Young modulus)

Whereas putting it into perspective.

Iron=110 Gpa

For the frustum to show deviations from the pressures of just the hand and a significant change in the endplate Z distance of 1mm (where tuning is the most critical) you would have to exert hundreds of pounds.

What they are more likely seeing is a thermal expansion of the copper from the heat in the hand on the copper causing a expansion and the endplate distances to change. Or it's likely we are changing the harmonic frequency from the capacitance added from the hand on the walls.

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/13/2016 11:37 pm
...

Are we talking about two different things Dr. Rodal? The Young's modulus verses thermal expansion coefficient of copper. If your talking about copper being changed from the pressures of a hand in the copper frustum you would have to exert.

Longitudinal stress = Force(F)/Cross sectional area (A) = F/A
Longitudinal strain = Extension(e)/Original length (Lo) = e/Lo
(E) = [F/A]/[e/Lo] = FLo/eA

Copper=120 Gpa (Young modulus)

Whereas putting it into perspective.

Iron=110 Gpa

For the frustum to show deviations from the pressures of just the hand and a significant change in the endplate Z distance of 1mm (where tuning is the most critical) you would have to exert hundreds of pounds.

What they are more likely seeing is a thermal expansion of the copper from the heat in the hand on the copper causing a expansion and the endplate distances to change. Or it's likely we are changing the harmonic frequency from the capacitance added from the hand on the walls.

No, we are not dealing with a solid bar of copper here, instead we are dealing with thin shell structures.

One way to simplify the problem of what is the stiffness of a cylindrical shell is to look at the change in diameter of a cylindrical shell with open ends, under the action of a uniform line load, for which there is an easy formula.


Change in diameter=(1 - nu^2)*1.78853*((Load per unit length)/ E) *(Radius/thickness) ^3

(Observe that the stiffness of a cylindrical shell is proportional to the cube of the ratio of the thickness to the diameter, so that thickness is an extremely important variable, going like the third power !!!)

for:

Radius=(0.28 m)/2
Thickness = 0.001 m
E = 17*10^6 psi = 117 GPa
Change in diameter = 0.001 m
Poisson's ratio= nu = 0.3

requires a force/unitLength = 0.15 lbf/in (0.15 pounds force per inch)

or just 1  pound force distributed every 6.7 inches of length

The calculation for solid ends is more complicated, but you get the idea, I hope.


Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/13/2016 11:41 pm
I propose that a common-sense tolerance for EM Drive thickness that DIY testing people should use for their frustums is the thickness of a commercial waveguide with similar diameter.

In this case, a common sense tolerance is that DIY people should use a thickness of waveguides with a diameter of 0.28 m to be used at ~2 GHz

(http://quinstar.com/wp-content/blogs.dir/1/files/2011/10/Standard-Gain-Horn-Antennas.jpg)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/13/2016 11:49 pm
I think if we look at monomorphics distortion models, the effects of sidewall deformation will have far less impact on resonance than magnetron frequency drift. Thin sidewalls are a not going to make or break an experiment imho. If we see unsustainable emdrive force, my bet would be on mag freq, not sidewall deformation due to heat. I measured very little heat rise on the sidewall mesh. We need to focus on reasonable materials for diy projects...thick sidewalls are not part of this. Perhaps institutional players can do this.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/13/2016 11:57 pm
I think if we look at monomorphics distortion models, the effects of sidewall deformation will have far less impact on resonance than magnetron frequency drift. Thin sidewalls are a not going to make or break an experiment imho. If we see unsustainable emdrive force, my bet would be on mag freq, not sidewall deformation due to heat. I measured very little heat rise on the sidewall mesh. We need to focus on reasonable materials for diy projects...thick sidewalls are not part of this. Perhaps institutional players can do this.

1) So , why are commercial waveguides with 0.28 m diameter made with thicker walls than 1mm? Or are you saying  that one might as well just use waveguides only 1 mm thick ?

2) There is a huge gap between rfmwguy defending the use of 1 mm thick walls for a fustrum and TheTraveller saying that Shawyer recommends 13 micrometer tolerance.

A whole lot of dissonance here.  It would be nice to be able to resolve this matter.

3) One should be able to defend the use of a given thickness without invoking uncertainty about the function of a magnetron: seems like that is a different thing...

4) The question here is what Q are you going to be able to achieve. The budget of DIY is not relevant to that question,  that is a different matter.  If a DIY's budget cannot get close to theoretical Q, that is a good thing to know.

It would be good if one could provide a calculation to defend the argument that 1 mm wall thickness is good enough to achieve high Q's close to theoretical
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/14/2016 12:06 am
Yes, the cone is not cut yet.

What thickness copper side walls? The 1/8 or sticking with 1mm?
1mm sidewalls. Was going to to spin thicker copper but no spinners responded with decent prices. A fully funded institutional project could spin then polish. A user here also suggested a lost wax pocess.

It is not going to be possible to have a high Q (quality of resonance) close to theoretical with 1 mm walls: very compliant (the opposite of stiff).  For a length of 0.26 meters and diameter of 0.28 meters, a 1 mm wall thickness is easy to deform out of shape just by applying hand pressure, and hence difficult to maintain geometrical tolerance.

I hope you don't mind me adding my .02 cents on a 1mm or .039" copper wall. Once the endplates are secured by soldering you could literally stand on the frustum, I did. That's not the biggest issue we face in deforming, it's the thermal aspect of deformation that is the Q killer.

Shell

Perhaps what I wrote was not readily understandable, so I will try to explain it further.   The issue I was concerned with is the issue of tolerance that DIY people should use.  TheTraveller quoted Shawyer as invoking a tolerance of 13 micrometers (which to me is way too stringent for 2.45 GHz microwaves with a free-space wavelength of 0.122 m).  On the other hand, it appears that rfmwguy and SeeShells have a much, much loser tolerance.

With a shell structure that is 1 mm thick but 0.28 m diameter and 0.26 m long the issue is deformation, not strength.

Stiffness is not the same thing as strength.

Strength is the highest stress that a structure can carry before it fails (it can be defined as permanent deformation  (*) for a tough material or fracture for a brittle material).
On the other hand, stiffness is the ratio of strain (change in length per unit original length) to stress, or the ratio of deformation by force.

A structure can be strong but not stiff enough for a given application.

The issue with the quality of resonance is not at all anything to do with strength.

When you say:

Quote
Once the endplates are secured by soldering you could literally stand on the frustum, I did.

you may be able to determine just by standing on it is whether you exceeded the strength of the structure, certainly if it fractures, or perhaps if it permanently deforms and the permanent deformation is large enough to be perceived.

To check the stiffness, you would need to be able to apply a load (stand on it) and simultaneously measure the deformation while the load is being applied.   This is usually done with universal testers (either mechanical, screw-driven, or servo-hydraulic testers).

 For elastic deformation, the structure will return to its original shape once you unload from it.

The concern is that the Q quality of deformation will be affected by deformations of the order of a mm.

There is a huge dissonance between TheTraveller writing that Shawyer is asking for a tolerance of 13 micrometers in order to achieve a Q close to theoretical and on the other hand, saying that all the tolerance needed is whether one can observe deformation of truncated cone just by standing on it.

I don't think that you would be able to determine an elastic deformation of a mm just by standing on it (you would need to have mirrors and an incredible vision to be able to tell a mm deformation !!! ). (*)


So what is needed here is to quantify stiffness: to quantify deformation of the structure. Even when looking for permanent deformation, since the expected permanent deformation is of the order of a mm (the wall thickness) (**) standing on the truncated cone may not be an accurate way to determine it..

And what is needed is for DIY experimenters to agree on a tolerance: there is a huge gap between the 13 micrometer tolerance invoked by TheTraveller/Shawyer and on the other hand invoking that if one can stand on the truncated cone, that is good enough.

_____

(*) Actually, one does not need to really stand on the structure to be able to figure out the deformation of a cylinder that is 0.26 m long by 0.28 m diameter with a wall thickness of only 1 mm .  One can readily use the theory of elasticity for thin shells to figure the deformation of cylindrical shell under load  :).  The problem, though, is what is the boundary condition fixing the end plates to the cylindrical section: is it simply supported (appropriate for thin end plates) or is it cantilevered ends  (which would be appropriate for very thick end plates). 

(**)  The "standing on the cone" structure did serve as a test that you did not reach snap-through permanent buckling, but permanent deformation of the order of thickness (mm) was still certainly possible.

The Q of the truncated cone will be affected by deformations much smaller than something like the snap-through buckling permanent deformation shown in this picture :

(http://www.ma.man.ac.uk/~mheil/MATTHIAS/GIF/LR5FullTube.gif)

It would be good for DIY to agree on a tolerance that may not be as extreme as the 13 micrometers invoked by TheTraveller/Shawyer, but yet is not as loose as "standing on it"

Well, Mr. Euler can be demonstrated with an empty beer can. Stand on it, carefully, and it will support your weight. Have a friend flick the can with a finger, and it will collapse. Just sayin'. The reality of mathematics when it's reduced to real world phenomenon is often non-intuitive.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 12:10 am
...

Well, Mr. Euler can be demonstrated with an empty beer can. Stand on it, carefully, and it will support your weight. Have a friend flick the can with a finger, and it will collapse. Just sayin'. The reality of mathematics when it's reduced to real world phenomenon is often non-intuitive.

(*) The issue at hand is that there is a huge gap between TheTraveller/Shawyer recommending 13 micrometers tolerance and rfmwguy polishing the plates to look like a mirror, while simultaneously using 1 mm wall thickness.

It seems to me more important to get to the bottom of this gap:

1) Shawyer recommending 13 micrometer tolerance

2) rfmwguyg polishing the copper to a mirror finish

the above appears incompatible with:

1 mm wall thickness.

Why do the endplates need to be polished like a mirror while the sidewalls can be 1 mm thick and hence susceptible to deformations (lack of straightness) of the order of 1 mm ?


Did any computer run by Monomorphic indicate that the endplates had to be polished like a mirror?

________

(*) That buckling load limits are very sensitive to initial imperfections is accounted for by Aerospace Engineers in their daily engineering life.  The sensitivity to initial imperfections can, and has been taken into account with mathematical formulations.  It can also be numerically analyzed (but it involves nonlinear formulations).

But I am not talking about buckling loads here, I'm just concerned with the stiffness of a shell that is 1 mm thick and 0.28 m in diameter.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/14/2016 12:23 am
Build Update: MHT1003NR3 arrives on Tuesday. I spent part of the day reworking the frustum in an effort to reduce the number of custom metal cuts required. I also hope to purchase the remainder of the aluminum for the interferometer and air track structure this week.

 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/14/2016 12:27 am
...

Well, Mr. Euler can be demonstrated with an empty beer can. Stand on it, carefully, and it will support your weight. Have a friend flick the can with a finger, and it will collapse. Just sayin'. The reality of mathematics when it's reduced to real world phenomenon is often non-intuitive.
That buckling load limits are very sensitive to initial imperfections is well known and accounted for by Aerospace Engineers in their daily engineering life.  The sensitivity to initial imperfections can be taken into account.

Anyway, the issue at hand is that there is a huge gap between TheTraveller/Shawyer recommending 13 micrometers tolerance and rfmwguy polishing the plates to look like a mirror, while simultaneously using 1 mm wall thickness.

We are in complete agreement. This forum has wandered between materials, fabrication techniques, wave models, magnetron tuning, thermal effects, vacuum issues, power supplies, antenna placement, and what have you. Not one experimenter has said:
1)What Shawyer claims (inject microwaves from a standard oven magnetron into a sealed frustrum and produce thrust) is testable, and I intend to prove it. If I don't, I'll know why.
2) If I do 1 above I will prove or disprove Shawyer's claim.

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 12:31 am
...

Well, Mr. Euler can be demonstrated with an empty beer can. Stand on it, carefully, and it will support your weight. Have a friend flick the can with a finger, and it will collapse. Just sayin'. The reality of mathematics when it's reduced to real world phenomenon is often non-intuitive.
That buckling load limits are very sensitive to initial imperfections is well known and accounted for by Aerospace Engineers in their daily engineering life.  The sensitivity to initial imperfections can be taken into account.

Anyway, the issue at hand is that there is a huge gap between TheTraveller/Shawyer recommending 13 micrometers tolerance and rfmwguy polishing the plates to look like a mirror, while simultaneously using 1 mm wall thickness.

We are in complete agreement. This forum has wandered between materials, fabrication techniques, wave models, magnetron tuning, thermal effects, vacuum issues, power supplies, antenna placement, and what have you. Not one experimenter has said:
1)What Shawyer claims (inject microwaves from a standard oven magnetron into a sealed frustrum and produce thrust) is testable, and I intend to prove it. If I don't, I'll know why.
2) If I do 1 above I will prove or disprove Shawyer's claim.

Much more important and relevant to the EM Drive thread than many things we have discussed, most recently for example "spooky quantum entanglement"
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/14/2016 12:40 am
...

Well, Mr. Euler can be demonstrated with an empty beer can. Stand on it, carefully, and it will support your weight. Have a friend flick the can with a finger, and it will collapse. Just sayin'. The reality of mathematics when it's reduced to real world phenomenon is often non-intuitive.

(*) The issue at hand is that there is a huge gap between TheTraveller/Shawyer recommending 13 micrometers tolerance and rfmwguy polishing the plates to look like a mirror, while simultaneously using 1 mm wall thickness.

It seems to me more important to get to the bottom of this gap:

1) Shawyer recommending 13 micrometer tolerance

2) rfmwguyg polishing the copper to a mirror finish

the above appears incompatible with:

1 mm wall thickness.

Why do the endplates need to be polished like a mirror while the sidewalls can be 1 mm thick and hence susceptible to deformations (lack of straightness) of the order of 1 mm ?


Did any computer run by Monomorphic indicate that the endplates had to be polished like a mirror?

________

(*) That buckling load limits are very sensitive to initial imperfections is accounted for by Aerospace Engineers in their daily engineering life.  The sensitivity to initial imperfections can, and has been taken into account with mathematical formulations.  It can also be numerically analyzed (but it involves nonlinear formulations).

But I am not talking about buckling loads here, I'm just concerned with the stiffness of a shell that is 1 mm thick and 0.28 m in diameter.

For me to see how a deformation in the sidewall of the cavity would seriously effect the resonate and tuning versus the distance required for resonance in the endplates I'd need to see some numbers. It's my contention that a deformation in the sidewalls of 1mm would not be seen or effect the Q of this system to anyserious degree. It's the endplates that set the resonance and Q.

I think on my next run I'll take a ball peen hammer and ding the sidewall to see if what I'm thinking here is true. Otherwise maybe someone could "ding" a depression in a FEKo sim to see what effects a sidewall deformation has in the Q and resonance.

Shell

Added: also there are outside circular copper strips on the sidewalls that could be used to increase the "stiffness dramatically. Builds have used this method.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheUberOverLord on 03/14/2016 12:43 am
I propose that a common-sense tolerance for EM Drive thickness that DIY testing people should use for their frustums is the thickness of a commercial waveguide with similar diameter.

In this case, a common sense tolerance is that DIY people should use a thickness of waveguides with a diameter of 0.28 m to be used at ~2 GHz

(http://quinstar.com/wp-content/blogs.dir/1/files/2011/10/Standard-Gain-Horn-Antennas.jpg)

This brings up a good point.

Was/is there any particular reason for waveguide thickness being what it is at these microwave frequencies. Besides power levels alone?

As was albeit, in the old days. In the USAF we had some flexible microwave waveguide for combat communications gear, that was not at the same tolerances as fixed waveguide. Meaning, it was a thinner thickness for waveguide walls. Yet they were both using at or near the same microwave frequencies and only differences were power levels:

Fixed

http://airforce.togetherweserved.com/usaf/servlet/tws.webapp.WebApp?cmd=ShadowBoxPersonPhoto&maxphoto=32&order=Sequence_desc&show_grid_View=1&ID=149788&type=PersonExt&photoIndex=1&page=1

Flexible

http://airforce.togetherweserved.com/usaf/servlet/tws.webapp.WebApp?cmd=ShadowBoxPersonPhoto&maxphoto=32&order=Sequence_desc&page=1&show_grid_View=1&ID=149788&type=PersonExt&photoIndex=6

Don
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 12:46 am
...

For me to see how a deformation in the sidewall of the cavity would seriously effect the resonate and tuning versus the distance required for resonance in the endplates I'd need to see some numbers. It's my contention that a deformation in the sidewalls of 1mm would not be seen or effect the Q of this system to anyserious degree. It's the endplates that set the resonance and Q.

I think on my next run I'll take a ball peen hammer and ding the sidewall to see if what I'm thinking here is true. Otherwise maybe someone could "ding" a depression in a FEKo sim to see what effects a sidewall deformation has in the Q and resonance.

Shell

Added: also there are outside circular copper strips on the sidewalls that could be used to increase the "stiffness dramatically. Builds have used this method.
But where do you stand on the following, which is the source of this huge contradictions in the last few pages of this thread:

1) Do you agree with TheTraveller/Shawyer that a tolerance of 13 micrometers is needed for the EM Drive?

2) Do you agree with rfmwguy that one needs to polish the end plates to look like a mirror?

It appears contradictory to argue for 13 micrometer tolerance and polishing the end plates to look like a mirror for the Q, and simultaneously to say that a deformation of 1 mm of the side walls doesn't matter for the Q
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: zellerium on 03/14/2016 01:14 am
I propose that a common-sense tolerance for EM Drive thickness that DIY testing people should use for their frustums is the thickness of a commercial waveguide with similar diameter.

In this case, a common sense tolerance is that DIY people should use a thickness of waveguides with a diameter of 0.28 m to be used at ~2 GHz


I don't understand your reasoning Dr. Rodal, commercial waveguides are designed to transmit power, not resonate, as I'm sure you're well aware of. I would expect the amount of conductive heat dissipation required by a transmission line (with a typical .5 dB loss per meter) is significantly less than a resonator with no output.

Why not create the thickest frustum possible within price constraints so that the steady state temperature is lower?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 01:22 am
I propose that a common-sense tolerance for EM Drive thickness that DIY testing people should use for their frustums is the thickness of a commercial waveguide with similar diameter.

In this case, a common sense tolerance is that DIY people should use a thickness of waveguides with a diameter of 0.28 m to be used at ~2 GHz


I don't understand your reasoning Dr. Rodal, commercial waveguides are designed to transmit power, not resonate, as I'm sure you're well aware of. I would expect the amount of conductive heat dissipation required by a transmission line (with a typical .5 dB loss per meter) is significantly less than a resonator with no output.

Why not create the thickest frustum possible within price constraints so that the steady state temperature is lower?

It is a question of logical consistency:

1) Shawyer/TheTraveller regularly use open waveguide explanations to explain the EM Drive  (please refer to Shawyer's paper).  For example, the cutoff frequency concept only applies to open waveguides.

2) In the post above SeeShells argues that <<It's the endplates that set the resonance and Q. >>.  Rfmwguy is polishing the end plates to look like a  mirror. 

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=39772.0,3Battach=1104565,3Bimage.pagespeed.ic.HOASI_qhWo.webp)

Both of these arguments run contrary to standing wave resonance inside a cavity at 2.45 GHz frequency (*):   for the eigenmodes and eigenfrequencies in a cavity, the roundness and concentricity of the walls is just as important as the end plates..   Both COMSOL and FEKO show this.  The exact solution also shows this.

3) I am not discussing anything to do with heat dissipation or thermal effects.  I am just arguing dimensional tolerance.

4) You write <<Commercial waveguides are designed to transmit power, not resonate>>.  That is not strictlly correct.  Commercial waveguides "resonate" only in the cross-dimensional direction: that is what TE01 for example means.  The mode shapes for waveguides are the result of solving the eigenvalue problem.

Here are the first "resonant" eigenmodes "mode shapes" for a waveguide with circular cross-section:

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36313.0;attach=631724)


  It is important for a waveguide to have certain tolerances in their cross-section, in order to maintain a given mode shape.

5) The question here is to justify the 1 mm thickness being used by DIY while they simultaneously polish the endplates like a mirror.  Where did that come from?  How is that justified?

6) It is not logical to say that only longitudinal resonance matters: that only the "p" matters in TEmnp for example.

7) How can people say that tight tolerances are needed in the longitudinal direction for "p" but not in the cross-section for "mn". ???

8) How could one say that the endplates need to look like a mirror (for 2.45 GHz frequency with wavelength of several cm) and that it is OK for example for the cross section  to look like an out-of-center star instead of  centered and circular ???

9) It seems to me that a logical proposition would be that if the walls can be 1 mm thick, then the endplates do not need to be polished like a mirror ... Alternatively, if the endplates need to look like a mirror, then dimensional tolerance in roundness and concentricity is just as crucial

___________

(*) optical resonance inside an optical "cavity" used in lasers is a completely different matter.  In that case one might as well have NO walls, as lasers (unlike masers) have open cavities.  However masers have closed cavities, and the roundness is just as important as the ends...
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/14/2016 01:55 am
...

For me to see how a deformation in the sidewall of the cavity would seriously effect the resonate and tuning versus the distance required for resonance in the endplates I'd need to see some numbers. It's my contention that a deformation in the sidewalls of 1mm would not be seen or effect the Q of this system to anyserious degree. It's the endplates that set the resonance and Q.

I think on my next run I'll take a ball peen hammer and ding the sidewall to see if what I'm thinking here is true. Otherwise maybe someone could "ding" a depression in a FEKo sim to see what effects a sidewall deformation has in the Q and resonance.

Shell

Added: also there are outside circular copper strips on the sidewalls that could be used to increase the "stiffness dramatically. Builds have used this method.
But where do you stand on the following, which is the source of this huge contradictions in the last few pages of this thread:

1) Do you agree with TheTraveller/Shawyer that a tolerance of 13 micrometers is needed for the EM Drive?

2) Do you agree with rfmwguy that one needs to polish the end plates to look like a mirror?

It appears contradictory to argue for 13 micrometer tolerance and polishing the end plates to look like a mirror for the Q, and simultaneously to say that a deformation of 1 mm of the side walls doesn't matter for the Q

I hope I can clarify what I'm talking about here as it is important.

Where I stand is that the endplates need to be of a good quality finish without any visible scratches. But do I think that a 13um or better finish is needed for what we're doing? No.

There is a large difference between 13um which is only 0.013mm in any deformations in the sidewalls.

Note: Although I have sidestepped that finishing issue by using a 99% pure silver electroplate process that fills in the slight scratches and buffs out to a mirror finish, also provides a real world increase in Q.

In every calculation you want to use the endplate spacing is shown to be the most critical. The sidewalls not so much and we cannot compare apples and oranges with the same analogies of the sidewall quality and slight deformation versus the endplates.

I've tried to do a search for when X_Ray did some calculations of the differences in Q and mode generation by varying the sidewall angles and couldn't find  what I was looking for. I do remember is wasn't a large effect. Maybe he has it still. Maybe he could using his spreadsheet vary one of his circular sections by 1mm and see what happens?

Do I think a 13um finish is really needed for what we're doing? No. Do I think that it needs to be carried out to the sidewalls? No.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/14/2016 01:58 am
Dr rodal, you seem to be bothered by diy methodology. I suggest no diyer has a correct methodology and neither do you. This topic has advanced well beyond being a roger shawyer comment thread to diy and theory beyond one person. My advice is to build one yourself and show others where errors are being made. Either that or publish a diy guide you would recommend to new diyers.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 01:59 am
...I've tried to do a search for when X_Ray did some calculations of the differences in Q and mode generation by varying the sidewall angles and couldn't find  what I was looking for. I do remember is wasn't a large effect. ...

Of relevance here is the roundness , instead of "side wall angles".

What would be required (I hope that monomorphic can run this) is to compare the following:

1) Random out-of-roundness  with perfect flat plates
(by this I mean an irregular random shape for the cross-section, using the random function in FEKO to model the cross-sectional shape)

vs

2) Random surface end plates with perfectly round conical walls

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/14/2016 02:01 am
Initial test of alphalabs trifield meter:
https://youtu.be/zLQ85la9pHo
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RotoSequence on 03/14/2016 02:02 am
Dr rodal, you seem to be bothered by diy methodology. I suggest no diyer has a correct methodology and neither do you. This topic has advanced well beyond being a roger shawyer comment thread to diy and theory beyond one person. My advice is to build one yourself and show others where errors are being made. Either that or publish a diy guide you would recommend to new diyers.

It's not a question of methodology as it is of logical consistency. Unless the side walls do not contribute meaningfully to the behavior of the EM drive system, the care and attention going into the end plates seems strange when the walls themselves have rough surfacing and some dimensional inconsistency.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 02:10 am
Dr rodal, you seem to be bothered by diy methodology. I suggest no diyer has a correct methodology and neither do you. This topic has advanced well beyond being a roger shawyer comment thread to diy and theory beyond one person. My advice is to build one yourself and show others where errors are being made. Either that or publish a diy guide you would recommend to new diyers.

Rather than discourage my comments on DIY construction and challenging me to do my own DIY, when questioning the 1 mm wall thickness you are using while simultaneously polishing the ends like a mirror, I would expect that you would encourage such comments, since they are more relevant to the subject matter of this thread, than, for example, your recent posts about spooky quantum entanglement.


The NSF threads are here for the user community to discuss subjects like these between the different members, they are not supposed to be just for people to post "look at what I'm doing, but don't comment on what I'm doing, if you don't like what I'm doing, go and conduct your own DIY or go and write your own DIY guide."
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: A_M_Swallow on 03/14/2016 02:16 am
I suspect that the mathematical models can be modified to to show what happens when the side walls are deformed by 1 mm. A long dent may be easier to program.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: zellerium on 03/14/2016 02:17 am
I propose that a common-sense tolerance for EM Drive thickness that DIY testing people should use for their frustums is the thickness of a commercial waveguide with similar diameter.

In this case, a common sense tolerance is that DIY people should use a thickness of waveguides with a diameter of 0.28 m to be used at ~2 GHz


I don't understand your reasoning Dr. Rodal, commercial waveguides are designed to transmit power, not resonate, as I'm sure you're well aware of. I would expect the amount of conductive heat dissipation required by a transmission line (with a typical .5 dB loss per meter) is significantly less than a resonator with no output.

Why not create the thickest frustum possible within price constraints so that the steady state temperature is lower?

It is a question of logical consistency:

1) Shawyer/TheTraveller regularly use open waveguide explanations to explain the EM Drive  (please refer to Shawyer's paper).  For example, the cutoff frequency concept only applies to open waveguides.

2) In the post above SeeShells argues that <<It's the endplates that set the resonance and Q. >>.  Rfmwguy is polishing the end plates to look like a  mirror.  Both of these arguments run contrary to standing wave resonance inside a cavity:   for the eigenmodes and eigenfrequencies in a cavity, the conical walls are just as important as the end plates.

3) I am not discussing anything to do with heat dissipation or thermal effects.  I am just arguing dimensional tolerance.

4) You write <<Commercial waveguides are designed to transmit power, not resonate>>.  That is not strictlly correct.  Commercial waveguides "resonate" only in the cross-dimensional direction: that is what TE01 for example means.  The mode shapes for waveguides are the result of solving the eigenvalue problem.

Here are the first "resonant" eigenmodes "mode shapes" for a waveguide with circular cross-section:



  It is important for a waveguide to have certain tolerances in their cross-section, in order to maintain a given mode shape.

5) The question here is to justify the 1 mm thickness being used by DIY.  Where did that come from?  How is that justified?

6) It is not logical to say that only longitudinal resonance matters: that only the "p" matters in TEmnp for example.

7) How can people say that tight tolerances are needed in the longitudinal direction for "p" but not in the cross-section for "mn". ???

8) How could one say that the endplates need to look like a mirror (for 2.45 GHz frequency with wavelength of several cm) and that it is OK for example for the cross section  to look like a star instead of circular ???

Okay I jumped in without fully reading the context. Thank you for reiterating what the discussion is all about.

Looking at the waveguide solutions presented in "Electromagnetic Fields and Waves" by Iskander, its clear that the broad dimensions determine the resonant frequency and dominant mode. A third resonance (in the z direction) will probably replace the exp(-j*beta*z) with a sin or cos function.

Therefore I would assume all dimensions should be designed to the highest tolerance possible and all of them will combine to produce a certain quality. Polishing the end plates surely wouldn't hurt but I'd polish the whole inner surface if possible.

But if the cavity is going to warp from thermal effects then you probably can't high quality resonance no matter how well it's polished... unless it was designed to be the perfect dimensions when thermally expanded if that's even feasible.

And then we're back to the problem of measuring uN-mN from a cavity radiating, convecting and conducting heat in all directions asymmetrically.  As many have brought up many many times, the heat is a major theme of all EM Drive experiments and has yet to be fully addressed.

And Dr. Rodal, I for one very much appreciate your feedback in all regards. But I have to wonder, why is it you are such a knowledgable top contributer on the topic but have yet to attempt an experiment?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/14/2016 02:23 am
Where do a couple of posters get the impression that sidewall tolerances are as important as endplate tolerances? If someone has an emdrive theory, please share it.
In addition, what is driving the assumption that sidewall deformations are not being addressed by builders?
Look at it this way, the reported emdrive force is perpendicular to the endplates, not the sidewalls. Seems like endplates are where precision is most needed. Just my build ideas...I'm not trying to tell anyone else what needs to be done...nor should anyone.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 02:31 am
...And Dr. Rodal, I for one very much appreciate your feedback in all regards. But I have to wonder, why is it you are such a knowledgable top contributer on the topic but have yet to attempt an experiment?
Because there is no need for me to duplicate the work that Dr. White's team is conducting at NASA, and because there are other new, unique, promising experiments for me to spend my time on.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: WhatAFeynDay on 03/14/2016 02:35 am
Dr rodal, you seem to be bothered by diy methodology. I suggest no diyer has a correct methodology and neither do you. This topic has advanced well beyond being a roger shawyer comment thread to diy and theory beyond one person. My advice is to build one yourself and show others where errors are being made. Either that or publish a diy guide you would recommend to new diyers.

I think I'm really misunderstanding the discussion here, because your comment has me very confused.

We have this device that Roger Shawyer has claimed makes thrust. He's the reason this thread exists, and has been (apparently) contributing advice to DIY experimenters. In that regard, TheTraveller has been kind enough to pass along the advice and specifications that the inventor, Shawyer, claims are required for the device to create thrust.

Among that advice is a tolerance of 13um.

If I'm understanding Dr. Rodal correctly, he is pointing out that your sidewall thickness of 1mm is susceptible to deformation which will cause its Q to be reduced significantly. Furthermore, there's an apparent contradiction between being concerned enough about these tolerances to polish the endcaps to a mirror finish, and yet not having any concerns about possible deformation of the frustum.

So, in light of that apparent contradiction, it's been suggested that DIY builders come to a consensus as to whether or not Shawyer's 13um tolerance is what should be adhered to, or if it should be some other number as yet to be determined.

I thought it was an attempt at solving an apparent fly in the ointment. I'd really like to know how DIY builders are going to reconcile these types of discrepancies, especially if we're ever going to prove this device works as claimed.

I think I'm just missing something here, forgive me.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 02:38 am
Dr rodal, you seem to be bothered by diy methodology. I suggest no diyer has a correct methodology and neither do you. This topic has advanced well beyond being a roger shawyer comment thread to diy and theory beyond one person. My advice is to build one yourself and show others where errors are being made. Either that or publish a diy guide you would recommend to new diyers.

I think I'm really misunderstanding the discussion here, because your comment has me very confused.

We have this device that Roger Shawyer has claimed makes thrust. He's the reason this thread exists, and has been (apparently) contributing advice to DIY experimenters. In that regard, TheTraveller has been kind enough to pass along the advice and specifications that the inventor, Shawyer, claims are required for the device to create thrust.

Among that advice is a tolerance of 13um.

If I'm understanding Dr. Rodal correctly, he is pointing out that your sidewall thickness of 1mm is susceptible to deformation which will cause its Q to be reduced significantly. Furthermore, there's an apparent contradiction between being concerned enough about these tolerances to polish the endcaps to a mirror finish, and yet not having any concerns about possible deformation of the frustum.

So, in light of that apparent contradiction, it's been suggested that DIY builders come to a consensus as to whether or not Shawyer's 13um tolerance is what should be adhered to, or if it should be some other number as yet to be determined.

I thought it was an attempt at solving an apparent fly in the ointment. I'd really like to know how DIY builders are going to reconcile these types of discrepancies, especially if we're ever going to prove this device works as claimed.

I think I'm just missing something here, forgive me.

I'm glad to see that you understood very well what I posted  ;)

This saves me the time to try to find another way to explain this again. 

Good night to all.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: meberbs on 03/14/2016 03:06 am
"Number of bounces" has limited meaning in this context....

Put an E field sensor through one end plate plus a lot of attenuation so it doesn't add significant load to the cavity.

Set up to measure the unloaded cavity Q and the number of positive peak events in the E field during 5 TCs of the cavity discharge time.

Fill the cavity with resonant Rf.

Stop the Rf input just as the Rf crosses zero.

Measure the time until the E field probe says there is no more Rf energy inside the cavity. Should be 5x TC.

Count the number of E field positive peak events during the 5 x TC time period (should occur at the rate of the Rf resonant freq). Should be the indicated end plate reflection count number.
Emphasis mine.

You are ignoring the sidewalls again. The radiation is reflecting off all of the surfaces. If you didn't have the side walls (for safety, please don't do this) the radiation would be going in all sorts of directions and would not stay neatly confined.

Also, 5 times TC as stated by others before is the time to get to about 0.7% of the maximum energy that was in the cavity. It is an exponential decay, and will take quite a while to get to truly 0 (the last single photon gets absorbed - although black body radiation would instead cause an equilibrium at some point). You are describing an experiment as if each photon could last a fixed number of bounces, that in itself is not true. If you were to do an experiment bouncing single photons between mirrors, somehow counting the bounces, you would find each individual photon is absorbed after a random number of bounces, with distribution based on the reflectivity of the mirrors.

There is good discussion going on right now about things more meaningful for the experiments (effect of tolerances, surface finish, machining errors, and thermal expansion on Q). I don't want to sidetrack too much from that, so this discussion can be taken to another thread or PM if you still disagree.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Amestad on 03/14/2016 04:21 am
Yes, the cone is not cut yet.

What thickness copper side walls? The 1/8 or sticking with 1mm?
1mm sidewalls. Was going to to spin thicker copper but no spinners responded with decent prices. A fully funded institutional project could spin then polish. A user here also suggested a lost wax pocess.

It is not going to be possible to have a high Q (quality of resonance) close to theoretical with 1 mm walls: very compliant (the opposite of stiff).  For a length of 0.26 meters and diameter of 0.28 meters, a 1 mm wall thickness is easy to deform out of shape just by applying hand pressure, and hence difficult to maintain geometrical tolerance.

If expansion due to thin sidewalls is an issue then reinforce the sidewalls.. There was talk about this previously, but personally I'd always take a "KISS" approach....

This assumes RFM's build technique so the frustum is formed and sealed with the endplates large than the truncated cone ends. Basically take the sealed frustum and stick in in a bucket slightly larger than the end plates then pour in a batch of concrete (any low expansion co-efficient, low melting point / setting point material..). Adds thermal mass to reduce rapid heating effects and limits expansion.

Or take a much more complicated and I think not yet thought of approach?
I've read much of these threads but I may have forgotten.

Follow RFM's build process (any process really as long as the frustum is sealed to the end plates) only this time ensuring the endplates are the same diameter.
Once formed the frustum could be inserted into a cylinder.. Let's think heavy duty steel casing..  and the external volume between endplates now becomes a separate internal volume of the cylinder.

Attach valves / ports to the  flange of the end plates and now you have a way to inject some form of fluid in to the annular space around the exterior of the frustum sealed by the end plates and cylinder walls.

This could either be done simply under a one way valve to inhibit expansion of the side walls (liquids don't compress easily) or add a second valve/port and with appropriate pressure regulation you also now have an active cooling fluid chamber and expansion inhibition control.
You could still do side wall injection by running all the feeds through appropriately sealed holes in the flange. Add threaded rods between flanges to control and inhibit expansion in the Z axis of the frustum / cylinder.. all sealed and cooled in the cylinder.

I think this is all quite well within the reach of the builders here and really doesn't take much to do....

granted you need to tune your source to the frustrum but seems like that's on the cards anyways..

Ok this might be tricky to visualise.. when I read it back, I fudged up a drawing in Ppt.

If you can't see it.. (this is my like third post) let me know and i'll do a imagehost link

Cheers
Amestad

Modified for typos





 



 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Amestad on 03/14/2016 04:32 am
Another method would be to actually wind something around the frustum. Material choice here is much more difficult... but in essence winding it around the frustum walls like cotton on a reel would provide significant inhibition to expansion. I think this has been discussed previously in any case.

Using the fluid filled cylinder method described above allows controlled deformation of the frustum if desired so it ticks many more boxes.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: ThinkerX on 03/14/2016 05:44 am
To me, the degree of fine machining called for by Shawyer sounds like the sort of precision found in the cylinders of automotive engines.  I also note these cylinders tend to be set in thick metal blocks. 

On the one hand, it sound insane, almost like adding another barrier. 

On the other hand, at least with automotive cylinder work, if you DON'T attain that kind of precision, then the vehicle either won't run, or will run poorly at best. 

Given a frustum of the proper thickness, maybe a professional engine rebuild guy could attain the precision Shawyer claims is needed? 

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: FattyLumpkin on 03/14/2016 07:17 am
Machining of cylinders in internal combustion engines (cars) involves 1000ths not 10s of 1000ths---so I suspect Shawyer is referring to the "finish" of the material (mirror like). The roundness that Dr. Rodal is referring to is difficult to achieve, but possible ...one way is by using male and female mandrels, and relaxing of the material being molded by heating it to a certain extent prior to pressing in the said mandrels. There are also other different methods. I'd go with .125" thick all the way around irrespective of cost. A system of heat rejection could also be put into place by soldering thin (inexpensive) strips of copper radially, perpendicularly all about the frustum.  Nothing like radiator fins to save the day.
While I didn't get EM resonance right I do still know my fabrication.  Ciao!  , F L  :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/14/2016 10:46 am
Also, 5 times TC as stated by others before is the time to get to about 0.7% of the maximum energy that was in the cavity.

This statement is wrong. Suggest you talk to any EE that has experience with charge & discharge rates of any electronics element that stores energy.

Here is a TC driven energy charge curve. Flip it vertically to get the discharge curve. 5x TC is what EEs use to determine effective full charge/discharge of energy storage electronic elements. And yes it also applies to Rf resonant cavities.

At 5 x TC, a cavity energy is discharged 99.3% (as attached), which as an EE I would consider as being, in practical terms, totally discharged.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/14/2016 12:38 pm
Dr rodal, you seem to be bothered by diy methodology. I suggest no diyer has a correct methodology and neither do you. This topic has advanced well beyond being a roger shawyer comment thread to diy and theory beyond one person. My advice is to build one yourself and show others where errors are being made. Either that or publish a diy guide you would recommend to new diyers.

I think I'm really misunderstanding the discussion here, because your comment has me very confused.

We have this device that Roger Shawyer has claimed makes thrust. He's the reason this thread exists, and has been (apparently) contributing advice to DIY experimenters. In that regard, TheTraveller has been kind enough to pass along the advice and specifications that the inventor, Shawyer, claims are required for the device to create thrust.

Among that advice is a tolerance of 13um.

If I'm understanding Dr. Rodal correctly, he is pointing out that your sidewall thickness of 1mm is susceptible to deformation which will cause its Q to be reduced significantly. Furthermore, there's an apparent contradiction between being concerned enough about these tolerances to polish the endcaps to a mirror finish, and yet not having any concerns about possible deformation of the frustum.

So, in light of that apparent contradiction, it's been suggested that DIY builders come to a consensus as to whether or not Shawyer's 13um tolerance is what should be adhered to, or if it should be some other number as yet to be determined.

I thought it was an attempt at solving an apparent fly in the ointment. I'd really like to know how DIY builders are going to reconcile these types of discrepancies, especially if we're ever going to prove this device works as claimed.

I think I'm just missing something here, forgive me.
Easy to clarify when you do the math: 2.450000 GHz has a wavelength of 122364.2685714 micrometers. A +/- 13 micrometer variation is 2.449739739248 GHz to 2.450260316059 GHz or 0.000520576811 GHz or 520.576811 (+/- 250) kHz. Its +/- 125 kHz if you consider +/- 6.5 micrometers for a total of 13 micrometers.

Magnetrons do not have this type of stability. A signal source would need +/- 0.005% accuracy at 2.45 GHz.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/14/2016 12:51 pm
To me, the degree of fine machining called for by Shawyer sounds like the sort of precision found in the cylinders of automotive engines.  I also note these cylinders tend to be set in thick metal blocks. 

On the one hand, it sound insane, almost like adding another barrier. 

On the other hand, at least with automotive cylinder work, if you DON'T attain that kind of precision, then the vehicle either won't run, or will run poorly at best. 

Given a frustum of the proper thickness, maybe a professional engine rebuild guy could attain the precision Shawyer claims is needed?
The endplates are easy to fabricate for 13 micrometer tolerance. I did this by hand with a lapping plate and wheel. I estimate about 8-9 micrometers worst-case flatness. The sidewalls are a different story. I believe it is overkill to design for 13 micrometers on the sidewalls given the signal source stability we have to work with. Only reason I prepped the endplates is they were relatively easy to do and I learned a new skill...AKA fun.

High-end mechanical precision is a latter-stage development AFTER people get consistent results at less precision. IOW, its likely a way to scale the emdrive effect up in power once people demonstrate its repeatability. We're still not there yet IMHO.


Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/14/2016 12:52 pm
Where do a couple of posters get the impression that sidewall tolerances are as important as endplate tolerances? If someone has an emdrive theory, please share it.
In addition, what is driving the assumption that sidewall deformations are not being addressed by builders?
Look at it this way, the reported emdrive force is perpendicular to the endplates, not the sidewalls. Seems like endplates are where precision is most needed. Just my build ideas...I'm not trying to tell anyone else what needs to be done...nor should anyone.
All I'm saying is that the influence of the endplate quality is seen as a action through the entire length of the frustum through all of the frustum modes, whereas a sidewall deformation is only seen in that local cross sectional area.

This isn't to say that the build should be as good as you can get for a DYIer.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/14/2016 01:20 pm
Dr rodal, you seem to be bothered by diy methodology. I suggest no diyer has a correct methodology and neither do you. This topic has advanced well beyond being a roger shawyer comment thread to diy and theory beyond one person. My advice is to build one yourself and show others where errors are being made. Either that or publish a diy guide you would recommend to new diyers.

I think I'm really misunderstanding the discussion here, because your comment has me very confused.

We have this device that Roger Shawyer has claimed makes thrust. He's the reason this thread exists, and has been (apparently) contributing advice to DIY experimenters. In that regard, TheTraveller has been kind enough to pass along the advice and specifications that the inventor, Shawyer, claims are required for the device to create thrust.

Among that advice is a tolerance of 13um.

If I'm understanding Dr. Rodal correctly, he is pointing out that your sidewall thickness of 1mm is susceptible to deformation which will cause its Q to be reduced significantly. Furthermore, there's an apparent contradiction between being concerned enough about these tolerances to polish the endcaps to a mirror finish, and yet not having any concerns about possible deformation of the frustum.

So, in light of that apparent contradiction, it's been suggested that DIY builders come to a consensus as to whether or not Shawyer's 13um tolerance is what should be adhered to, or if it should be some other number as yet to be determined.

I thought it was an attempt at solving an apparent fly in the ointment. I'd really like to know how DIY builders are going to reconcile these types of discrepancies, especially if we're ever going to prove this device works as claimed.

I think I'm just missing something here, forgive me.

Obi Wan would say: Fly in the ointment you're not.

<quoted from a past post>
Yes, I'm using ceramic plates <.05um flatness, they provide these very critical build and design points.

Force the endplate flat. The copper 101 O2 free .032" from the factory is better then .3um flat. (best I can measure) When bonded I don't need to do extreme lapping to get high flatness and plus it makes it easier to lap.

Keep deformations to a minimum even during a build from soldering or handling.

They maintain the flatness of the plates during cavity heating.

They make sure the plates stay together via the Quartz rod during tune and maintain parallelism during runs and thermal heating.

Allow the sidewalls expand up and past the small endplate which isn't captured but has a beryllium gasket.

Makes a stiffer overall frustum.

Shell
<end>


Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/14/2016 01:40 pm
Where do a couple of posters get the impression that sidewall tolerances are as important as endplate tolerances? If someone has an emdrive theory, please share it.
In addition, what is driving the assumption that sidewall deformations are not being addressed by builders?
Look at it this way, the reported emdrive force is perpendicular to the endplates, not the sidewalls. Seems like endplates are where precision is most needed. Just my build ideas...I'm not trying to tell anyone else what needs to be done...nor should anyone.
All I'm saying is that the influence of the endplate quality is seen as a action through the entire length of the frustum through all of the frustum modes, whereas a sidewall deformation is only seen in that local cross sectional area.

This isn't to say that the build should be as good as you can get for a DYIer.

Shell
Its not you Shell. Think you've got the idea. Oh, guess I'll share my conical conformity "trick" from my post on January 8th:

Take your pick: http://tinyurl.com/h9ju53q
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/14/2016 01:48 pm
Oh, guess I'll share my conical conformity "trick" from my post on January 8th:

Can confirm, Dave's hoop idea does work.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: meberbs on 03/14/2016 01:50 pm
Also, 5 times TC as stated by others before is the time to get to about 0.7% of the maximum energy that was in the cavity.

This statement is wrong. Suggest you talk to any EE that has experience with charge & discharge rates of any electronics element that stores energy.

Here is a TC driven energy charge curve. Flip it vertically to get the discharge curve. 5x TC is what EEs use to determine effective full charge/discharge of energy storage electronic elements. And yes it also applies to Rf resonant cavities.

At 5 x TC, a cavity energy is discharged 99.3% (as attached), which as an EE I would consider as being, in practical terms, totally discharged.
Did you even read the rest of my post?
Also you said I'm wrong and then posted information that confirms what I said (100% minus 99.3% discharged equals 0.7% remaining)

Again 5 TCs is an arbitrary number. It is "good enough" for many applications, but you keep treating it like an absolute, which it isn't. If the starting point is 1 MJ, there would still be 7kJ left, so you might want to wait a few more TCs before sticking your hand inside.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/14/2016 02:03 pm
Also, 5 times TC as stated by others before is the time to get to about 0.7% of the maximum energy that was in the cavity.

This statement is wrong. Suggest you talk to any EE that has experience with charge & discharge rates of any electronics element that stores energy.

Here is a TC driven energy charge curve. Flip it vertically to get the discharge curve. 5x TC is what EEs use to determine effective full charge/discharge of energy storage electronic elements. And yes it also applies to Rf resonant cavities.

At 5 x TC, a cavity energy is discharged 99.3% (as attached), which as an EE I would consider as being, in practical terms, totally discharged.
Did you even read the rest of my post?
Also you said I'm wrong and then posted information that confirms what I said (100% minus 99.3% discharged equals 0.7% remaining)

Again 5 TCs is an arbitrary number. It is "good enough" for many applications, but you keep treating it like an absolute, which it isn't. If the starting point is 1 MJ, there would still be 7kJ left, so you might want to wait a few more TCs before sticking your hand inside.

Apologies. Read your 0.7% as 70%.

Never stated 5x was absolute. Did use approx & ~ when quoting levels.

You may be interested to know forward power, into a empty cavity follows the same curve. In fact it is possible to measure unloaded cavity Q by simply measuring how long it takes forward power to climb from 0W at cavity fill start to 63.2% of the final fully charged value. Knowing that time, it is then possible to calc unloaded Q & never need to use a VNA to measure -3dB bandwidth, which only gives you loaded Q.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/14/2016 02:15 pm
Currently this site hosts half a dozen builders of EMDrives. Some are on their first or second or third  build (some are keeping quiet and just building), but the common thread throughout it all is the quality of the build has increased dramatically in the last year.  This is due to no small part by the mass contributions of so many here pushing the envelope of theory, creativity, and DYI quality. I never could have made it this far if it wasn't for the contributions and guidance and the heartfelt giving of others.

We need to thank those who offer their time, their expertise and encouragement to quantify whether this drive will be a curiosity in the annals of time or reinventing fire for humanity.

Thank You.


Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 02:18 pm
Where do a couple of posters get the impression that sidewall tolerances are as important as endplate tolerances? If someone has an emdrive theory, please share it.
...

OK, we are in thread number 7 of the EM drive, let's recapitulate the EM Drive theories discussed in previous threads:

*Shawyer (the initiator of the EM Drive and frequently quoted by TheTraveller)
*McCulloch (who you have invited to post again in these posts)
*Notsosureofit
*DeAquino


All these theories have the claimed anomalous force/inputPower proportional to the Q quality of resonance.

All of them have this simple relationship, and as it is trivially shown, it is due to the Q that it is claimed that the EM Drive can exceed the force/PowerInput of a photon rocket.  We have gone over these myriads of times in this thread.

The quality of resonance relationship to the geometry (including the side walls) is known from countless textbooks.   Look at Collin's and Jackson's textbooks for example.  Furthermore, this has been shown in these EM Drive threads: as COMSOL Finite Element Analysis and FEKO Boundary Element Method analyses have shown the dependence on all geometrical parameters.  (Even the COMSOL analyses run by NASA have shown these dependence).

Let's start by asking, since you are posting about your DIY efforts, about your Q quality of resonance measurements.  Are you concerned about reaching a high Q in your tests? Did you measure Q for your tests? If so, what was the Q quality of resonance for your tests?

And looking at your future tests you are posting about, what % of the theoretical Q quality of resonance are you aiming for your in your DIY tests? 

As previously discussed, the discussion about tolerances has to do with its influence on the Q, quality of resonance.

Let's remmber that this is prompted by TheTraveller's post that Shawyer says that a tolerance of 13 micrometers is needed (for present EM Drive geometry and testing frequency) to get 75% of the theoretical Q quality of resonance and that's how this discussion of tolerance started. 


Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 02:29 pm
Currently this site hosts half a dozen builders of EMDrives. Some are on their first or second or third  build (some are keeping quiet and just building), but the common thread throughout it all is the quality of the build has increased dramatically in the last year.  This is due to no small part by the mass contributions of so many here pushing the envelope of theory, creativity, and DYI quality. I never could have made it this far if it wasn't for the contributions and guidance and the heartfelt giving of others.

We need to thank those who offer their time, their expertise and encouragement to quantify whether this drive will be a curiosity in the annals of time or reinventing fire for humanity.

Thank You.


Shell

Shell, what do you think of rfmwguy's post below ?


Dr rodal, you seem to be bothered by diy methodology. I suggest no diyer has a correct methodology and neither do you. This topic has advanced well beyond being a roger shawyer comment thread to diy and theory beyond one person. My advice is to build one yourself and show others where errors are being made. Either that or publish a diy guide you would recommend to new diyers.

Rfmwguy posted this upon my questioning the 1 mm wall thickness he is using while simultaneously polishing the ends like a mirror, and after I saw TheTraveller quoting Shawyer's advice that the tolerance should be 13 micrometers.  I thought that the NSF threads were here for the user community to discuss NSF posts like these between NSF readers, rather than  "look at what I'm doing, but don't comment on what I'm doing, if you don't like what I'm doing, go and conduct your own DIY or go and write your own DIY guide."

What do you think of such comments on your DIY construction?

Is it worthwhile for readers not involved in DIY EM Drive to spend time on comments on DIY construction?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/14/2016 02:39 pm
Here is a comparison of distorting the dimensions of end-plates vs side-wall vs both. I would not have believed the results had I not run them myself: Resonance got stronger with side-wall distortion before it got weaker.

Not surprising, distorting the end-plates had an immediate effect on the strength of resonance. The effect was obvious with distortions as small as 1.5 - 2.0mm having up to 17% reduction in frustum E-field power. This effect seems to follow a linear pattern as distortion increases.

EDIT: Original image had a duplicate in end-plate distortion. Image was corrected
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 02:44 pm
Here is a comparison of distorting the dimensions of end-plates vs side-wall vs both. I would not have believed the results had I not run them myself: Resonance got stronger with side-wall distortion before it got weaker.

Not surprising, distorting the end-plates had an immediate effect on the strength of resonance. The effect was obvious with distortions as small as 1.5mm having up to 17% reduction in frustum E-field power. This effect seems to follow a linear pattern as distortion increases.
Thanks so much for running these comparisons.

More light and less heat  ;)

This is enlightening.  We learn a lot from these comparisons.

Could you please further discuss what is the meaning of these numbers 0.1, 0.2, 0.4, 0.6 and how do they relate to distortion in mm ?  Did you run a random distortion? What is the expression used by FEKO to model a geometrical distortion and what was the maximum and average (mm) distortion for each of those numbers?

Thanks again
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 02:47 pm
Here is a comparison of distorting the dimensions of end-plates vs side-wall vs both. I would not have believed the results had I not run them myself: Resonance got stronger with side-wall distortion before it got weaker.

Not surprising, distorting the end-plates had an immediate effect on the strength of resonance. The effect was obvious with distortions as small as 1.5 - 2.0mm having up to 17% reduction in frustum E-field power. This effect seems to follow a linear pattern as distortion increases.

Why is it that the side wall distortion looks much more regular, and less random (more smooth) in the run for only side-wall distortion and it looks more random and higher amplitude for the run having both side wall and end plate distortion?

Is the amount of actual side wall distortion different for both runs?

Can you instead fix the amount of distortion so that the Max and Average distortion, and geometrical frequency (not time frequency) of distortion is the same in all runs?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/14/2016 02:50 pm
Could you please further discuss what is the meaning of these numbers 0.1, 0.2, 0.4, 0.6 and how do they relate to distortion in mm ?  Did you run a random distortion? What is the expression used by FEKO to model a geometrical distortion and what was the maximum and average (mm) distortion for each of those numbers?

I build the geometry and add the distortions in another program. 0.1 distortion is equal to 1.75mm and 0.6 distortion is right at 1cm. The distortion is random in all 3 dimensions applied to each vertex. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/14/2016 02:55 pm
Why is it that the side wall distortion looks much more regular, and less random in the run for only side-wall distortion and it looks more random and higher amplitude for the run having both side wall and end plate distortion?

Is the amount of actual side wall distortion different for both runs?

Can you instead fix the amount of distortion so that the Max and Average distortion, and geometrical frequency (not time frequency) of distortion is the same in all runs?

The end-plates have more triangles (and vertices) in the geometry. So the distortion has more noise in it there.  I could add more geometry to the side wall.

Just noticed I have two identical images in there. Must have copied the wrong one. Will update the image with correct version.

 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 02:59 pm
Why is it that the side wall distortion looks much more regular, and less random in the run for only side-wall distortion and it looks more random and higher amplitude for the run having both side wall and end plate distortion?

Is the amount of actual side wall distortion different for both runs?

Can you instead fix the amount of distortion so that the Max and Average distortion, and geometrical frequency (not time frequency) of distortion is the same in all runs?

The end-plates have more triangles (and vertices) in the geometry. So the distortion has more noise in it there.  I could add more geometry to the side wall.

Just noticed I have two identical images in there. Must have copied the wrong one. Will update the image with correct version.
I understand that the comparisons shown, only show the effect of geometrical tolerance on the electromagnetic fields.

Can you also run these geometrical comparisons to show the effect on theoretical Q quality of resonance?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Flyby on 03/14/2016 03:07 pm
Could you please further discuss what is the meaning of these numbers 0.1, 0.2, 0.4, 0.6 and how do they relate to distortion in mm ?  Did you run a random distortion? What is the expression used by FEKO to model a geometrical distortion and what was the maximum and average (mm) distortion for each of those numbers?

I build the geometry and add the distortions in another program. 0.1 distortion is equal to 1.75mm and 0.6 distortion is right at 1cm. The distortion is random in all 3 dimensions applied to each vertex.

Must say , I'm rather surprised about the "robustness" of the resonance patterns. I was expecting it to be much more sensitive...
which leads me to draw conclusions on the micron-meter requirements... I don't think it is required to fall within those extreme precisions, unless you're going for the super, super efficiency...
But those are not the aim of most DIY builds. As it is now, we still need to establish whether or not it delivers a force...
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 03:11 pm
Why is it that the side wall distortion looks much more regular, and less random in the run for only side-wall distortion and it looks more random and higher amplitude for the run having both side wall and end plate distortion?

Is the amount of actual side wall distortion different for both runs?

Can you instead fix the amount of distortion so that the Max and Average distortion, and geometrical frequency (not time frequency) of distortion is the same in all runs?

The end-plates have more triangles (and vertices) in the geometry. So the distortion has more noise in it there.  I could add more geometry to the side wall.

Just noticed I have two identical images in there. Must have copied the wrong one. Will update the image with correct version.

So, as I understand it, the mesh has more nodes on the end-plates than on the side wall?

Could you run these comparisons with a mesh having the same (mm) distance between mesh nodes in the vertical longitudinal direction as the distance between nodes in the horizontal direction along the diameters?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/14/2016 03:13 pm
Can you also run these geometrical comparisons to show the effect on theoretical Q quality of resonance?

Sure.  I will need to figure out something with the antenna, as a distorted frustum wall does not make a very good connector! So I skipped that problem and didn't request S-parameters.  I can probably do it but will need a little time.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 03:14 pm
Can you also run these geometrical comparisons to show the effect on theoretical Q quality of resonance?

Sure.  I will need to figure out something with the antenna, as a distorted frustum wall does not make a very good connector! So I skipped that problem and didn't request S-parameters.  I can probably do it but will need a little time.

This is really excellent work and very illuminating !

(Also great comment from Flyby about the robustness of the fields to distortion)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/14/2016 03:18 pm
Could you run these comparisons with a mesh having the same (mm) distance between mesh nodes in the vertical longitudinal direction as the distance between nodes in the horizontal direction along the diameters?

This is what the mesh looks like. Looks like all I need to do is double up on the horizontal edge loops to do this. I will run one or two and see if it makes a big difference.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 03:24 pm
Could you run these comparisons with a mesh having the same (mm) distance between mesh nodes in the vertical longitudinal direction as the distance between nodes in the horizontal direction along the diameters?

This is what the mesh looks like. Looks like all I need to do is double up on the horizontal edge loops to do this. I will run one or two and see if it makes a big difference.

Does that mean doubling up the number of nodes in the vertical direction? (it looks like the distance between the nodes in the vertical longitudinal direction is smaller than the distance between nodes in the radial horizontal direction)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/14/2016 03:36 pm
Does that mean doubling up the number of nodes in the vertical direction? (it looks like the distance between the nodes in the vertical longitudinal direction is smaller than the distance between nodes in the radial horizontal direction)

This is the difference. It is impossible to get exact since a frustum expands towards one end.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/14/2016 03:47 pm
Currently this site hosts half a dozen builders of EMDrives. Some are on their first or second or third  build (some are keeping quiet and just building), but the common thread throughout it all is the quality of the build has increased dramatically in the last year.  This is due to no small part by the mass contributions of so many here pushing the envelope of theory, creativity, and DYI quality. I never could have made it this far if it wasn't for the contributions and guidance and the heartfelt giving of others.

We need to thank those who offer their time, their expertise and encouragement to quantify whether this drive will be a curiosity in the annals of time or reinventing fire for humanity.

Thank You.


Shell

Shell, what do you think of rfmwguy's post below ?


Dr rodal, you seem to be bothered by diy methodology. I suggest no diyer has a correct methodology and neither do you. This topic has advanced well beyond being a roger shawyer comment thread to diy and theory beyond one person. My advice is to build one yourself and show others where errors are being made. Either that or publish a diy guide you would recommend to new diyers.

Rfmwguy posted this upon my questioning the 1 mm wall thickness he is using while simultaneously polishing the ends like a mirror, and after I saw TheTraveller quoting Shawyer's advice that the tolerance should be 13 micrometers.  I thought that the NSF threads were here for the user community to discuss NSF posts like these between NSF readers, rather than  "look at what I'm doing, but don't comment on what I'm doing, if you don't like what I'm doing, go and conduct your own DIY or go and write your own DIY guide."

What do you think of such comments on your DIY construction?

Is it worthwhile for readers not involved in DIY EM Drive to spend time on comments on DIY construction?
Dr. Rodal,

Undoubtedly there are some great theories out there proposed here by very sharp minds, also residing in this forum are great techs, engineers and PHd's and just dang smart people.

You really think I'd be here if the highlights of the day was chatting nonsense on the current picture of what I had for lunch?  The question is, would you be?

Sure I have friends with Facebook accounts and they post lovely pictures of a cat or a bird outside of their window and that's truly ok with me, but dude you know the same disagreeing and bickering and he said she said are present in both sites. It's like IQ or sharpness has nothing to do with normal human behavior.

Dave you were a little over the top criticizing Dr. Rodal like that, he has provided a wealth of information and we wouldn't be here in the same way if it wasn't for him.

Dr. Rodal, you can get your panties in a wad sometimes when someone steps on your toes. Dave is doing a great job trying to sift through all the information to do a great build.

You both have contributed way over the top and if I was closer I'd make you stand in the corner for 10.

We have way bigger things to discover here. The stars or not. So let's lighten up and listen and be respectful.

Now my cute puppy says please smile because I'm cute.


Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/14/2016 03:47 pm
Paul Kocyla in Aachen, Germany is beginning to test the 24 GHz emdrive on a rotary flotation pad. Unquantified force measurements, appears to be calibration tests:

https://www.youtube.com/watch?v=i4UKDVtRRxI
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/14/2016 04:04 pm
Could you please further discuss what is the meaning of these numbers 0.1, 0.2, 0.4, 0.6 and how do they relate to distortion in mm ?  Did you run a random distortion? What is the expression used by FEKO to model a geometrical distortion and what was the maximum and average (mm) distortion for each of those numbers?

I build the geometry and add the distortions in another program. 0.1 distortion is equal to 1.75mm and 0.6 distortion is right at 1cm. The distortion is random in all 3 dimensions applied to each vertex.

Must say , I'm rather surprised about the "robustness" of the resonance patterns. I was expecting it to be much more sensitive...
which leads me to draw conclusions on the micron-meter requirements... I don't think it is required to fall within those extreme precisions, unless you're going for the super, super efficiency...
But those are not the aim of most DIY builds. As it is now, we still need to establish whether or not it delivers a force...

Thank you for this wonderful comment.
 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 04:08 pm
Paul Kocyla in Aachen, Germany is beginning to test the 24 GHz emdrive on a rotary flotation pad. Unquantified force measurements, appears to be calibration tests:

https://www.youtube.com/watch?v=i4UKDVtRRxI
Would appreciate somebody familiar with this testing program to clarify:

1) are the battery and the mini-EM-drive integrated together on the testing platform for the Kocyla test?  DeltaMass and I had agreed that by far the best proposed test was TheTraveller's proposal to have a battery and the EM Drive on a rotary platform together (rather than having the power be fed from a stationary source to a moving EM Drive which has a big testing flaw: the center of energy-mass is outside the moving EM Drive, therefore measuring an acceleration in such a test is flawed since in space the source of power would need to be in the same spaceship as the EM Drive)

2) What is the present testing platform arrangement?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/14/2016 05:25 pm
It's definitely the big end that can cause all the problems! Also, the higher frequency the distortion (how rough it is) the better. This is because 2.45Ghz cannot "see" features smaller than 1/2 the wavelength (~6cm). This means that frustums that are skewed or warped in large ways, perform worse than those with a rough surface of equal displacement. In my opinion gross geometric tolerances of 0.5mm (or less) should be a goal for DIYers.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 05:34 pm
It's definitely the big end that can cause all the problems! Also, the higher frequency the distortion (how rough it is) the better. This is because 2.45Ghz cannot "see" features smaller than 1/2 the wavelength. This means that frustums that are skewed or warped in large ways, perform worse than those with a rough surface of equal displacement. In my opinion gross geometric tolerances of 0.5mm (or less) should be a goal for DIYers.

This is really great work!

We learned a lot from it, not just the overall tolerance to aim for but also what is most crucial in order of importance.  It is posts such as this that make it worthwhile to spend time at NSF !

I am looking forward to further comparisons comparing the geometrical distortion effect on the Q quality factor !
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: X_RaY on 03/14/2016 05:44 pm
Sorry for interrupting the current discussions, have to read several posts to come close to the last posts of today.
The discussion about 13µm differences of the endplates is crazy.
At first what does it mean?
https://en.wikipedia.org/wiki/Surface_roughness (definition?)

As Dr.Rodal stated the sidewalls are of interest as the endplates, there are also losses due to eddy currents.

At the moment and in general there are much bigger problems (thermal expansion, antenna matching, thermal rise/ballooning and so on)  than to polish the wall and plates of the frustum up to mirrors quality. Structures much smaller than lets say 1/10 of the wavelenght are less of interrest since it decrease the Q only by a small amount.

It make no difference if the theoretical Q_u is 60000 or 60500 or even 58000 until the general problems are solved by the DIY.

To get a look to formula of unround shapes serarch for it in the pdf-file below or run simulations.
For me the biggest problem is still (pic):
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 06:04 pm
Paul Kocyla in Aachen, Germany is beginning to test the 24 GHz emdrive on a rotary flotation pad. Unquantified force measurements, appears to be calibration tests:

https://www.youtube.com/watch?v=i4UKDVtRRxI
Would appreciate somebody familiar with this testing program to clarify:

1) are the battery and the mini-EM-drive integrated together on the testing platform for the Kocyla test?  DeltaMass and I had agreed that by far the best proposed test was TheTraveller's proposal to have a battery and the EM Drive on a rotary platform together (rather than having the power be fed from a stationary source to a moving EM Drive which has a big testing flaw: the center of energy-mass is outside the moving EM Drive, therefore measuring an acceleration in such a test is flawed since in space the source of power would need to be in the same spaceship as the EM Drive)

2) What is the present testing platform arrangement?

I tried to find answers by going to the hackaday website but I was quickly disillusioned:

* unlabeled plots
* grainy picture
* lack of technical clarity on the presentation of test results

very unclear as to what they describe as noise, what they describe as signal, thermal effects, etc.

I confess however that I don't have the time to read all the information they have on that website, as I just speed-read to try to gather some information.

************

* on another subject, I agree with X-Ray regarding the importance of the RF feed for all these tests.

When I have the time I would like to formally analyze the flaw in all these tests (with the exception of the proposed test by TheTraveller with the battery integrated together with the EM Drive in a self-contained package) regarding the center of energy-mass of the system.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/14/2016 06:12 pm

At the moment and in general there are much bigger problems (thermal expansion,

How much will a ~20cm copper frustum expand due to heating? If it is less than 1/2 a cm or so, then it shouldn't be too much of a concern.

Best to have a tunable frustum IMHO. And from what I've learned today, it might be best to have the big end be the side that is tuned. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SteveD on 03/14/2016 06:17 pm
It's definitely the big end that can cause all the problems! Also, the higher frequency the distortion (how rough it is) the better. This is because 2.45Ghz cannot "see" features smaller than 1/2 the wavelength (~6cm). This means that frustums that are skewed or warped in large ways, perform worse than those with a rough surface of equal displacement. In my opinion gross geometric tolerances of 0.5mm (or less) should be a goal for DIYers.

If resonance increases with some value of sidewall distortion any chance those genetic algorithms you were working on can optimize it?  Wondering if the future here might be some kind of 3D printed sidewall together with precision endplates.  Suggest also running spherical endplates.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: X_RaY on 03/14/2016 06:25 pm

At the moment and in general there are much bigger problems (thermal expansion,

How much will a ~20cm copper frustum expand due to heating? If it is less than 1/2 a cm or so, then it shouldn't be too much of a concern.

Best to have a tunable frustum IMHO. And from what I've learned today, it might be best to have the big end be the side that is tuned.
1) https://forum.nasaspaceflight.com/index.php?topic=39772.msg1502437#msg1502437


2) Better tune the small side, its less sensitive to the plate displacement (due to larger guide wavelength)(finetuning).
Thats one reason why I like Shells design.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/14/2016 06:35 pm
It's definitely the big end that can cause all the problems! Also, the higher frequency the distortion (how rough it is) the better. This is because 2.45Ghz cannot "see" features smaller than 1/2 the wavelength (~6cm). This means that frustums that are skewed or warped in large ways, perform worse than those with a rough surface of equal displacement. In my opinion gross geometric tolerances of 0.5mm (or less) should be a goal for DIYers.

THANKS!!! Very very nice work Monomorphic!

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/14/2016 06:52 pm
It's definitely the big end that can cause all the problems! Also, the higher frequency the distortion (how rough it is) the better. This is because 2.45Ghz cannot "see" features smaller than 1/2 the wavelength. This means that frustums that are skewed or warped in large ways, perform worse than those with a rough surface of equal displacement. In my opinion gross geometric tolerances of 0.5mm (or less) should be a goal for DIYers.

This is really great work!

We learned a lot from it, not just the overall tolerance to aim for but also what is most crucial in order of importance.  It is posts such as this that make it worthwhile to spend time at NSF !

I am looking forward to further comparisons comparing the geometrical distortion effect on the Q quality factor !

Sometimes a picture is worth a thousand words.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/14/2016 07:15 pm

At the moment and in general there are much bigger problems (thermal expansion,

How much will a ~20cm copper frustum expand due to heating? If it is less than 1/2 a cm or so, then it shouldn't be too much of a concern.

Best to have a tunable frustum IMHO. And from what I've learned today, it might be best to have the big end be the side that is tuned.
You will like my new mechanical design on NSF-1701A then. More later, still working out the mechanicals.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: zen-in on 03/14/2016 07:36 pm

At the moment and in general there are much bigger problems (thermal expansion,

How much will a ~20cm copper frustum expand due to heating? If it is less than 1/2 a cm or so, then it shouldn't be too much of a concern.

Best to have a tunable frustum IMHO. And from what I've learned today, it might be best to have the big end be the side that is tuned.

It all depends on what you are measuring.   For example the Eagleworks tests from 2014 measured the displacement of the fustrum as it, in theory, pushed against the torque of the torque pendulum.   That displacement ( ~18 micrometers) was actually smaller than the thermal expansion of some parts of the apparatus.   To date no one knows how much of their anomalous force results were from thermal expansion. 

Your margin of 5,000 micrometers is quite a bit larger.   If you have a test force device on your apparatus that will provide a means of comparison.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: X_RaY on 03/14/2016 08:40 pm
I have implemented the expansion coefficient into my spreadsheet to get an idea of the frequency shift. I added the delta length(for endplates and sidewall length{not center heigth}) to the reference data of Frank Davies, for reference temp I used 20°C.
Using the expression (https://upload.wikimedia.org/math/1/c/2/1c2cc554cecab97f02a2eb92e1b2eda6.png)
I come to the conclusion that a temperature rise of 80K (20°C -->100°C) leads to a frequency shift of ≈-2,87MHz** for the TE012 mode.

**other deformities than linear shifts are not included
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 08:54 pm
A few people posting are assuming thermal expansion is uniform throughout and that EM Drive is unrestrained in the experiments,  calculating the thermal expansion as the coefficient of thermal expansion times the change in temperature.

Admittedly, of course, such a simplified calculation is a good first cut at understanding the problem.

However, the actual temperature rise is nonuniform, it depends on the pattern of induction heating which depends on the actual mode shape being excited.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36313.0;attach=846719;image)

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36313.0;attach=846720;image)

For such a realistic thermal expansion, the problem is thermoelastic and not just a trivial problem of unrestrained thermal expansion.  For the actual thermoelastic problem (due to non-uniform temperature, one has non-uniform thermal expansion), the actual stiffness of the shell comes into play: hence the importance of the thickness to radius ratio (as well as the modulus of elasticity) in the thermoelastic problem as well.

Most important, the temperature rise is not constant through the thickness as people are assuming as a first cut.

The temperature is highest in the interior(due to the skin depth of 1 micrometer or so) and it will slowly diffuse out with time.  This fact (non-uniform temperature through the thickness) plus the fact that the temperature is non-uniform thought the shell will lead to bending deformations of the shell and not just membrane deformations.  Hence the thickness of the shell plays an important role also for the thermal expansion effect.  In addition, there is the issue of thermal buckling (which I have addressed previously) and is also related to the thickness of the shell.

Hence the distortion of the EM Drive shell due to thermal expansion is more complicated, and in addition it is time dependent and so is the effect on Q due to shifting of the natural frequency because of distortion of the shell.

Use of thin shells (1 mm) with stiffeners, although better than just a thin shell, further complicates the understanding of the problem.   Unless there is a paramount interest in reducing weight, use of thicker shells is simpler to analyze and hence easier to understand.


Use of different material for the end plates (for example ceramic at the ends) also changes the nature of the thermal distortion.  If the end plates are made thicker (stiff enough) that's admittedly better.

Common sense solution: unless one can show that weight is a big issue, a clean solution is to use a thicker overall construction, (as used in commercial waveguides).
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: X_RaY on 03/14/2016 09:00 pm
Have to agree! As I said I did this only to get an idea of the dimension in general of the frequency shift using this linear approximation.  :)


Its much more than the few KHz rfmwguy stated about the 13µm differences of a single endplate.

@Rfmwguy
Does you multiply it by a factor of two for both plates or do you meant the total displacement or surface roughness? ???

https://forum.nasaspaceflight.com/index.php?topic=39772.msg1503691#msg1503691


Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/14/2016 09:11 pm
Have to agree! As I said I did this only to get an idea of the dimension in general of the frequency shift using this linear approximation.  :)


Its much more than the few KHz TT stated about the 13µm differences of a single endplate. Does he multiply it by two for both plates or does he meant the total displacement or surface roughness? ???

Please review Rogers advise:

Quote
The route to high Q is to achieve very high precision in the machining of cavity components and their alignment, together with mirror finish on the conducting surface (copper, silver or gold) of at least 10X skin depth. Maintaining this quality of finish also requires a clean dry environment. This is typical flight standard for space qualified microwave equipment, and is therefore expensive to achieve.
 
If you aim for something like 75% of theoretical Q you will still get viable levels of thrust within a reasonable budget for a small business.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/14/2016 09:13 pm
Have to agree! As I said I did this only to get an idea of the dimension in general of the frequency shift using this linear approximation.  :)


Its much more than the few KHz TT stated about the 13µm differences of a single endplate. Does he multiply it by two for both plates or does he meant the total displacement or surface roughness? ???

Please review Rogers advise:

Quote
The route to high Q is to achieve very high precision in the machining of cavity components and their alignment, together with mirror finish on the conducting surface (copper, silver or gold) of at least 10X skin depth. Maintaining this quality of finish also requires a clean dry environment. This is typical flight standard for space qualified microwave equipment, and is therefore expensive to achieve.
 
If you aim for something like 75% of theoretical Q you will still get viable levels of thrust within a reasonable budget for a small business.

Thanks.  We have seen this before.  What is not clear to different viewers is whether the mirror finish advise is only for the ends or also for the interior conical walls.  Please further clarify Shawyer's statement. Is Shawyer asking for a mirror finish only on the end plate interior surfaces as shown by rfmwguy for example:

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1104565;image)

 or also on the lateral interior round conical walls?

(http://quinstar.com/wp-content/blogs.dir/1/files/2011/10/Standard-Gain-Horn-Antennas.jpg)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/14/2016 09:19 pm
Have to agree! As I said I did this only to get an idea of the dimension in general of the frequency shift using this linear approximation.  :)


Its much more than the few KHz TT stated about the 13µm differences of a single endplate. Does he multiply it by two for both plates or does he meant the total displacement or surface roughness? ???

Please review Rogers advise:

Quote
The route to high Q is to achieve very high precision in the machining of cavity components and their alignment, together with mirror finish on the conducting surface (copper, silver or gold) of at least 10X skin depth. Maintaining this quality of finish also requires a clean dry environment. This is typical flight standard for space qualified microwave equipment, and is therefore expensive to achieve.
 
If you aim for something like 75% of theoretical Q you will still get viable levels of thrust within a reasonable budget for a small business.

Thanks.  Is Shawyer asking for a mirror finish only on the end plate interior surfaces as shown by rfmwguy for example:

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1104565;image)

 or also on the lateral interior round conical walls?

(http://quinstar.com/wp-content/blogs.dir/1/files/2011/10/Standard-Gain-Horn-Antennas.jpg)

My understanding, from other discussions, is that a scratch & pit free mirror like finish is required on ALL conducting interior surfaces of the frustum and any feed waveguides.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: X_RaY on 03/14/2016 09:39 pm
OK all surfaces sounds good  :)

If this mechanical quality of surface roughness is required(for space applications), do you plan to Measure your Rz or whatever definition is meant in a machinist shop to be sure ALL of the dimensions of a frustum and the surface roughness is inside of these error bars of 13 micron?


Would be a lot of work and for sure expensive  ::)

On the other hand I am with you, make the experiment as good as possible to get good results.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/14/2016 09:54 pm
To accurately measure below 10um, you would need to use an optical measuring method such as laser 3D scan. A tabletop formtester like this can go down to 15um. 

https://www.youtube.com/watch?v=6NYWPUVve8E
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/14/2016 10:25 pm
OK all surfaces sounds good  :)

If this mechanical quality of surface roughness is required(for space applications), do you plan to Measure your Rz or whatever definition is meant in a machinist shop to be sure ALL of the dimensions of a frustum and the surface roughness is inside of these error bars of 13 micron?


Would be a lot of work and for sure expensive  ::)

On the other hand I am with you, make the experiment as good as possible to get good results.
I will be sanding and planing the internal sheet metal surfaces in the same fashion...dry sand with planing wheel to 2000 grit then 9, 3 and 1 micron hand polishing. The small end was about 4.5 hours worth of work. It will be a mirror finish, just not the same thickness as the end plates.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: R.W. Keyes on 03/14/2016 10:29 pm
Back on New Year's Day, I posted a link to an article which was a popular-science explanation of this article at Science:http://science.sciencemag.org/content/351/6268/58l (http://science.sciencemag.org/content/351/6268/58l). Since that time, I have been busy with other projects and not had much time for EMDrive, but I now have a bit more time and resources. I have been reading about electroless deposition, and found a paper on the electroless deposition of superconductor Magnesium diboride (I found the abstract, but haven't been able to obtain the full paper) This would help solve some of the smoothness issues, but there is still the issue of imperfect 3d printing and and subsequent machining.

I have some crude, warped, and not-full-formed ideas in my head about defeating the warping and aparallelism of frustums, which has been discussed here as of late, perhaps by harnessing resonance of the frustum during forming. That is, having active RF energy help form the field, in a way which improves its Q far beyond the methods we now have. I can only roughly describe it as blowing a bubble, pumping RF into it, and the heat-loss inherent in use of an imperfect frustum keeps the bubble reforming until a near-perfect chamber is formed. No, I don't have any practical idea of how to do this, or any examples, but it is currently an idea bouncing around my head. I hope to have the idea better refined and more eloquently stated in the near future, but I thought I'd just try to drop it into some of the great minds around here ahead of time.

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Flyby on 03/14/2016 11:03 pm

Please review Rogers advise:

Quote
The route to high Q is to achieve very high precision in the machining of cavity components and their alignment, together with mirror finish on the conducting surface (copper, silver or gold) of at least 10X skin depth. Maintaining this quality of finish also requires a clean dry environment. This is typical flight standard for space qualified microwave equipment, and is therefore expensive to achieve.
 
If you aim for something like 75% of theoretical Q you will still get viable levels of thrust within a reasonable budget for a small business.

I'm still not convinced that a higher Q will automatically lead towards a higher generated force as it has yet to be established that there is a relation between them.

I'm still having trouble with the concept of having almost no energetic losses (= high Q) on one side and an increased force, which means a transfer of energy, on the other side.
In my mind, these to are in an apparent conflict.. no?

The only possible way i can see a high Q result in a higher force, is when the force is not generated on the frustum walls, but is somehow created inside the frustum and causes it to move "somehow" (the gravity/gravity field EMtheory). The only result of a high Q is that you store more electromagnetic energy in the cavity.

If the force is generated on the frustum walls (either on front/back plates or the side walls) it must come at the expense of the Q of the electromagnetic waves. Any (yet to be determined) interaction between the walls and the electromagnetic waves must come at the expense of the Q.

So that's , after nearly 2 years of following this topic, i remain a skeptic of the extreme high Q pursuit and the floating car promises they hold.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/14/2016 11:18 pm
Have to agree! As I said I did this only to get an idea of the dimension in general of the frequency shift using this linear approximation.  :)


Its much more than the few KHz TT stated about the 13µm differences of a single endplate. Does he multiply it by two for both plates or does he meant the total displacement or surface roughness? ???

Please review Rogers advise:

Quote
The route to high Q is to achieve very high precision in the machining of cavity components and their alignment, together with mirror finish on the conducting surface (copper, silver or gold) of at least 10X skin depth. Maintaining this quality of finish also requires a clean dry environment. This is typical flight standard for space qualified microwave equipment, and is therefore expensive to achieve.
 
If you aim for something like 75% of theoretical Q you will still get viable levels of thrust within a reasonable budget for a small business.

This implies a surface finish of 13 microns, not a dimensional tolerance of 13 microns. Correct? A 13 micron surface finish is actually pretty crappy. As a SWAG on my part, it looks like Dave got better than 2 microns on his polished end plates (based on observation of haze and geometric distortion).

What we really need is a proper mechanical drawing, with dimensional tolerances and required flatness and surface finish, as any drafting student is taught to do.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: spupeng7 on 03/14/2016 11:26 pm

Please review Rogers advise:

Quote
The route to high Q is to achieve very high precision in the machining of cavity components and their alignment, together with mirror finish on the conducting surface (copper, silver or gold) of at least 10X skin depth. Maintaining this quality of finish also requires a clean dry environment. This is typical flight standard for space qualified microwave equipment, and is therefore expensive to achieve.
 
If you aim for something like 75% of theoretical Q you will still get viable levels of thrust within a reasonable budget for a small business.

I'm still not convinced that a higher Q will automatically lead towards a higher generated force as it has yet to be established that there is a relation between them.

I'm still having trouble with the concept of having almost no energetic losses (= high Q) on one side and an increased force, which means a transfer of energy, on the other side.
In my mind, these to are in an apparent conflict.. no?

The only possible way i can see a high Q result in a higher force, is when the force is not generated on the frustum walls, but is somehow created inside the frustum and causes it to move "somehow" (the gravity/gravity field EMtheory). The only result of a high Q is that you store more electromagnetic energy in the cavity.

If the force is generated on the frustum walls (either on front/back plates or the side walls) it must come at the expense of the Q of the electromagnetic waves. Any (yet to be determined) interaction between the walls and the electromagnetic waves must come at the expense of the Q.

So that's , after nearly 2 years of following this topic, i remain a skeptic of the extreme high Q pursuit and the floating car promises they hold.

Flyby,
any thrust produced will raise these same issues, no matter how small. It is clear, however, that the best results do seem to be from frustums with very flat interior surfaces. I think the Traveler's point is a good one.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/14/2016 11:35 pm
Have to agree! As I said I did this only to get an idea of the dimension in general of the frequency shift using this linear approximation.  :)


Its much more than the few KHz TT stated about the 13µm differences of a single endplate. Does he multiply it by two for both plates or does he meant the total displacement or surface roughness? ???

Please review Rogers advise:

Quote
The route to high Q is to achieve very high precision in the machining of cavity components and their alignment, together with mirror finish on the conducting surface (copper, silver or gold) of at least 10X skin depth. Maintaining this quality of finish also requires a clean dry environment. This is typical flight standard for space qualified microwave equipment, and is therefore expensive to achieve.
 
If you aim for something like 75% of theoretical Q you will still get viable levels of thrust within a reasonable budget for a small business.

This implies a surface finish of 13 microns, not a dimensional tolerance of 13 microns. Correct? A 13 micron surface finish is actually pretty crappy. As a SWAG on my part, it looks like Dave got better than 2 microns on his polished end plates (based on observation of haze and geometric distortion).

My understanding is the actual skin depth layer (outer boundary if you will) should not vary from a perfect frustum model by more than +- 10 skin depth.

Mirror finish, as an ex telescope mirror grinder & polisher is understood to be just that. Mirror finish as Dave achieved.

We need to understand scratches of skin depth or deeper will cause alteration in surface current formation as they will stop or reduce current flowing across them. To me scratch free means any scratch or pit to be much less than skin depth deep.

I do remember the long hours it took to polish a 250mm diameter mirror & the use of a low power microscope to check the mirror surface to see if the polishing had removed all the grind pits & scratches.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/14/2016 11:43 pm
If the force is generated on the frustum walls (either on front/back plates or the side walls) it must come at the expense of the Q of the electromagnetic waves. Any (yet to be determined) interaction between the walls and the electromagnetic waves must come at the expense of the Q.

Exactly correct. The conversion of internal cavity energy to external kinetic energy is at the expense of reduced internal cavity energy & Q as this conversions adds to cavity Q losses.

No free lunches.

It is all detailed in Rogers papers.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/15/2016 02:10 am
Have to agree! As I said I did this only to get an idea of the dimension in general of the frequency shift using this linear approximation.  :)


Its much more than the few KHz TT stated about the 13µm differences of a single endplate. Does he multiply it by two for both plates or does he meant the total displacement or surface roughness? ???

Please review Rogers advise:

Quote
The route to high Q is to achieve very high precision in the machining of cavity components and their alignment, together with mirror finish on the conducting surface (copper, silver or gold) of at least 10X skin depth. Maintaining this quality of finish also requires a clean dry environment. This is typical flight standard for space qualified microwave equipment, and is therefore expensive to achieve.
 
If you aim for something like 75% of theoretical Q you will still get viable levels of thrust within a reasonable budget for a small business.

This implies a surface finish of 13 microns, not a dimensional tolerance of 13 microns. Correct? A 13 micron surface finish is actually pretty crappy. As a SWAG on my part, it looks like Dave got better than 2 microns on his polished end plates (based on observation of haze and geometric distortion).

What we really need is a proper mechanical drawing, with dimensional tolerances and required flatness and surface finish, as any drafting student is taught to do.
I hate to bring up too much in the way of mechanical speculation. I'm just trying to get something more than I witnessed last time, but...
I have researched a lot on surface finishing and know where to obtain 100 angstrom flatness, or 0.001 microns. This is a semiconductor processor in chicago. It is hundreds of dollars per piece. Perhaps down the road if scaling is successful, this level of endplate precision could be useful. Now, I just think its something to keep in the back of our minds for future reference.
Tomorrow, the big diameter endplate will take shape, then the sidewalls.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: dustinthewind on 03/15/2016 02:11 am
If the force is generated on the frustum walls (either on front/back plates or the side walls) it must come at the expense of the Q of the electromagnetic waves. Any (yet to be determined) interaction between the walls and the electromagnetic waves must come at the expense of the Q.

Exactly correct. The conversion of internal cavity energy to external kinetic energy is at the expense of reduced internal cavity energy & Q as this conversions adds to cavity Q losses.

No free lunches.

It is all detailed in Rogers papers.

I am fairly sure that a force in itself won't use up energy until the cavity actually begins to free accelerate by F.dx = Energy (if it does accelerate purely via light) .  This should be similar to two mirrors accelerated away from each other and the light between them red-shifts when the mirrors actually start to accelerate.  If the mirrors are held stationary and are perfectly reflective no red-shifting of the light between the mirrors should happen but a force will still be present.  (While the two systems [cavity or mirrors] are different, I am assuming if there were a force purely by the pressure of light inside the cavity that we could parallel between the two systems.)

On the other hand if the light is accelerating something other than the cavity as a propellant that passes through the walls then there is a chance of seeing Q or energy content drop even when the cavity isn't accelerating because the light is accelerating something else via F.dx=E . 

If there is some anomalous force the difference between these two scenarios might be a way to narrowing down where it is coming from. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/15/2016 02:32 am
EM propulsion study for USAF written in 1989 contains a lot about some of the theories and speculations similar to emdrive. 169 pages...5 D math...I suspect theory people will find this old paper interesting:

https://drive.google.com/file/d/0B4Ez9NDUxpYLZThJTy15TUdPVnM/view
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: CW on 03/15/2016 09:34 am

At the moment and in general there are much bigger problems (thermal expansion,

How much will a ~20cm copper frustum expand due to heating? If it is less than 1/2 a cm or so, then it shouldn't be too much of a concern.

Best to have a tunable frustum IMHO. And from what I've learned today, it might be best to have the big end be the side that is tuned.

I would design it in a way, that the frustum reaches its final (resonance-optimized) dimensions, when the final average operational temperature of the cavity metal walls is reached. I do not know, whether the EM drive designers are doing this already. So I thought it can not hurt to point this out. It's better to have the frustum expand into its perfect dimensions and work WITH nature, instead of trying to compensate for expansion and work AGAINST nature. Also, if the sought after effect is reproducible and we can go to space with it, we better design this thing mechanically in a self-calibrating/adjusting way.
:)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/15/2016 11:20 am
If the force is generated on the frustum walls (either on front/back plates or the side walls) it must come at the expense of the Q of the electromagnetic waves. Any (yet to be determined) interaction between the walls and the electromagnetic waves must come at the expense of the Q.

Exactly correct. The conversion of internal cavity energy to external kinetic energy is at the expense of reduced internal cavity energy & Q as this conversions adds to cavity Q losses.

No free lunches.

It is all detailed in Rogers papers.

I am fairly sure that a force in itself won't use up energy until the cavity actually begins to free accelerate by F.dx = Energy (if it does accelerate purely via light) .  This should be similar to two mirrors accelerated away from each other and the light between them red-shifts when the mirrors actually start to accelerate.  If the mirrors are held stationary and are perfectly reflective no red-shifting of the light between the mirrors should happen but a force will still be present.  (While the two systems [cavity or mirrors] are different, I am assuming if there were a force purely by the pressure of light inside the cavity that we could parallel between the two systems.)

On the other hand if the light is accelerating something other than the cavity as a propellant that passes through the walls then there is a chance of seeing Q or energy content drop even when the cavity isn't accelerating because the light is accelerating something else via F.dx=E . 

If there is some anomalous force the difference between these two scenarios might be a way to narrowing down where it is coming from.

As per attached.

Quote
Note that the reaction is either the acceleration a, or a force equal to Ma, but not both.

EmDrive Force Measurement:
http://www.emdrive.com/EmDriveForceMeasurement.pdf

The EmDrive is not a rocket. It does not generate acceleration unless it is free to move. When constrained there is no external Force generated.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: VAXHeadroom on 03/15/2016 11:53 am
If the force is generated on the frustum walls (either on front/back plates or the side walls) it must come at the expense of the Q of the electromagnetic waves. Any (yet to be determined) interaction between the walls and the electromagnetic waves must come at the expense of the Q.

Exactly correct. The conversion of internal cavity energy to external kinetic energy is at the expense of reduced internal cavity energy & Q as this conversions adds to cavity Q losses.

No free lunches.

It is all detailed in Rogers papers.

I am fairly sure that a force in itself won't use up energy until the cavity actually begins to free accelerate by F.dx = Energy (if it does accelerate purely via light) .  This should be similar to two mirrors accelerated away from each other and the light between them red-shifts when the mirrors actually start to accelerate.  If the mirrors are held stationary and are perfectly reflective no red-shifting of the light between the mirrors should happen but a force will still be present.  (While the two systems [cavity or mirrors] are different, I am assuming if there were a force purely by the pressure of light inside the cavity that we could parallel between the two systems.)

On the other hand if the light is accelerating something other than the cavity as a propellant that passes through the walls then there is a chance of seeing Q or energy content drop even when the cavity isn't accelerating because the light is accelerating something else via F.dx=E . 

If there is some anomalous force the difference between these two scenarios might be a way to narrowing down where it is coming from.

As per attached.

Quote
Note that the reaction is either the acceleration a, or a force equal to Ma, but not both.

EmDrive Force Measurement:
http://www.emdrive.com/EmDriveForceMeasurement.pdf

The EmDrive is not a rocket. It does not generate acceleration unless it is free to move. When constrained there is no external Force generated.

"Clearly, in a static situation, where T and R both exist as forces , they will cancel out."

Not clear, and not proven, and only if Fg1=Fg2, an assertion I do not believe is accurate.
I have not read the whole paper, but will do so soon and comment further.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/15/2016 01:03 pm
If the force is generated on the frustum walls (either on front/back plates or the side walls) it must come at the expense of the Q of the electromagnetic waves. Any (yet to be determined) interaction between the walls and the electromagnetic waves must come at the expense of the Q.

Exactly correct. The conversion of internal cavity energy to external kinetic energy is at the expense of reduced internal cavity energy & Q as this conversions adds to cavity Q losses.

No free lunches.

It is all detailed in Rogers papers.

I am fairly sure that a force in itself won't use up energy until the cavity actually begins to free accelerate by F.dx = Energy (if it does accelerate purely via light) .  This should be similar to two mirrors accelerated away from each other and the light between them red-shifts when the mirrors actually start to accelerate.  If the mirrors are held stationary and are perfectly reflective no red-shifting of the light between the mirrors should happen but a force will still be present.  (While the two systems [cavity or mirrors] are different, I am assuming if there were a force purely by the pressure of light inside the cavity that we could parallel between the two systems.)

On the other hand if the light is accelerating something other than the cavity as a propellant that passes through the walls then there is a chance of seeing Q or energy content drop even when the cavity isn't accelerating because the light is accelerating something else via F.dx=E . 

If there is some anomalous force the difference between these two scenarios might be a way to narrowing down where it is coming from.

As per attached.

Quote
Note that the reaction is either the acceleration a, or a force equal to Ma, but not both.

EmDrive Force Measurement:
http://www.emdrive.com/EmDriveForceMeasurement.pdf

The EmDrive is not a rocket. It does not generate acceleration unless it is free to move. When constrained there is no external Force generated.

"Clearly, in a static situation, where T and R both exist as forces , they will cancel out."

Not clear, and not proven, and only if Fg1=Fg2, an assertion I do not believe is accurate.
I have not read the whole paper, but will do so soon and comment further.

As Roger has stated in his papers, there needs to exist a directionally differential doppler shift of the resonant EM waves to trigger the EmDrive into either Motor or Generator mode. In testing, this external tigger is generated by vibration. As Roger states in the paper linked, when external forces (vibrations) were eliminated, the reaction force stopped being generated.

To say it again. The EmDrive is not a fancy fuelless rocket. Thinking that it is a rocket & should work / act like a rocket is a really bad way to think.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RERT on 03/15/2016 01:05 pm
EM propulsion study for USAF written in 1989 contains a lot about some of the theories and speculations similar to emdrive. 169 pages...5 D math...I suspect theory people will find this old paper interesting:

https://drive.google.com/file/d/0B4Ez9NDUxpYLZThJTy15TUdPVnM/view

rfmwguy - thanks!! A breath of fresh air. Helps the thesis that I'm not mad to find one other person who thinks that we should be investigating the coupling between EM and gravitational fields. Or maybe just a cellmate...

Section 2.10 looks interesting, esp equation 271. Made me wonder whether FEKO could map E.Edot and E.CurlB across the frustrum.

I think equation 168 may speak to CW's thought on the variation of the rate of flow of time.

Interesting the remarks around equation 221!

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: meberbs on 03/15/2016 01:07 pm
...

Quote
Note that the reaction is either the acceleration a, or a force equal to Ma, but not both.

EmDrive Force Measurement:
http://www.emdrive.com/EmDriveForceMeasurement.pdf

The EmDrive is not a rocket. It does not generate acceleration unless it is free to move. When constrained there is no external Force generated.

That force diagram is drawn in a nonsensical way. For now, I will assume Fg1 is not equal to Fg2, and there is no external force on the side walls (which implies some interaction with something that is not contained by the cavity, or breaking conservation of momentum). I will also absorb the factor of Q into the F terms, because for a force balance the total force is what matters.

To do the force balance:
ΣF = M*a
Fg2 - Fg1 = M*a (note: Fg1 is taken to be positive value, acting in opposite direction)

The diagram shows the vector for the net force R = M*a. The diagram also shows T. I have no idea what T is, there is no explanation. It has no place in this force balance.

Quote from: SPR
This internal force F is measured by an outside observer as the Thrust T, a force acting against the observer in the direction shown.
This statement is completely nonsensical. The outside observer would see the device accelerate with acceleration a. Why would the observer feel a force on them? You don't feel a force just from looking at an accelerating object.

T could be the equal and opposite force to R that is felt by the mystery field/particles that carry away the balancing momentum, or it could be the tension in a rope holding the drive still. Assuming the second case, the force balance becomes:

Fg2 - Fg1 - T = M*a
Fg2 - Fg1 - T = 0 (because the rope holds it still)
Fg2 - Fg1 = T

You could do something similar where a rope tied to the back of the drive is connected to a mechanism that is designed to apply a constant force T. In this case the M*a term sticks around and the device will accelerate at a = (Fg2 - Fg1 - T)/M. (neglecting the mass of the rope tied to the back)

The following quote is just a mangling of terminology, an object with a net applied force R accelerates at a=R/M. you call R the reaction, "a" the acceleration.
Quote from: SPR
Note that the reaction is either the acceleration a, or a force equal to Ma, but not both.

One more quote:
Quote from: SPR
In  free  space,  the  thruster  will  simply  accelerate  at a m/s/s,  and R will  not  be measurable.
Except that R is defined as M*a, you know M and a is easy to measure.

The rest of this paper is not worth discussing, because it is clear the author does not understand the most basic concepts of applying a force balance or is just deliberately being confusing to come to a result they know is wrong. I will assume the first, since the second is an accusation that shouldn't be made without strong evidence.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/15/2016 01:09 pm

At the moment and in general there are much bigger problems (thermal expansion,

How much will a ~20cm copper frustum expand due to heating? If it is less than 1/2 a cm or so, then it shouldn't be too much of a concern.

Best to have a tunable frustum IMHO. And from what I've learned today, it might be best to have the big end be the side that is tuned.

I would design it in a way, that the frustum reaches its final (resonance-optimized) dimensions, when the final average operational temperature of the cavity metal walls is reached. I do not know, whether the EM drive designers are doing this already. So I thought it can not hurt to point this out. It's better to have the frustum expand into its perfect dimensions and work WITH nature, instead of trying to compensate for expansion and work AGAINST nature. Also, if the sought after effect is reproducible and we can go to space with it, we better design this thing mechanically in a self-calibrating/adjusting way.
:)

1) Concerning <<I do not know, whether the EM drive designers are doing this already>> they are certainly not (*) conducting their room temperature EM Drive experiments so that <<the frustum reaches its final (resonance-optimized) dimensions, when the final average operational temperature of the cavity metal walls is reached>>.

2) As to whether what you propose is feasible, and whether such a test would be representative of space propulsion, consider the following:

a) whether a "final steady state" will be reached during the testing time available, is a function of the amount of cooling provided (and a function of how much % time is the RF feed on).  As long as the RF feed is on you have a constant source of induction heat (all EM Drive experiments have been conducted with either the RF feed constantly on, or with the RF feed pulsating on and off) .

b) Cooling only takes place by thermal conduction, convection or radiation:

b1) thermal conduction: this is limited by the amount of metal "sink" available.  For constructions such as for example, those of rfmwguy who has only 1 mm thickness on the side walls, this is very limited.  EM Drive constructions with thick walls have substantially more heat sink available.  The time at which a given temperature is reached is inversely proportional to the square of the thickness.  Everything else being the same, a wall thickness that is twice as thick means that a given temperature will be reached in four times longer time.  This follows from the Fourier number: (https://upload.wikimedia.org/math/b/c/f/bcfc1beb362573ce5e792a4d55f9bef6.png)
where L is the thickness, t is time and alpha is the thermal diffusivity of the metal (copper has a thermal diffusivity 111 mm^2/s).

b2)  convection:  all room temperature (*) EM Drive experiments have been conducted without any forced air convection (and certainly without fluid convection like water, or any other fluids that have substantially more cooling capability).  They rely on natural convection.  It is known that the amount of convection provided by natural air convection is very limited due to the very small coefficient of heat transfer due to natural air convection.

Natural convection - air ~0.5 to 20 (W/(m^2K))
Forced Convection - air ~ 10 to 1000 (W/(m^2K))
Forced Convection - water and liquids up to 10000 (W/(m^2K))


Most importantly, natural air convection is not available in space and hence tests relying on natural convection would be very unrepresentative of what would happen in space.

b3) radiation: the amount of heat radiation is proportional to the temperature to the fourth power. 
(https://upload.wikimedia.org/math/1/8/c/18cf894a30413a663488637ce71512c2.png)

where σ is the Stefan–Boltzmann constant (σ = 5.670367×10^−8 W m^−2 K^−4) and epsilon are the emissivities.   Hence it is very nonlinear.  It would take a very large temperature increase for radiation to be effective and to be able to equal the amount of heat produced by induction heating.  Hence if you are counting on radiation, the "final temperature" would be high, and it would take place at a late time, considerably longer than what EM Drive experiments have been conducted for.

______________


(*) An exception are Superconducting EM Drive tests.  Although Fetta (Cannae) and Shawyer (SPR) have discussed such tests, there is no reported information on temperature vs. time to ascertain the effectiveness of the cooling system, but certainly this is of paramount importance to maintain superconductivity, so that a working superconducting EM Drive (under present superconducting materials) entails a forced cooling design.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Willem Staal on 03/15/2016 01:33 pm
 
I have a sort of a theory, maybe too novel, but still.

In the original setup of the Roger Shawyer EM drive they use a hefty Microwave transmitter.

The other day my smartphone smashed on the floor  in pieces. (grumble) So i  examine all the parts in this device. (i was always puzzled how they achieve to build a reception antenna into these little devices)

And i found out that  the antenna in fact is build as a fractal unit!

That gives me a another  idea; is it possible to translate the shape of the EM frustrum into a fractal design? Maybe this is enoegh to boost the overall effect, as i think a fractal antenna has a great effect on reception, so it must have effect on transmitting as well (if you do the math right)   
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: CW on 03/15/2016 01:50 pm

(...)

1) Concerning <<I do not know, whether the EM drive designers are doing this already>> they are certainly not conducting their experiments so that <<the frustum reaches its final (resonance-optimized) dimensions, when the final average operational temperature of the cavity metal walls is reached>>.

2) As to whether what you propose is feasible, and whether such a test would be representative of space propulsion, consider the following:

a) whether a "final steady state" will be reached is a function of the amount of cooling provided.  As long as the RF feed is on you have a constant source of induction heat (all EM Drive experiments have been conducted with either the RF feed constantly on, or with the RF feed pulsating on and off) .

b) Cooling only takes place by:

b1) thermal conductivity: this is limited by the amount of metal "sink" available.  For constructions such as for example, those of rfmwguy who has only 1 mm thickness on the side walls, this is very limited.  EM Drive constructions with thick walls have substantially more heat sink available.  The time at which a given temperature is reached is inversely proportional to the square of the thickness.  This follows from the Fourier number: (https://upload.wikimedia.org/math/b/c/f/bcfc1beb362573ce5e792a4d55f9bef6.png)

b2)  convection:  all EM Drive experiments have been conducted without any forced air convection (and certainly without fluid convection like water, or any other fluids that have substantially more cooling capability).  They rely on natural convection.  It is known that the amount of convection provided by natural air convection is very limited due to the very small coefficient of heat transfer due to natural air convection.

Natural convection - air ~0.5 to 20 (W/(m^2K))
Forced Convection - air ~ 10 to 1000 (W/(m^2K))
Forced Convection - water and liquids up to 10000 (W/(m^2K))


Most importantly, natural air convection is not available in space and hence tests relying on natural convection would be very unrepresentative of what would happen in space.

b3) radiation: the amount of heat radiation is proportional to the temperature to the fourth power. 
(https://upload.wikimedia.org/math/1/8/c/18cf894a30413a663488637ce71512c2.png)
Hence it is very nonlinear.  It would take a very large temperature increase for radiation to be effective and to be able to equal the amount of heat produced by induction heating.  Hence if you are counting on radiation, the "final temperature" would be high, and it would take place at a late time, considerably longer than what EM Drive experiments have been conducted for.

Thanks for your great reply, because it should remind all here of the fact that this 'propulsion system' is eventually supposed to work in free space with its absence of convective cooling. I don't think, that the sort of testing that's going on right now, has any real merit, because the test articles never reach e.g. their thermodynamical operating point, which is, by the way, not even defined yet. The test articles not being in thermodynamical equilibrium can certainly cause readings that seem to indicate force production. But is it so?

Let me just say, that at my old workplace, we had 300+k€ high-end oscilloscopes, which needed to reach their operational temperature within about an hour after switching on, just to be able to make reliable measurements. Defining and keeping points of operation is vital in any engineering, which seems to have happily been forgone. At least it seems to me like this, with the information accessible to me. If the hitherto undertaken experiments have not run long enough for the frustum to even closely reach their stable operating points, then that is a problem of the hitherto taken approaches, not of me stating the fact. I think that I would never dare making any assumptions about any experimental setup without it having reached its operating point.

Just think LIGO, e.g. does anyone seriously think that they did not heavily control environmental conditions to the point where they could be practically 100% confident, that the measurement apparatus had reached its stable operating point and could hopefully produce expected results? The EM drive contraptions are all in fact measuring apparatuses that hope to measure a hitherto elusive way of producing propulsive forces in the low µN range. Don't you think we should apply similarly rigid considerations like in LIGO (although much simpler to achieve in this case) for trying to find out, whether there is really something going on, or whether there is some curious transitional thermodynamical effect emulating what is looked for? Since the EM drive seeks noting less than to overthrow centuries of confirmed physical experimental results so far, it is the greatest duty of experimenters to rigidly make sure that not only confirmed physical knowledge so far is applied correctly, but that especially the physical implementation and measurement setups in the form of test articles is made with prudent and known to be correct engineering approaches.

BR,
CW
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/15/2016 02:01 pm
...
Thanks for your great reply, because it should remind all here of the fact that this 'propulsion system' is eventually supposed to work in free space with its absence of convective cooling. I don't think, that the sort of testing that's going on right now, has any real merit, because the test articles never reach e.g. their thermodynamical operating point, which is, by the way, not even defined yet. The test articles not being in thermodynamical equilibrium can certainly cause readings that seem to indicate force production. But is it so?

Let me just say, that at my old workplace, we had 300+k€ high-end oscilloscopes, which needed to reach their operational temperature within about an hour after switching on, just to be able to make reliable measurements. Defining and keeping points of operation is vital in any engineering, which seems to have happily been forgone. At least it seems to me like this, with the information accessible to me. If the hitherto undertaken experiments have not run long enough for the frustum to even closely reach their stable operating points, then that is a problem of the hitherto taken approaches, not of me stating the fact. I think that I would never dare making any assumptions about any experimental setup without it having reached its operating point.

Just think LIGO, e.g. does anyone seriously think that they did not heavily control environmental conditions until the point where they could be practically 100% confidential, that the measurement apparatus had reached its stable operating point and could hopefully produce expected results? The EM drive contraptions are all in fact measuring apparatuses that hope to measure a hitherto elusive way of producing propulsive forces in the low µN range. Don't you think we should apply similarly rigid considerations like in LIGO (although much simpler to achieve in this case) for trying to find out, whether there is really something going on, or whether there is some curious transitional effect emulating what is looked for?

BR,
CW
Great points.

Although relying on natural convection is not representative of operation in space, artificially incorporating forced convection to control the temperature is certainly an option. 

Superconducting EM Drive designs certainly need such forced convection cooling in order to achieve and maintain superconductivity (presently only achievable at temperatures below room temperature).
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/15/2016 03:04 pm
Oh joy...jigsaw cut large endplate...grinding then finishing...
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/15/2016 03:27 pm

(...)

1) Concerning <<I do not know, whether the EM drive designers are doing this already>> they are certainly not conducting their experiments so that <<the frustum reaches its final (resonance-optimized) dimensions, when the final average operational temperature of the cavity metal walls is reached>>.

2) As to whether what you propose is feasible, and whether such a test would be representative of space propulsion, consider the following:

a) whether a "final steady state" will be reached is a function of the amount of cooling provided.  As long as the RF feed is on you have a constant source of induction heat (all EM Drive experiments have been conducted with either the RF feed constantly on, or with the RF feed pulsating on and off) .

b) Cooling only takes place by:

b1) thermal conductivity: this is limited by the amount of metal "sink" available.  For constructions such as for example, those of rfmwguy who has only 1 mm thickness on the side walls, this is very limited.  EM Drive constructions with thick walls have substantially more heat sink available.  The time at which a given temperature is reached is inversely proportional to the square of the thickness.  This follows from the Fourier number: (https://upload.wikimedia.org/math/b/c/f/bcfc1beb362573ce5e792a4d55f9bef6.png)

b2)  convection:  all EM Drive experiments have been conducted without any forced air convection (and certainly without fluid convection like water, or any other fluids that have substantially more cooling capability).  They rely on natural convection.  It is known that the amount of convection provided by natural air convection is very limited due to the very small coefficient of heat transfer due to natural air convection.

Natural convection - air ~0.5 to 20 (W/(m^2K))
Forced Convection - air ~ 10 to 1000 (W/(m^2K))
Forced Convection - water and liquids up to 10000 (W/(m^2K))


Most importantly, natural air convection is not available in space and hence tests relying on natural convection would be very unrepresentative of what would happen in space.

b3) radiation: the amount of heat radiation is proportional to the temperature to the fourth power. 
(https://upload.wikimedia.org/math/1/8/c/18cf894a30413a663488637ce71512c2.png)
Hence it is very nonlinear.  It would take a very large temperature increase for radiation to be effective and to be able to equal the amount of heat produced by induction heating.  Hence if you are counting on radiation, the "final temperature" would be high, and it would take place at a late time, considerably longer than what EM Drive experiments have been conducted for.

Thanks for your great reply, because it should remind all here of the fact that this 'propulsion system' is eventually supposed to work in free space with its absence of convective cooling. I don't think, that the sort of testing that's going on right now, has any real merit, because the test articles never reach e.g. their thermodynamical operating point, which is, by the way, not even defined yet. The test articles not being in thermodynamical equilibrium can certainly cause readings that seem to indicate force production. But is it so?

Let me just say, that at my old workplace, we had 300+k€ high-end oscilloscopes, which needed to reach their operational temperature within about an hour after switching on, just to be able to make reliable measurements. Defining and keeping points of operation is vital in any engineering, which seems to have happily been forgone. At least it seems to me like this, with the information accessible to me. If the hitherto undertaken experiments have not run long enough for the frustum to even closely reach their stable operating points, then that is a problem of the hitherto taken approaches, not of me stating the fact. I think that I would never dare making any assumptions about any experimental setup without it having reached its operating point.

Just think LIGO, e.g. does anyone seriously think that they did not heavily control environmental conditions to the point where they could be practically 100% confidential, that the measurement apparatus had reached its stable operating point and could hopefully produce expected results? The EM drive contraptions are all in fact measuring apparatuses that hope to measure a hitherto elusive way of producing propulsive forces in the low µN range. Don't you think we should apply similarly rigid considerations like in LIGO (although much simpler to achieve in this case) for trying to find out, whether there is really something going on, or whether there is some curious transitional thermodynamical effect emulating what is looked for? Since the EM drive seeks noting less than to overthrow centuries of confirmed physical experimental results so far, it is the greatest duty of experimenters to rigidly make sure that not only confirmed physical knowledge so far is applied correctly, but that especially the physical implementation and measurement setups in the form of test articles is made with prudent and known to be correct engineering approaches.

BR,
CW

These are points that are to be taken seriously in a build  considering the limits of a pocketbook funding.

Personally it's been one of the cornerstones of my build to remove as best I could the thermal issues from powering the frustum, as much as the pocketbook would allow and still stay within basic design considerations.

It is a fine line to walk in the design. Providing enough power into the frustum to assure you will push the device out of the noise and error bars is no mean feat, even when you have a deep pocket for funding. EagleWorks found this out as well.

How a builder does it is truly up to them, but they should at least consider these points.

Thickness of the walls equates to not only to a greater heat sink but also adds increased structural stability to deformation of the cavity. That said it still will not remove all thermal expansion issues of the aluminum or copper frustum and provisions should be made in either the cavity compensating for thermal changes or tracking of the resonate changing frequency due to shape changes.

Keeping the RF amp or magnetron away from the frustum if at all possible otherwise you will need to profile the extra thermals from the devices. If you don't It just adds complexity to the build IMHO. Not insurmountable although the error bars widen out dramatically.

To this point one thing I have found is trying to keep the thermal signature as uniform as possible and migrate hot spots from mode generation, also waveguides and antennas (which cause deformations end endplates) to the sidewalls, so the deformations of the frustum are a more uniform in nature. I was excited to see the current sims and how they showed deformation issues.
Cooling it?
This is a inexpensive way to do it and it's the main reason your cell phones don't melt in your hands.
http://www.digikey.com/en/product-highlight/p/panasonic/pyrolytic-graphite-sheets


Well, that's my 2 cents this morning. Great insights from great posts.


Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/15/2016 04:31 pm
...How a builder does it is truly up to them, but they should at least consider these points. ...
Shell
OK, but it is not up to the builder what the results of the experiment are, it is up to "Mother Nature" that rules the experimental outcome, not the builder (if the builder reports the true outcome of the experiments, of course).

Therefore, experiments conducted at institutions like universities, CERN, the Cambridge Electron Accelerator (MIT and Harvard), Fermilab, etc., the experimenters do discuss (in the scientific community) and design their experiments following our knowledge of the laws of nature.

If a "builder" were to design an experiment "up to them" without taking into account the laws of nature, then the builder should not be surprised if their results are not accepted by others. 

NASA's experiments stand out as a great example (and they are the reason why many viewers at NSF look at this thread: because NASA is conducting such experiments) because they reported their experiments with much more disclosure than Shawyer but also because Paul March was actively engaged at NSF in discussing their experiments: fully provided all dimensions and materials, thoroughly answered all questions and rather than being defensive about the NASA experiment or saying that it was up to their team what they did, carefully discussed and considered all theoretical and experimental arguments from NSF contributors. 
Paul March, addressed issues brought to him at NSF (rather than dismissing them), for example:

* the effect of the stainless steel chamber
* the effect of thermal buckling
* the effect of thermal expansion and tipping of the balance due to shifting of the center of mass
* the effect of different forms of damping (magnetic vs. oil)
* the effect of Lorentz forces
* the effect of air convection (eliminating it by conducting tests in vacuum)

Some experimental issues remain, but their attitude has not been defensive.  That's the way to get acceptance by the scientific community.   NASA has a review team and White's group methodically follows the agreed experimental recommendations.  Thus my confidence is with NASA: that NASA will finally arrive at a conclusion (positive or negative) regarding the usefulness for space propulsion of what is being investigated.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/15/2016 04:53 pm
...How a builder does it is truly up to them, but they should at least consider these points. ...
Shell
OK, but it is not up to the builder what the results of the experiment are, it is up to "Mother Nature" that rules the experimental outcome, not the builder (if the builder reports the true outcome of the experiments, of course).

Therefore, experiments conducted at institutions like universities, CERN, the Cambridge Electron Accelerator (MIT and Harvard), Fermilab, etc., the experimenters do discuss (in the scientific community) and design their experiments following our knowledge of the laws of nature.

If a "builder" were to design an experiment up to them" without taking into account the laws of nature, then the builder should not be surprised if their results are not accepted by others. 

NASA's experiments stand out as a great example (and they are the reason why many viewers at NSF look at this thread: because NASA is conducting such experiments) because they reported their experiments with much more disclosure than Shawyer but also because Paul March was actively engaged at NSF in discussing their experiments: fully provided all dimensions and materials, thoroughly answered all questions and rather than being defensive about the NASA experiment or saying that it was up to their team what they did, carefully discussed and considered all theoretical and experimental arguments from NSF contributors.  That's the way to get acceptance by the scientific community.
I stated first thing: These are points that are to be taken seriously in a build  considering the limits of a pocketbook funding.


Whether it's LIGO or CERN or MIT, FERMILAB they all have one thread in common Dr. Rodal and that's funding.

You bet I'd like to have a better lab table and another computer and waveguides I didn't have to build myself, but I'm limited just like the organizations you mentioned, by budget. I will do my best and even when this project was budgeted out I mentioned 20K in the gofundme as a basic goal to acquire what I felt was the basic lab to do the testing. I'm still only half way there. Sure I build my own waveguides and scrounge from my own piles of goodies and snipe deals on Ebay but that takes time and I'm not the only one who wants to see this project bear fruit.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/15/2016 05:01 pm
...You bet I'd like to have a better lab table and another computer and waveguides I didn't have to build myself, but I'm limited just like the organizations you mentioned, by budget. ...
I was not referring to you, you have always been positive and welcoming of comments on your build  ;)

------
Concerning <<waveguides I didn't have to build myself>> and <<considering the limits of funding>>, I am involved in a project dealing with evanescent wave coupling (from a multilayer dielectric waveguide, which I plan to couple using prisms, grating is also under consideration) that may require several metal waveguides as well, most likely using TM polarization.  In the range of 2 GHz (or less) these waveguides list for several thousand dollars.

Do you have an actual comparison you can share of the performance of a home-built metal waveguide with the commercial waveguides?  I would also appreciate any comparison you may have of thinner waveguides with the commercial waveguide constructions, or data showing that a thinner waveguide can do just as well (*)

Thanks

_______

(*) The UberOverLord was also interested on this issue, based on his experience at the US Air Force
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/15/2016 05:41 pm
...You bet I'd like to have a better lab table and another computer and waveguides I didn't have to build myself, but I'm limited just like the organizations you mentioned, by budget. ...
I was not referring to you, you have always been positive and welcoming of comments on your build  ;)

------
Concerning <<waveguides I didn't have to build myself>> and <<considering the limits of funding>>, I am involved in a project dealing with evanescent wave coupling (from a multilayer dielectric waveguide, which I plan to couple using prisms, grating is also under consideration) that may require several metal waveguides as well, most likely using TM polarization.  In the range of 2 GHz (or less) these waveguides list for several thousand dollars.

Do you have an actual comparison you can share of the performance of a home-built metal waveguide with the commercial waveguides?  I would also appreciate any comparison you may have of thinner waveguides with the commercial waveguide constructions, or data showing that a thinner waveguide can do just as well (*)

Thanks

_______

(*) The UberOverLord also commented on this issue, based on his experience at the US Air Force
Thank YOU!


Honestly I used a OTS rectangular aluminum stock that I had to clean up quite a bit. It received a silver electroplating on top of that. I followed this template
http://www.wikarekare.org/Antenna/Waveguide.html but build a better quality guide. The lucky thing was the waveguide is right in the middle of the spectrum for the guide @ 2.45GHz.

I don't have any real specs to compare on the thinner walled guides vs what I built.
If I had my old shop back I'd make it from heavy copper O2 free stock and bend on the industrial bender. You could contact any local shops that have the capability to bend thick copper and send it out to be electroplated with Cu and flashed over with a gold finish. That would be about 1/4 of the cost vs a commercial.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/15/2016 06:01 pm
MHT1003NR3 arrived. It is a little smaller than I expected. This little 3-pin RF LDMOSFET transistor can output 250 watts @ 2.45Ghz with 32v DC!

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/15/2016 06:15 pm
...
Thank YOU!


Honestly I used a OTS rectangular aluminum stock that I had to clean up quite a bit. It received a silver electroplating on top of that. I followed this template
http://www.wikarekare.org/Antenna/Waveguide.html but build a better quality guide. The lucky thing was the waveguide is right in the middle of the spectrum for the guide @ 2.45GHz.

I don't have any real specs to compare on the thinner walled guides vs what I built.
If I had my old shop back I'd make it from heavy copper O2 free stock and bend on the industrial bender. You could contact any local shops that have the capability to bend thick copper and send it out to be electroplated with Cu and flashed over with a gold finish. That would be about 1/4 of the cost vs a commercial.

Shell

Thanks ! Much appreciated.  Love the fact that you even included the template and a cost comparison vs. commercial !

Just what I was looking for.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: CW on 03/15/2016 07:05 pm
Great points.

Although relying on natural convection is not representative of operation in space, artificially incorporating forced convection to control the temperature is certainly an option. 

Superconducting EM Drive designs certainly need such forced convection cooling in order to achieve and maintain superconductivity (presently only achievable at temperatures below room temperature).

I would like to take up this opportunity and encourage builders to embrace the new 3D manufacturing technologies and design a frustum with embedded cooling channels in the metal walls. If the coolant were running in two separate channels with counter directed coolant flow, there should be no net angular momentum at any given point in time (I think).
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/15/2016 07:16 pm
Great points.

Although relying on natural convection is not representative of operation in space, artificially incorporating forced convection to control the temperature is certainly an option. 

Superconducting EM Drive designs certainly need such forced convection cooling in order to achieve and maintain superconductivity (presently only achievable at temperatures below room temperature).

I would like to take up this opportunity and encourage builders to embrace the new 3D manufacturing technologies and design a frustum with embedded cooling channels in the metal walls. If the coolant were running in two separate channels with counter directed coolant flow, there should be no net angular momentum at any given point in time (I think).

NSF also had sporadic news from a University project in a Western province of Canada (I thought it was in Alberta, if my memory is correct) involving very large power input (much larger than what any EM Drive test has reported up to now).  The project did not involve a superconducting design. Due to the very large power input, forced cooling of the EM Drive was discussed and deemed necessary for the project.  It has been several weeks since we last heard anything concerning this EM Drive project.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/15/2016 07:53 pm
Finishing starts on large diameter endplate. Lapping plate and Lapping wheel undersized but will have to do...
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: MazonDel on 03/15/2016 08:47 pm
Great points.

Although relying on natural convection is not representative of operation in space, artificially incorporating forced convection to control the temperature is certainly an option. 

Superconducting EM Drive designs certainly need such forced convection cooling in order to achieve and maintain superconductivity (presently only achievable at temperatures below room temperature).

I would like to take up this opportunity and encourage builders to embrace the new 3D manufacturing technologies and design a frustum with embedded cooling channels in the metal walls. If the coolant were running in two separate channels with counter directed coolant flow, there should be no net angular momentum at any given point in time (I think).

I am quite willing to do the CAD work necessary for this, provided someone can provide me with the dimensions and further desires. Exactly what adjustments I might need to make to account for production method are dependent on how they want the device made.

One thing I was considering actually was the possibility of designing a sort of "jacket" that others could place their frustum in (slather the outside in some sort of thermal compound) and use to help cool it.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/15/2016 09:12 pm
I think a 3D printed shawyer-class frustum is beyond most DIY budgets. I can't imagine it costing less than $thousands.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: dustinthewind on 03/15/2016 09:24 pm
If the force is generated on the frustum walls (either on front/back plates or the side walls) it must come at the expense of the Q of the electromagnetic waves. Any (yet to be determined) interaction between the walls and the electromagnetic waves must come at the expense of the Q.

Exactly correct. The conversion of internal cavity energy to external kinetic energy is at the expense of reduced internal cavity energy & Q as this conversions adds to cavity Q losses.

No free lunches.

It is all detailed in Rogers papers.

I am fairly sure that a force in itself won't use up energy until the cavity actually begins to free accelerate by F.dx = Energy (if it does accelerate purely via light) .  This should be similar to two mirrors accelerated away from each other and the light between them red-shifts when the mirrors actually start to accelerate.  If the mirrors are held stationary and are perfectly reflective no red-shifting of the light between the mirrors should happen but a force will still be present.  (While the two systems [cavity or mirrors] are different, I am assuming if there were a force purely by the pressure of light inside the cavity that we could parallel between the two systems.)

On the other hand if the light is accelerating something other than the cavity as a propellant that passes through the walls then there is a chance of seeing Q or energy content drop even when the cavity isn't accelerating because the light is accelerating something else via F.dx=E . 

If there is some anomalous force the difference between these two scenarios might be a way to narrowing down where it is coming from.

As per attached.

Quote
Note that the reaction is either the acceleration a, or a force equal to Ma, but not both.

EmDrive Force Measurement:
http://www.emdrive.com/EmDriveForceMeasurement.pdf

The EmDrive is not a rocket. It does not generate acceleration unless it is free to move. When constrained there is no external Force generated.

I think I am detecting some nonsense in this document.  It is claimed if the cavity impacts a wall and stops moving it stops generating a force.  I.e. when it is on a scale and not free to move no force is exerted.  However if the cavity is free to accelerate it will accelerate.  Ok well here is the problem.

Our cavity sits in an empty room and is free to roll and suddenly hits the wall of the room but the wall in the room absorbs the impact with out letting it bounce so now the cavity sits against the wall of the room.  The room now sits in empty space and is free to accelerate but since the cavity isn't free to move the room doesn't accelerate.  The problem here is if the cavity is ever going to be used to accelerate a space ship it must be attached in such a way to the ship that it can't move relative to the ship.  Now consider space ship earth which is a mass and is free to accelerate as well.  The cavity is always free to accelerate and therefore a force must be there and if the cavity is ever going to accelerate there must be a force. 

Quote from paper that doesn't sit right with me:
"Because the thruster is at rest, no force will be measured on the load cell.
i.e. F = T-R = 0

It therefore appears that a force measurement can only be made in a dynamic
environment, ideally by allowing the thruster to accelerate, measuring that
acceleration, and then calculating the thrust from T = -Ma."  page 3
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: dustinthewind on 03/15/2016 10:05 pm
EM propulsion study for USAF written in 1989 contains a lot about some of the theories and speculations similar to emdrive. 169 pages...5 D math...I suspect theory people will find this old paper interesting:

https://drive.google.com/file/d/0B4Ez9NDUxpYLZThJTy15TUdPVnM/view

This paper was an interesting read.  What caught my attention was the "Rotation of Magnets" on page D-3.  I did my thesis on this.  My conclusion was that the magnetic field can't rotate axially and for quite a few reasons but first we did an experimental test which came out negative for axial field rotation.  We rotated a magnet axially and put a capacitor axially around the magnet such that an EMF should have been induced in the capacitor and predicted what we should see. 

After the negative results "I expected to see the magnetic field rotate" I looked into it and found why it can not.  Some simple reasons are that information in free space doesn't travel in the direction "omega x r" or in circles but rather radially.  By rotating a magnet or changing a magnetic field the induction is actually radial though nature conspires to make it appear as if the induction can also occur by angular velocity but not beyond a maximum distance r in which the speed of light will be exceeded. 

Long story short a 3 phase coil can give the impression of a rotating magnetic field but the coils don't rotate.  Magnetars give off pulses and are considered to be giant magnet stars and the induction of them rotating should be radial with great distance. 

The main reason is to consider a single loop of wire in which current travels in a circle but the positive charges are stationary.  a moving observer moving beside the current loop will observe some negative charge to be moving faster (opposite direction) with respect to their frame than the charge that is moving with their frame.  The charge moving faster is slowed in time and charge tends to build up on that side of the loop.  This is small but the great power of the electric field and charge density makes the magnetic field one of the few phenomena where we observe relativity on a daily basis.  This relative velocity with respect to the current loop results in a dipole charge on the current loop because the positive charge is not rotating in a circle but the negative charge is.  For an infinitely long solenoid most of the magnetic field is contained inside because it is in reality a velocity dependent dipole electric potential. 

Many books make the error of trying to simulate the magnetic field lines as a dipole electric field but the magnetic field lines are actually a velocity dependent dipole electric potential.  The electric field line pass perpendicular to the potential lines.  The electric dipole rotates depending on the observers direction of velocity.  I thought it was pretty neat once I began to understand this.  I understood later that if I rotate the current loop axially in the lab frame and the magnetic field rotates axially also that this implies that the magnet would give every observer in the lab frame a relative velocity with respect to the current loop.  This relative velocity would require a lab-frame observer to undergo no acceleration and their relative velocity would increase with radial distance.  An axially rotating magnetic field implies in the lab-frame we could observe this dipole electric field and be moving faster with respect to some charges in the axially rotating current loop than others, which is nonsense, and my conclusion was the magnetic field can not axially rotate.  I have my doubts it rotates at all and I think induction is generally radial.  That is unless, the observer is the one rotating and not the magnet. 

After this I became interested in the radial induction of the phased arrays as a form of propulsion and eventually found my way here.  Later on the EM drive and then the Mach effect mentioned in this paper you posted.  I enjoy much of the great discussion and articles posted here and want to say thanks to everyone for their curiosity and sharing knowledge to weed through to see if any new form of propulsion may be possible. 

Thesis defense:
https://www.youtube.com/watch?v=snDp2_GjLvQ
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/16/2016 12:14 am
Forgive me if this has been posted already, but there appears to be a new Emdrive paper. Any thoughts?

http://www.helsinki.fi/~aannila/arto/emdrive.pdf

The paper is written by Arto Annila, a Professor in Physics at the University of Helsinki, Erkki Kolehmainen, a Professor of Chemistry at the University of Jyväskylä and Patrick Grahn, an engineer with a specialization in COSMOL Multiphysics at the University of Helsinki.

The abstract to the paper notes:

" Recent reports about propulsion without reaction mass have been met with disbelief. Closed metal cavities, when fueled with microwaves, have delivered thrust without any apparent exhaust. Thus the Law of Action-Reaction seems to have been violated. We consider the possibility that the exhaust is in a form that has so far escaped both experimental detection and theoretical attention. In the thruster’s cavity microwaves interfere with each other and invariably some photons will also end up co-propagating with opposite phases. At the destructive interference electromagnetic fields cancel. However, the photons themselves do not vanish for nothing but continue in propagation. These photon pairs without net electromagnetic field do not reflect back from the metal walls but escape from the resonator. By this action momentum is lost from the cavity which, according to the conservation of momentum, gives rise to an equal and opposite reaction. We examine theoretical corollaries and practical concerns that follow from the paired –photon conclusion."
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/16/2016 12:45 am
Large endplate of NSF-1701A complete  :P
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/16/2016 01:24 am
Forgive me if this has been posted already, but there appears to be a new Emdrive paper. Any thoughts?

http://www.helsinki.fi/~aannila/arto/emdrive.pdf

The paper is written by Arto Annila, a Professor in Physics at the University of Helsinki, Erkki Kolehmainen, a Professor of Chemistry at the University of Jyväskylä and Patrick Grahn, an engineer with a specialization in COSMOL Multiphysics at the University of Helsinki.

The abstract to the paper notes:

" Recent reports about propulsion without reaction mass have been met with disbelief. Closed metal cavities, when fueled with microwaves, have delivered thrust without any apparent exhaust. Thus the Law of Action-Reaction seems to have been violated. We consider the possibility that the exhaust is in a form that has so far escaped both experimental detection and theoretical attention. In the thruster’s cavity microwaves interfere with each other and invariably some photons will also end up co-propagating with opposite phases. At the destructive interference electromagnetic fields cancel. However, the photons themselves do not vanish for nothing but continue in propagation. These photon pairs without net electromagnetic field do not reflect back from the metal walls but escape from the resonator. By this action momentum is lost from the cavity which, according to the conservation of momentum, gives rise to an equal and opposite reaction. We examine theoretical corollaries and practical concerns that follow from the paired –photon conclusion."

Thank you for this interesting paper, which I'm sure has never been discussed at NSF EM Drive thread previously.

My take: it would have been beneficial for the authors to read the NSF EM Drive threads, because early on we discussed that one of the most concerning claims about the EM Drive was not just the possible violation of conservation of momentum (which is dealt with in this paper by the hypothesis that some photons are able to escape) but that the claimed anomalous force/inputPower is orders of times greater than a perfectly collimated photon rocket.

That's why in the compilation of experimental results wiki, we endeavored to compare all claimed results with the force/powerInput of a perfectly collimated photon rocket:   http://emdrive.wiki/Experimental_Results

This, the authors fail to do.  They claim that a few of the photons are able to escape the EM Drive.  Although there is no experimental proof of this, and no real physical-mathematical theory by which this can happen, the question still remains, of how could this result in a force/powerInput greater than a perfectly collimated photon rocket  ???
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Amestad on 03/16/2016 01:45 am
Great points.

Although relying on natural convection is not representative of operation in space, artificially incorporating forced convection to control the temperature is certainly an option. 

Superconducting EM Drive designs certainly need such forced convection cooling in order to achieve and maintain superconductivity (presently only achievable at temperatures below room temperature).

I would like to take up this opportunity and encourage builders to embrace the new 3D manufacturing technologies and design a frustum with embedded cooling channels in the metal walls. If the coolant were running in two separate channels with counter directed coolant flow, there should be no net angular momentum at any given point in time (I think).

I am quite willing to do the CAD work necessary for this, provided someone can provide me with the dimensions and further desires. Exactly what adjustments I might need to make to account for production method are dependent on how they want the device made.

One thing I was considering actually was the possibility of designing a sort of "jacket" that others could place their frustum in (slather the outside in some sort of thermal compound) and use to help cool it.

I suggested an incredibly simple method for providing support for the frustum side walls and 'simultaneous  cooling method', just a few pages back..
See the attached image, or if it isn't working follow this link
http://i67.tinypic.com/ejc5r6.png

Cheers
Amestad

Shell
I bet you could do this.. bolt 2 equal sized plates to your endplates that are sized for the correct cylinder..

 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/16/2016 01:51 am
Thank you for this interesting paper, which I'm sure has never been discussed at NSF EM Drive thread previously.

The authors seem to be claiming that because of destructive interference at the frustum-wall interface, photons are exiting the apparatus. My understanding is that when there is destructive interference, photons are directed back to the source.

https://www.youtube.com/watch?v=RRi4dv9KgCg
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/16/2016 02:10 am
Thank you for this interesting paper, which I'm sure has never been discussed at NSF EM Drive thread previously.

The authors seem to be claiming that because of destructive interference at the frustum-wall interface, photons are exiting the apparatus. My understanding is that when there is destructive interference, photons are directed back to the source.

https://www.youtube.com/watch?v=RRi4dv9KgCg

Lovely to see Professor Ezekiel !

It feels like it was yesterday.  Brings back great memories I had at MIT.  His Laboratory was in the main corridor of the Aero & Asto department, so hardly a day went by without hearing or seeing him involved in experiments with students as one walked that corridor, connecting several MIT buildings   ;).  Unfortunately Professor Emeritus Shaoul “Ziggy” Ezekiel passed away one year ago (suffering from soft-tissue sarcoma cancer).  "Ziggy" (as he liked to be called, even as a full Professor) was also an MIT alumnus (where he received his doctorate in the 1960's) who spent 46 years at MIT as a professor in both the departments of Aeronautics and Astronautics (Course XVI, AeroAstro) and Electrical Engineering and Computer Sciences (Course VI, EECS).

He taught classes in dynamics, optics, laser fundamentals, basics of measurement systems, and optical sensors.
His research interests were in the fields of lasers and optics and their applications in atom-field interactions; ultra-high resolution spectroscopy; optical frequency/wavelength standards; and sensors, including optical/fiberoptical gyroscopes, magnetic field sensors, and spectroscopic sensors. He exploited nonlinear optical effects to create a variety of new sensors and optical devices, and novel high frequency sources.  He was universally liked by all students because of his friendliness, and his enthusiasm.  He was always upbeat and loved to discuss  experiments with optics and lasers.  We miss him !
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: spupeng7 on 03/16/2016 03:18 am
EM propulsion study for USAF written in 1989 contains a lot about some of the theories and speculations similar to emdrive. 169 pages...5 D math...I suspect theory people will find this old paper interesting:

https://drive.google.com/file/d/0B4Ez9NDUxpYLZThJTy15TUdPVnM/view

rfmwguy - thanks!! A breath of fresh air. Helps the thesis that I'm not mad to find one other person who thinks that we should be investigating the coupling between EM and gravitational fields. Or maybe just a cellmate...

Section 2.10 looks interesting, esp equation 271. Made me wonder whether FEKO could map E.Edot and E.CurlB across the frustrum.

I think equation 168 may speak to CW's thought on the variation of the rate of flow of time.

Interesting the remarks around equation 221!

R.

Unification, well I'm right with you there Rert. It all makes perfect sense if electric fields are in fact dilations of time same as gravity. You can put me in the cell next door...  JMN..
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: aero on 03/16/2016 03:21 am
Dr. Rodal - I'm still wondering about ratio-ing Ag/CU * copper conductivity to obtain a valid Ag conductivity, but in the mean time, I have a new question for you, and all. meep is converging nicely now to positive Q values but they are still unreal. I just completed a run of the NSF-1701A model and meep calculated Q as 328,441. That's nice but it seems to me that it is about an order of magnitude to large.

Is it possible that you or DeltaMass misplaced a decimal point giving conductivity off by a factor of 10? I doubt that you did because in following the symbolic math you provided, I calculated the same number that you did. But we both started with the number for sigma, CU-sigmaSI 3.25E+8. Perhaps that should have been 10^+7 instead.

Does that seem reasonable?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: spupeng7 on 03/16/2016 03:25 am
http://www.bbc.co.uk/programmes/b0752f85

Quote
Project Greenglow - The Quest for Gravity Control
Horizon, 2015-2016

This is the story of an extraordinary scientific adventure - the attempt to control gravity. For centuries, the precise workings of gravity have confounded the greatest scientific minds - from Newton to Faraday and Einstein - and the idea of controlling gravity has been seen as little more than a fanciful dream. Yet in the mid 1990s, UK defence manufacturer BAE Systems began a ground-breaking project code-named 'Greenglow', which set about turning science fiction into reality. On the other side of the Atlantic, Nasa was simultaneously running its own Breakthrough Propulsion Physics Project. It was concerned with potential space applications of new physics, including concepts like 'faster-than-light travel' and 'warp drives'.

Looking into the past and projecting into the future, Horizon explores science's long-standing obsession with the idea of gravity control. It looks at recent breakthroughs in the search for loopholes in conventional physics and examines how the groundwork carried out by Project Greenglow has helped change our understanding of the universe. Gravity control may sound like science fiction, but the research that began with Project Greenglow is very much on-going, and the dream of flying cars and journeys to the stars no longer seems quite so distant.

The program segment will probably be geo blocked outside the UK. Do trust it will make the jump to open access YouTube.

THANKYOU  PHIL   :) :D :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: spupeng7 on 03/16/2016 03:32 am
MHT1003NR3 arrived. It is a little smaller than I expected. This little 3-pin RF LDMOSFET transistor can output 250 watts @ 2.45Ghz with 32v DC!

Can't wait to see what difference a clean signal will make  :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: spupeng7 on 03/16/2016 03:51 am
Paul Kocyla in Aachen, Germany is beginning to test the 24 GHz emdrive on a rotary flotation pad. Unquantified force measurements, appears to be calibration tests:

https://www.youtube.com/watch?v=i4UKDVtRRxI
Would appreciate somebody familiar with this testing program to clarify:

1) are the battery and the mini-EM-drive integrated together on the testing platform for the Kocyla test?  DeltaMass and I had agreed that by far the best proposed test was TheTraveller's proposal to have a battery and the EM Drive on a rotary platform together (rather than having the power be fed from a stationary source to a moving EM Drive which has a big testing flaw: the center of energy-mass is outside the moving EM Drive, therefore measuring an acceleration in such a test is flawed since in space the source of power would need to be in the same spaceship as the EM Drive)

2) What is the present testing platform arrangement?


Dr Rodal,
very slowly I am working toward a similar experiment with the entire system under test being housed in a single closed container (not hermetically sealed).

The picture below shows the battery pack [light grey], power conditioning (dark grey), 60GHz resonator (brass) and frustum array (blue). Measuring just 15cm by 12cm x 7cm and weighing less than 600g. Hoping that some of these factors will compensate for lack of RF power capacity within frustum array.

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Star One on 03/16/2016 08:51 am
This is the Horizon episode on the BBC 23/03/16 featuring EM drive.

http://www.bbc.co.uk/programmes/b0752f85
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/16/2016 10:01 am
This is the Horizon episode on the BBC 23/03/16 featuring EM drive.

http://www.bbc.co.uk/programmes/b0752f85

Interesting statement:

Quote
It looks at recent breakthroughs in the search for loopholes in conventional physics
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RERT on 03/16/2016 10:02 am
This caught my eye on another forum where EM-drive was being discussed (off-topic):

Quote
superconductors (even Type I) have a finite RF resistance and so don't produce infinite Q cavities.  Ordinary conductors like Cu and Ag have their surface resistance continuously declining with temperature, extrapolated to 0 resistance at 0K.  For *RF* purposes, just cold copper is approaching the performance of a Type 1 superconductor at the low temperatures that would be needed for Type I superconductivity.  But, Cu and Ag have the advantage that they do not have a critical temperature where everything falls apart.

I don't know if this is true, but if it is it seems quite interesting.

R.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/16/2016 10:15 am
This caught my eye on another forum where EM-drive was being discussed (off-topic):

Quote
superconductors (even Type I) have a finite RF resistance and so don't produce infinite Q cavities.  Ordinary conductors like Cu and Ag have their surface resistance continuously declining with temperature, extrapolated to 0 resistance at 0K.  For *RF* purposes, just cold copper is approaching the performance of a Type 1 superconductor at the low temperatures that would be needed for Type I superconductivity.  But, Cu and Ag have the advantage that they do not have a critical temperature where everything falls apart.

I don't know if this is true, but if it is it seems quite interesting.

R.

When a copper coil is cooled by LN2, the resistance drops approx 8 times, which relates to a Q increase of approx 2.8x.

https://www.youtube.com/watch?v=LmdPB3AwRWo

Don't believe the statement is correct. Also believe copper skin depth, at cryo temps & 2.45GHz excitation, flattens out.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/16/2016 10:39 am
Build UpDate,

Due to continuing issues with my prostate cancer, there has not been any work done on my test rig. Following discussions with Roger on the poor Q (some shared here), I have decided to stop working with the existing frustum build.

Working on a new build that will be machined & commercially polished to the very high standards Roger has set. This design will have spherical end plates and the side walls will be 6mm thick, with minimal 6mm thick end plates.

The end plates will be attached as Roger did in his Flight Thruster, so to allow differential pressure around the flange bolts to slightly alter the end plate to end plate alignment so to allow Q tuning with a torque wrench as happens in high Q accelerator cavities.

This will not be a cheap or quick build but as I have seen 8mNs of reaction, I have full confidence this build will deliver the min 20mN of reaction force (out of a theoretical 39mN) needed to take this to the independent measurement verification stage and then to release the data.

What I can say of this journey so far is a cheap & quick build MAY work somewhat if you are lucky. BUT to get consistent results that are close to those predicted, the build has to be to the quality levels Roger has shared.

Plus EmDrive DIYers really do need to read, fully understand & accept what is shared in the Test and Measurement paper:
http://www.emdrive.com/EmDriveForceMeasurement.pdf

Please study this photo. It is a gold mine. Especially the test setup. Note the spring. Then read the paper. As far as I know the prototype Flight Thruster was working and generating a reaction force. This is also the only known photo showing the Rf input connector and the mechanical arm on the left that allows the coupler to be adjusted inside the frustum. As Roger shared with me, every successful EmDrive build he knows of has some means to adjust the internal coupler to obtain optimal results.

I would add that both Dave & Shell are following the same pathway, ie:

 Next Frustum Build Quality is a LOT higher than the 1st.

Newbie EmDrive builders please take note.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/16/2016 11:20 am
Stream of consciousness alert - in T6 posted about a paper talking about a supercharged sputtering magnetron in which particles jumped to a higher energy state.
Photon collisions creating mass require about 1 MeV of energy, far above a magnetrons power which I would guess is 1 KeV. (Edit - actually its around 12 microelectronvolts)
Have to find that paper to see the energy jump factor.
Still, if mass were be created, is it still a closed system and where does the mass go? Do the mass particles slam against the small end with more kinetic force or does CoM remain in effect as I would speculate. Have to study more when time permits.

https://en.m.wikipedia.org/wiki/Matter_creation
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/16/2016 11:24 am
Build UpDate,

Due to continuing issues with my prostate cancer, there has not been any work done on my test rig. Following discussions with Roger on the poor Q (some shared here), I have decided to stop working with the existing frustum build.

Working on a new build that will be machined & commercially polished to the very high standards Roger has set. This design will have spherical end plates and the side walls will be 6mm thick, with minimal 6mm thick end plates.

The end plates will be attached as Roger did in his Flight Thruster, so to allow differential pressure around the flange bolts to slightly alter the end plate to end plate alignment so to allow Q tuning with a torque wrench as happens in high Q accelerator cavities.

This will not be a cheap or quick build but as I have seen 8mNs of reaction, I have full confidence this build will deliver the min 20mN of reaction force (out of a theoretical 39mN) needed to take this to the independent measurement verification stage and then to release the data.

...
Alternatively, how about testing instead with your proposed setup having the battery and the EM-drive integrated together on the testing platform? 

Such a test would be by far the most convincing test to anyone.  A number of people (including strong skeptics like DeltaMass) agreed that by far the best proposed test was your (TheTraveller's) proposal to have a battery and the EM Drive together (rather than having the power be fed from a stationary source to a moving EM Drive which has a big testing flaw: the center of energy-mass is outside the moving EM Drive, therefore measuring an acceleration in such a test is flawed since in space the source of power would need to be in the same spaceship as the EM Drive).

The flaw in all tests having the power source separate from a moving EM Drive is that the mass of a power source (for example the mass of a battery) must decrease as the electromagnetic field carries power away to the EM Drive. As the EM Drive acts like a resistor, it absorbs the power, and its mass must increase in the process. As the mass of the EM Drive increases with time, so the EM Drive must move in the opposite direction in order to conserve momentum.  In this situation, the center of energy-mass never accelerates, it is just the EM Drive that must accelerate (a tiny amount) in order to conserve momentum.  In a propulsion system where the power source and the EM Drive are integrated together its center of mass would not accelerate and would not be useful for propulsion in space.  Thus, any test that has the power separate from a moving EM Drive is subject to this objection.  Therefore the most convincing test is one where the EM Drive is powered by a battery, integrated in the same system.
(*)

Brito, Marini and Galian succeeded in nullifyng a Mach-Lorentz Thruster (MLT) by doing just that: integrating a battery together with the MLT together in a Cavendish type experiment. ("Null Findings on Electromagnetic Inertia Thruster Experiments using a Torsion Pendulum" 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference 2 - 5 August 2009 and Ricardo L. Marini and Eugenio S. Galian.  "Torsion Pendulum Investigation of Electromagnetic Inertia Manipulation Thrusting", Journal of Propulsion and Power, Vol. 26, No. 6 (2010), pp. 1283-1290)

I hope that NASA is carrying on the proposed test with John Hopkins in a Cavendish type of pendulum (as proposed in their 2004 report  "Anomalous Thrust Production from an RF Test Device Measured on a Low-Thrust Torsion Pendulum, p. 21") with a battery supplying the power.  Such a test would be the most convincing test to the scientific community.

___________

(*) When I have the time I will show this flaw analytically, with a post in the "Resonant Cavity Space-Propulsion: institutional experiments and theory " thread, showing the Poynting vectors and conservation of momentum

(**) This simple, conventional, increase in mass-energy of the EM Drive due to being powered by an RF feed is much simpler, and hence more plausible (using Occam's razor https://en.wikipedia.org/wiki/Occam%27s_razor

Among competing hypotheses, the one with the fewest assumptions should be selected.

) than the proposed "mass creation" being proposed elsewhere: https://forum.nasaspaceflight.com/index.php?topic=39772.msg1504407#msg1504407, or the also proposed "negative mass" explanation proposed elsewhere.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/16/2016 11:42 am
Alternatively, how about testing instead with your proposed setup having the battery and the EM-drive integrated together on the testing platform?... 

As the next build is based on spherical end plates, the self contained rotary table testing will follow the quasi-static testing of this new generation frustum.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/16/2016 12:29 pm
Photon collisions creating mass require about 1 MeV of energy, far above a magnetrons power which I would guess is 1 KeV.

At 2.45Ghz the quantum energy of a microwave photon is 10^-5 eV. I believe hard X-rays approach 1MeV.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/16/2016 12:43 pm
Photon collisions creating mass require about 1 MeV of energy, far above a magnetrons power which I would guess is 1 KeV.

At 2.45Ghz the quantum energy of a microwave photon is 10^-5 eV. I believe hard X-rays approach 1MeV.

This sort of leaves this out as a possibility. If mass appears because of a photo collision, I would assume the resulting mass would travel in the direction of the photon with the highest energy. A large-diameter fired frustum would have photons colliding with the highest energy leaving the source (reflected photons having lower energy) meaning the newly found mass would travel away from the source(?) until it struck something...the small end or the sidewalls...that energy then being converted into kinetic energy/heat. Thus a loophole for CoE/M..."fresh" matter striking sidewalls or small diameter.

Oh well, the search continues...

(edit - Found the topic of the paper, still way too low of a potential energy..."In addition to increased number of ions, HiPIMS plasma generates ions with energies in the range of 50 eV to 100 eV (compared to only about 2 eV to 10 eV in conventional sputtering). ) - http://www.mantisdeposition.com/mantis/latest-technology/hipims.html
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/16/2016 01:28 pm
Dr. Rodal - I'm still wondering about ratio-ing Ag/CU * copper conductivity to obtain a valid Ag conductivity, but in the mean time, I have a new question for you, and all. meep is converging nicely now to positive Q values but they are still unreal. I just completed a run of the NSF-1701A model and meep calculated Q as 328,441. That's nice but it seems to me that it is about an order of magnitude to large.

Is it possible that you or DeltaMass misplaced a decimal point giving conductivity off by a factor of 10? I doubt that you did because in following the symbolic math you provided, I calculated the same number that you did. But we both started with the number for sigma, CU-sigmaSI 3.25E+8. Perhaps that should have been 10^+7 instead.

Does that seem reasonable?

As explained in http://forum.nasaspaceflight.com/index.php?topic=38577.msg1453093#msg1453093


Quote from: Rodal


3.25E+8 was not the conductivity. 

3.25E+8 is the number in SI units that corresponds to the expression used in Meep: it is not the conductivity, it is instead the imaginary part of the relative complex permittivity

Therefore 3.25E+8 corresponds instead to epsilon"/epsilon_o =  0.00288/epsilon_o

According to the exact solutions and to the COMSOL and FEKO runs, these copper cavities, for these dimensions ( ~0.3 m) can have theoretical Q's of 70,000 to 95,000.

So, a calculated Meep Q of 328,441 is about 3 to 4 times larger than what is supposed to be.

This factor of 3 to 4 may be due to the numerical method used in Meep to calculate Q's.   If interested in studying this, I suggest to study the numerical convergence:




* Output Q's for the same problem, everything else being the same, with the mesh progressively refined such that the distance between nodes is cut by 1/2, (the purpose here being to study the behavior of the calculated Q vs space discretization):

Q for  N number of nodes
Q for 2*N nodes
Q for 4*N nodes
Q for 8*N nodes
etc

==> Plot Q vs number of nodes




* Output Q's for the same problem with the same mesh, everything else being the same, with the deltaT  of the central difference time discretization solution (the purpose here being to study the behavior of the calculated Q vs time discretization)

Q for deltaT = t
Q for deltaT = t/2
Q for deltaT = t/4
Q for deltaT = t/8
etc


==> Plot Q vs deltaT




* Output Q's for the same problem with the same mesh and same deltaT, everything else being the same, vs. the final termination time T (the purpose here being to study the behavior of the calculated Q vs the transient solution, as Q determined from too early a time maybe erroneous)

Q for T
Q for 2*T
Q for 4*T
Q for 8*T
etc


==> Plot Q vs final time T (fractions of a second)



_________________

Don't use the same discretization used in COMSOL Finite Element or FEKO Boundary Element methods:  the finite difference scheme used in Meep (central difference method) requires a larger number of nodes to achieve similar convergence as COMSOL or FEKO or ANSYS.  COMSOL or FEKO or ANSYS have higher rates of convergence because Finite Element methods and Boundary Element Methods are higher order and hence converge faster to a solution than the low order finite difference method used in Meep.  For example, Finite Element Methods use polynomial interpolation functions between nodes and the Finite Element Method is based on a variational principle that ensures higher rate of convergence (for the same number of nodes) than the finite difference method.

The finite difference method implementation in Meep is optimized for solutions of optical frequency nonlinear problems, not for solution of microwave frequency linear problems.

Meep is efficient for optical frequency nonlinear problems.  It may be inefficient (compared to FEKO or COMSOL) when applied to microwave frequency, linear problems that can be handled more optimally with methods like FEM or BEM.

(http://image.slidesharecdn.com/solidworkssimulationnightschool-201407-140721184236-phpapp02/95/solidworks-simulation-night-school-stress-and-flow-analysis-47-638.jpg?cb=1405968514)

(http://www.scielo.br/img/revistas/jbsmse/v34n1/a02fig03.jpg)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/16/2016 03:38 pm
For linear problems with well-behaved solutions, methods like Finite Element (FEM) and Boundary Element (BEM, also called "Method of Moments") are better than Finite Difference (FD) because the FEM uses polynomial interpolation between nodes and the BEM uses Green's functions.  However the BEM entails fully populated matrices and the FEM entails matrices that are much more populated (with off-diagonal coupling terms) than the finite difference method.  For nonlinear problems, finite difference is often more efficient because one must use high discretization anyway because the solution space may not be well-behaved: polynomial interpolation (specially high order polynomials) are not good for such problems. Ditto for Green's functions for nonlinear problems.  Also for nonlinear problems one needs to use a Newton's method (or modified Newton's or Secant or BFGS etc.) that entail frequent computation of inverse of the solution matrix, therefore making the FEM or BEM much more inefficient than the finite difference method for such problems.

Just like it is good to have a collection of tools, because every problem is not best handled by a hammer, so it is with numerical methods.  Meep is meant to be used for optical frequency problems, particularly able for nonlinear optical problems.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Chrochne on 03/16/2016 04:14 pm
This is the Horizon episode on the BBC 23/03/16 featuring EM drive.

http://www.bbc.co.uk/programmes/b0752f85

I must say EmDrive will probably hit news again.

Also the conversation here really started to get very interesting lately! Thanks in part of Monomorphic landing in this thread :-). There is also that paper from University of Helsinky. I think that it was Dr. Rodal that stated that there are many groups we do not know about that dig into the research of the EmDrive. I did not believe that. I am glad I was wrong.
It is also interesting to see the development of the Baby-Emdrive. I just do not fully understand that each report of the positive thrust is hit with the tsunami of pessimism.

Mod: Added the last sentence.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: aero on 03/16/2016 04:22 pm
Well, Dr. Rodal, thank you for that extensive tutorial reply. While waiting, I went ahead and changed the number from 10^8 to 10^7 and as I suspected, it reduced the Q value calculated by meep by one order of magnitude. That is, meep calculated Q = 32,900 with all else being the same as had resulted in Q = 329,436 before. Resonant frequency was the same as before while energy in the fields was reduced. All that is as should be expected.

I do need to do a convergence study because I already know that, for this model, the calculated resonant frequency is higher with higher resolution. But that won't happen with this machine as I've noted previously. Not enough of either memory or cpu to double resolution more than once.

What meep does do and do well as is, is to calculate comparative values of Q for different cavities. This is a nice capability when the cavity differences are seemingly minor, such as antenna changes or minor shape modification to the same frustum. What I mean by that is, meep will calculate that this cavity modification increases or decreases the Q over it's previous value, and the percent change can be calculated even though the absolute magnitude of Q remains to be determined.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/16/2016 04:35 pm
Well, Dr. Rodal, thank you for that extensive tutorial reply. While waiting, I went ahead and changed the number from 10^8 to 10^7 and as I suspected, it reduced the Q value calculated by meep by one order of magnitude. That is, meep calculated Q = 32,900 with all else being the same as had resulted in Q = 329,436 before. Resonant frequency was the same as before while energy in the fields was reduced. All that is as should be expected.

I do need to do a convergence study because I already know that, for this model, the calculated resonant frequency is higher with higher resolution. But that won't happen with this machine as I've noted previously. Not enough of either memory or cpu to double resolution more than once.

Yes, the fact that the Q is proportional to that number was expected.  However, that does not ensure that the Q calculated according to a given scaling is correct.

Another idea to cope with your lack of computer time resources:

1) synchronize with Monomorphic, for Monomorphic to calculate the Q with FEKO for a given problem that is well specified: using a given geometry (thickness, diameters, length) and using pure copper as material input.  Then run yourself with MEEP the same geometry: identical thickness, and other dimensions. Upon determining the Q from Meep, then proportionally scale the copper material input into Meep so that the Q agrees with the FEKO Q.

2) ask Monomorphic to run a completely different EM Drive geometry (different thickness, and dimensions as different as possible, for example run the mini-EM Drive from Tajmar or the Baby EM Drive from Aachen Germany).  Then compare the FEKO Q with the Meep Q based on the scaling factor according to step #1 above. If they agree, you should feel somewhat comfortable about the calculated Q's

3) the comparisons above for steps 1 & 2 should be preferably made with a high order mode, for example TM212  because the Q is more sensitive to higher order modes.  Using a low order mode like TE012 is not a good idea for this comparison because such low order modes are insensitive to the field variation in the cavity (such low order mode Q's  are mostly dependent on the ratio of volume to surface area).
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/16/2016 04:54 pm
using a given geometry (thickness, diameters, length) and using pure copper as material input.

For my runs, I have been using pure copper at 0.1cm wall thickness. When running monopole sims, I'm a little uncertain what diameter to make the antenna. Shell showed me some images and took some measurements, and it looks like 0.5 to 0.7cm. The antenna is pinched at the end in magnetrons.

Both antenna design and placement are critical depending on the modes you want to excite.

I think i'm going to help illustrate this by running frequency sweeps (2 - 3Ghz) on the same frustum dimensions, but with a number of different antenna types and locations. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/16/2016 05:33 pm
using a given geometry (thickness, diameters, length) and using pure copper as material input.

For my runs, I have been using pure copper at 0.1cm wall thickness. When running monopole sims, I'm a little uncertain what diameter to make the antenna. Shell showed me some images and took some measurements, and it looks like 0.5 to 0.7cm.

Both antenna design and placement are critical depending on the modes you want to excite.

I think i'm going to help illustrate this by running frequency sweeps (2 - 3Ghz) on the same frustum dimensions, but with a number of different antenna types and locations.
Good idea...it was originally suggested to me to off-center the RF insert on the large diameter...did that but no cigar. Went to centering it on the large plate. Side insertion was also a topic of discussion...centered or offset? Seems depends on whom you asked.

Nice that you have the modeling, but I will say this, models have described modes, but I remain unconvinced there is a magic mode that needs to be designed for (yet anyway). Otherwise, we'd have blueprints and working EMDrives all over the planet.

Here's something else to think about, Eagleworks' project is dead...for all intents and purposes. Dead in the fact that there is an information blackout that has been in effect for many months. Designing something to try and match a 2-3 year old design whose specifics have not been released is counterproductive IMHO.

I can tell you that there were rumblings that the 2014 tests yielded results WITHOUT a dielectric. I cannot say any more than that as am trying to respect the overall blackout. That being an old 2014 test, seems OK to provide the info. So...long story short...no one has a magic design yet so feel free to experiment with the guidance you have here...you will get some who want you to do this or that...but the key word here is YOU.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Chrochne on 03/16/2016 05:41 pm
If the NASA EW project would be completely dead I guess we would have at least some post from Star-Drive to have some closure I think. ???
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/16/2016 05:45 pm
using a given geometry (thickness, diameters, length) and using pure copper as material input.

For my runs, I have been using pure copper at 0.1cm wall thickness. When running monopole sims, I'm a little uncertain what diameter to make the antenna. Shell showed me some images and took some measurements, and it looks like 0.5 to 0.7cm.

Both antenna design and placement are critical depending on the modes you want to excite.

I think i'm going to help illustrate this by running frequency sweeps (2 - 3Ghz) on the same frustum dimensions, but with a number of different antenna types and locations.
Good idea...it was originally suggested to me to off-center the RF insert on the large diameter...did that but no cigar. Went to centering it on the large plate. Side insertion was also a topic of discussion...centered or offset? Seems depends on whom you asked.

Nice that you have the modeling, but I will say this, models have described modes, but I remain unconvinced there is a magic mode that needs to be designed for (yet anyway). Otherwise, we'd have blueprints and working EMDrives all over the planet.

Here's something else to think about, Eagleworks' project is dead...for all intents and purposes. Dead in the fact that there is an information blackout that has been in effect for many months. Designing something to try and match a 2-3 year old design whose specifics have not been released is counterproductive IMHO.

I can tell you that there were rumblings that the 2014 tests yielded results WITHOUT a dielectric. I cannot say any more than that as am trying to respect the overall blackout. That being an old 2014 test, seems OK to provide the info. So...long story short...no one has a magic design yet so feel free to experiment with the guidance you have here...you will get some who want you to do this or that...but the key word here is YOU.

Keeping sources confidential, I disagree with these characterizations and interpretations:

1) <<Eagleworks' project is dead...for all intents and purposes. Dead in the fact that there is an information blackout that has been in effect for many months. >>
NASA Eagleworks project is not dead, it is ongoing.


The fact that Star-Drive has not been posting at NSF for a while does not make the NASA project "dead" for NSF discussion purposes, nor is posting at NSF the only means of existence of NASA projects. Lots of NASA and non-NASA projects are still "alive" for NSF discussion purposes even when the project individuals are not actively posting at NSF.

The LIGO project was not "dead" for NSF discussion because there was no public information until the article appeared in Science Magazine (http://www.sciencemag.org/news/2016/02/gravitational-waves-einstein-s-ripples-spacetime-spotted-first-time) , for example.  It was active: people working at LIGO were of course aware of the information being accumulated.  No public information was released until the article appeared on Science, as it is the norm.

It is perfectly normal for NASA to observe similar standards concerning reporting of ongoing R&D projects.

People "with a need to know" at NASA receive information on ongoing NASA R&D projects.  The general public is informed when the managing authorities determine that the information is robust enough to be disclosed.

2) << there were rumblings that the 2014 tests yielded results WITHOUT a dielectric. I cannot say any more than that as am trying to respect the overall blackout. That being an old 2014 test, seems OK to provide the info>>

Just stating "without a dielectric" can be a misleading characterization if the testing apparatus is not taken into account: 

* tests without a dielectric yielded "no significant results", both for the Canae and for the Shawyer-type-truncated-cone devices when tested in the same torsional pendulum, even when a power more than 10 times higher was used as input for the tests without a dielectric. That is a reported fact.

* unreported new tests (to be performed after the 2014 report) without a dielectric were NOT to be performed in the same torsional pendulum as used for the 2014 report.  Preliminary tests in a completely different testing apparatus (a teeter-totter balance, as disclosed previously in the EM Drive threads was the proposed testing apparatus) are not directly comparable. (*)

Suggestion: let's either discuss what was reported or otherwise let's discuss details of unreported tests.  Loose discussion of unreported tests without a dielectric without characterizing the testing apparatus or the testing results (with and without a dielectric) can be misleading.

If test results with and without a dielectric are going to be discussed, the testing apparatus, other details, and most importantly, the results should be discussed.

Subjective interpretation of reported results (*) can be confusing enough, so imagine how much more confusing can be when people subjectively interpret unreported results, or suggest <<I cannot say any more than that as am trying to respect the overall blackout.>>

____

(*) Examples of previous confusion in reporting published tests by people that did not understand how to interpret the published NASA report:

a) whether the 2014 reports were performed in vacuum or not: many reported the tests to be performed in a vacuum because they assumed that being performed in a chamber was tantamount to being performed in a vacuum, which was incorrect

b) the confusion regarding the terminology of "Null test" for the Canae device without grooves vs the one with grooves

If such confusion can arise from people misreading and misinterpreting a published, written report, imagine what confusion can arise from people misunderstanding and misinterpreting unpublished results  ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: tchernik on 03/16/2016 06:54 pm
If the NASA EW project would be completely dead I guess we would have at least some post from Star-Drive to have some closure I think. ???

Indeed. If one day they said "the show is over, people", I'm certain most of us would like to know.

The very reason why I keep an eye of this, is because it's believable enough that some serious institutional effort has been mustered to test it.

If they say "it doesn't work", then it's time to move on.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: bprager on 03/16/2016 07:10 pm
These guys have been claiming gravitational effects based on electromagnetic sources for a while now:
http://www.hpcc-space.de/publications/index.html (http://www.hpcc-space.de/publications/index.html)
None of this is tested as far as I know. Could become interesting again though.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/16/2016 07:13 pm
If the NASA EW project would be completely dead I guess we would have at least some post from Star-Drive to have some closure I think. ???

Indeed. If one day they said "the show is over, people", I'm certain most of us would like to know.

The very reason why I keep an eye of this, is because it's believable enough that some serious institutional effort has been mustered to test it.

If they say "it doesn't work", then it's time to move on.
Agreed, however, many of us have moved on from both Eagleworks and SPR. If I put on my old cynical hat, I would say that I've never seen ANYTHING with my own eyes and NOBODY has proof that these things exist outside the lab.

edit - WHICH is why my build continues and glad others are as well.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: MazonDel on 03/16/2016 07:15 pm
Here's a question for people, apologies if it was asked/answered before.

What sort of effect does having a less rounded frustum have on things?

I've been toying around with a design for a re-configurable frustum. Sort of like a three dimensional iris shutter system. While I "should" be able to figure out how to make the blades rounded, unless I get super fancy with adjustable curves on the blades, they will still somewhat only be optimized for a particular shape.

Additionally, is having the RF input on the side of the frustum necessary compared with one of the endplates?

The goal of this particular mental exercise is to attempt to come up with a design of a frustum that can to some extent have most variables about its shape adjustable via computer control (possibly via stepper motors).

Thanks

-Mazon
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/16/2016 07:24 pm
Official English version by the author, of Trunev's paper:

http://ej.kubagro.ru/2016/02/pdf/107.pdf

GENERAL RELATIVITY AND DYNAMICAL MODEL OF ELECTROMAGNETIC DRIVE

Alexander Trunev

Quote
The data shown in Fig. 3 and 7 demonstrate that in the electromagnetic drive thrust increases by several orders of magnitude compared to photon rockets. In the Yang-Mills theory, this increase can be explained by the fact that nonlinear waves carry momentum from the system more effectively than photons.


In the present study we examined the mechanism of excitation waves in the Yang-Mills field, leading to the appearance of traction effect at resonance of electromagnetic waves in a conical cavity.The inclusion of the Yang-Mills field in the model has a double scientific interest. On the one hand, this model allows us to explain the processes in electromagnetic drive. On the other hand, these devices themselves may be used to register the mechanical effects caused by the Yang-Mills field.

Bold added for emphasis
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/16/2016 08:29 pm
Here's a question for people, apologies if it was asked/answered before.

What sort of effect does having a less rounded frustum have on things?

I've been toying around with a design for a re-configurable frustum. Sort of like a three dimensional iris shutter system. While I "should" be able to figure out how to make the blades rounded, unless I get super fancy with adjustable curves on the blades, they will still somewhat only be optimized for a particular shape.

Additionally, is having the RF input on the side of the frustum necessary compared with one of the endplates?

The goal of this particular mental exercise is to attempt to come up with a design of a frustum that can to some extent have most variables about its shape adjustable via computer control (possibly via stepper motors).

Thanks

-Mazon
Think I might have answered this on TT's site, but think slipping plates will cause a resonance problem and low Q.

Here's something to consider. Do what I did on my first design, construct the sidewalls with copper mesh screen, 11 threads per inch, use adjustable compression bands at 3 places along the sidewall. Mesh is quite pliable and it does give good resonance. Side-mount injection is not my choice and would be difficult with this or similar methodology.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: MazonDel on 03/16/2016 09:15 pm
Here's a question for people, apologies if it was asked/answered before.

What sort of effect does having a less rounded frustum have on things?

I've been toying around with a design for a re-configurable frustum. Sort of like a three dimensional iris shutter system. While I "should" be able to figure out how to make the blades rounded, unless I get super fancy with adjustable curves on the blades, they will still somewhat only be optimized for a particular shape.

Additionally, is having the RF input on the side of the frustum necessary compared with one of the endplates?

The goal of this particular mental exercise is to attempt to come up with a design of a frustum that can to some extent have most variables about its shape adjustable via computer control (possibly via stepper motors).

Thanks

-Mazon
Think I might have answered this on TT's site, but think slipping plates will cause a resonance problem and low Q.

Here's something to consider. Do what I did on my first design, construct the sidewalls with copper mesh screen, 11 threads per inch, use adjustable compression bands at 3 places along the sidewall. Mesh is quite pliable and it does give good resonance. Side-mount injection is not my choice and would be difficult with this or similar methodology.

During the writing of my previous post, I did have the idea of adjustable bars (in place of the blades) that could manipulate some sort of metallic cloth around and decided to do some looking before mentioning. At a glance, something like http://www.lessemf.com/fabric4.html#1212 was what I was thinking. Does something like the fabric or mesh make sense from an end-plate perspective?

Definitely having end-plate injection would simplify my setup. On an aside about that, there is probably no real value in having an ability to similarly offset the RF port is there? It wouldn't be that hard to do with an end-plate, for what I have in mind if people thought there would be value in it.

-Mazon
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/16/2016 10:23 pm
Here's a question for people, apologies if it was asked/answered before.

What sort of effect does having a less rounded frustum have on things?

I've been toying around with a design for a re-configurable frustum. Sort of like a three dimensional iris shutter system. While I "should" be able to figure out how to make the blades rounded, unless I get super fancy with adjustable curves on the blades, they will still somewhat only be optimized for a particular shape.

Additionally, is having the RF input on the side of the frustum necessary compared with one of the endplates?

The goal of this particular mental exercise is to attempt to come up with a design of a frustum that can to some extent have most variables about its shape adjustable via computer control (possibly via stepper motors).

Thanks

-Mazon
Think I might have answered this on TT's site, but think slipping plates will cause a resonance problem and low Q.

Here's something to consider. Do what I did on my first design, construct the sidewalls with copper mesh screen, 11 threads per inch, use adjustable compression bands at 3 places along the sidewall. Mesh is quite pliable and it does give good resonance. Side-mount injection is not my choice and would be difficult with this or similar methodology.

During the writing of my previous post, I did have the idea of adjustable bars (in place of the blades) that could manipulate some sort of metallic cloth around and decided to do some looking before mentioning. At a glance, something like http://www.lessemf.com/fabric4.html#1212 was what I was thinking. Does something like the fabric or mesh make sense from an end-plate perspective?

Definitely having end-plate injection would simplify my setup. On an aside about that, there is probably no real value in having an ability to similarly offset the RF port is there? It wouldn't be that hard to do with an end-plate, for what I have in mind if people thought there would be value in it.

-Mazon

This is the only photographic evidence we have of how and where Rf was injected into the SPR Flight Thruster, which is the most modern non cryo design. That Rf coax injection by a coupler (sort of antenna) of some design.

It is the method I have used and plan to use again on my next thruster build.

Good luck with your build.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/16/2016 10:37 pm
This is the only photographic evidence we have of how and where Rf was injected into the SPR Flight Thruster, which is the most modern non cryo design. That Rf coax injection by a coupler (sort of antenna) of some design.

Can anyone tell me what this square thing is protruding near the RF coax inject? Is it some kind of mechanism for changing the shape of the antenna? 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/16/2016 10:46 pm
Here's a question for people, apologies if it was asked/answered before.

What sort of effect does having a less rounded frustum have on things?

I've been toying around with a design for a re-configurable frustum. Sort of like a three dimensional iris shutter system. While I "should" be able to figure out how to make the blades rounded, unless I get super fancy with adjustable curves on the blades, they will still somewhat only be optimized for a particular shape.

Additionally, is having the RF input on the side of the frustum necessary compared with one of the endplates?

The goal of this particular mental exercise is to attempt to come up with a design of a frustum that can to some extent have most variables about its shape adjustable via computer control (possibly via stepper motors).

Thanks

-Mazon
Think I might have answered this on TT's site, but think slipping plates will cause a resonance problem and low Q.

Here's something to consider. Do what I did on my first design, construct the sidewalls with copper mesh screen, 11 threads per inch, use adjustable compression bands at 3 places along the sidewall. Mesh is quite pliable and it does give good resonance. Side-mount injection is not my choice and would be difficult with this or similar methodology.

During the writing of my previous post, I did have the idea of adjustable bars (in place of the blades) that could manipulate some sort of metallic cloth around and decided to do some looking before mentioning. At a glance, something like http://www.lessemf.com/fabric4.html#1212 was what I was thinking. Does something like the fabric or mesh make sense from an end-plate perspective?

Definitely having end-plate injection would simplify my setup. On an aside about that, there is probably no real value in having an ability to similarly offset the RF port is there? It wouldn't be that hard to do with an end-plate, for what I have in mind if people thought there would be value in it.

-Mazon
Recently Monomorphic conducted some very interesting computer runs using FEKO, showing the effect of random distortions of each end as well as of the sidwalls, on the electric field strength contour lines.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1105077;image)

https://forum.nasaspaceflight.com/index.php?topic=39772.msg1503825#msg1503825

Please notice that these comparisons were on the iso-contours of the electric field strength, and not on the Q.

According to all the EM Drive theories:

1) Shawyer's
2) McCulloch
3) Notsosureofit
4) DeAquino

the most important parameter governing force/InputPower is the quality factor of resonance Q, which is also the parameter allowing the force/InputPower to exceed the one of a photon rocket.

Therefore I think you should wait until Monomorphic runs a numerical comparison of the effect of random distortions of each end, and of the sidewalls on the Q, before making a decision on how to proceed.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/16/2016 10:56 pm
Therefore I think you should wait until Monomorphic runs a comparison of the effect of random distortions of each end, and of the sidewalls on the Q, before making a decision on how to proceed.

I'm working on doing just that. I hope to have something by this weekend. The higher number of triangles in these meshes (500+) greatly increases the compute time and I've been pretty busy this week.

I'm also going to work with aero on comparing FEKO and MEEP runs. Hope to have results on that in the next day or so.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/16/2016 11:18 pm
Therefore I think you should wait until Monomorphic runs a comparison of the effect of random distortions of each end, and of the sidewalls on the Q, before making a decision on how to proceed.

I'm working on doing just that. I hope to have something by this weekend. The higher number of triangles in these meshes (500+) greatly increases the compute time and I've been pretty busy this week.

I'm also going to work with aero on comparing FEKO and MEEP runs. Hope to have results on that in the next day or so.

Great !

We also need to have these comparisons at least for both TE and TM modes.

The above comparison for the electric strength appears to be a TE mode showing the transverse electric iso-contours (please correct me if I'm wrong).

Such a TE mode shape has a magnetic field in the longitudinal direction, along the axis of axi-symmetry of the frustum, therefore it stands to reason that the endplates are the most affected by the magnetic field along the axis.


However, in a TM mode (as used for example by NASA in their experiments), the magnetic field will take place in the azimuthal (transverse) direction. 

It would be interesting to see this comparison also for a TM mode shape.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/17/2016 12:01 am
Therefore I think you should wait until Monomorphic runs a comparison of the effect of random distortions of each end, and of the sidewalls on the Q, before making a decision on how to proceed.

I'm working on doing just that. I hope to have something by this weekend. The higher number of triangles in these meshes (500+) greatly increases the compute time and I've been pretty busy this week.

I'm also going to work with aero on comparing FEKO and MEEP runs. Hope to have results on that in the next day or so.
Good! I'm glad to see it. It's needed.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/17/2016 12:30 am
This is the only photographic evidence we have of how and where Rf was injected into the SPR Flight Thruster, which is the most modern non cryo design. That Rf coax injection by a coupler (sort of antenna) of some design.

Can anyone tell me what this square thing is protruding near the RF coax inject? Is it some kind of mechanism for changing the shape of the antenna?
My best guess is that it is a matching stub. Note the screw adjustment on the left of the box. No idea on the interior antenna design.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/17/2016 12:51 am
This is the only photographic evidence we have of how and where Rf was injected into the SPR Flight Thruster, which is the most modern non cryo design. That Rf coax injection by a coupler (sort of antenna) of some design.

Can anyone tell me what this square thing is protruding near the RF coax inject? Is it some kind of mechanism for changing the shape of the antenna?
My best guess is that it is a matching stub. Note the screw adjustment on the left of the box. No idea on the interior antenna design.

It also could be a loop antenna for exciting a TE012 mode and the attachment on the side allows you to rotate the loop for max Q and minimum mode distortion in the cavity.

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/17/2016 12:59 am
emdrive will be on the bbc horizon episode per this article
http://www.radiotimes.com/episode/d2zck4/horizon--project-greenglow-the-quest-for-gravity-control
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: oyzw on 03/17/2016 02:32 am
emdrive will be on the bbc horizon episode per this article
http://www.radiotimes.com/episode/d2zck4/horizon--project-greenglow-the-quest-for-gravity-control
   Who is he?The device looks very cool!!!I completed the microwave amplifier using NXP chip, I was measuring platform
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Star-Drive on 03/17/2016 03:36 am

Here's something else to think about, Eagleworks' project is dead...for all intents and purposes. Dead in the fact that there is an information blackout that has been in effect for many months. Designing something to try and match a 2-3 year old design whose specifics have not been released is counterproductive IMHO.

I can tell you that there were rumblings that the 2014 tests yielded results WITHOUT a dielectric. I cannot say any more than that as am trying to respect the overall blackout. That being an old 2014 test, seems OK to provide the info. So...long story short...no one has a magic design yet so feel free to experiment with the guidance you have here...you will get some who want you to do this or that...but the key word here is YOU.

Dave:

The Eagleworks Lab is NOT dead and we continue down the path set by our NASA management.  Past that I can't say more other than to listen to Dr. Rodal on this topic, and please have patience about when our next EW paper is going to be published.  Peer reviews are glacially slow...

Best, Paul March
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: spupeng7 on 03/17/2016 06:13 am
If a Methanol laser can lase at a wavelength of 0.5mm, are there any lasers with an even longer wavelength?

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Willem Staal on 03/17/2016 06:34 am
Here's a question for people, apologies if it was asked/answered before.

What sort of effect does having a less rounded frustum have on things?

I've been toying around with a design for a re-configurable frustum. Sort of like a three dimensional iris shutter system. While I "should" be able to figure out how to make the blades rounded, unless I get super fancy with adjustable curves on the blades, they will still somewhat only be optimized for a particular shape.

Additionally, is having the RF input on the side of the frustum necessary compared with one of the endplates?

The goal of this particular mental exercise is to attempt to come up with a design of a frustum that can to some extent have most variables about its shape adjustable via computer control (possibly via stepper motors).

Thanks

-Mazon
"Sort of like a three dimensional iris shutter system".. Like the way the nozzle of a jet engine works? I dunno, could be possible, but the thing is; the frustrum is closed! Unless its possible to make a flexible system to cap off the whide end..
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Willem Staal on 03/17/2016 07:14 am
If a Methanol laser can lase at a wavelength of 0.5mm, are there any lasers with an even longer wavelength?
I think not under the name laser anymore, but in fact it will called a  a Maser ('Microwave Amplification by Stimulated Emission of Radiation')
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/17/2016 07:36 am
emdrive will be on the bbc horizon episode per this article
http://www.radiotimes.com/episode/d2zck4/horizon--project-greenglow-the-quest-for-gravity-control

Roger shared Horizon spent a very long day filming EmDrive thrusters that were at least 5 years old as that was the earliest he could show them. Said they filmed an early cryo EmDrive moving on an air track. Hope it gets into the episode as it seems both the USAF and UK MOD had rights to edit.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/17/2016 07:43 am
This is the only photographic evidence we have of how and where Rf was injected into the SPR Flight Thruster, which is the most modern non cryo design. That Rf coax injection by a coupler (sort of antenna) of some design.

Can anyone tell me what this square thing is protruding near the RF coax inject? Is it some kind of mechanism for changing the shape of the antenna?
My best guess is that it is a matching stub. Note the screw adjustment on the left of the box. No idea on the interior antenna design.

It also could be a loop antenna for exciting a TE012 mode and the attachment on the side allows you to rotate the loop for max Q and minimum mode distortion in the cavity.

Believe it is an adjuster that can rotate & slide in & out of the cavity when needed to adjust the internal couplers position to get best VSWR. Note the arm on the left end of the rod to allow rotation.

Roger did share that every successful EmDrive build he knows of had some ability to externally adjust the internal coupler to best results.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Flyby on 03/17/2016 08:20 am
Therefore I think you should wait until Monomorphic runs a comparison of the effect of random distortions of each end, and of the sidewalls on the Q, before making a decision on how to proceed.

I'm working on doing just that. I hope to have something by this weekend. The higher number of triangles in these meshes (500+) greatly increases the compute time and I've been pretty busy this week.

I'm also going to work with aero on comparing FEKO and MEEP runs. Hope to have results on that in the next day or so.

Monomorphic,
so far I've only seen frequency shifts done with FEKO.
 Is there a possibility to also do time related animations?

It would be nice to either confirm or discredit the idea of internal moving resonance patterns, something that popped up when aero did his MEEP calculations (when he added antenna feed).

It is my personal opinion these internal created "moving patterns" are somehow related to the possible force creation.
So...It would be nice to have some additional  info on that...either to continue working on it, or just to put in the bin.. either way is fine.. ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/17/2016 09:15 am

Here's something else to think about, Eagleworks' project is dead...for all intents and purposes. Dead in the fact that there is an information blackout that has been in effect for many months. Designing something to try and match a 2-3 year old design whose specifics have not been released is counterproductive IMHO.

I can tell you that there were rumblings that the 2014 tests yielded results WITHOUT a dielectric. I cannot say any more than that as am trying to respect the overall blackout. That being an old 2014 test, seems OK to provide the info. So...long story short...no one has a magic design yet so feel free to experiment with the guidance you have here...you will get some who want you to do this or that...but the key word here is YOU.

Dave:

The Eagleworks Lab is NOT dead and we continue down the path set by our NASA management.  Past that I can't say more other than to listen to Dr. Rodal on this topic, and please have patience about when our next EW paper is going to be published.  Peer reviews are glacially slow...

Best, Paul March

Hi Paul,

Good to learn you guys are still alive and giving it your best.

As Shell, Dave & myself are building much higher quality 2nd gen frustums and there has been some discussion of side wall thickness, could you share a bit of info on the Alum frustum as attached?

What are the side wall and end plate thickness?

Was the frustum cast with the flanges, machined and polished or was it rolled, sidewall edge seam welded, flanges welded on, machined and then polished?

Are the interior dimensions shareable?

Any other breadcrumbs to share?

Phil
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/17/2016 11:21 am

Here's something else to think about, Eagleworks' project is dead...for all intents and purposes. Dead in the fact that there is an information blackout that has been in effect for many months. Designing something to try and match a 2-3 year old design whose specifics have not been released is counterproductive IMHO.

I can tell you that there were rumblings that the 2014 tests yielded results WITHOUT a dielectric. I cannot say any more than that as am trying to respect the overall blackout. That being an old 2014 test, seems OK to provide the info. So...long story short...no one has a magic design yet so feel free to experiment with the guidance you have here...you will get some who want you to do this or that...but the key word here is YOU.

Dave:

The Eagleworks Lab is NOT dead and we continue down the path set by our NASA management.  Past that I can't say more other than to listen to Dr. Rodal on this topic, and please have patience about when our next EW paper is going to be published.  Peer reviews are glacially slow...

Best, Paul March
Thank you Paul. I've not pressed you privately out of personal respect and was hoping my post would elicit something concrete for our NSF audience.  Thanks for taking the time to update us...that was my "ruthless" objective.  ;)

Onwards and outwards - Dave
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/17/2016 11:23 am

Here's something else to think about, Eagleworks' project is dead...for all intents and purposes. Dead in the fact that there is an information blackout that has been in effect for many months. Designing something to try and match a 2-3 year old design whose specifics have not been released is counterproductive IMHO.

I can tell you that there were rumblings that the 2014 tests yielded results WITHOUT a dielectric. I cannot say any more than that as am trying to respect the overall blackout. That being an old 2014 test, seems OK to provide the info. So...long story short...no one has a magic design yet so feel free to experiment with the guidance you have here...you will get some who want you to do this or that...but the key word here is YOU.

Dave:

The Eagleworks Lab is NOT dead and we continue down the path set by our NASA management.  Past that I can't say more other than to listen to Dr. Rodal on this topic, and please have patience about when our next EW paper is going to be published.  Peer reviews are glacially slow...

Best, Paul March

Hi Paul,

Good to learn you guys are still alive and giving it your best.

As Shell, Dave & myself are building much higher quality 2nd gen frustums and there has been some discussion of side wall thickness, could you share a bit of info on the Alum frustum as attached?

What are the side wall and end plate thickness?

Was the frustum cast with the flanges, machined and polished or was it rolled, sidewall edge seam welded, flanges welded on, machined and then polished?

Are the interior dimensions shareable?

Any other breadcrumbs to share?

Phil

NSF readers are encouraged to look at previous EM Drive threads (and to use Google's advanced search function) to find previous answers to several of the questions asked in the above post, for example, for the truncated cone (*) reported results :

dimensions, including thickness of NASA's EM Drive:

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36313.0;attach=862498;image)

construction of NASA's EM Drive:

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36313.0;attach=856572;image)

__________

(*) ADDED a posteriori: NASA's frustum that resulted in the highest measured anomalous force
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/17/2016 11:36 am
NSF readers are encouraged to look at previous EM Drive threads (and to use Google's advanced search function) to find previous answers to some of the questions asked in the above post, for example :

dimensions, including thickness of NASA's EM Drive:

The questions I asked were about the Aluminium Frustum EW built and have NOT been answered. What you provided was info on the copper frustum that Paul built. Please reread my questions to Paul.

BTW I have a complete Google Drive archive of all of Paul, Dave, Shell, your and my posts and attachments, so it is easy to search.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/17/2016 11:43 am
NSF readers are encouraged to look at previous EM Drive threads (and to use Google's advanced search function) to find previous answers to some of the questions asked in the above post, for example :

dimensions, including thickness of NASA's EM Drive:

The questions I asked were about the Aluminium Frustum EW built and have NOT been answered. What you provided was info on the copper frustum that Paul built. Please reread my questions to Paul.

BTW I have a complete Google Drive archive of all of Paul, Dave, Shell, mine and your posts and attachments so it is easy to search.

Yes, I provided the answers for the truncated cone used for the results published by NASA, which I believe is the relevant construction to many readers at NSF, because of the anomalous force results they obtained with the copper frustum.

I believe that the most important thing is what constructions resulted in the highest anomalous force.

Regarding NASA's thicker, plated, aluminum frustum, (https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1105319;image)

 please see the message that Star-Drive posted regarding the anomalous force results they obtained with that Aluminum frustum (including the fact that this thicker aluminum frustum used a dielectric with a much higher permittivity

εr = 43  (similar to the high permittivity dielectric used by Shawyer in his patents using a dielectric which resulted, as admitted by Shawyer, in lower Q, and hence Shawyer abandoned the use of such high permittivity dielectrics)

than the HDPE dielectric NASA used for their reported results:

εr = 2.26 (much lower electric permittivity for NASA's reported results.  Shawyer has never reported any results for dielectric with low electric permittivity and properties as polymers like HDPE and PTFE)

It is also interesting to compare the values of ε" and other material properties.

).

I believe it is very important to compare the anomalous force resuts of these different frustums to make a valid comparison.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/17/2016 11:57 am
emdrive will be on the bbc horizon episode per this article
http://www.radiotimes.com/episode/d2zck4/horizon--project-greenglow-the-quest-for-gravity-control
   Who is he?The device looks very cool!!!I completed the microwave amplifier using NXP chip, I was measuring platform

Hi Oyzw,

Looks interesting:
http://www.nxp.com/products/rf/rf-power-transistors/rf-cooking/2450-mhz-250-w-cw-32-v-rf-ldmos-transistor-for-consumer-and-commercial-cooking:MHT1003N?

Might just consider building my own 250W 2.45GHz Rf amp using that chip.

What price will you sell your Rf amp build?

Phil
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/17/2016 12:00 pm
so far I've only seen frequency shifts done with FEKO.
 Is there a possibility to also do time related animations?

FEKO supports time domain analysis and I've performed a few of them. Here is one:

https://www.youtube.com/watch?v=JM1UQpB_en4
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/17/2016 12:04 pm
I believe it is very important to compare the anomalous force resuts of these different frustums to make a valid comparison.

As I have measured ~8mN with my 1st non dielectric build, dielectrics are of no interest to me. I believe they are a waste of time. I know of NO build that has shown above multiple SnowFlake level of force generation using dielectrics other than Roger's Experimental EmDrive, after which he abandoned using dielectrics.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/17/2016 12:11 pm
I believe it is very important to compare the anomalous force resuts of these different frustums to make a valid comparison.

As I have measured ~8mN with my 1st non dielectric build, dielectrics are of no interest to me. I believe they are a waste of time. I know of NO build that has shown above multiple SnowFlake level of force generation using dielectrics other than Roger's Experimental EmDrive, after which he abandoned using dielectrics.

But NASA's Aluminum frustum with a high electric permittivity dielectric (similar dielectric as used by Shawyer in his patents) resulted in much lower anomalous force than NASA's copper frustum with HDPE or PTFE dielectric.

So, if you are not interested in low anomalous force  (you name-call them "SnowFlake level of force") frustum's why are you interested in the dimensions of  the aluminum frustum that NASA found to have a much lower anomalous force?  ???

That's why I gave the dimensions for the NASA frustum that gave the higher anomalous force...
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/17/2016 12:25 pm
I completed the microwave amplifier using NXP chip, I was measuring platform

Please show us the amplifier. I have a NXP transistor i'm working on building an amp around. Would love some advice as i'm just getting started.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/17/2016 12:53 pm
I completed the microwave amplifier using NXP chip, I was measuring platform

Please show us the amplifier. I have a NXP transistor i'm working on building an amp around. Would love some advice as i'm just getting started.

Chip only has ~15.5dB gain. Needs ~38.5dBm (~7W) of drive to get ~54dBm (~250W) of output.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/17/2016 01:05 pm
...why are you interested in the dimensions of  the aluminum frustum that NASA found to have a much lower anomalous force?  ???

As I asked in the post to Paul, I'm interested to how they constructed it and what were the sidewall and end plate thickness.

As for the force generation, if I had it I would throw out the dielectric, put in a good 1/2 (180 deg) loop coupler, find the TE013 resonance and get it to generate decent force. I do have a concern it is not highly polished and so may not generate a much force as if it were highly polished.

Maybe Paul can share the force EW measured when they ran the Alum frustum on the Teeter Totter balance beam and excited it with a 1.2kW maggie and without a dielectric. Paul has shared with us this test rig was built but as of yet no measurement data other than some force was measured.

With respect, I really think you are flogging a dead horse, running down a dead end alley, chasing the dielectric.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/17/2016 01:28 pm
...With respect, I really think you are flogging a dead horse, running down a dead end alley, chasing the dielectric.
With respect, I think that either you have not had access to the information on the results with dielectrics, or you are not properly taking into account their role because you bunch up all dielectrics as having the same properties, which is incorrect, because there is a huge difference between the ceramic dielectrics used by Shawyer in his patents (having electric permittivity 38 or higher) and the dielectric polymers used by NASA to obtain higher anomalous forces (having much lower electric permittivities of 2, and very different complex permittivity and piezoelectric properties) (*).

To bunch up all dielectric materials together and jumping to the conclusion that dielectrics

Quote from: TheTraveller
I believe they are a waste of time...
[snip]
 a dead horse, running down a dead end alley, chasing the dielectric.
 

is incorrect.  Dielectric materials have a huge range of properties.  To bunch all dielectric materials together and reject them out of hand based on a few results by Shawyer based on a restricted set of dielectrics Shawyer tested (*) would be like:

somebody in the late 1940's saying that semiconductors cannot possibly compete with vacuum tubes because they tested a few semiconductors and had bad results,

or somebody saying, more than a century ago, that it doesn't make sense for Edison to test filaments for electric lighting, because they tested a few filaments and they could not get an electric light bulb to work  ;)

It is technically incorrect to compare results for dielectric inserts having completely different properties, and to refer to them simply as "they all are just dielectrics so they are a waste of time"
________________

(*) The aluminum frustum tested by NASA (that you are interested in) is most interesting because it used a similar dielectric as used by Shawyer in his patents, and NASA measured a much smaller anomalous force with it than with the copper frustum  using HDPE or PTFE polymer dielectrics
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/17/2016 01:52 pm
It is technically incorrect to compare results for dielectric inserts having completely different properties, and to refer to them simply as "they all are just dielectrics so they are a waste of time"

They are a waste of time because:

1) Roger abandoned using them after he built the Experimental EmDrive.

2) EW's best force results, using dielectrics, are approx equivalent to 3 SnowFlakes (30uN each).

Other than Roger's Experimental EmDrive results of 16mN at 850W and EW's 3 SnowFlakes, no one that I know has reported any Force generation using dielectrics in an EmDrive.

However we have a range of much more than a few SnowFlakes of experimental force results reported by NOT using dielectrics.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/17/2016 01:54 pm
...Maybe Paul can share the force EW measured when they ran the Alum frustum on the Teeter Totter balance beam and excited it with a 1.2kW maggie and without a dielectric. ...
Again, such a comparison would be interesting if and when NASA can share the results under identical testing conditions (compared as a function of Input Power, under same identical conditions: same testing apparatus, same atmospheric pressure, etc.) for both:

1) with a dielectric insert vs.

2) without a dielectric insert.

Discussion of force results without taking into account the testing conditions, testing apparatus, is misleading.

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/17/2016 01:56 pm
It is technically incorrect to compare results for dielectric inserts having completely different properties, and to refer to them simply as "they all are just dielectrics so they are a waste of time"

They are a waste of time because:

1) Roger abandoned using them after he built the Experimental EmDrive.

2) EW's best force results, using dielectrics, are approx equivalent to 3 SnowFlakes (30uN each).

Other than Roger's Experimental EmDrive results of 16mN at 850W and EW's 3 SnowFlakes, no one that I know has reported any Force generation using dielectrics in an EmDrive.

However we have a range of much more than a few SnowFlakes of experimental force results reported by NOT using dielectrics.
Since you continue to bunch up all dielectric inserts together without properly taking into account their different dielectric and other material properties, I will not continue answering any further posts from you on this matter until you properly take into account the technical material properties instead of bunching different material results saying "they are all dielectrics".

Also it is technically improper to bunch up, and compare the anomalous force measured by NASA and claimed by Shawyer, using different testing techniques, different apparatus, different mode shapes, different Q, different coupling, and different testing conditions, and very different standards of reporting (Shawyer has never even reported the full range of dimensions, for example, used in his claimed results, and never, ever reported a single test in partial vacuum).  For example, it is very improper to compare the force of 16mN that Shawyer claims with a different testing apparatus and conditions, using 850 Watts of input, with the forces reported by NASA, who reported the highest force/InputPower in their 2014 with just 2.6  Watts, in other words, 327 times more input power used by Shawyer ( http://emdrive.wiki/Experimental_Results ).

I can see, and I hope I have clarified in my previous posts, the source of confusion that arises in this discussion about dielectrics.  This confusion is due to bunching up all dielectric materials together without properly taking into account their material properties and carefully considering the testing conditions.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/17/2016 02:37 pm
Since you continue to bunch up all dielectric inserts together without properly taking into account their different dielectric and other material properties, I will not continue answering any further posts from you on this matter until you properly take into account the technical material properties instead of bunching different material results saying "they are all dielectrics".

I have not asked you any questions about dielectrics as I have NO INTEREST in them. Dielectrics = very little, if any, force generation. End of story unless you have experimental data to show otherwise.

My question, which you jumped on and hijacked into talking about dielectrics, was to Paul and it was about how EW constructed their Aluminium frustum.

Please refrain from hijacking a question I directed to Paul.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/17/2016 03:19 pm
Since you continue to bunch up all dielectric inserts together without properly taking into account their different dielectric and other material properties, I will not continue answering any further posts from you on this matter until you properly take into account the technical material properties instead of bunching different material results saying "they are all dielectrics".

I have not asked you any questions about dielectrics as I have NO INTEREST in them. Dielectrics = very little, if any, force generation. End of story unless you have experimental data to show otherwise.

My question, which you jumped on and hijacked into talking about dielectrics, was to Paul and it was about how EW constructed their Aluminium frustum.

Please refrain from hijacking a question I directed to Paul.
I would agree that dielectrics are the least know commodity amongst active DIY participants. To my knowledge, only Eagleworks mentioned them a couple of years ago. Cannae might have, but their design is not a classic EMDrive.

There is no formal release of dielectric material, properties or dimensions that allowed me to use it in my design. In the use of dielectrics in the past, Q was lower and real estate was saved because of the dielectric constant being well above air. I am unaware of anything a dielectric could do to help create an emdrive effect...there is no accepted theory last time I checked.

If someone has advanced dielectric/theory facts, no reason to keep it withheld from DIY folks...I'll cut some Teflon of whatever...
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/17/2016 03:27 pm
Since you continue to bunch up all dielectric inserts together without properly taking into account their different dielectric and other material properties, I will not continue answering any further posts from you on this matter until you properly take into account the technical material properties instead of bunching different material results saying "they are all dielectrics".

I have not asked you any questions about dielectrics as I have NO INTEREST in them. Dielectrics = very little, if any, force generation. End of story unless you have experimental data to show otherwise.

My question, which you jumped on and hijacked into talking about dielectrics, was to Paul and it was about how EW constructed their Aluminium frustum.

Please refrain from hijacking a question I directed to Paul.
I would agree that dielectrics are the least know commodity amongst active DIY participants. To my knowledge, only Eagleworks mentioned them a couple of years ago. Cannae might have, but their design is not a classic EMDrive.

There is no formal release of dielectric material, properties or dimensions that allowed me to use it in my design. In the use of dielectrics in the past, Q was lower and real estate was saved because of the dielectric constant being well above air. I am unaware of anything a dielectric could do to help create an emdrive effect...there is no accepted theory last time I checked.

If someone has advanced dielectric/theory facts, no reason to keep it withheld from DIY folks...I'll cut some Teflon of whatever...

I don't understand your post.  I have a  number of posts previous to your posts quoting specific dielectric properties, and the mistake of bunching all dielectric materials together for this purpose as just "dielectrics".
Also, in previous threads, Star-Drive had a number of posts discussing the topic of dielectrics in detail (much more detail than we ever got from Shawyer, for example) , including the aforementioned aluminum frustum with a high electric permittivity material that resulted in low anomalous force.  Star-Drive has given dimensions, material properties, location, and theoretical justification for the dielectric used by NASA.  He even discussed a number of dielectric material results, including neoprene and ceramics.

Also NSF contributor Notsosureofit has discussed formulas including the effect of asymmetric dielectric inserts and his theoretical explanation for a force produced by asymmetric insertion of a dielectric.

NSF contributor Mulletron has a large number of posts with a huge number of references on why a dielectric crystal polymer could be the key to self-acceleration ( CP-symmetry violation ).

Prof. Woodward is of the opinion that NASA's results with a dielectric may be explainable by Woodward's Mach effect.

I would agree that dielectrics are the least know commodity amongst active DIY participants.

NSF contributor Zellerium (California Polytechnic State Univ., San Luis Obispo, Zeller, Kraft, Echols) has discussed his University project including the use of a dielectric insert in a constant cross-section cavity.

Why are you not taking into account Zellerium's contribution (is Zellerium not a DIY in your opinion?) and the numerous posts of Star-Drive giving your requested dimensions and properties?

Sorry, but I think that your statement:

Quote
There is no formal release of dielectric material, properties or dimensions

is unjustified and incorrect.  If you look at the pictures I just reposted, Star-Drive included the dielectric material, properties and dimensions.

Here is the information on dimensions and locations, (posted again, as it was posted in the previous page  ??? )
(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36313.0;attach=862498;image)

Star-Drive went even as far as providing the specific source where you can buy the dielectric he used (extruded High Density Polyethylene from McMaster Carr).  I don't understand how can you state that he did not provide enough information.

I would say the contrary: nobody has been more forthcoming with information than Star-Drive !

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1105319;image)

Here is an image from Zellerium's DIY including a dielectric insert:

(http://image.slidesharecdn.com/b1156da7-f4aa-4456-a0f9-2423464971b9-151009171919-lva1-app6892/95/investigation-of-anomalous-thrust-from-a-partially-loaded-resonant-cavity10515zellerkraft-3-638.jpg?cb=1444411208)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/17/2016 04:03 pm
For those who want to have their cake and eat it too.

I'm going to provide a link to a company that will produce the basic frustum parts even a curved endplate.

https://www.fabricorproducts.com/online-store/conical-spun-shapes-tapers.html

Shell

https://www.fabricorproducts.com/images/stories/products/conical-category.jpg
https://www.fabricorproducts.com/images/stories/products/bobeche-category.jpg
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/17/2016 05:08 pm
It is technically incorrect to compare results for dielectric inserts having completely different properties, and to refer to them simply as "they all are just dielectrics so they are a waste of time"

They are a waste of time because:

1) Roger abandoned using them after he built the Experimental EmDrive.

2) EW's best force results, using dielectrics, are approx equivalent to 3 SnowFlakes (30uN each).

Other than Roger's Experimental EmDrive results of 16mN at 850W and EW's 3 SnowFlakes, no one that I know has reported any Force generation using dielectrics in an EmDrive.

However we have a range of much more than a few SnowFlakes of experimental force results reported by NOT using dielectrics.

It's interesting to note that a dielectric resonant oscillator (DRO) uses a dielectric "puck" to exchange energy, at resonance, with a tuned cavity. In this case, the puck increases the Q of the system, sometimes by orders of magnitude. Emdrive experimenters, however, seem to be focused on using the dielectric to "absorb" or detune the resonance, thereby decreasing the Q
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/17/2016 05:13 pm
Here's a question for people, apologies if it was asked/answered before.

What sort of effect does having a less rounded frustum have on things?

I've been toying around with a design for a re-configurable frustum. Sort of like a three dimensional iris shutter system. While I "should" be able to figure out how to make the blades rounded, unless I get super fancy with adjustable curves on the blades, they will still somewhat only be optimized for a particular shape.

Additionally, is having the RF input on the side of the frustum necessary compared with one of the endplates?

The goal of this particular mental exercise is to attempt to come up with a design of a frustum that can to some extent have most variables about its shape adjustable via computer control (possibly via stepper motors).

Thanks

-Mazon
Think I might have answered this on TT's site, but think slipping plates will cause a resonance problem and low Q.

Here's something to consider. Do what I did on my first design, construct the sidewalls with copper mesh screen, 11 threads per inch, use adjustable compression bands at 3 places along the sidewall. Mesh is quite pliable and it does give good resonance. Side-mount injection is not my choice and would be difficult with this or similar methodology.

During the writing of my previous post, I did have the idea of adjustable bars (in place of the blades) that could manipulate some sort of metallic cloth around and decided to do some looking before mentioning. At a glance, something like http://www.lessemf.com/fabric4.html#1212 was what I was thinking. Does something like the fabric or mesh make sense from an end-plate perspective?

Definitely having end-plate injection would simplify my setup. On an aside about that, there is probably no real value in having an ability to similarly offset the RF port is there? It wouldn't be that hard to do with an end-plate, for what I have in mind if people thought there would be value in it.

-Mazon

This is the only photographic evidence we have of how and where Rf was injected into the SPR Flight Thruster, which is the most modern non cryo design. That Rf coax injection by a coupler (sort of antenna) of some design.

It is the method I have used and plan to use again on my next thruster build.

Good luck with your build.

A nice Agilent synthesizer, and not a magnetron in sight! Guess even Roger finally realized what I've been saying all along. Tune the source to the cavity, not the cavity to the source. I wonder if he modulates the synthesizer to make it act like a magnetron?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/17/2016 05:18 pm
MHT1003NR3 arrived. It is a little smaller than I expected. This little 3-pin RF LDMOSFET transistor can output 250 watts @ 2.45Ghz with 32v DC!

Just to get you started, NXP has a dxf file for the printed circuit board on their site. I'm sure it involves Rogers Duroid or some other special substrate, and I'm also sure you're looking at a massive heatsink and/or water cooling.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/17/2016 05:52 pm
Since you continue to bunch up all dielectric inserts together without properly taking into account their different dielectric and other material properties, I will not continue answering any further posts from you on this matter until you properly take into account the technical material properties instead of bunching different material results saying "they are all dielectrics".

I have not asked you any questions about dielectrics as I have NO INTEREST in them. Dielectrics = very little, if any, force generation. End of story unless you have experimental data to show otherwise.

My question, which you jumped on and hijacked into talking about dielectrics, was to Paul and it was about how EW constructed their Aluminium frustum.

Please refrain from hijacking a question I directed to Paul.
I would agree that dielectrics are the least know commodity amongst active DIY participants. To my knowledge, only Eagleworks mentioned them a couple of years ago. Cannae might have, but their design is not a classic EMDrive.

There is no formal release of dielectric material, properties or dimensions that allowed me to use it in my design. In the use of dielectrics in the past, Q was lower and real estate was saved because of the dielectric constant being well above air. I am unaware of anything a dielectric could do to help create an emdrive effect...there is no accepted theory last time I checked.

If someone has advanced dielectric/theory facts, no reason to keep it withheld from DIY folks...I'll cut some Teflon of whatever...
(multi-snip)

Sorry, but I think that your statement:

Quote
There is no formal release of dielectric material, properties or dimensions

is unjustified and incorrect.  If you look at the pictures I just reposted, Star-Drive included the dielectric material, properties and dimensions.

Here is an image from Zellerium's DIY including a dielectric insert:

As the start of my build, I found no convenient list/summary of dielectric options nor any theories as to how a dielectric creates the emdrive effect. A dielectric is commonly used to scale down real estate. If you have a specific theory, please share, otherwise it seems as though you are "throwing stones" at those not using a dielectric.

Kurt and I communicate...his dielectric experiment yielded no results. He may or may not have dielectric in his next design. Mulletron as well. The majority of builders do not, nor has their been any convincing evidence that a dielectric is required.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/17/2016 06:16 pm
Just to get you started, NXP has a dxf file for the printed circuit board on their site. I'm sure it involves Rogers Duroid or some other special substrate, and I'm also sure you're looking at a massive heatsink and/or water cooling.

Thanks! I can't believe I missed the DXF.

I think I will need to dump about 80 watts of heat, so I will try the heatsink first.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Oakey on 03/17/2016 06:19 pm
Hi guys. Has anyone considered heat annealing of frostrum? I hear a lot of conjecture around the action on the copper frostrum with examples of what could cause anomalous thrust if it exists. Some have mentioned SPR. Would this increase the resonance within the copper medium?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/17/2016 06:28 pm
...
As the start of my build, I found no convenient list/summary of dielectric options nor any theories as to how a dielectric creates the emdrive effect. A dielectric is commonly used to scale down real estate. If you have a specific theory, please share, otherwise it seems as though you are "throwing stones" at those not using a dielectric.

...

Rfmwguy I don't understand your latest comments.

Yesterday you state that <<Eagleworks' project is dead...for all intents and purposes. Dead in the fact that there is an information blackout that has been in effect for many months.>>

When it is confirmed that NASA Eagleworks project is not dead you answer <<was hoping my post would elicit something concrete for our NSF audience. >>

I didn't throw stones at DIY not using dielectrics.  Rather, you prompted  the discussion about dielectrics by writing about "rumblings" <<I can tell you that there were rumblings that the 2014 tests yielded results WITHOUT a dielectric. I cannot say any more than that as am trying to respect the overall blackout. >> which  I showed to be an incorrect interpretation.

I am not throwing stones at DIY, I am challenging your assertion that << the 2014 tests yielded results WITHOUT a dielectric>> which is demonstrably wrong, when referring to "significant results" even at power inputs more than 10 times higher than with dielectric.  Something got mixed up in what you wrote...

Today you state that

<<There is no formal release of dielectric material, properties or dimensions>>

when I spend my time repeating the NASA data that shows your statement is completely incorrect, as Star-Drive has indeed provided dielectric material, properties and dimensions (even the source where you can buy them: McMaster-Carr), instead of admitting that you were either wrong, forgetful, or unaware, you charge that <<it seems as though you are "throwing stones" at those not using a dielectric>> ???

What do you mean by requiring that I share a specific theory?   I already pointed out the contributions from NSF user Notsosureofit, Prof. Woodward, and the multiple posts by Star-Drive.

What constitutes a specific theory according to you and what does not constitute a specific theory?

Perhaps you can show this by example.  What specific theory are you basing your efforts on that is more specific or more theoretical than the above-mentioned theories? 

TheTraveller is basing his DIY on Shawyer's theory.  Do you consider Shawyer's a specific theory or some other theory a "specific theory" and you don't consider the above mentioned contributions specific theories?

And why do you need a specific theory? You have the material specifications (extruded HDPE rod from McMaster Carr) and the dimensions, as well as a drawing where the dielectric is inserted.  What else do you require?   ???
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/17/2016 06:52 pm
Just to get you started, NXP has a dxf file for the printed circuit board on their site. I'm sure it involves Rogers Duroid or some other special substrate, and I'm also sure you're looking at a massive heatsink and/or water cooling.

Thanks! I can't believe I missed the DXF.

I think I will need to dump about 80 watts of heat, so I will try the heatsink first.

Just as I suspected, the board is fabricated from Rogers Corp 6035HTC ceramic filled polytetrafluoroethylene, with an unusually thick (1 ounce) copper layer. Rogers tends to be quite liberal with samples, but board houses generally don't like dealing with small, one off, fabrication with weird materials.

You've got nothing to lose by contacting Freescale/NXP and asking for a board. You can be sure there are dozens of them sitting in some engineer's desk drawer.

The power added efficiency of your device is 58%, so you'll be shedding the other 42% as heat. Quite a bit more than 80 watts. You'll also need a hefty driver of about 7 watts, and an oscillator or synthesizer to drive your driver. Be safe. At this power level, you can expect cataracts pretty quickly just from radiation from the board. It needs to be in a well shielded enclosure.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/17/2016 07:11 pm
A nice Agilent synthesizer, and not a magnetron in sight! Guess even Roger finally realized what I've been saying all along. Tune the source to the cavity, not the cavity to the source. I wonder if he modulates the synthesizer to make it act like a magnetron?

The Flight Thruster was designed (2008 to 2009) to be driven by dual space rated variable freq gens that calculates and tracks the best resonance freq and a dual TWTA for the 350W of Rf power.

The meter is attached to the sample port on the upper right, via the small Blue cable, and monitors what is going inside the frustum. It appears to be indicating a 3khz modulation of the 5.85GHz signal. The 350W of Rf is from the black unit to the left, via the thick Red cable, which I assume is the TWTA, circulator and Rf load.

My understanding is the prototype Flight Thruster was actually working and showing a weight reduction on the scale. Note the spring above the Flight Thruster and then read Roger's notes on Force Measurement.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/17/2016 07:11 pm
Couldn't I fabricate a board with some duroid based on the DXF? 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/17/2016 07:22 pm
Couldn't I fabricate a board with some duroid based on the DXF?

You really do want to operate that board INSIDE a metal box. There will be Rf everywhere and maybe enough to cook an eyeball or 2. Or other balls........

BTW nice build.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/17/2016 08:32 pm
Couldn't I fabricate a board with some duroid based on the DXF?

By all means. Just note that like most microwave boards, it's almost certainly double sided, with the rear surface acting as a ground plane. The holes (8 for mounting screws, many small ones for RF ground) are plated through. The ground plane sets the "reference" for the distributed capacitance for the strip-line feeds into and out of the transistor.

Duroid is a industry generic term for Rogers Corp products. Not all their products are Duroid. This one is not. It's a ceramic filled, high thermal conductivity material. The one you need is 30 mils (0.03 inches) thick, double sided, with 1 ounce copper.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/17/2016 09:02 pm
USB Spectrum analyzer that is just within a DIY budget (~$500). Could this be useful for analyzing the RF inside the frustum?

http://triarchytech.com/product_ESA4G.html
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/17/2016 09:21 pm
Couldn't I fabricate a board with some duroid based on the DXF?
I'd recommend BeO or Alumina...be very careful with the BeO. Duroid might have trouble with the temp. The expansion coefficient of duroid versus aluminum (heat sink) might be an issue, not sure (?). Also, be sure to enclose it like another user said. No mountain oysters!  ;)

Edit - here's stuff similar to what I used to work with, a test fixture for VNAs type design might be a good way to go, just build an enclosure. Note the copper heatsink on the bottom. Lots of places to find either copper or aluminum, finned stuff.

(https://sv1ixp.files.wordpress.com/2013/01/power-attenuator.jpg)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/17/2016 11:04 pm
Couldn't I fabricate a board with some duroid based on the DXF?
I'd recommend BeO or Alumina...be very careful with the BeO. Duroid might have trouble with the temp. The expansion coefficient of duroid versus aluminum (heat sink) might be an issue, not sure (?). Also, be sure to enclose it like another user said. No mountain oysters!  ;)

Edit - here's stuff similar to what I used to work with, a test fixture for VNAs type design might be a good way to go, just build an enclosure. Note the copper heatsink on the bottom. Lots of places to find either copper or aluminum, finned stuff.

(https://sv1ixp.files.wordpress.com/2013/01/power-attenuator.jpg)

Why re-invent the wheel? The manufacturer of the device provides the artwork to manufacture the board, including the material used. Sure, you could create a huge hassle and expense for yourself by using a ceramic substrate, but if it were necessary don't you think the manufacturer would have done it, too?

If you do decide to go with a ceramic substrate, you'll need a complete re-design of the board layout. Different substrate dielectric constants require different strip-line dimensions.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/17/2016 11:28 pm
Couldn't I fabricate a board with some duroid based on the DXF?
I'd recommend BeO or Alumina...be very careful with the BeO. Duroid might have trouble with the temp. The expansion coefficient of duroid versus aluminum (heat sink) might be an issue, not sure (?). Also, be sure to enclose it like another user said. No mountain oysters!  ;)

Edit - here's stuff similar to what I used to work with, a test fixture for VNAs type design might be a good way to go, just build an enclosure. Note the copper heatsink on the bottom. Lots of places to find either copper or aluminum, finned stuff.


Why re-invent the wheel? The manufacturer of the device provides the artwork to manufacture the board, including the material used. Sure, you could create a huge hassle and expense for yourself by using a ceramic substrate, but if it were necessary don't you think the manufacturer would have done it, too?

If you do decide to go with a ceramic substrate, you'll need a complete re-design of the board layout. Different substrate dielectric constants require different strip-line dimensions.
50 Ohm ceramic transmission lines on a substrate are a commodity. Here's one: http://www.usmicrowaves.com/microstrip/50_ohm_impedance_microstrip_microwave_transmission_line_z50-25-171xxx.htm there are many more. Ceramic provides a better thermal conductivity and frequency response. Its not a huge expense nor reinvention of the wheel. Alumina Nitride is a safe ceramic. A little indium solder on the ground plane and your good to go.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: spupeng7 on 03/17/2016 11:32 pm
This is the Horizon episode on the BBC 23/03/16 featuring EM drive.

http://www.bbc.co.uk/programmes/b0752f85

I must say EmDrive will probably hit news again.

Also the conversation here really started to get very interesting lately! Thanks in part of Monomorphic landing in this thread :-). There is also that paper from University of Helsinky. I think that it was Dr. Rodal that stated that there are many groups we do not know about that dig into the research of the EmDrive. I did not believe that. I am glad I was wrong.
It is also interesting to see the development of the Baby-Emdrive. I just do not fully understand that each report of the positive thrust is hit with the tsunami of pessimism.

Mod: Added the last sentence.


Chrochne,

that pessimism is a direct consequence of standards of proof not being met. Results not statistically analysed, graphical axes unlabelled and lack of methodological detail, all conspire to make the emdrive look like Science Fiction. Even the most successful emdrive builders suffer from these flaws which can only be cured by properly funded experimentation conducted by established research institutions.

Meantime this, this is the crucial moment for amateur builders. This is when love and desire for interplanetary travel can raise the unemployed technician or the inspired misfit to the top of what may yet prove to be the biggest game in town. El Gordo has nothing on this. Attempting to build an emdrive, which proves itself, is a bid to reinvent the meaning and purpose and security of humanity. Pessimism comes of disbelief and the only proper answer to that is the scientific method.

Take your dream, analyse what you must do to realise it, theorise how that can be achieved, predict the consequences and then test for success. If you fail, repeat the cycle till you succeed. That is optimism and to an optimist other people’s pessimism is a compliment.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: meberbs on 03/17/2016 11:54 pm
...
My understanding is the prototype Flight Thruster was actually working and showing a weight reduction on the scale. Note the spring above the Flight Thruster and then read Roger's notes on Force Measurement.

By Roger's notes on force measurement, do you mean that pdf you posted a couple pages ago?

The only thing that paper should convince anyone of is that the author of that paper should not be trusted with making force measurements.

Both me and dustinthewind posted issues we saw with that document. The fact there are issues with the document should be obvious to anyone who has taken high school physics. Could you please respond confirming that you understand this? If you don't see the issues with that paper, then I (and other posters) can help explain, and any understanding you gain may help you improve your emDrive setup.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SteveD on 03/18/2016 01:01 am
I believe it is very important to compare the anomalous force resuts of these different frustums to make a valid comparison.

As I have measured ~8mN with my 1st non dielectric build, dielectrics are of no interest to me. I believe they are a waste of time. I know of NO build that has shown above multiple SnowFlake level of force generation using dielectrics other than Roger's Experimental EmDrive, after which he abandoned using dielectrics.

Dr. Rodal did have a point about builds with dielectrics seemingly having a higher force generation in vacuum.  Unfortunately these test are a bit suspect as they're not at near same mode and near same frequency with simular equipment. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/18/2016 01:11 am
Antenna Magus can export ready made antennas to FEKO. These are all the antennas available. Some look very promising.

http://www.antennamagus.com/antennas.php?page=antennas
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: zen-in on 03/18/2016 06:15 am
Couldn't I fabricate a board with some duroid based on the DXF?
I'd recommend BeO or Alumina...be very careful with the BeO. Duroid might have trouble with the temp. The expansion coefficient of duroid versus aluminum (heat sink) might be an issue, not sure (?). Also, be sure to enclose it like another user said. No mountain oysters!  ;)

Edit - here's stuff similar to what I used to work with, a test fixture for VNAs type design might be a good way to go, just build an enclosure. Note the copper heatsink on the bottom. Lots of places to find either copper or aluminum, finned stuff.

(https://sv1ixp.files.wordpress.com/2013/01/power-attenuator.jpg)

Why re-invent the wheel? The manufacturer of the device provides the artwork to manufacture the board, including the material used. Sure, you could create a huge hassle and expense for yourself by using a ceramic substrate, but if it were necessary don't you think the manufacturer would have done it, too?

If you do decide to go with a ceramic substrate, you'll need a complete re-design of the board layout. Different substrate dielectric constants require different strip-line dimensions.

The RF board in the pic is not an amplifier.  It is a power attenuator.   There is no gate bias circuit, no input or output matching network and no terminals for DC power.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/18/2016 12:31 pm
Couldn't I fabricate a board with some duroid based on the DXF?
I'd recommend BeO or Alumina...be very careful with the BeO. Duroid might have trouble with the temp. The expansion coefficient of duroid versus aluminum (heat sink) might be an issue, not sure (?). Also, be sure to enclose it like another user said. No mountain oysters!  ;)

Edit - here's stuff similar to what I used to work with, a test fixture for VNAs type design might be a good way to go, just build an enclosure. Note the copper heatsink on the bottom. Lots of places to find either copper or aluminum, finned stuff.

(https://sv1ixp.files.wordpress.com/2013/01/power-attenuator.jpg)

Why re-invent the wheel? The manufacturer of the device provides the artwork to manufacture the board, including the material used. Sure, you could create a huge hassle and expense for yourself by using a ceramic substrate, but if it were necessary don't you think the manufacturer would have done it, too?

If you do decide to go with a ceramic substrate, you'll need a complete re-design of the board layout. Different substrate dielectric constants require different strip-line dimensions.

The RF board in the pic is not an amplifier.  It is a power attenuator.   There is no gate bias circuit, no input or output matching network and no terminals for DC power.
Yes, it is a passive circuit designed for maximum thermal dissipation. bias and filtering are simple adds. My experience on this is designing for hi-reliability, meaning even heat distribution throughout the assembly and using transmission line material that has great thermal & mw properties, such as ceramic. I have seen non-ceramic boards burn, warp and peel, lifting above ground and inducing failure on passive and active devices.
Ceramic carriers are rather common and the expansion coefficients are very compatible with metals, especially when using indium solder. Yes, I did hi-rel stuff, but if we think about what an emdrive will have to do on long missions, it doesn't hurt to think about using the good stuff, even on observational tests.

Of course, this is only my opinion and Jamie has the freedom to pick and choose humble suggestions like everyone else building. Thought I'd pass along my experience. Specifically it was on 1.5kW passive attenuators and loads rated to 2.4 GHz. I was product manager for this device (note 7/16 DIN) used in Digital Broadcast transmitters:
http://www.birdrf.com/Products/Terminations_Loads/Coaxial-Terminations/1-5kW/1500-CT_1-5-kW-Conduction-Cooled-Dry-Termination.aspx#.VuwCi8v2ZxA

(http://www.birdrf.com/~/media/Bird/Images/Products/terminations/1500-ct_1-5-kw-conduction-cooled-dry-termination.ashx?h=137&la=en&w=200)

Edit - In a form factor like this, feedthrus would supply the bias voltage from a centered, perpendicular (thin) side (compared to the connector axis). Jamie could get creative and have a monopole extend downward from a center point on the assembly directly into a frustum. The opposite side could be the finned heatsink or coolant carrier. Lots of choices...
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: meberbs on 03/18/2016 12:35 pm
(Mod alert - NSF staff deleted linked posts per a user request...I'll delete this to limit discussion on deleted posts.)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/18/2016 02:06 pm
Fun Alert - Hey, lets have a contest to lighten the mood...I'll fork over the $$$ for any single emdrive related post that get the most likes between now and March 31st, 2016.

Rules are simple:  That single must be emdrive related and have the highest number of LIKES from our readership between now and March 31, 2016.

Prize? Anything up to $25 from our gracious host's webstore: http://www.cafepress.com/nasasf

I'm not eligible, just doing this as something different and giving a little back to the outstanding readership/users here. In case of a tie, I'll read those posts and select one to break it. In the meantime, I will not be posting LIKEs myself so as not to influence the outcome.

Could it be that experimental result post wins? A breakthrough theory is presented? Cool pics of in-process builds or models? The first to point out some breaking EMDrive news? YOU decide. Go! Clock is ticking.

(http://logo.cafepress.com/1/25388091.jpg)

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: mwvp on 03/18/2016 04:37 pm
Fun Alert - Hey, lets have a contest to lighten the mood...I'll fork over the $$$ for any single emdrive related post that get the most likes between now and March 31st, 2016.

Rules are simple:  That single must be emdrive related and have the highest number of LIKES from our readership between now and March 31, 2016.

Prize? Anything up to $25 from our gracious host's webstore: http://www.cafepress.com/nasasf


I shall request 2 coffee mugs with my winnings, and give one to whomever likes this post the most times (provided I can find out, otherwise I'll randomly select).

Thankyou for your likes!
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/18/2016 05:31 pm
Fun Alert - Hey, lets have a contest to lighten the mood...I'll fork over the $$$ for any single emdrive related post that get the most likes between now and March 31st, 2016.

Rules are simple:  That single must be emdrive related and have the highest number of LIKES from our readership between now and March 31, 2016.

Prize? Anything up to $25 from our gracious host's webstore: http://www.cafepress.com/nasasf


I shall request 2 coffee mugs with my winnings, and give one to whomever likes this post the most times (provided I can find out, otherwise I'll randomly select).

Thankyou for your likes!
Always somebody out there trying to beat the system...lol  ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: mwvp on 03/18/2016 06:42 pm
Fun Alert - Hey, lets have a contest to lighten the mood...I'll fork over the $$$ for any single emdrive related post that get the most likes between now and March 31st, 2016.

Rules are simple:  That single must be emdrive related and have the highest number of LIKES from our readership between now and March 31, 2016.

Prize? Anything up to $25 from our gracious host's webstore: http://www.cafepress.com/nasasf


I shall request 2 coffee mugs with my winnings, and give one to whomever likes this post the most times (provided I can find out, otherwise I'll randomly select).

Thankyou for your likes!
Always somebody out there trying to beat the system...lol  ;)

Beat? I prefer exploit or hack. It's what technology and innovation are about.

Speaking of which, perhaps you don't need 7 watts to drive that solid state S band amp, if you use a "bootstrap"; i.e. turn it into a (power) oscillator. That would complicate things a bit, but perhaps result in a cheaper tradeoff.

One of my favorite hacks is using digital CMOS hex inverter gates as analog amplifiers, or in a ring-oscillator configuration. By varying the chip's supply voltage/current, it can function as a sine-wave VCO over a 20:1 range, or with distortion, greater than 100:1. Alas, the high-speed devices (74HCT4069) can only hit 200MHz.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/18/2016 07:18 pm
Fun Alert - Hey, lets have a contest to lighten the mood...I'll fork over the $$$ for any single emdrive related post that get the most likes between now and March 31st, 2016.

Rules are simple:  That single must be emdrive related and have the highest number of LIKES from our readership between now and March 31, 2016.

Prize? Anything up to $25 from our gracious host's webstore: http://www.cafepress.com/nasasf


I shall request 2 coffee mugs with my winnings, and give one to whomever likes this post the most times (provided I can find out, otherwise I'll randomly select).

Thankyou for your likes!
Always somebody out there trying to beat the system...lol  ;)

Beat? I prefer exploit or hack. It's what technology and innovation are about.

Speaking of which, perhaps you don't need 7 watts to drive that solid state S band amp, if you use a "bootstrap"; i.e. turn it into a (power) oscillator. That would complicate things a bit, but perhaps result in a cheaper tradeoff.

One of my favorite hacks is using digital CMOS hex inverter gates as analog amplifiers, or in a ring-oscillator configuration. By varying the chip's supply voltage/current, it can function as a sine-wave VCO over a 20:1 range, or with distortion, greater than 100:1. Alas, the high-speed devices (74HCT4069) can only hit 200MHz.
Interesting idea and perhaps useful for Jamie. I do have an 8 Watt wifi booster for him. It will need a 100 mW source, but that would save some hassle. I never used it since I went directly to a mag:

http://www.ebay.com/itm/like/281686883954?lpid=82&chn=ps&ul_noapp=true
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/18/2016 07:48 pm
Interesting idea and perhaps useful for Jamie. I do have an 8 Watt wifi booster for him. It will need a 100 mW source, but that would save some hassle. I never used it since I went directly to a mag:

The MHT1003 can operate at three frequencies. 2.4Ghz is one of them. I would need to adjust my frustum dims to match 2.4 as they are optimized for TE311 @2.45.

So I can have something to experiment with while working on the RF amp, I did order a 600W microwave from Amazon. It's supposed to get here today but traffic is terrible. This unit has all mechanical dials, so it should be easy to make work with the flip of a switch. I hope to use it in concert with my infrared camera to verify resonance patterns predicted by FEKO, specifically TE311, like NASA/Eagleworks did in their experiments. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: X_RaY on 03/18/2016 08:04 pm
I think I had post this sometime in the past but think it's quite interesting to follow the video lessons of Susskind Lectures at Stanford university.
The pic below shows one of the most important formulas and it may be the source of some confusion(regarding to Shawyers theory) because it illustrates that momentum ρ of a wave function ψ depends on the wavenumber κ which changes along the central axis of the frustum (beside of his red/blue shift postulate in relation to the unclear reference frame problems  :o  ).
Since we are dealing with very complex problems in this case the lectures can be very helpful to learn and refresh the already known basics.
I think is it possible that we running into the problems of the uncertainty principle using such approximations*!
Would be nice to know the other side of the coin. ::)


*For sure it delivers a true quantity of energy.

https://www.youtube.com/watch?v=epzh76hNl8I&index=11&list=PLB64419BFD176F2FD

I know about the particle interpretation ;) (as nicely created by Monomorphic) but I mean the explicit reason why there should be thrust at all.
https://www.youtube.com/watch?v=MxhT5_Hh2CA
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/18/2016 09:56 pm
Couldn't I fabricate a board with some duroid based on the DXF?
I'd recommend BeO or Alumina...be very careful with the BeO. Duroid might have trouble with the temp. The expansion coefficient of duroid versus aluminum (heat sink) might be an issue, not sure (?). Also, be sure to enclose it like another user said. No mountain oysters!  ;)

Edit - here's stuff similar to what I used to work with, a test fixture for VNAs type design might be a good way to go, just build an enclosure. Note the copper heatsink on the bottom. Lots of places to find either copper or aluminum, finned stuff.


Why re-invent the wheel? The manufacturer of the device provides the artwork to manufacture the board, including the material used. Sure, you could create a huge hassle and expense for yourself by using a ceramic substrate, but if it were necessary don't you think the manufacturer would have done it, too?

If you do decide to go with a ceramic substrate, you'll need a complete re-design of the board layout. Different substrate dielectric constants require different strip-line dimensions.
50 Ohm ceramic transmission lines on a substrate are a commodity. Here's one: http://www.usmicrowaves.com/microstrip/50_ohm_impedance_microstrip_microwave_transmission_line_z50-25-171xxx.htm there are many more. Ceramic provides a better thermal conductivity and frequency response. Its not a huge expense nor reinvention of the wheel. Alumina Nitride is a safe ceramic. A little indium solder on the ground plane and your good to go.

Dave, I'm thinking you didn't even take a cursory glance at the manufacturer provided artwork? It has rectangular cutouts, ground vias, mounting holes, cap/ind tuning stubs, impedance transistion strips, etc. Not trivial in ceramic. The last item I had made in alumina of similar size and complexity cost ~$5K.

Telling monomorphic to basically buy some pre-printed 50 ohm stripline on alumina (with the stripline being WAY too thin anyway), tack it to a heatsink with indium solder, and Bob's your uncle is a bit...weird.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/18/2016 10:02 pm
Interesting idea and perhaps useful for Jamie. I do have an 8 Watt wifi booster for him. It will need a 100 mW source, but that would save some hassle. I never used it since I went directly to a mag:

The MHT1003 can operate at three frequencies. 2.4Ghz is one of them. I would need to adjust my frustum dims to match 2.4 as they are optimized for TE311 @2.45.

So I can have something to experiment with while working on the RF amp, I did order a 600W microwave from Amazon. It's supposed to get here today but traffic is terrible. This unit has all mechanical dials, so it should be easy to make work with the flip of a switch. I hope to use it in concert with my infrared camera to verify resonance patterns predicted by FEKO, specifically TE311, like NASA/Eagleworks did in their experiments.

No, the MHT1003 can operate at an infinite number of frequencies, they just happen to be fairly close together. It's design was centered at the middle of the ISM 2.4GHz microwave band, and it's a fairly narrow band amplifier.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rq3 on 03/18/2016 10:07 pm
Couldn't I fabricate a board with some duroid based on the DXF?
I'd recommend BeO or Alumina...be very careful with the BeO. Duroid might have trouble with the temp. The expansion coefficient of duroid versus aluminum (heat sink) might be an issue, not sure (?). Also, be sure to enclose it like another user said. No mountain oysters!  ;)

Edit - here's stuff similar to what I used to work with, a test fixture for VNAs type design might be a good way to go, just build an enclosure. Note the copper heatsink on the bottom. Lots of places to find either copper or aluminum, finned stuff.

(https://sv1ixp.files.wordpress.com/2013/01/power-attenuator.jpg)

Why re-invent the wheel? The manufacturer of the device provides the artwork to manufacture the board, including the material used. Sure, you could create a huge hassle and expense for yourself by using a ceramic substrate, but if it were necessary don't you think the manufacturer would have done it, too?

If you do decide to go with a ceramic substrate, you'll need a complete re-design of the board layout. Different substrate dielectric constants require different strip-line dimensions.

The RF board in the pic is not an amplifier.  It is a power attenuator.   There is no gate bias circuit, no input or output matching network and no terminals for DC power.

Nor is the RF board in the pic ceramic. I'm unclear why Dave thought it necessary to gainsay the manufacturer of the device and recommend a very expensive alternative to the material actually recommended by the device manufacturer. His reasoning got so circular it was a waste of time trying to follow it. Good luck, monomorphic!
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/18/2016 10:42 pm
Couldn't I fabricate a board with some duroid based on the DXF?
I'd recommend BeO or Alumina...be very careful with the BeO. Duroid might have trouble with the temp. The expansion coefficient of duroid versus aluminum (heat sink) might be an issue, not sure (?). Also, be sure to enclose it like another user said. No mountain oysters!  ;)

Edit - here's stuff similar to what I used to work with, a test fixture for VNAs type design might be a good way to go, just build an enclosure. Note the copper heatsink on the bottom. Lots of places to find either copper or aluminum, finned stuff.


Why re-invent the wheel? The manufacturer of the device provides the artwork to manufacture the board, including the material used. Sure, you could create a huge hassle and expense for yourself by using a ceramic substrate, but if it were necessary don't you think the manufacturer would have done it, too?

If you do decide to go with a ceramic substrate, you'll need a complete re-design of the board layout. Different substrate dielectric constants require different strip-line dimensions.
50 Ohm ceramic transmission lines on a substrate are a commodity. Here's one: http://www.usmicrowaves.com/microstrip/50_ohm_impedance_microstrip_microwave_transmission_line_z50-25-171xxx.htm there are many more. Ceramic provides a better thermal conductivity and frequency response. Its not a huge expense nor reinvention of the wheel. Alumina Nitride is a safe ceramic. A little indium solder on the ground plane and your good to go.

Dave, I'm thinking you didn't even take a cursory glance at the manufacturer provided artwork? It has rectangular cutouts, ground vias, mounting holes, cap/ind tuning stubs, impedance transistion strips, etc. Not trivial in ceramic. The last item I had made in alumina of similar size and complexity cost ~$5K.

Telling monomorphic to basically buy some pre-printed 50 ohm stripline on alumina (with the stripline being WAY too thin anyway), tack it to a heatsink with indium solder, and Bob's your uncle is a bit...weird.
Of course I did not tell him to buy ceramic, but think about the possibility. I also did not say tack it. There is a reflow process I'm sure you're familiar with. He is a big boy, he's smart enough to make his own decisions without people lobbying for one methodology or another. His design, his budget and his decision. Simple as that.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: zen-in on 03/19/2016 01:33 am

Nor is the RF board in the pic ceramic. I'm unclear why Dave thought it necessary to gainsay the manufacturer of the device and recommend a very expensive alternative to the material actually recommended by the device manufacturer. His reasoning got so circular it was a waste of time trying to follow it. Good luck, monomorphic!

It does have 4 holes drilled through the Copper heat spreader for attaching an Aluminum heat sink.  Most of the HF through UHF power amplifiers I have seen use this same construction; just different transistors and matching techniques.     I have several 1.9 - 2.2 GHz  10 Watt amps that are all ceramic inside.    It's difficult to see what is going on inside but they do put out the rated class C power. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Carl G on 03/19/2016 05:04 pm
Small blog sites will often leech comments made on this site and overblow them in an attempt to get linked by larger sites like this. The one in question does it often, and as usual misrepresents it. Removed the reference as it provides no value to the thread.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: wallofwolfstreet on 03/20/2016 03:20 pm
Just as an FYI, a letter written to New Scientist on why EADS Astrium didn't pursue the emdrive was recently posted by a helpful redditor.  It's short so I will post it here:

Quote
Published 18 October 2006

Emdrive?  No thanks

The article about Roger Shawyer implies that EADS Astrium suppressed this miracle drive for nefarious business reasons (9 September, p 30). The truth (sorry, conspiracy theorists!) is rather different. As the then technical director of Astrium, I reviewed Roger’s work and concluded that both theory and experiment were fatally flawed. Roger was advised that the company had no interest in the device, did not wish to seek patent coverage, and in fact did not wish to be associated with it in any way. The letters you have published point out some of the issues (7 October, p 24).

I was also surprised by the “end of wings and wheels?” tagline on the cover. Even if the device did work, the thrust/power ratio claimed by Roger would make it impractical for any terrestrial transport application.

https://www.newscientist.com/letter/mg19225740-300-emdrive-no-thanks/
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/20/2016 05:20 pm
Just as an FYI, a letter written to New Scientist on why EADS Astrium didn't pursue the emdrive was recently posted by a helpful redditor.  It's short so I will post it here:

Quote
Published 18 October 2006

Emdrive?  No thanks

The article about Roger Shawyer implies that EADS Astrium suppressed this miracle drive for nefarious business reasons (9 September, p 30). The truth (sorry, conspiracy theorists!) is rather different. As the then technical director of Astrium, I reviewed Roger’s work and concluded that both theory and experiment were fatally flawed. Roger was advised that the company had no interest in the device, did not wish to seek patent coverage, and in fact did not wish to be associated with it in any way. The letters you have published point out some of the issues (7 October, p 24).

I was also surprised by the “end of wings and wheels?” tagline on the cover. Even if the device did work, the thrust/power ratio claimed by Roger would make it impractical for any terrestrial transport application.

https://www.newscientist.com/letter/mg19225740-300-emdrive-no-thanks/

Surprising EADS (Alvin Wilby) didn't visit Roger (just a short flight across the channel) and view the Demonstrator EmDrive spinning on the rotary table? Then again it seems EADS / AirBus has their own propellantless drive tech patent application:

7,571N/kW!

http://tinyurl.com/hksu5re

Wonder if they were working on this when they told Roger "No Thanks"?

As a side note James Woodward has been granted a US patent on his propellantless drive tech:

http://tinyurl.com/jmdbdhe

So it seems we now have at least 3 propellantless drive techs in existence:

Roger Shawyer, Satellite Propulsion Research
Jean-Francois Geneste, EADS / AirBus
James Woodward, Space Studies Institute

May the best tech win.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/20/2016 05:48 pm
The US patent application prosecution history for the Geneste ( US 20150260168 Assignee: EADS) application does not bode well for its future: readers please note that the broader, first 13 claims have already been cancelled.

(A patent is literally infringed only when the accused action or device meets all of the elements of the invention as defined by the patent claims.)

As to why EADS did not pursue Shawyer's ideas, the letter to New Scientist by Alvin Wilby answers this completely:

Quote
The article about Roger Shawyer implies that EADS Astrium suppressed this miracle drive for nefarious business reasons (9 September, p 30). The truth (sorry, conspiracy theorists!) is rather different. As the then technical director of Astrium, I reviewed Roger’s work and concluded that both theory and experiment were fatally flawed. Roger was advised that the company had no interest in the device, did not wish to seek patent coverage, and in fact did not wish to be associated with it in any way. The letters you have published point out some of the issues (7 October, p 24).

I was also surprised by the “end of wings and wheels?” tagline on the cover. Even if the device did work, the thrust/power ratio claimed by Roger would make it impractical for any terrestrial transport application.

That is a very potent statement:  <<both theory and experiment were fatally flawed.>>

As Meberbs recently pointed out,  even something as simple as a force balance is incorrectly addressed by Shawyer. (*)

It is noteworthy that Wilby just doesn't say that they decided not to pursue Shawyer's ideas, but he goes as far as stating:

Quote
in fact did not wish to be associated with it in any way.

It is difficult to conceive what else could a Technical Director of a major aerospace company have stated to make it clear that he thinks that there is something very wrong and to distance himself.

________

(*) I still don't understand why Mr. Shawyer, upon the negative reception to his "theoretical explanation" and his NewScientist article, didn't seek cooperation from British Universities.  The UK has some outstanding universities: why doesn't he go to Cambridge University for example, and tell them: I have an experiment that shows a force, but my explanation is not well received in the scientific/engineering community, can you help me with a better explanation and to show that my experimental results are valid?

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: chavv on 03/20/2016 06:44 pm
That patents like those can be received is simply a prove how dumb is the US patent service.
At least in Em Drive there is some hope that the effect is real & explainable by science
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/20/2016 06:53 pm
(*) I still don't understand why Mr. Shawyer, upon the negative reception to his "theoretical explanation" and his NewScientist article, didn't seek cooperation from British Universities.  The UK has some outstanding universities: why doesn't he go to Cambridge University for example, and tell them: I have an experiment that shows a force, but my explanation is not well received in the scientific/engineering community, can you help me with a better explanation and to show that my experimental results are valid?

Just maybe that has been done.

Ah to hell with the games. Roger told me that has been done. In fact several universities have been involved. That said I believe Roger may be holding some of the theory stuff very close to his chest. Which I perfectly understand. I mean it is, in the end, about $$.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: wallofwolfstreet on 03/20/2016 07:32 pm
Ah to hell with the games. Roger told me that has been done. In fact several universities have been involved. That said I believe Roger may be holding some of the theory stuff very close to his chest. Which I perfectly understand. I mean it is, in the end, about $$.

Rogers first patent on an emdrive like technology was in 1989.  He's had almost thirty years to come up with a more coherent theoretical explanation for the emdrive, and yet in his latest paper from July of 2015 (see here (http://"http://www.emdrive.com/IAC14publishedpaper.pdf")), he offers up the exact same nonsense theoretical explanation he has offered up since day one.

So if Roger is "holding some theory stuff very close to his chest", then are we to believe that in your opinion the most recent paper contains an intentionally incorrect theoretical explanation?  Because I can guarantee you no one from any of these collaborating universities would have let him use such a trivially incorrect explanation.  So how to reconcile this issue?  If he knows his theoretical explanation is bogus, why is he still using it in his published works?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/20/2016 07:39 pm
Ah to hell with the games. Roger told me that has been done. In fact several universities have been involved. That said I believe Roger may be holding some of the theory stuff very close to his chest. Which I perfectly understand. I mean it is, in the end, about $$.

Rogers first patent on an emdrive like technology was in 1989.  He's had almost thirty years to come up with a more coherent theoretical explanation for the emdrive, and yet in his latest paper from July of 2015 (see here (http://"http://www.emdrive.com/IAC14publishedpaper.pdf")), he offers up the exact same nonsense theoretical explanation he has offered up since day one.

So if Roger is "holding some theory stuff very close to his chest", then are we to believe that in your opinion the most recent paper contains an intentionally incorrect theoretical explanation?  Because I can guarantee you no one from any of these collaborating universities would have let him use such a trivially incorrect explanation.  So how to reconcile this issue?  If he knows his theoretical explanation is bogus, why is he still using it in his published works?

You never heard of Industrial Secrets?

Roger is not a Publish or Die academic. Why should he give away the combination to the vault?

BTW I have advised him to get on his skates and open the commercial propellantless drive market NOW as there are 2 other propellantless drive techs coming on stream.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: wallofwolfstreet on 03/20/2016 07:58 pm
You never heard of Industrial Secrets?

Roger is not a Publish or Die academic. Why should he give away the combination to the vault?

BTW I have advised him to get on his skates and open the commercial propellantless drive market as there are now 2 other propellantless drive techs coming on stream.

Because he is publishing works in conferences and in patents and in at least one academic journal?  Is he or is he not intentionally using an incorrect physical explanation in his published works?  If he is, than what else might be left intentionally incorrect?

If someone publishes articles pretending to give a theoretical explanation, but it's only a smoke screen for your "industrial secret", then they're lying.  Simple as that. 

Quote
BTW I have advised him to get on his skates and open the commercial propellantless drive market as there are now 2 other propellantless drive techs coming on stream.

You can't be serious.  There have been propellantless drive technologies "coming on stream" since the 1920's when T. T. Brown first started the whole "asymmetric capacitor" concept.  The patent literature is absolutely replete with propellantless drive applications, ranging from countless gyroscopic propulsion designs to more esoteric magic superconductor designs. 

Ever hear of Sandy Kidd or Eric Laithwaite?  Dr. Laithwaite was actually a successful electrical engineer (major role in inventing the mag lev train) who was bestowed the honour of giving a lecture to the Royal Institution.  Unfortunately, he was already off the deep end and started claiming gyroscopes could be used in propulsion applications (P.S. they can't).

Hell, Dr. Laithwaite even had the same dubious honor of getting to do a BBC doc on the subject as well!
https://www.youtube.com/watch?v=1eQp4grGdqY

I don't know who said it, but it was someone on this forum: 
Quote
propellantless propulsion is just perpetual motion for space nerds
   
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/21/2016 01:47 am
The time and expense needed to create a patent plus allowing the company's name on it for the world to see makes me wonder...was a working prototype built? Airbus doesn't strike me as a company that would engage in frivolous patents on non-working concepts. If they do, shame on them...its setting a poor example for the world to see. There is only one other possibility, they have something. The 2006 article in newscientist should have discredited the patent app...yet it was published in 2015. Boeing once had an emdrive and silence since then except for a quote they aren't working with shawyer. 2 of the worlds largest aerospace companies have been evaluating peopellantless propulsion...perpetual motion machines for space nerds...why would they have even tried? And why is there a 2015 patent on the books? Dismissing this as "nothing to see here" is either naive or wishful opinion. A simple interest in a propellantless engine should not have lead to a patent, yet it did. Perhaps airbus can clarify.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: meberbs on 03/21/2016 02:26 am
Dismissing this as "nothing to see here" is either naive or wishful opinion.
You apparently didn't read the patent, you can go look at my summary on the other thread, but this concept is trivially nonsensical.

The cost of a patent is fairly trivial for even a moderate sized company. Big defense contractors will patent basically anything that they think can get through the patent process.

Also, the amount of dysfunction inside these companies can be surprisingly large. It is not worth reading into why did they investigate this or make that decision. (Go check out some of the ULA threads on this site for people trying to pick apart their strategy and arguing about why they make decisions that leave them with limited ability to compete). Silence from Boeing most likely means that they looked into it, realized there was no way it would ever work and have dropped it. If it did work, they might classify some specifics (if the government started funding it, since only the government can classify info), but are unlikely to have taken it completely dark.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/21/2016 02:33 am
Build Update:  "NSF-TE311" is well underway. I worked most of the day on the frustum. By far, the side-walls are the most difficult part of the emdrive to fabricate!

Also shown is the first-surface mirror attached to the emdrive that is part of the interferometer.

Pro-tip. If you order your copper from onlinemetals.com, it comes attached to a cardboard honeycomb. Leave it attached and tape it down to make it easier to cut the 1mm copper.



Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: FattyLumpkin on 03/21/2016 04:22 am
Is there a prevailing consensus Emdrive theory of function here on NSF forum? (not rhetorical)  Thank you  ,  FL
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: FattyLumpkin on 03/21/2016 04:25 am
BTW Monomorphic, beautiful work!!!  ,  F L
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Chrochne on 03/21/2016 05:10 am
The time and expense needed to create a patent plus allowing the company's name on it for the world to see makes me wonder...was a working prototype built? Airbus doesn't strike me as a company that would engage in frivolous patents on non-working concepts. If they do, shame on them...its setting a poor example for the world to see. There is only one other possibility, they have something. The 2006 article in newscientist should have discredited the patent app...yet it was published in 2015. Boeing once had an emdrive and silence since then except for a quote they aren't working with shawyer. 2 of the worlds largest aerospace companies have been evaluating peopellantless propulsion...perpetual motion machines for space nerds...why would they have even tried? And why is there a 2015 patent on the books? Dismissing this as "nothing to see here" is either naive or wishful opinion. A simple interest in a propellantless engine should not have lead to a patent, yet it did. Perhaps airbus can clarify.

I believe you are right there. I saw this happen in companies I worked for. They discredited the inventors in order to take over their patents later. Zen-In do well to believe in the numbers, but there is always more than that. That is where Trallever is right. It is about the $$.
I would not be suprised if Airbus intention was to discredit him. They done their research well and know that just s little push will damage his reputation even more... I do not have any idealistic visions about the american companies. Money is first motivator for them.

Also I do not think this dabate have any meaning here. Zen-In may I ask you why do you repeatedly bring this subject here?  I know you are very sceptical to Em-Drive and that is understatement, but damaging Mr. Shawyer reputation any further do not bring us any closer to solving this anomalous device.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RotoSequence on 03/21/2016 05:33 am
I believe you are right there. I saw this happen in companies I worked for. They discredited the inventors in order to take over their patents later. Zen-In do well to believe in the numbers, but there is always more than that. That is where Trallever is right. It is about the $$.

To play the devil's advocate, can you give an example of the invention, discrediting, and subsequent usage of technology cycle?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Chrochne on 03/21/2016 05:43 am
I believe you are right there. I saw this happen in companies I worked for. They discredited the inventors in order to take over their patents later. Zen-In do well to believe in the numbers, but there is always more than that. That is where Trallever is right. It is about the $$.

To play the devil's advocate, can you give an example of the invention, discrediting, and subsequent usage of technology cycle?

Only on the example from the company where I worked for as I said before. First ever kind of flexible sander that is able to sand concave and convex surface. It is manily used on larger surface as are the yachts for example. It is a different debate than concerning that of the EmDrive. PM me if you want details Mr. Devil.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Stormbringer on 03/21/2016 09:00 am
I believe you are right there. I saw this happen in companies I worked for. They discredited the inventors in order to take over their patents later. Zen-In do well to believe in the numbers, but there is always more than that. That is where Trallever is right. It is about the $$.

To play the devil's advocate, can you give an example of the invention, discrediting, and subsequent usage of technology cycle?
perhaps the windshield wiper and then in a separate example; the interval windshield wiper? There were some corporate vs inventor shenanigins there but i don't remember the precise details.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/21/2016 12:24 pm
https://www.google.com/#q=Michelle+Broyles+Patents+and+applications

These patents and patent applications do not include major parts on how they really work. Critical items were  left out just to protect my corporate IP at the time. They may not even be related to the subject matter called out in the patent.

With patent trolls reviewing every patent for IP sometimes a small thing like "picket fencing" can help protect your companies IP and bottom line. Investors are happy because you have patents and you somewhat have protected yourself.

A patent is nothing more than a tool to be used in business operations and don't always reflect or describe the true operating nature of the device.

I would say on the patents concerning propellantless systems that you might not truly see the hows and whys of the device or why it really works. It would help to look at them all in this light.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: zen-in on 03/21/2016 01:06 pm
The time and expense needed to create a patent plus allowing the company's name on it for the world to see makes me wonder...was a working prototype built? Airbus doesn't strike me as a company that would engage in frivolous patents on non-working concepts. If they do, shame on them...its setting a poor example for the world to see. There is only one other possibility, they have something. The 2006 article in newscientist should have discredited the patent app...yet it was published in 2015. Boeing once had an emdrive and silence since then except for a quote they aren't working with shawyer. 2 of the worlds largest aerospace companies have been evaluating peopellantless propulsion...perpetual motion machines for space nerds...why would they have even tried? And why is there a 2015 patent on the books? Dismissing this as "nothing to see here" is either naive or wishful opinion. A simple interest in a propellantless engine should not have lead to a patent, yet it did. Perhaps airbus can clarify.

I believe you are right there. I saw this happen in companies I worked for. They discredited the inventors in order to take over their patents later. Zen-In do well to believe in the numbers, but there is always more than that. That is where Trallever is right. It is about the $$.
I would not be suprised if Airbus intention was to discredit him. They done their research well and know that just s little push will damage his reputation even more... I do not have any idealistic visions about the american companies. Money is first motivator for them.

Also I do not think this dabate have any meaning here. Zen-In may I ask you why do you repeatedly bring this subject here?  I know you are very sceptical to Em-Drive and that is understatement, but damaging Mr. Shawyer reputation any further do not bring us any closer to solving this anomalous device.

I think you are mistaking me for someone else.  I have not recently posted anything to discredit Shawyer.   I have an open mind.  I am still waiting to see a demonstration that the EM-Drive produces thrust.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: birchoff on 03/21/2016 01:12 pm
(*) I still don't understand why Mr. Shawyer, upon the negative reception to his "theoretical explanation" and his NewScientist article, didn't seek cooperation from British Universities.  The UK has some outstanding universities: why doesn't he go to Cambridge University for example, and tell them: I have an experiment that shows a force, but my explanation is not well received in the scientific/engineering community, can you help me with a better explanation and to show that my experimental results are valid?

Just maybe that has been done.

Ah to hell with the games. Roger told me that has been done. In fact several universities have been involved. That said I believe Roger may be holding some of the theory stuff very close to his chest. Which I perfectly understand. I mean it is, in the end, about $$.

If Roger actually has a working EmDrive. It will be blatantly obvious that he is holding on to some important piece of theory or experimental setup to help explain it. However, If your holding on to theory to protect IP then there is ZERO need for any public pronouncements at all about the EmDrive. Not even a need for a website or youtube videos showing it is working.

See from where I stand your either doing basic science and seek to contribute to basic scientific knowledge of humanity. Which means open disclosure on not just your hypothesis, but also your experimental setup. Or your doing this for commercial gain. In which case feel free to hold on to as much information as you think is worthwhile. It just means that any disagreement thrown your way must be accepted. Since the decision was made to withhold information for the sake of commercial gain.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/21/2016 02:04 pm
The time and expense needed to create a patent plus allowing the company's name on it for the world to see makes me wonder...was a working prototype built? Airbus doesn't strike me as a company that would engage in frivolous patents on non-working concepts. If they do, shame on them...its setting a poor example for the world to see. There is only one other possibility, they have something. The 2006 article in newscientist should have discredited the patent app...yet it was published in 2015. Boeing once had an emdrive and silence since then except for a quote they aren't working with shawyer. 2 of the worlds largest aerospace companies have been evaluating peopellantless propulsion...perpetual motion machines for space nerds...why would they have even tried? And why is there a 2015 patent on the books? Dismissing this as "nothing to see here" is either naive or wishful opinion. A simple interest in a propellantless engine should not have lead to a patent, yet it did. Perhaps airbus can clarify.
No, if you are familiar with patent applications submitted by aerospace companies, you know that a working prototype does not need to have been built.  Thus, many aerospace companies submit patent applications for which there is no working prototype.  Let's familiarize ourselves with patenting in the aerospace industry: the cost of filing a patent application is insignificant compared to the cost of a working aerospace prototype, and there is no requirement to have a working prototype to submit a patent application.  Many patent applications are submitted for defensive purposes: just in case that something useful could come out of the invention, and to have a patent application submitted prior to a competing company, just in case, since the invention goes to the "first to patent".

What you are presenting is a false choice.  Submitting such a patent is not at all the same thing as engaging in frivolous patents.   Aerospace companies like Airbus often submit patent applications early in the R&D process. What we know for a fact is that 13 of Geneste's patent application broadest claims have already been cancelled.  You don't know the reason why they were cancelled, but obviously they were cancelled after the patent application was submitted.

You state:   <<The 2006 article in newscientist should have discredited the patent app...yet it was published in 2015.>>

Why would the decade-old article in New Scientist serve to discredit Geneste's application? Geneste's application is an entirely different concept, not connected to Shawer's theoretical or experimental claims. You fail to make any connection besides the fact that they are both propellant-less inventions.

<<A simple interest in a propellantless engine should not have lead to a patent, yet it did. >>

This is a non-sequitur.  There is no evidence you have presented that there is any connection between Geneste's patent application and Shawyer's invention, and there is no evidence that Geneste's patent application was motivated by Shawyer's invention.  As already reported by WallofWolfStreet in these pages, there are myriads of propellant-less space drive concepts that precede Mr. Shawyer's claims. There is no apparent connection between Mr. Geneste and Mr.  Wilby, besides the fact that they both worked, at different times for different divisions of a very large multinational company, in different departments.

Geneste filed all 3 patent applications: for the US patent application US 20150260168 A1, the European Patent Application EP 2923082 A1 and the World Patent Application  WO2014067810A1, all on the same date: Oct 22, 2013, which is 7 years after the letter from Alvin Wilby to New Scientist concerning Shawyer's invention, and it is also after the company Wilby worked for (Astrium), at a different country, at a different time, was merged into the defence division of EADS (a different company than the company Geneste works for: Airbus Group Innovations) .

Jean-Francois Geneste, is a staff member of Airbus Group Innovations, who apparently has an interest in esoteric concepts like propellant-less propulsion and LENR.   Alvin Wilby (the person that wrote the letter to New Scientist stating that Shawyer's invention was deeply flawed) used to be the technical director, at an earlier time, for Astrium, a different company.  Different people at different companies, different countries, and different times.

Astrium (the company were Wilby worked), no longer exists, it was an aerospace manufacturer subsidiary of the European Aeronautic Defence and Space Company (EADS) that provided civil and military space systems and services from 2006 to 2013. In 2012, Astrium had 18,000 employees in France, Germany, the United Kingdom, Spain and the Netherlands.  In late 2013 Astrium was merged with Cassidian, the defence division of EADS and Airbus Military to form Airbus Defence and Space. EADS itself was reorganized as the Airbus Group, with three divisions that include Airbus, Airbus Defence and Space, and Airbus Helicopters
 
As to the fact that Geneste is employed by the Airbus Group, see this, to understand how large an organization is the Airbus Group and how tenuous is to imply that there is a connection between Geneste's present patent application and the letter of Wilby to New Scientist from a decade ago (who used to work for Astrium):

http://news.newenergytimes.net/2015/01/16/airbus-staff-scientist-sees-potential-of-lenrs/
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/21/2016 04:44 pm
Concerning Jean-Francois Geneste's patent applications for "Propulsion device for transmitting momentum" (**), the following facts are also of interest:

1) Neither the author, nor the patent examiner has ever cited any of Shawyer's patents as being relevant to Geneste's invention, instead, the patent examiner has cited the following patents as being relevant to Geneste's invention:


Cited Patent(*)          Filing date          Publication date   Applicant                     Title
WO2005003556A1 *   May 14, 2004   Jan 13, 2005   Chiu Chin-Ho    Method and apparatus for power generation
http://www.google.com/patents/WO2005003556A1?cl=de

US5782134 *           Dec 6, 1996   Jul 21, 1998   Booden; James D.   Electromagnetically actuated thrust generator
https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US5782134.pdf

US6109123 *           Sep 15, 1998   Aug 29, 2000   Baskis; Paul T.   Rotational inertial motor
https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US6109123.pdf

US20060060013 *   Feb 15, 2005   Mar 23, 2006   Norman Robinson   Motion providing unit
https://docs.google.com/viewer?url=patentimages.storage.googleapis.com/pdfs/US20060060013.pdf

* Cited by examiner

2) On Apr 30, 2015,  there was a Non-entry into the national-phase legal event ("NENP") for the World Patent application, into the national phase in Germany (DE)   


3) On Feb 3, 2016, the extension to Germany (DAX) of the European Patent application was deleted

4) The deletion of the first 13 claims of Geneste's patent application.

The NENP for Germany of the World Patent and the deletion of the extension to Germany are significant events since Germany is a very important country for aerospace technology and for Airbus.

_______

(**) US patent application US 20150260168 A1, the European Patent Application EP 2923082 A1 and the World Patent Application  WO2014067810A1, filed on the same date: Oct 22, 2013.   Geneste claims (in his patent application):

Quote from: Geneste
The device can function using energy in electrical form alone, to power primarily the electromagnets and to a lesser extent all of the accessories required for the operation of the propulsion device.
...
On board an interstellar space vehicle, electrical energy is for example produced by a radioisotope generator, the technology of which is known, and the operating life of which is more than 20 years
...
at constant acceleration the star Proxima Centauri (Alpha Centauri C) located at a distance of 270,000 astronomical units (4.22 light years) could be reached in 18 years with a constant acceleration of 0.265 m/s^2 (ignoring the effects of general relativity), the speed reached on arrival therefore being c/2, i.e. half the speed of light
...
In the hypothetical case of a space vehicle with a mass of a 300 kg such as a probe vehicle, the acceleration presumes the application of an average force of 79.5 N (the mass multiplied by the acceleration).
...
The force generated by the propulsion device being internal to the system formed by the space vehicle, it is applied to an object at a relative speed of zero with respect to said propulsion device. In this case, assuming the average force to be a constant, the average power continuously transmitted to the space vehicle for its acceleration is 10.5 W
...
With a hypothetical output of the propulsion system of only 1%, taking into account the impulsive aspect of said propulsion system and the losses in the various mechanical and electrical components, it was established that 1 kW of onboard power is enough to complete the mission. A radioisotope generator having the capacity to produce such power is perfectly accessible with the current technologies.

Using as powerInput, the average power continuously transmitted to the space vehicle (this is the power input used in previous posts in the EM Drive thread):

Force/PowerInput
                  = 79.5 N / 10.5 W
                  = 7.57 N / W
                  = 7.57 *10^6 mN/kW
                  = 7570 (thousands of) times the 1,000 mN/kW claimed by Yang for her EM Drive experiments
                  = 2.27*10^9  (billions of times) the Force/PowerInput of a perfectly collimated photon rocket


_________________

Using as powerInput the power from the power plant, and assuming the very low 1%  (one per cent) efficiency assumed by Genestes:

Force/PowerInput
                  = 79.5 N / 1000 W
                  = 0.0795 N / W
                  = 79 500 mN/kW
                  = 79.5 times the 1,000 mN/kW claimed by Yang for her EM Drive experiments
                  = 2.38*10^7  (two dozen millions of times) the Force/PowerInput of a perfectly collimated
                      photon rocket
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/21/2016 06:03 pm
What is a fact about the EADS (Airbus) Patent is that it is for a Propellantless Engine that is not a photon rocket nor a solar sail.

And science writers persist: "Despite what the Internet is saying, nobody has confirmed anything, and those silly physical laws still say propellantless space drives are impossible." - http://www.wired.com/2015/07/really-propellantless-space-drives-still-not-thing/





Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: X_RaY on 03/21/2016 07:05 pm
Is there a demonstrator available for the EADS patent? http://tinyurl.com/hksu5re
It seems to be impossible to generate a force in a specific direction based on such mechanical setup. (Many people may think the same about the em drive).
While thinking about the applied momenta and back reactions and force vectors during rotation on the inertia mass I dont see that is possible because the average of all these forces have to cancel each other perfectly. Even the patent is authentic I would wonder if it workes as described.
I don't say it's impossible but seems unlikely to me.
Please correct me when I miss something related to this machine.

EDIT
It would be relatively easy for a company like EADS to confirm or to reject this, in regarding to the pure numbers posted by Dr.Rodal. https://forum.nasaspaceflight.com/index.php?topic=39772.msg1506249#msg1506249
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/21/2016 07:25 pm
Is there a demonstrator available for the EADS patent? http://tinyurl.com/hksu5re
It seems to be impossible to generate a force in a specific direction based on such mechanical setup. (Many people may think the same about the em drive).
While thinking about the applied momenta and back reactions and force vectors during rotation on the inertia mass I dont see that is possible because the average of all these forces have to cancel each other perfectly. Even the patent is authentic I would wonder if it worked as described.
I don't say it's impossible but seems unlikely to me.
Please correct me when I miss something related to this machine.
I agree. It makes no sense in a closed system with what the patent describes. Shell makes a good point that something could not be fully disclosed, but the question is why would something so obvious get through corporate due-diligence? Strange.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/21/2016 07:45 pm
Is there a demonstrator available for the EADS patent? http://tinyurl.com/hksu5re
It seems to be impossible to generate a force in a specific direction based on such mechanical setup. (Many people may think the same about the em drive).
While thinking about the applied momenta and back reactions and force vectors during rotation on the inertia mass I dont see that is possible because the average of all these forces have to cancel each other perfectly. Even the patent is authentic I would wonder if it worked as described.
I don't say it's impossible but seems unlikely to me.
Please correct me when I miss something related to this machine.

EDIT
It would be relatively easy for a company like EADS to confirm or to reject this, in regarding to the pure numbers posted by Dr.Rodal. https://forum.nasaspaceflight.com/index.php?topic=39772.msg1506249#msg1506249

X-Ray, given the fact that the first 13 claims have already been deleted and that early on there was a Non-entry into the national-phase legal event ("NENP") for the World Patent application, into the national phase in Germany (DE)  and that just a few days ago, on Feb 3, 2016, the extension to Germany (DAX) of the European Patent application was deleted, it doesn't appear that Airbus Group is making much of this patent application.  I also agree that it violates conservation of momentum.  I don't see much of interest here, either from a technical viewpoint, or from a patent viewpoint (with this history).

This patent application was introduced into the EM Drive thread discussion by others that did not discuss its  prosecution history.

These companies have patent departments with many patent lawyers.  It is very easy for engineers and scientists to submit applications to their patent departments.  The cost of applying for a patent is insignificant compared to the cost of an aerospace prototype, for example.  The fact that the extension to Germany of the European Patent application was deleted a few days ago shows that Airbus Group is not pursuing this strongly.  Airbus speaks loudly and clear by pursuing or not pursuing extension to important countries like Germany and other future events and fees that have not  taken place.  To see whether, and how strongly is Airbus is pursuing this patent, just monitor future patent events for this application.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: spupeng7 on 03/22/2016 12:58 am
Build Update:  "NSF-TE311" is well underway. I worked most of the day on the frustum. By far, the side-walls are the most difficult part of the emdrive to fabricate!

Also shown is the first-surface mirror attached to the emdrive that is part of the interferometer.

Pro-tip. If you order your copper from onlinemetals.com, it comes attached to a cardboard honeycomb. Leave it attached and tape it down to make it easier to cut the 1mm copper.


Monomorphic,
is that a bent clock on the wall behind your nice solid alloy angle test stand, or just a distorted reflection? Your build and cutting techniques look good and I admire your choice of scooter.

Could you maybe explain your test stand operation and general experimental method in more detail.  :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/22/2016 02:46 am
I've completed the constant diameter tuning section. At a little over 6cm in length, I can tune the frustum as much as 1/2 wavelength @ 2.45Ghz.

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/22/2016 02:54 am
Could you maybe explain your test stand operation and general experimental method in more detail.  :)

The build is actually very simple. There are two main components: an air track and an interferometer. They are designed to be used independently, as well as together.

The air track is the horizontal square tube the emdrive hangs beneath. This is an air bearing that can be used to simulate a frictionless environment.

The 450nm interferometer is built into the support structure. It is used to measure displacement with extreme precision.

*That is a Salvador Dali clock I picked up some years ago. Not a reflection. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RotoSequence on 03/22/2016 03:30 am
Nice build, Monomorphic. Don't forget to record every test, including the ones you expect to be boring/no-thrust/just a dry test runs!
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: R.W. Keyes on 03/22/2016 05:24 am
Regarding the mysteries of patents, disclosures, claims, refutations, etc: A working EMdrive is bigger than patents. You could call it a military technology, or a world-changing invention. Many groups may be jostling for position in attempts to get valuable information, or funding, while at the same time protecting their own secrets. "Dirty tricks" may happen. My advice is to be wary.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Slyver on 03/22/2016 05:41 am
Could you maybe explain your test stand operation and general experimental method in more detail.  :)

The build is actually very simple. There are two main components: an air track and an interferometer. They are designed to be used independently, as well as together.

The air track is the horizontal square tube the emdrive hangs beneath. This is an air bearing that can be used to simulate a frictionless environment.

The 450nm interferometer is built into the support structure. It is used to measure displacement with extreme precision.

*That is a Salvador Dali clock I picked up some years ago. Not a reflection.

This looks to be a promising build. IF you observe a thrust greater than a perfectly collimated photon rocket towards the small end, as predicted by the models that have been put forth, I request you also build a symmetric model, resonating at ~ the same freq. (a cylinder) of the same material and put it through the same test regime.  In other words, I would like to see a control experiment, testing specifically the hypothesis of "a geometry based anomalous force of a closed microwave cavity".

Thank you for your fine effort!
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Willem Staal on 03/22/2016 06:28 am
Ah to hell with the games. Roger told me that has been done. In fact several universities have been involved. That said I believe Roger may be holding some of the theory stuff very close to his chest. Which I perfectly understand. I mean it is, in the end, about $$.

Rogers first patent on an emdrive like technology was in 1989.  He's had almost thirty years to come up with a more coherent theoretical explanation for the emdrive, and yet in his latest paper from July of 2015 (see here (http://"http://www.emdrive.com/IAC14publishedpaper.pdf")), he offers up the exact same nonsense theoretical explanation he has offered up since day one.

So if Roger is "holding some theory stuff very close to his chest", then are we to believe that in your opinion the most recent paper contains an intentionally incorrect theoretical explanation?  Because I can guarantee you no one from any of these collaborating universities would have let him use such a trivially incorrect explanation.  So how to reconcile this issue?  If he knows his theoretical explanation is bogus, why is he still using it in his published works?

You never heard of Industrial Secrets?

Roger is not a Publish or Die academic. Why should he give away the combination to the vault?

BTW I have advised him to get on his skates and open the commercial propellantless drive market NOW as there are 2 other propellantless drive techs coming on stream.
Agree. But you have to be aware of patent trolls, they are like flies on a fat t**d, and they are everywhere..
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RERT on 03/22/2016 10:04 am
Regarding the mysteries of patents, disclosures, claims, refutations, etc: A working EMdrive is bigger than patents. You could call it a military technology, or a world-changing invention. Many groups may be jostling for position in attempts to get valuable information, or funding, while at the same time protecting their own secrets. "Dirty tricks" may happen. My advice is to be wary.

Amen to that. What is happening here is actually pretty bizzare - people are trying to replicate what would be extremely valuable technology in open cyberspace - the equivalent of a sunny open field, where every so often strangers wander up and chip in comments. Particularly interesting are the visitors who say "That's definitely not worth trying!" or "This way not that way!" when there is no publicly accepted theory of operation. Wary is definitely good, as is being wary of conspiracy theories. Nonetheless "Cui Bono?" is a very good question to bear in mind.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Paul451 on 03/22/2016 10:49 am

Since no-one else has asked:

A) How have you measured the minimum force required to move a EMdrive-equivalent mass on that air-track? (And what is the minimum force?)

B) Do you have a way of measuring the force produced by your EMDrive, or are you just looking at a binary yes/no result from displacement?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/22/2016 01:15 pm

Since no-one else has asked:

A) How have you measured the minimum force required to move a EMdrive-equivalent mass on that air-track? (And what is the minimum force?)

B) Do you have a way of measuring the force produced by your EMDrive, or are you just looking at a binary yes/no result from displacement?

A properly designed air track has no minimum force required to get it moving because it has zero stiction. All retarding forces it experiences (drag/friction) are dynamic and dependent on being in motion.

The air-track is pretty much binary, it either moves or it doesn't. The interferometer will allow me to do much more precise measurements of displacement. This is accomplished by counting the interference fringe patterns as they change.

Lastly, there is a third set-up mode: the White-Juday Field Interferometer. In this configuration the laser passes through the center of the frustum to look for variations in the path time.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/22/2016 01:36 pm

Since no-one else has asked:

A) How have you measured the minimum force required to move a EMdrive-equivalent mass on that air-track? (And what is the minimum force?)

B) Do you have a way of measuring the force produced by your EMDrive, or are you just looking at a binary yes/no result from displacement?

A properly designed air track has no minimum force required to get it moving because it has zero stiction. All retarding forces it experiences (drag/friction) are dynamic and dependent on being in motion.

The air-track is pretty much binary, it either moves or it doesn't. The interferometer will allow me to do much more precise measurements of displacement. This is accomplished by counting the interference fringe patterns as they change.

Lastly, there is a third set-up mode: the White-Juday Field Interferometer. In this configuration the laser passes through the center of the frustum to look for variations in the path time.
Unless you perform this experiment in a vacuum chamber, there will be air resistance, characterized by a coefficient of drag, CD (dependent on the Reynolds number) and (approximately) the square of the velocity.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1105838;image)

Looking at the picture of your setup, this air drag will produce a torque moment on the EM Drive, tilting the leading end of the EM Drive, because the air drag force has a moment arm around the air track support  (the axis of application of the air drag force is located at a distance from the air track support), since the EM Drive is unsymmetrically located, on one side, of the air track.  This moment will produce additional resistance, as well as additional aerodynamic contributions, and it will produce pressure on the air track support.

Normally one doesn't worry about such small contributions but since the forces that experimenters want to measure in these EM Drive experiments are so small (microNewtons for NASA's and Tajmar's experiments, milliNewtons for Yang's experiments), it may be worthwhile to consider their contributions in the experiment.



PS: A summary of other experimental small forces. There is also the issue of how is the EM Drive powered.  Ideally it would be powered from a battery, self-integrated, as this would avoid issues due the fact that energy is transmitted from an outside source to the EM Drive (hence there is a tiny amount of momentum due to this which would only be eliminated when using a battery source in a self-integrated configuration).

There is also the issue of possible Lorentz forces from cables, and the issue of unequal heated surfaces and unequal surface areas of the EM Drive due to induction heating, producing unsymmetric thermal convection (if not tested in a vacuum): buoyancy (lower internal air density) resulting in pressure on the track, convection asymmetry resulting in line force (due to external air density asymmetry) and torque (due to the moment arm), and asymmetric thermal radiation asymmetry (also present in a vacuum, but probably negligible), which I will not repeat here in the interest of brevity, since they have been discussed in previous threads. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/22/2016 02:49 pm

Since no-one else has asked:

A) How have you measured the minimum force required to move a EMdrive-equivalent mass on that air-track? (And what is the minimum force?)

B) Do you have a way of measuring the force produced by your EMDrive, or are you just looking at a binary yes/no result from displacement?

A properly designed air track has no minimum force required to get it moving because it has zero stiction. All retarding forces it experiences (drag/friction) are dynamic and dependent on being in motion.

The air-track is pretty much binary, it either moves or it doesn't. The interferometer will allow me to do much more precise measurements of displacement. This is accomplished by counting the interference fringe patterns as they change.

Lastly, there is a third set-up mode: the White-Juday Field Interferometer. In this configuration the laser passes through the center of the frustum to look for variations in the path time.
Unless you perform this experiment in a vacuum chamber, there will be air resistance, characterized by a coefficient of drag, CD (dependent on the Reynolds number) and (approximately) the square of the velocity.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1105838;image)

Looking at the picture of your setup, this air drag will produce a torque moment on the EM Drive, tilting the leading end of the EM Drive, because the air drag force has a moment arm around the air track support  (the axis of application of the air drag force is located at a distance from the air track support), since the EM Drive is unsymmetrically located, on one side, of the air track.  This moment will produce additional resistance, as well as additional aerodynamic contributions, and it will produce pressure on the air track support.

Normally one doesn't worry about such small contributions but since the forces that experimenters want to measure in these EM Drive experiments are so small (microNewtons for NASA's and Tajmar's experiments, milliNewtons for Yang's experiments), it may be worthwhile to consider their contributions in the experiment.



PS: There is also the issue of how is the EM Drive powered.  Ideally it would be powered from a battery, self-integrated, as this would avoid issues due the fact that energy is transmitted from an outside source to the EM Drive (hence there is a tiny amount of momentum due to this which would only be eliminated when using a battery source in a self-integrated configuration).

There is also the issue of possible Lorentz forces from cables, and the issue of unequal heated surfaces and unequal surface areas of the EM Drive due to induction heating, producing unsymmetric thermal convection (if not tested in a vacuum): buoyancy resulting in pressure on the track, convection asymmetry resulting in line force (due to density asymmetry) and torque (due to the moment arm), and asymmetric thermal radiation asymmetry, which I will not repeat here in the interest of brevity, since they have been discussed in previous threads.

I see what your saying Dr. Rodal. But let's take a look at the air pressure and the forces that are brought to the beam and how small of an effect an accelerating drive would impact to the beam. It looks like monomorphic has a 4x4 hollow beam that the bearing surface is about 24" long. If he even inputs 10 PSI unto the hollow beam that gives a surface area of 10 PSI across one square inch. One side of the air bearing is 4x4x24 = 384 Square inches x 10PSI = 3840 pounds times 2 to include the other side 3840x2=7,680 pounds for a lifting force. He could float a truck on the beam.

The placement of the drive in the center balance point is minor the other issues. The jets aligned in rows symmetrically placed around the air beam, the carriage will have to "push" into these row of jets as it travels down the beam which will give a leading edge resistance when the carriage tries to move over it.

I might have done it a little differently using a solid hollow beam and building a large 12x24" PCV pipe airtank on top that could provide a regulated 3-4 PSI in a floating air bearing carriage assembly. Then balance the drive and  hardware.  This would eliminate issues that you and I just brought up.

My .02 cents is maybe worth .01 cent, but we're just being picky old fuddy dutties. ;)

Shell

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/22/2016 02:54 pm
Regarding the mysteries of patents, disclosures, claims, refutations, etc: A working EMdrive is bigger than patents. You could call it a military technology, or a world-changing invention. Many groups may be jostling for position in attempts to get valuable information, or funding, while at the same time protecting their own secrets. "Dirty tricks" may happen. My advice is to be wary.

Amen to that. What is happening here is actually pretty bizzare - people are trying to replicate what would be extremely valuable technology in open cyberspace - the equivalent of a sunny open field, where every so often strangers wander up and chip in comments. Particularly interesting are the visitors who say "That's definitely not worth trying!" or "This way not that way!" when there is no publicly accepted theory of operation. Wary is definitely good, as is being wary of conspiracy theories. Nonetheless "Cui Bono?" is a very good question to bear in mind.
The hibernating author in me is fascinated by all the drama surrounding the emdrive. It would make a great book...but I'm not in a writing mode. As a builder, I am very wary of advice, especially from those who are not building or testing. It certainly is worth trying and its been a great learning experience and polishing up my rusty electromechanical skills. Just need to stress that safety is first, these things can be deadly if in the wrong hands.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/22/2016 03:10 pm
I might have done it a little differently using a solid hollow beam and building a large 12x24" PCV pipe airtank on top that could provide a regulated 3-4 PSI in a floating air bearing carriage assembly. Then balance the drive and  hardware.  This would eliminate issues that you and I just brought up.

I'm still working on the air pressure system. Right now i'm using a simple shop vac and a PVC water valve to control the flow. It's crude, but works. However, the shop vac just can't generate the PSI past a certain point, so this air-track is limited in how much it can lift unless I switch to a more robust air system.

The whole apparatus must be balanced AND the glider must be balanced. The structure is balanced using 4 fine thread bolts attached to each foot. Works very well. The glider is balanced by hanging it by a wire.

I have no doubt there will be a lot of calibration required to get results.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/22/2016 03:13 pm
A summary of other experimental small forces. There is also the issue of how is the EM Drive powered.  Ideally it would be powered from a battery, self-integrated, as this would avoid issues due the fact that energy is transmitted from an outside source to the EM Drive (hence there is a tiny amount of momentum due to this which would only be eliminated when using a battery source in a self-integrated configuration).

I've always planned on going with a battery eventually. That's why I am pursuing the RF transmitter route as well. A system like that could be run with a couple of high discharge li-po RC batteries. Heck, with a 1200 watt inverter, I could run a 600 watt magnetron off RC batteries for several minutes at a time.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/22/2016 03:22 pm
I might have done it a little differently using a solid hollow beam and building a large 12x24" PCV pipe airtank on top that could provide a regulated 3-4 PSI in a floating air bearing carriage assembly. Then balance the drive and  hardware.  This would eliminate issues that you and I just brought up.

I'm still working on the air pressure system. Right now i'm using a simple shop vac and a PVC water valve to control the flow. It's crude, but works. However, the shop vac just can't generate the PSI past a certain point, so this air-track is limited in how much it can lift.

The whole apparatus must be balanced AND the glider must be balanced. The structure is balanced using 4 fine thread bolts attached to each foot. Works very well. The glider is balanced by hanging it by a wire.

I have no doubt there will be a lot of calibration required to get results.

I can see that air requirement going up very high Monomorphic when your providing air for the whole hollow beam instead of just a floating carriage.

When we did air bearing carriages for our dicing machines we didn't do the whole beam we did just the carriage and that dropped the air requirements orders of magnitude.

Fine tuning on a air bearing surface can be very fine work, you have that right.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/22/2016 04:40 pm
When we did air bearing carriages for our dicing machines we didn't do the whole beam we did just the carriage and that dropped the air requirements orders of magnitude.

If I attached an air system to the glider and got thrust, critics could claim it was torque from spinning fans/motors. I've seen this mentioned about Shawyer's demonstration model and the pump for the water coolant.

It's not so much that I need a much higher PSI, it's that the air-vac is simply incapable of providing more than a few PSI. The air backs out through the fan. The frustum floats now, but once loaded with batteries, magnetron and transformer... I may need to go to a pressurized tank. Once the RF transistor amp is completed, that should eliminate the heavy transformer and magnetron.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: FattyLumpkin on 03/22/2016 06:07 pm
Monomorphic , what does your modeling predict for "amount" expected thrust?  Thanks  ,
 F L
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/22/2016 06:34 pm
When we did air bearing carriages for our dicing machines we didn't do the whole beam we did just the carriage and that dropped the air requirements orders of magnitude.

If I attached an air system to the glider and got thrust, critics could claim it was torque from spinning fans/motors. I've seen this mentioned about Shawyer's demonstration model and the pump for the water coolant.

It's not so much that I need a much higher PSI, it's that the air-vac is simply incapable of providing more than a few PSI. The air backs out through the fan. The frustum floats now, but once loaded with batteries, magnetron and transformer... I may need to go to a pressurized tank. Once the RF transistor amp is completed, that should eliminate the heavy transformer and magnetron.


If you did a stand alone air tank on the top of the beam driving the carriage you could eliminate the air shooting from the rest of the beam causing issues if you drove it this way.
You can wrap the outside of the center area for strength. I've seen 100+ pound fishing line wrapped around to strengthen the walls laid in with a epoxy.

Like this http://beamalarm.com/Documents/building_an_external_air_compressor.html

I hope you don't mind me talking about your project.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/22/2016 06:46 pm
If you did a stand alone air tank on the top of the beam driving the carriage you could eliminate the air shooting from the rest of the beam causing issues if you drove it this way.
You can wrap the outside of the center area for strength. I've seen 100+ pound fishing line wrapped around to strengthen the walls laid in with a epoxy.

Like this http://beamalarm.com/Documents/building_an_external_air_compressor.html

I hope you don't mind me talking about your project.

Shell

I actually like this idea a lot. It would be easy to incorporate into the current design. It would eliminate the air-vac and noise associated with the motor and fan.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/22/2016 06:52 pm
Tuning section complete. To move the small end-plate through the tuning section simply turn the three wing nuts equally.

I hope to have the interferometer up and running soon. I have everything, I just need to figure out how to mount my beam splitter horizontally and create an adjustable mount for the laser.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/22/2016 07:17 pm
If you did a stand alone air tank on the top of the beam driving the carriage you could eliminate the air shooting from the rest of the beam causing issues if you drove it this way.
You can wrap the outside of the center area for strength. I've seen 100+ pound fishing line wrapped around to strengthen the walls laid in with a epoxy.

Like this http://beamalarm.com/Documents/building_an_external_air_compressor.html

I hope you don't mind me talking about your project.

Shell

I actually like this idea a lot. It would be easy to incorporate into the current design. It would eliminate the air-vac and noise associated with the motor and fan.

It would only take enough air pressure from the tank to "float" a couple thousands off the beam.  I found out I could float me standing on a flat 12"x12" air bearing on a smooth concrete floor with just a few pounds of air and surprising very little air flow.

 Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: X_RaY on 03/22/2016 07:19 pm
Tuning section complete. To move the small end-plate through the tuning section simply turn the three wing nuts equally.

I hope to have the interferometer up and running soon. I have everything, I just need to figure out how to mount my beam splitter horizontally and create an adjustable mount for the laser.
Hi,
is this a slot/gap between the frustum and the big end plate in your pic?
Please be aware of possible radiation through the gap using a high power level magnetron source! Such a gap can act as a kind of slot antenna. Safety first!!  :)

Best regards

BTW nice construction, good luck!!
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/22/2016 07:27 pm
is this a slot/gap between the frustum and the big end plate in your pic?
Please be aware of possible radiation through the gap using a high power level magnetron source! Such a gap can act as a kind of slot antenna.

Please note that there has not yet been any soldering on the build except for some of the internal components related to the tuning section. After happy with overall tolerances, I will slightly compress the frustum using clamps, which closes any gaps, and then flow the silver solder into the gaps.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/22/2016 08:49 pm
Such a gap can act as a kind of slot antenna. Safety first!!  :)

To illustrate what X-RaY is talking about I ran a sim of my build using perfect geometry and one with 2mm gaps along one side of all major joints.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/22/2016 09:23 pm
I also ran some sims using the tuning section. Based on this, I may remove the tuning section and run some tests with just the perfect geometry. I'm not so sure tuning will have much benefit for me as the dimensions were already highly optimized for TE311. The added complexity, with possible gaps may not be worth it. I can always add the tuning section later.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Oakey on 03/22/2016 10:54 pm
Hi Monomorphic, nice build. Do you have any info/pics of the beam splitter your using and how your detecting the interference?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/22/2016 11:23 pm
Hi Monomorphic, nice build. Do you have any info/pics of the beam splitter your using and how your detecting the interference?

This is the beam splitter I am using. http://www.edmundoptics.com/optics/beamsplitters/plate-beamsplitters/plate-beamsplitters/32269/ (http://www.edmundoptics.com/optics/beamsplitters/plate-beamsplitters/plate-beamsplitters/32269/)

The interference is seen in real time as fringe patterns. Displacement is measured by counting the fringe patterns as they move.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Oakey on 03/22/2016 11:29 pm
Thanks Monomorphic. Good luck with mounting it.
Title: EM Drive Developments - related to space flight applications - Thread 7
Post by: The_Optimist on 03/23/2016 10:55 am
http://www.bbc.com/news/magazine-35861334

Link to BBC article explaining the contents of the Horizon episode, Project Greenglow: The Quest for Gravity Control, broadcast at 20:00 GMT on BBC Two tonight
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SimonFD on 03/23/2016 10:55 am
Looks like the BBC Horizon programme is featuring EmDrive tonight in the UK
http://www.bbc.co.uk/news/magazine-35861334
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/23/2016 11:16 am
http://www.bbc.com/news/magazine-35861334

Link to BBC article explaining the contents of the Horizon episode, Project Greenglow: The Quest for Gravity Control, broadcast at 20:00 GMT on BBC Two tonight

Thank you for the BBC article.  Upon reading it, I noticed the following quote in this BBC article:

Quote
John Ellis at Cern is particularly scathing: "With the EmDrive, unlike a rocket, nothing comes out of it. So I don't see how you can generate momentum out of nothing."

Shawyer uses only Maxwell's laws and Special Relativity (not General Relativity !) to try to explain his EM Drive claimed anomalous results.  Ellis, is a British theoretical physicist who is currently Clerk Maxwell Professor of Theoretical Physics at King's College London. 

(https://upload.wikimedia.org/wikipedia/commons/thumb/9/9f/Johnellis.jpg/250px-Johnellis.jpg) Ellis attended King's College, Cambridge, earning his Ph.D. in physics in 1971. After brief post-doc positions at SLAC and Caltech, he went to CERN and has held an indefinite contract there since 1978. He was awarded the Maxwell Medal and the Paul Dirac Prize by the Institute of Physics in 1982 and 2005 respectively, and is an Elected Fellow of the Royal Society of London since 1985 and of the Institute of Physics since 1991.

With this background and interest, Ellis is the kind of scientist that Shawyer should reach for help, he could drive to see him.

Both Shawyer and Ellis are quoted in the BBC article.  So Shawyer must know about Ellis's opinion expressed in the BBC article.

Why doesn't Shawyer drive to see people like Ellis and tell him: please look at my experiments, I think they show an anomalous force.  The engineering and scientific community does not accept my explanation, could you please help me analyze my experiments?  Could you please help me with my force balance analysis and microwave force equations that are not accepted by the engineering and scientific community?

Since Prof. Ellis was interviewed by the BBC for the same program that featured Shawyer and Ellis twice won the highest award in the Gravity Research Foundation essay competition (in 1999 and 2005), it is not unreasonable to assume that Ellis would be willing to help Shawyer, and give him his scientific opinion.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/23/2016 01:12 pm
http://www.bbc.com/news/magazine-35861334

Link to BBC article explaining the contents of the Horizon episode, Project Greenglow: The Quest for Gravity Control, broadcast at 20:00 GMT on BBC Two tonight

Thank you for the BBC article.  Upon reading it, I noticed the following quote in this BBC article:

Quote
John Ellis at Cern is particularly scathing: "With the EmDrive, unlike a rocket, nothing comes out of it. So I don't see how you can generate momentum out of nothing."

Shawyer uses only Maxwell's laws and Special Relativity (not General Relativity !) to try to explain his EM Drive claimed anomalous results.  Ellis, is a British theoretical physicist who is currently Clerk Maxwell Professor of  Ellis attended King's College, Cambridge, earning his Ph.D. in physics in 1971. After brief post-doc positions at SLAC and Caltech, he went to CERN and has held an indefinite contract there since 1978. He was awarded the Maxwell Medal and the Paul Dirac Prize by the Institute of Physics in 1982 and 2005 respectively, and is an Elected Fellow of the Royal Society of London since 1985 and of the Institute of Physics since 1991.

With this background and interest, Ellis is the kind of scientist that Shawyer should reach for help, he could drive to see him.

Both Shawyer and Ellis are quoted in the BBC article.  So Shawyer must know about Ellis's opinion expressed in the BBC article.

Why doesn't Shawyer drive to see people like Ellis and tell him: please look at my experiments, I think they show an anomalous force.  The engineering and scientific community does not accept my explanation, could you please help me analyze my experiments?  Could you please help me with my force balance analysis and microwave force equations that are not accepted by the engineering and scientific community?

Since Prof. Ellis was interviewed by the BBC for the same program that featured Shawyer and Ellis twice won the highest award in the Gravity Research Foundation essay competition (in 1999 and 2005), it is not unreasonable to assume that Ellis would be willing to help Shawyer, and give him his scientific opinion.
Thank you for the Ellis quote. I believe it exemplifies what many experimenters have trouble with. If one has a genuine interest and would be willing to help, its best to state so; as opposed to "With the EmDrive, unlike a rocket, nothing comes out of it. So I don't see how you can generate momentum out of nothing."
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 01:12 pm
Since Prof. Ellis was interviewed by the BBC for the same program that featured Shawyer and Ellis twice won the highest award in the Gravity Research Foundation essay competition (in 1999 and 2005), it is not unreasonable to assume that Ellis would be willing to help Shawyer, and give him his scientific opinion.

Some background on how the Boeing Flight Thruster contract with SPR occurred. I suggest Roger went through a LOT of theory guys during the below process:

Quote from: Roger Shawyer email
In response to a recent request by a respected US journalist, I provided the following background information.

Background.

  EmDrive development started in 2001 at SPR Ltd, funded by UK government and monitored by MOD experts.

  Proof of concept phase completed by 2006 and all technical reports accepted by funding agencies.

  Export licence to US granted by UK government 2007. End User Undertaking states end user is US armed forces and purpose is use on a test satellite.

  December 2008. Meetings held in Washington (including in the Pentagon) with USAF, DARPA and NSSO.

  Technology Transfer Contract, covering the design and test of a Flight Thruster agreed with Boeing under a State Department TAA and completed in July 2010.

  2010 First reports of high thrust EmDrive results received from Xi’an University in China. All contact with Boeing then stopped and no public comment was permitted under the 5 year NDA.

 
In addition, I supplied a copy of the End User Undertaking signed by Boeing in 2007 which I have attached. This is an unclassified UK document which is available under the UK Freedom of Information Act. We will not release the large pile of American documents as I doubt that there is the same freedom in the US.

It is my understanding that during the Flight Thruster contract negotiation process, the Demonstrator EmDrive, spinning on the rotary test rig, was available and tested by the US interested parties.

Knowing the process SPR when through, it is very difficult to accept the US licensee did not have 100% solid proof the EmDrive worked and had a working theory PRIOR to awarding SPR the contract to build the Flight Thruster.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/23/2016 01:23 pm
"With the EmDrive, unlike a rocket, nothing comes out of it. So I don't see how you can generate momentum out of nothing."

"Thank you Captain Obvious!" was the first thing that popped into my mind when I read that quote. Hopefully the Clerk Maxwell Professor of Theoretical Physics can do a little better than that - like providing specific critiques of Shawyer's theory and experimental methodology. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Willem Staal on 03/23/2016 01:39 pm
 This look like a good read..

http://www.ibtimes.co.uk/emdrive-nasa-eagleworks-confirms-paper-controversial-space-propulsion-under-peer-review-1551210
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/23/2016 01:40 pm
"With the EmDrive, unlike a rocket, nothing comes out of it. So I don't see how you can generate momentum out of nothing."

"Thank you Captain Obvious!" was the first thing that popped into my mind when I read that quote. Hopefully the Clerk Maxwell Professor of Theoretical Physics can do a little better than that - like providing specific critiques of Shawyer's theory and experimental methodology.
It sure is frustrating that a top scientist cannot simply say "Look, I don't think the emdrive will work, but I'm willing to help you set up an experiment to prove me wrong. Perhaps we both can learn something in the process."

To me, this is such an easy thing to say. Then, if an experimenter says "no", shame on the experimenter.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 01:44 pm
This look like a good read..

http://www.ibtimes.co.uk/emdrive-nasa-eagleworks-confirms-paper-controversial-space-propulsion-under-peer-review-1551210

Interesting statement in that article:

Quote
Rodal is building his own version of the Nasa aluminium frustum, while pointing out how differences in dielectric materials, among other things, can affect how the results are interpreted.

Did I miss something?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Willem Staal on 03/23/2016 01:50 pm
This look like a good read..

http://www.ibtimes.co.uk/emdrive-nasa-eagleworks-confirms-paper-controversial-space-propulsion-under-peer-review-1551210

Interesting statement in that article:

Quote
Rodal is building his own version of the Nasa aluminium frustum, while pointing out how differences in dielectric materials, among other things, can affect how the results are interpreted.

Did I miss something?
Dunno, but you can bet other options than copper will be used for frustrums.  Paul Kocyla for instance  is working on a YBCO superconducter frustrum..
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 01:51 pm
"With the EmDrive, unlike a rocket, nothing comes out of it. So I don't see how you can generate momentum out of nothing."

"Thank you Captain Obvious!" was the first thing that popped into my mind when I read that quote. Hopefully the Clerk Maxwell Professor of Theoretical Physics can do a little better than that - like providing specific critiques of Shawyer's theory and experimental methodology.
It sure is frustrating that a top scientist cannot simply say "Look, I don't think the emdrive will work, but I'm willing to help you set up an experiment to prove me wrong. Perhaps we both can learn something in the process."

To me, this is such an easy thing to say. Then, if an experimenter says "no", shame on the experimenter.

That is how science is supposed to work. However we live in a world where mathematical models are built, instead of physical models and the results from the math models trump physical results, well at least in the case of the EmDrive.

Sad really, sad.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/23/2016 01:54 pm
...
Thank you for the Ellis quote. I believe it exemplifies what many experimenters have trouble with. If one has a genuine interest and would be willing to help, its best to state so; as opposed to "With the EmDrive, unlike a rocket, nothing comes out of it. So I don't see how you can generate momentum out of nothing."
Back in 1989 I was invited to give a paper at Cambridge University at a Conference (that was later published in book form).  I was lucky to have beautiful weather, I remember for example how beautiful it was to see punting on river cam, Bridge of Sighs, Cambridge University.

Since I was at Cambridge, I took advantage of the opportunity to call a famous Professor at Cambridge University I had never met, who had nothing to do with the conference I was attending, to ask to see him at his office. 

Much to my surprise, his secretary replied with a time at which I could meet the famous professor.  I remember the meeting well to this date: I was surprised that he was willing to talk for over an hour on a number of R&D subjects to somebody much younger, who he had never met.  The famous professor even went further, he invited me to have tea at a room in Cambridge University where famous professors gathered at tea time.  It was a memorable experience. 

The moral of this story is that one has to be willing to reach to famous knowledgeable people, as one has nothing to lose and much to gain and learn from talking to them.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/23/2016 02:07 pm
This look like a good read..

http://www.ibtimes.co.uk/emdrive-nasa-eagleworks-confirms-paper-controversial-space-propulsion-under-peer-review-1551210

Interesting statement in that article:

Quote
Rodal is building his own version of the Nasa aluminium frustum, while pointing out how differences in dielectric materials, among other things, can affect how the results are interpreted.

Did I miss something?
Dunno, but you can bet other options than copper will be used for frustrums.  Paul Kocyla for instance  is working on a YBCO superconducter frustrum..
Thank you but, the ibtimes article is incorrect.  I never posted at NSF that I was building my <<own version of the Nasa aluminium frustum>>
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/23/2016 02:15 pm
This look like a good read..

http://www.ibtimes.co.uk/emdrive-nasa-eagleworks-confirms-paper-controversial-space-propulsion-under-peer-review-1551210

Interesting statement in that article:

Quote
Rodal is building his own version of the Nasa aluminium frustum, while pointing out how differences in dielectric materials, among other things, can affect how the results are interpreted.

Did I miss something?
Dunno, but you can bet other options than copper will be used for frustrums.  Paul Kocyla for instance  is working on a YBCO superconducter frustrum..
Thank you but, the ibtimes article is incorrect.  I never posted at NSF that I was building building my <<own version of the Nasa aluminium frustum>>
Thank you for the clarification. The natural question is now "Are you building your own version of the EMdrive?".

I think your answer to this will clear it up for science writers who visit NSF.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/23/2016 02:20 pm
Has anyone tried modeling the fields inside the prototype C-band geometry? It seems this is a shape that is much easier to fabricate. Even if the end-plates are curved, they are done so along one axis and not as a hemisphere.

If Shawyer's hands are about the same size as mine, that would make it about 14cm high. Base looks about 10cm x 12 cm and the top 5m x 12 cm. I suspect the end-plates are machined to be curved. It also looks like the frustum material is aluminum. Will do a quick model and C-band sweep.

I suspect Shawyer is going higher in frequency so he can shrink the size of the emdrive. It might be interesting to see a 2.45Ghz emdrive in this shape.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 02:22 pm
Thank you but, the ibtimes article is incorrect.  I never posted at NSF that I was building my <<own version of the Nasa aluminium frustum>>

If you are ever interested in doing so, once I publish my min 20mN data, you will be able to access the full plans. Additionally fully built and tested frustums will be available.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 02:26 pm
Has anyone tried modeling the fields inside the prototype C-band geometry? It seems this is a shape that is much easier to fabricate. Even if the end-plates are curved, they are done so along one axis and not as a hemisphere.

If Shawyer's hands are about the same size as mine, that would make it about 14cm high. Base looks about 10cm x 12 cm and the top 5m x 12 cm. I suspect the end-plates are machined to be curved. It also looks like the frustum material is aluminum. Will do a quick model and C-band sweep.

I suspect Shawyer is going higher in frequency so he can shrink the size of the emdrive. It might be interesting to see a 2.45Ghz emdrive in this shape.

As far as I know, that was the 1st Flight Thruster prototype C band build. More data on that build is attached. Better image page 3.

I do note it is similar to the only cryo EmDrive photo that has been released to the public as attached.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/23/2016 02:41 pm
...Thank you for the clarification. The natural question is now "Are you building your own version of the EMdrive?".

I think your answer to this will clear it up for science writers who visit NSF.
The EM Drive is a completely closed metallic cavity.  I am not building a completely closed metallic cavity.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/23/2016 02:51 pm
...Thank you for the clarification. The natural question is now "Are you building your own version of the EMdrive?".

I think your answer to this will clear it up for science writers who visit NSF.
The EM Drive is a completely closed metallic cavity.  I am not presently building a completely closed metallic cavity.
Thank you Dr Rodal. The rephrased question remains, are you building your own version of a propellantless and/or electromagnetic thruster? (This sets aside the nomenclature of EMDrive being a closed metallic cavity which you correctly pointed out). Thank you in advance for your reply.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/23/2016 02:55 pm
...Thank you for the clarification. The natural question is now "Are you building your own version of the EMdrive?".

I think your answer to this will clear it up for science writers who visit NSF.
The EM Drive is a completely closed metallic cavity.  I am not presently building a completely closed metallic cavity.
Thank you Dr Rodal. The rephrased question remains, are you building your own version of a propellantless and/or electromagnetic thruster? (This sets aside the nomenclature of EMDrive being a closed metallic cavity which you correctly pointed out). Thank you in advance for your reply.
Off topic  :) for this thread <<EM Drive Developments - related to space flight applications>>
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Left Field on 03/23/2016 02:55 pm
...Thank you for the clarification. The natural question is now "Are you building your own version of the EMdrive?".

I think your answer to this will clear it up for science writers who visit NSF.
The EM Drive is a completely closed metallic cavity.  I am not building a completely closed metallic cavity.
So it is one of these possibilities:

Not completely closed & metallic
Completely closed & non-metallic
Not completely closed & non-metallic

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/23/2016 03:01 pm
...Thank you for the clarification. The natural question is now "Are you building your own version of the EMdrive?".

I think your answer to this will clear it up for science writers who visit NSF.
The EM Drive is a completely closed metallic cavity.  I am not building a completely closed metallic cavity.

I wish you the very best of luck!!!

Shell

PS: I think I see what you're doing but I will not let the cat out of the bag.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/23/2016 03:04 pm
...Thank you for the clarification. The natural question is now "Are you building your own version of the EMdrive?".

I think your answer to this will clear it up for science writers who visit NSF.
The EM Drive is a completely closed metallic cavity.  I am not presently building a completely closed metallic cavity.
Thank you Dr Rodal. The rephrased question remains, are you building your own version of a propellantless and/or electromagnetic thruster? (This sets aside the nomenclature of EMDrive being a closed metallic cavity which you correctly pointed out). Thank you in advance for your reply.
Off topic  :) for this thread <<EM Drive Developments - related to space flight applications>>
Dr Rodal, I totally understand and personally wish you the best of luck. Welcome to the (emdrive or whatever)  builders club.  8)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/23/2016 03:08 pm
I get something like this for the internal geometry of the c-band and superconducting. Left is flat end-plates, the right is curved. Will run sweep on flat geometry first. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 03:12 pm
...Thank you for the clarification. The natural question is now "Are you building your own version of the EMdrive?".

I think your answer to this will clear it up for science writers who visit NSF.
The EM Drive is a completely closed metallic cavity.  I am not presently building a completely closed metallic cavity.
Thank you Dr Rodal. The rephrased question remains, are you building your own version of a propellantless and/or electromagnetic thruster? (This sets aside the nomenclature of EMDrive being a closed metallic cavity which you correctly pointed out). Thank you in advance for your reply.
Off topic  :) for this thread <<EM Drive Developments - related to space flight applications>>

(mod note - Dr Rodal is pursuing something without disclosure and without us asking too many questions...not that we're not curious, but that's the way it is  :P )
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/23/2016 03:13 pm
I get something like this for the internal geometry of the c-band and superconducting. Left is flat end-plates, the right is curved. Will run sweep on flat geometry first.
Is the cavity at the left not axi-symmetric ?

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1106577;image)

In this picture it also looks looks not axi-symmetric:

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1106569;image)

Not sure whether this is an issue of parallax.  If not axi-symmetric, why do people think it would be made not axi-symmetric ?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 03:15 pm
I get something like this for the internal geometry of the c-band and superconducting. Left is flat end-plates, the right is curved. Will run sweep on flat geometry first.

On the non cryo unit, you can also get a very good idea of where the cavity was excited and where the smaller sample port was located.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 03:18 pm
Not sure whether this is an issue of parallax.  If not axi-symmetric, why do people think it would be made not axi-symmetric ?

Much better image of the C band thruster is attached.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/23/2016 03:22 pm
Not sure whether this is an issue of parallax.  If not axi-symmetric, why do people think it would be made not axi-symmetric ?

Much better image of the C band thruster is attached.
Thank you.  It appears to be axi-symmetric in that picture.  Makes more sense to me.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/23/2016 03:39 pm
Much better image of the C band thruster is attached.
Somebody knowledgeable about permits, perhaps can clarify:

Isn't the C band (4 to 8 GHz) reserved for long-distance radio telecommunications ?

Can one use the C band for these purposes ? (or was the C band only used for R&D purposes and he would not be able to use it for commercial purposes?)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/23/2016 03:39 pm
Is the cavity at the left not axi-symmetric ?

They are both axi-symmetric. I think it's just the perspective view I am using that makes it look weird.

I did a single frequency run first as the sweep take a while. This is at 6Ghz. Very interesting surface currents. Not sure which face Shawyer is injecting RF, so tried the other direction. Does anyone have an opinion which inject method I should use before I run the sweep?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/23/2016 03:42 pm
Does anyone have an opinion which inject method I should use before I run the sweep?

Is Shawyer injecting RF into both of these coax or is one for spectrum analysis?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/23/2016 03:53 pm
Does anyone have an opinion which inject method I should use before I run the sweep?

Is Shawyer injecting RF into both of these coax or is one for spectrum analysis?
Pure guess...alternative injection and sampling ports.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 03:59 pm
Much better image of the C band thruster is attached.
Somebody knowledgeable about permits, perhaps can clarify:

Isn't the C band (4 to 8 GHz) reserved for long-distance radio telecommunications ?

Can one use the C band for these purposes ? (or was the C band only used for R&D purposes and he would not be able to use it for commercial purposes?)

As I understand it Boeing designed the dual redundant Rf system based on space tech to work at 5.85GHz (C band). SPR then designed the Flight Thruster to work at that freq.

2nd sample port is visible on other photos of the Flight Thruster. It provides feedback to maintain freq is always at cavity resonance.

Flight Thruster electronics as attached.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/23/2016 04:01 pm
I had the rf source oriented the wrong way for this geometry. Here is a familiar friend TE012. I think I have the top part too narrow (below cutoff). Just guessing at the dimensions.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 04:03 pm
I had the rf source oriented the wrong way for this geometry. Here is a familiar friend TE012. I think I have the top part too narrow (below cutoff). Just guessing at the dimensions.

Roger told me the Flight Thruster worked in TE013 mode.

BTW the attached is not a round cryo thruster. It is more like a thick slice of Pizza that has a circular bite taken out of the pointy end.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/23/2016 04:04 pm
Roger told me the Flight Thruster worked in TE013 mode.

This would probably be TE013 if the top weren't cut off. I will have to try different dimensions.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/23/2016 04:05 pm
Much better image of the C band thruster is attached.
Somebody knowledgeable about permits, perhaps can clarify:

Isn't the C band (4 to 8 GHz) reserved for long-distance radio telecommunications ?

Can one use the C band for these purposes ? (or was the C band only used for R&D purposes and he would not be able to use it for commercial purposes?)
Its all over the map:

http://www.tech-faq.com/c-band.shtml
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 04:07 pm
Much better image of the C band thruster is attached.
Somebody knowledgeable about permits, perhaps can clarify:

Isn't the C band (4 to 8 GHz) reserved for long-distance radio telecommunications ?

Can one use the C band for these purposes ? (or was the C band only used for R&D purposes and he would not be able to use it for commercial purposes?)
Its all over the map:

http://www.tech-faq.com/c-band.shtml

As I understand it the 5.85GHz that the Flight Thruster worked at was decided by Boeing.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/23/2016 04:21 pm
Much better image of the C band thruster is attached.
Somebody knowledgeable about permits, perhaps can clarify:

Isn't the C band (4 to 8 GHz) reserved for long-distance radio telecommunications ?

Can one use the C band for these purposes ? (or was the C band only used for R&D purposes and he would not be able to use it for commercial purposes?)
Its all over the map:

http://www.tech-faq.com/c-band.shtml

As I understand it the 5.85GHz that the Flight Thruster worked at was decided by Boeing.
I've been out of satcom for years, but C band dishes disappeared long ago from people's yards. I haven't followed re-allocation of the band...if there has been one. Would have to think so since its been underutilized in recent years:

Direct broadcast satellite TV downlink (Europe) 11.7 to 12.5 GHz
Direct broadcast satellite TV downlink (US) for example, Echostar's Dish Network 12.2 to 12.7 GHz
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 05:25 pm
Seems a race is on.

May the best propellantless propulsion tech win.

While the worldwide DIY EmDrive builder community shares plans for anyone to replicate.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/23/2016 05:26 pm
I had the rf source oriented the wrong way for this geometry. Here is a familiar friend TE012. I think I have the top part too narrow (below cutoff). Just guessing at the dimensions.

Roger told me the Flight Thruster worked in TE013 mode.

BTW the attached is not a round cryo thruster. It is more like a thick slice of Pizza that has a circular bite taken out of the pointy end.
The drawing

(http://forum.nasaspaceflight.com/xindex.php,qaction=dlattach,3Btopic=39772.0,3Battach=1106595,3Bimage.pagespeed.ic.8F8wC3PhaV.webp)

was previously interpreted as a truncated spherical cone by others in previous EM Drive threads (if my memory is correct, there may have even been 3-D CAD renderings of such interpretation), which is a possible interpretation if one imagines the drawing to be a cross-section that can be rotated by 360 degrees about a vertical axis of axi-symmetry to form a solid spherical truncated cone (albeit excluding certain obvious left-right asymmetries, for example the RF feeding, etc.).

I assume (please correct me I am wrong) that Shawyer has disclosed to you that this is not representing a cross-section of a truncated spherical cone but instead it is

Quote
more like a thick slice of Pizza that has a circular bite taken out of the
small end.

Or that you have arrived at that conclusion based on Shawyer documents.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 05:34 pm
Quote
more like a thick slice of Pizza that has a circular bite taken out of the
small end.

Suggest you read Roger's papers and checkout the attached drawing, which shows the 8 cavities of the lift engine. Note their shape.

The spherical housing is stated to be 790mm is diameter, which implies each of the 8 cavity is fairly small, probably something like 100mm thick, 200mm high and 400mm wide.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Chrochne on 03/23/2016 05:53 pm
http://www.bbc.com/news/magazine-35861334

Link to BBC article explaining the contents of the Horizon episode, Project Greenglow: The Quest for Gravity Control, broadcast at 20:00 GMT on BBC Two tonight

Thank you for the BBC article.  Upon reading it, I noticed the following quote in this BBC article:

Quote
John Ellis at Cern is particularly scathing: "With the EmDrive, unlike a rocket, nothing comes out of it. So I don't see how you can generate momentum out of nothing."

Shawyer uses only Maxwell's laws and Special Relativity (not General Relativity !) to try to explain his EM Drive claimed anomalous results.  Ellis, is a British theoretical physicist who is currently Clerk Maxwell Professor of Theoretical Physics at King's College London. 

(https://upload.wikimedia.org/wikipedia/commons/thumb/9/9f/Johnellis.jpg/250px-Johnellis.jpg) Ellis attended King's College, Cambridge, earning his Ph.D. in physics in 1971. After brief post-doc positions at SLAC and Caltech, he went to CERN and has held an indefinite contract there since 1978. He was awarded the Maxwell Medal and the Paul Dirac Prize by the Institute of Physics in 1982 and 2005 respectively, and is an Elected Fellow of the Royal Society of London since 1985 and of the Institute of Physics since 1991.

With this background and interest, Ellis is the kind of scientist that Shawyer should reach for help, he could drive to see him.

Both Shawyer and Ellis are quoted in the BBC article.  So Shawyer must know about Ellis's opinion expressed in the BBC article.

Why doesn't Shawyer drive to see people like Ellis and tell him: please look at my experiments, I think they show an anomalous force.  The engineering and scientific community does not accept my explanation, could you please help me analyze my experiments?  Could you please help me with my force balance analysis and microwave force equations that are not accepted by the engineering and scientific community?

Since Prof. Ellis was interviewed by the BBC for the same program that featured Shawyer and Ellis twice won the highest award in the Gravity Research Foundation essay competition (in 1999 and 2005), it is not unreasonable to assume that Ellis would be willing to help Shawyer, and give him his scientific opinion.

Interesting opinion Dr. Rodal. However, Mr. Shawyer is ridiculed from the start he came up with the idea. If I would be on his place, I would be very careful to work with science community. Perhaps, it is the science community and those respectable scientists you speak about, that need to approach Mr. Shawyer now. He tried to approach them for decades, only to be harshly put back to "his place". And please do not take this as offensive from my side. I am just trying to read what he must went trought.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/23/2016 06:18 pm
BBC Horizon should be playing now...when their link appears...be sure and share!  ;D
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 06:22 pm
BBC Horizon should be playing now...when their link appears...be sure and share!  ;D

It will be probably be Geo blocked outside the UK.

My phone says 30 minutes till it starts.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Chrochne on 03/23/2016 06:27 pm
BBC Horizon should be playing now...when their link appears...be sure and share!  ;D

http://www.time4tv.com/2011/09/bbc-two.php

try this... I think and click on streams until you find working one.

PS: I just checked it with the  programm it is live and It works for people outside UK.
It will pop window out, where stream works. You might want to check your ad-blocks if dont and allow it for the time of watching and than restore it back...

http://www.bbc.co.uk/bbctwo/programmes
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/23/2016 06:38 pm
Popular Mechanics article today on EMDrive:

http://www.popularmechanics.com/space/news/a20076/the-emdrive-will-undergo-peer-review-that-it-wont-pass/

On record as dismissing the possibility, now seems they're covering their bets:

"Of course, there's the small-fraction-of-a-chance that it could survive the peer review process, at which point it maybe, just maybe, EmDrive technology has a ghost of a chance of being a reality."
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 06:40 pm
BBC Horizon should be playing now...when their link appears...be sure and share!  ;D

http://www.time4tv.com/2011/09/bbc-two.php

try this... I think and click on streams until you find working one.

PS: I just checked it with the  programm it is live and It works for people outside UK.
It will pop window out, where stream works. You might want to check your ad-blocks if dont and allow it for the time of watching and than restore it back...

http://www.bbc.co.uk/bbctwo/programmes

Stream 3 works for me. Farming video on now, then GreenGlow.
Title: EM Drive Developments - related to space flight applications - Thread 7
Post by: Star One on 03/23/2016 06:54 pm
Popular Mechanics article today on EMDrive:

http://www.popularmechanics.com/space/news/a20076/the-emdrive-will-undergo-peer-review-that-it-wont-pass/

On record as dismissing the possibility, now seems they're covering their bets:

"Of course, there's the small-fraction-of-a-chance that it could survive the peer review process, at which point it maybe, just maybe, EmDrive technology has a ghost of a chance of being a reality."

Wasn't it the very same PM that recently featured an article about the upper stage for ExoMars exploding which it doesn't actually seem to have?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 07:32 pm
They showed the air track with an EmDrive on a self contained, self powered platform moving by itself.

Have videoed the segment & will shortly post.

Nicely done Roger!!!!
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: tchernik on 03/23/2016 07:38 pm
They also show Dr. Tajmar, and he seems to still be working at it. Sweet.  ;D
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 07:41 pm
They also show Dr. Tajmar, and he seems to still be working at it. Sweet.  ;D

Dr. Tajmar's EmDrive build is about as bad as it gets.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/23/2016 07:57 pm
Roger told me the Flight Thruster worked in TE013 mode.

Got TE013 in the "pizza slice" frustum. I could likely adjust the dimensions to make TE013 work at 2.45Ghz.

https://youtu.be/-qTLkVGu9iI
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Oakey on 03/23/2016 07:59 pm
Anyone know who the military guy 'coyote' is?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/23/2016 08:00 pm
Quote
more like a thick slice of Pizza that has a circular bite taken out of the
small end.

Suggest you read Roger's papers and checkout the attached drawing, which shows the 8 cavities of the lift engine. Note their shape.

The spherical housing is stated to be 790mm is diameter, which implies each of the 8 cavity is fairly small, probably something like 100mm thick, 200mm high and 400mm wide.
Thank you.  What paper is is the attached Fig. 5 from?  Please provide a link (preferably) or the reference (authors, title, journal, date, etc.).

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1106600;image)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/23/2016 08:03 pm
They also show Dr. Tajmar, and he seems to still be working at it. Sweet.  ;D

Dr. Tajmar's EmDrive build is about as bad as it gets.
My hope is that he will build a more "conventional" size...glad he's pursuing.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 08:05 pm
Self powered EmDrive on an air track.

More to add as I process them.

BTW Roger told me all the tech he could show had to be old stuff.

Images Courtesy of BBC Horizon.

(Mod note - Be sure to include "Image Courtesy of BBC Horizon")

Well past my bedtime. Nite all. Yes I did record the whole episode.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 08:17 pm
Thank you.  What paper is is the attached Fig. 5 from?  Please provide a link (preferably) or the reference (authors, title, journal, date, etc.).

Try Roger's latest & peer reviewed paper:
http://www.emdrive.com/IAC14publishedpaper.pdf
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/23/2016 08:23 pm
Self powered EmDrive on an air track.

More to add as I process them.

BTW Roger told me all the tech he could show had to be old stuff.

Images Courtesy of BBC Horizon.

(Mod note - Be sure to include "Image Courtesy of BBC Horizon")

Well past my bedtime. Nite all. Yes I did record the whole episode.

HA! He's using two airtracks with the emdrive mounted between. An idea I know I've discussed with others in the past.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/23/2016 08:29 pm
This image is particularly important. It shows that the large end-plate is perfectly square. It also shows the emdrive next to standard sizes of aluminum angle.  I can use these standard sizes to get almost exact dimensions for his c-band emdrive. Then it should be a simple scaling problem to get it working at 2.45Ghz.
Title: EM Drive Developments - related to space flight applications - Thread 7
Post by: Star One on 03/23/2016 08:44 pm
Did you see this magazine article from the BBC?

Quote
One device survived, almost unnoticed, from the Greenglow days - a propellant-less electromagnetic or EmDrive, created by British aerospace engineer Roger Shawyer.
What sets the EmDrive apart from other concepts? As Shawyer puts it: "We're no longer looking to control gravity itself. We're beating gravity the smart way." Because the EmDrive actually appears to do something. In tests, it seems to move under its own steam.

http://www.bbc.co.uk/news/magazine-35861334
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 09:05 pm
This image is particularly important. It shows that the large end-plate is perfectly square. It also shows the emdrive next to standard sizes of aluminum angle.  I can use these standard sizes to get almost exact dimensions for his c-band emdrive. Then it should be a simple scaling problem to get it working at 2.45Ghz.

Try 3.85GHz.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: FattyLumpkin on 03/23/2016 09:37 pm
Changing subject back to open cavity thruster. Operating on Sonny's assertion that RF energy can act upon the QV.
1st image...What does this remind you of? (the copper item being the most germane [for now])
The second image: far more familiar?
Take 3rd image (the horn) and inject RF into a multiple of these cavities (image 4) and you end up with:  high volume , high Q,  OPEN END, directional thrust?    F. L.     It was just a thought. --so here it is...
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/23/2016 09:37 pm
Higher resolution images posted here: http://imgur.com/a/EBw08
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: FattyLumpkin on 03/23/2016 09:41 pm
 In image four the proton beam et al related to a LINAC should be ignored+ sorry about redundant image 5 (same as image 1)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: skrock on 03/23/2016 10:10 pm
They showed the air track with an EmDrive on a self contained, self powered platform moving by itself.

Have videoed the segment & will shortly post.

Nicely done Roger!!!!

Hi TT, Please correct me if I'm mistaken, but to me it (Horizon segment) just showed Roger pushing it with his hands.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/23/2016 10:18 pm
Based on a quick analysis of the video, and the convenient fact that the UK sells angle aluminum in inches like the US, I have come to these dimensions for the c-band "flare" emdrive shown in the BBC video.

Please note, the units shown in the image are cm, and I have tried to estimate the interior cavity, not the exterior dimensions.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Star One on 03/23/2016 10:34 pm

Popular Mechanics article today on EMDrive:

http://www.popularmechanics.com/space/news/a20076/the-emdrive-will-undergo-peer-review-that-it-wont-pass/

On record as dismissing the possibility, now seems they're covering their bets:

"Of course, there's the small-fraction-of-a-chance that it could survive the peer review process, at which point it maybe, just maybe, EmDrive technology has a ghost of a chance of being a reality."

More straightforward article without the additional commentary.

http://www.ibtimes.co.uk/emdrive-nasa-eagleworks-confirms-paper-controversial-space-propulsion-under-peer-review-1551210
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: FattyLumpkin on 03/23/2016 10:50 pm
DaileyMail : Is deep space travel a step closer to reality? Nasa reveals successful test of 'impossible' fuel-free engine that breaks the laws of physics

Read more: http://www.dailymail.co.uk/sciencetech/article-3305990/Nasa-conducts-secret-tests-impossible-engine-Study-reveals-fuel-free-thrusters-work-no-one-knows-why.html#ixzz43lzBhbSA
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Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: knowles2 on 03/23/2016 11:05 pm
Just wondering does Roger Sawyer still works alone or does he have other people with him at SPR Ltd?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/23/2016 11:10 pm
It appears a full size version is on the workbench by the blue parts bin In the background. It also appears to have brackets for affixing to airtrack. The smaller one appears dusty and not often shown or used. Amateur photo analysis, of course...

(http://i.imgur.com/VnPA5ap.jpg)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/23/2016 11:12 pm
It appears a full size version is on the workbench by the blue parts bin In the background. It also appears to have brackets for affixing to airtrack. The smaller one appears dusty and not often shown or used. Amateur photo analysis, of course...

That is the smaller one on the airtrack. In the video it is moving to the end, where it stops. It just looks like it is sitting on the workbench because of perspective.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/23/2016 11:13 pm
From the label in the images, it looks like Shawyer is using one of these amps: http://www.maltd.com/am5.html
http://www.maltd.com/power-amplifiers-25-watts-am4.html

EDIT: I misidentified the amp. This is the correct one: http://www.maltd.com/am49.html
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/23/2016 11:16 pm
It appears a full size version is on the workbench by the blue parts bin In the background. It also appears to have brackets for affixing to airtrack. The smaller one appears dusty and not often shown or used. Amateur photo analysis, of course...

(http://i.imgur.com/VnPA5ap.jpg)

Roger told me he could only show an old non cryo EmDrive because of several reasons.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/23/2016 11:27 pm
Able to get much stronger TE013 from estimated dimensions from BBC video. Honing in on the mode and trying to shift the dimensions to 2.45Ghz now. TE013 was found at ~4.78Ghz using estimated dimensions.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/23/2016 11:28 pm
It appears a full size version is on the workbench by the blue parts bin In the background. It also appears to have brackets for affixing to airtrack. The smaller one appears dusty and not often shown or used. Amateur photo analysis, of course...

That is the smaller one on the airtrack. In the video it is moving to the end, where it stops. It just looks like it is sitting on the workbench because of perspective.
Good call thanks jamie
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/23/2016 11:43 pm
Another observation. Shawyer has a very robust circular rotating winch system installed in the ceiling of his laboratory. It appears aligned so he can lower emdrives, some rather large obviously, onto the heavily reinforced dual air-track system.

Roger is experimenting with much larger systems than what is shown!



Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: A_M_Swallow on 03/23/2016 11:46 pm
I see the Daily Mail article reported these threads and nasaspaceflight.com.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: meberbs on 03/24/2016 12:10 am
...
Interesting opinion Dr. Rodal. However, Mr. Shawyer is ridiculed from the start he came up with the idea. If I would be on his place, I would be very careful to work with science community. Perhaps, it is the science community and those respectable scientists you speak about, that need to approach Mr. Shawyer now. He tried to approach them for decades, only to be harshly put back to "his place". And please do not take this as offensive from my side. I am just trying to read what he must went trought.

Shawyer's basic description of what he claims is roughly that he has found "a closed, propellentless system which generates thrust but does not break conservation of momentum". That part in quotes translates to physicists as "This breaks conservation of momentum, but does not break conservation of momentum." In response to this being pointed out as fundamentally inconsistent, he has written multiple papers all of which contain multiple major errors, and most of which pile so many errors on top of each other that by the end, his statements are too far removed from reality to even classify as correct or incorrect.

Unless Shawyer shows willingness to accept that there are flaws in his "theory" (such as by asking for help in the ways Rodal has suggested) I do not see how the scientific community can be expected to engage further with him.

That is how science is supposed to work. However we live in a world where mathematical models are built, instead of physical models and the results from the math models trump physical results, well at least in the case of the EmDrive.

Sad really, sad.

This is entirely untrue. The models that mathematical models that physicists use have been developed to match reality very closely over literally hundreds of years. The limits of applicability for them are known (e.g. Newtownian mechanics does not work at speeds approaching c). Scientists have no problem with modifying them when experiments show they do not match reality (see the cosmological constant for example).

In the case of the EM drive, the models that are used are Maxwell's equations (such as in Egan's solutions). These are the same equations that are at the root of Cullen's result which is one of many, many experiments that validate them.

Shawyer is the only one who may be taking mathematical models over physical reality here.* He takes Cullen's result for a constant area wave guide, and uses it outside its region of applicability, by using it for a frustum resonator. This is taking a mathematical model and applying it while ignoring physical reality, which is what you are accusing others of. I have a simple example of the type of mistake to clarify:

Take a math model of a constant velocity particle in 1D motion:
x = x0 +v0*t
the particle will be at point x1 at time (x1-x0)/v0.

Now lets apply that to a particle with constant acceleration. (after all, constant velocity means constant acceleration of 0)
The model still says that the particle will be at point x1 at time (x1-x0)/v0.
We then run an experiment and find that it actually takes a time that happens to be dependent on the value of the acceleration. We should have used the model with the applicability to this situation: x = x0 +v*t +0.5*a*t^2

In this case, Shawyer is using Cullen's result which has a narrow applicability, rather than backing up to the more general model Cullen's result originates from which is known to have a wide range of applicability including a frustum resonator. (All of the finite element programs used in this thread use Maxwell's equations as their basis and have shown good matching with the observed resonances by DIYers)

*I cannot speak to Shawyer's experiments, but none of the experiments performed by anyone who has released enough information to analyze their experiment have shown sufficient thrust to even characterize how the physical models should be updated, if there is any need to at all.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: knowles2 on 03/24/2016 12:19 am
If he builds one that can lift 9 tonnes, then they will have no option but to engage with him, because even if his theory is completely wrong, his engines would clearly be working and the best way to build up the theory would be to experiment with working engines.  Sawyer approach seem to be just build his engines an see if they work, if they don't move on to the next design.

If some photographs analyse here is right it would be nice to see some of his bigger engines.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/24/2016 12:41 am
This image is particularly important. It shows that the large end-plate is perfectly square. It also shows the emdrive next to standard sizes of aluminum angle.  I can use these standard sizes to get almost exact dimensions for his c-band emdrive. Then it should be a simple scaling problem to get it working at 2.45Ghz.
It makes perfect sense that the end plate is square rather than rectangular, because the Q quality factor of resonance is maximized for a square cross-section.  A rectangular cross-section (with unequal sides), all other things being equal, would have lower Q than a square cross section.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: mwvp on 03/24/2016 12:50 am
...Thank you for the clarification. The natural question is now "Are you building your own version of the EMdrive?".

I think your answer to this will clear it up for science writers who visit NSF.
The EM Drive is a completely closed metallic cavity.  I am not building a completely closed metallic cavity.
So it is one of these possibilities:

Not completely closed & metallic
Completely closed & non-metallic
Not completely closed & non-metallic



Last night, while viewing http://emlab.utep.edu/ee5390em21.htm lecture 13 and 14 on metamaterials and photonic crystals, it occurred to me that a frustrum, either solid or shell, may be possible that has lower loss than copper at ambient temperature. First thing that comes to mind would be a very low loss alumina aerogel.

This article: http://arxiv.org/abs/1506.01099 discusses using a dielectric sphere to boost cavity Q, by pulling flux away from sidewalls and reducing induced currents, however there's a couple problems.

First, boosting the Q from ~10,000 to 100k or millions may result in intensities which lead to breakdown, especially around the dielectric marble.

Second, there's Fresnel drag. The marble will be moving in the same inertial frame as the frustrum, dragging flux with it. It may be the Abraham, rather than the Minkowski radiation momenta responsible for a doppler/acceleration induced momenta imbalance and thrust.

A metallic reflector doesn't drag much flux at all along with it, and is the surface the radiation reacts against. I can see why Shawyer might not think well of dielectrics, save for fine-tuning.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: mwvp on 03/24/2016 12:58 am

...Ellis is the kind of scientist that Shawyer should reach for help
...
Why doesn't Shawyer drive to see people like Ellis and tell him: please look at my experiments

Perhaps Shawyer is trying to have his cake and eat it. He doesn't want clever folks figuring it out, and besting or not needing him, so he contrives an obvious bogus theory to be dismissed off-hand by experts while hyping promises of hover-cars and green orbiting solar panels to the press to get government funding. Or he's simply mistaken. Or its a scam. The last two don't seem likely, as he would either consider the criticism, or devise a more elaborate new-physics theory impossible to validate.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/24/2016 12:59 am
From the label in the images, it looks like Shawyer is using one of these amps: http://www.maltd.com/am5.html
http://www.maltd.com/power-amplifiers-25-watts-am4.html

I misidentified the amp. This is the correct one: http://www.maltd.com/am49.html
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/24/2016 01:56 am
Another observation. Shawyer has a very robust circular rotating winch system installed in the ceiling of his laboratory. It appears aligned so he can lower emdrives, some rather large obviously, onto the heavily reinforced dual air-track system.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1106690;image)

Roger is experimenting with much larger systems than what is shown!
How sure are you that that is a winch system? It looks like something else to me.   Why would a winch have a guard around its periphery ?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/24/2016 02:28 am
Another observation. Shawyer has a very robust circular rotating winch system installed in the ceiling of his laboratory. It appears aligned so he can lower emdrives, some rather large obviously, onto the heavily reinforced dual air-track system.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1106690;image)

Roger is experimenting with much larger systems than what is shown!
How sure are you that that is a winch system? It looks like something else to me.   Why would a winch have a guard around its periphery ?
I thought it was a fan... but what do I know?

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: zen-in on 03/24/2016 05:19 am
Another observation. Shawyer has a very robust circular rotating winch system installed in the ceiling of his laboratory. It appears aligned so he can lower emdrives, some rather large obviously, onto the heavily reinforced dual air-track system.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1106690;image)

Roger is experimenting with much larger systems than what is shown!
How sure are you that that is a winch system? It looks like something else to me.   Why would a winch have a guard around its periphery ?

Maybe it's the part of his EM-Drive invention no one else knows about.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: FattyLumpkin on 03/24/2016 05:26 am
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Chrochne on 03/24/2016 05:35 am
My intelligence network just sent me a link on whole document of the Project Greenglow - The Quest for Gravity Control

http://www.dailymotion.com/video/x3zqmo9

Enjoy :D.

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Willem Staal on 03/24/2016 06:29 am
I've learned a lot about metal working the past couple of weeks, regarding flatness. If it looks flat...it really isn't.

The 1/8 copper disk (small diameter) looked great from the supplier until I put it on a lapping plate with a backing disk. Progressing from 60 to 2000 grit sandpaper, I was amazed at the material I had to remove to make it close to "flat".

At 2000 grit last night, serious striations are gone but there is still a micron level "unflatness" even after about 4 hours of hand sanding. What this taught me is there is almost no way DIYers can ever achieve perfection in sidewalls. I agree its desirable to maintain shape and symmetry, but I think its best not to worry about it too much. A fully machined and polished frustum is well beyond our budgets. I received a quote for leveling and polishing the small endplate and it was $675  :o
I wonder.. Does the overall thickness of the front and endplate of the frustrum have any effect on the endresult? Maybe its better to have a thick copperplate for the small end and a thin copperplate for the big end..
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: knowles2 on 03/24/2016 08:48 am

...Ellis is the kind of scientist that Shawyer should reach for help
...
Why doesn't Shawyer drive to see people like Ellis and tell him: please look at my experiments

Perhaps Shawyer is trying to have his cake and eat it. He doesn't want clever folks figuring it out, and besting or not needing him, so he contrives an obvious bogus theory to be dismissed off-hand by experts while hyping promises of hover-cars and green orbiting solar panels to the press to get government funding. Or he's simply mistaken. Or its a scam. The last two don't seem likely, as he would either consider the criticism, or devise a more elaborate new-physics theory impossible to validate.
Or perhaps he just doesn't really care about the theory and it more interested in the practical sides of building bigger, better EM-Drives and scaling up his engines to the point where critics can argue about the maths and the physics till they are blue in the face, he will just leave his engine floating in the middle of the room for them all to observe while they do it.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: spupeng7 on 03/24/2016 10:07 am
After five years of typing 'emdrive' into the arXiv search box I finally got a match  8)
This is about Lorentz forces on balance beams  :)

BBC picture of Shawyer from magazine because we can't get BBC iview in Aussieland  :-\
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/24/2016 11:59 am
I've learned a lot about metal working the past couple of weeks, regarding flatness. If it looks flat...it really isn't.

The 1/8 copper disk (small diameter) looked great from the supplier until I put it on a lapping plate with a backing disk. Progressing from 60 to 2000 grit sandpaper, I was amazed at the material I had to remove to make it close to "flat".

At 2000 grit last night, serious striations are gone but there is still a micron level "unflatness" even after about 4 hours of hand sanding. What this taught me is there is almost no way DIYers can ever achieve perfection in sidewalls. I agree its desirable to maintain shape and symmetry, but I think its best not to worry about it too much. A fully machined and polished frustum is well beyond our budgets. I received a quote for leveling and polishing the small endplate and it was $675  :o
I wonder.. Does the overall thickness of the front and endplate of the frustrum have any effect on the endresult? Maybe its better to have a thick copperplate for the small end and a thin copperplate for the big end..
Good question, I took Rodal's thoughts of thicker material, which solved a possible problem of buckling on the endplates and also provided a surface easier to polish and flatten. Am not certain on the outcome, but the testing in May should give us an answer. The sidewalls are about 1 mm thickness.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/24/2016 12:06 pm
I've learned a lot about metal working the past couple of weeks, regarding flatness. If it looks flat...it really isn't.

The 1/8 copper disk (small diameter) looked great from the supplier until I put it on a lapping plate with a backing disk. Progressing from 60 to 2000 grit sandpaper, I was amazed at the material I had to remove to make it close to "flat".

At 2000 grit last night, serious striations are gone but there is still a micron level "unflatness" even after about 4 hours of hand sanding. What this taught me is there is almost no way DIYers can ever achieve perfection in sidewalls. I agree its desirable to maintain shape and symmetry, but I think its best not to worry about it too much. A fully machined and polished frustum is well beyond our budgets. I received a quote for leveling and polishing the small endplate and it was $675  :o
I wonder.. Does the overall thickness of the front and endplate of the frustrum have any effect on the endresult? Maybe its better to have a thick copperplate for the small end and a thin copperplate for the big end..
Good question, I took Rodal's thoughts of thicker material, which solved a possible problem of buckling on the endplates and also provided a surface easier to polish and flatten. Am not certain on the outcome, but the testing in May should give us an answer. The sidewalls are about 1 mm thickness.
Let's also remember Minotti's theory of gravito-electromagnetism to explain an anomalous force of the EM Drive:

http://arxiv.org/abs/1302.5690

Minotti predicts a force proportional to the thickness of metal used in the cavity, as long as the thickness is thin enough (of the order of 1 mm).  The thicker the cavity, the greater the force according to Minotti.
2 mm thick cavity = twice the force of a 1 mm thick cavity, everything else being the same, at microwave frequencies.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/24/2016 12:32 pm
Another observation. Shawyer has a very robust circular rotating winch system installed in the ceiling of his laboratory. It appears aligned so he can lower emdrives, some rather large obviously, onto the heavily reinforced dual air-track system.

(https://forum.nasaspaceflight.com/index.php?action=dlattach;topic=39772.0;attach=1106690;image)

Roger is experimenting with much larger systems than what is shown!
How sure are you that that is a winch system? It looks like something else to me.   Why would a winch have a guard around its periphery ?
I thought it was a fan... but what do I know?

Shell

I agree 100% that it is a fan.

My industrial experience is with massive overhead cranes.  I am very familiar with 50 ton, 75 ton and up to 100 ton overhead cranes (including double girder cranes).  I'm not familiar with any <<circular rotating winch system >> overhead lifting system, but it strikes me that the blades are way too flimsy to be able to be structural parts of a lifting system.

An industrial fan as the one shown in the picture is commonplace, and it is useful to rapidly evacuate the room from any fumes, and for facilities (as usual in Europe) without air conditioning, it can be quite pleasant to have in the summer. 

When it's cold, fans can also be a big help with helping draw hot air in from the ceiling to circulate lower to the ground, and move the air better, since hot air naturally rises.

The guard at the periphery, as well as the blades are typical of industrial overhead fans.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: TheTraveller on 03/24/2016 12:39 pm
I noticed the Rf amp doesn't appear to have power applied & Roger is seen to be pushing the platform. Have emailed Roger to explain

He did tell me the air track was designed for high thrust cryo drives & he was limited to showing only non cryo thrusters that were not embargoed.

The unit he showed was 2008 vintage & a build prior to the Flight Thruster. At 80W Rf input, thrust was probably only 20mN, so a lot lower than say 100N for a cryo thruster.

A direct link to the video is here:
http://www.dailymotion.com/video/x3zqmo9#video/x3zqmo9

Phil
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/24/2016 12:40 pm
I've learned a lot about metal working the past couple of weeks, regarding flatness. If it looks flat...it really isn't.

The 1/8 copper disk (small diameter) looked great from the supplier until I put it on a lapping plate with a backing disk. Progressing from 60 to 2000 grit sandpaper, I was amazed at the material I had to remove to make it close to "flat".

At 2000 grit last night, serious striations are gone but there is still a micron level "unflatness" even after about 4 hours of hand sanding. What this taught me is there is almost no way DIYers can ever achieve perfection in sidewalls. I agree its desirable to maintain shape and symmetry, but I think its best not to worry about it too much. A fully machined and polished frustum is well beyond our budgets. I received a quote for leveling and polishing the small endplate and it was $675  :o
I wonder.. Does the overall thickness of the front and endplate of the frustrum have any effect on the endresult? Maybe its better to have a thick copperplate for the small end and a thin copperplate for the big end..
Good question, I took Rodal's thoughts of thicker material, which solved a possible problem of buckling on the endplates and also provided a surface easier to polish and flatten. Am not certain on the outcome, but the testing in May should give us an answer. The sidewalls are about 1 mm thickness.
Let's also remember Minotti's theory of gravito-electromagnetism to explain an anomalous force of the EM Drive:

http://arxiv.org/abs/1302.5690

Minotti predicts a force proportional to the thickness of metal used in the cavity, as long as the thickness is thin enough (of the order of 1 mm).  The thicker the cavity, the greater the force according to Minotti.
2 mm thick cavity = twice the force of a 1 mm thick cavity, everything else being the same, at microwave frequencies.
Endplates are ~3.1 mm after lapping and polishing. (edit - proper term is lapping, not planing).
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/24/2016 12:49 pm
I noticed the Rf amp doesn't appear to have power applied & Roger is seen to be pushing the platform. Have emailed Roger to explain

He did tell me the air track was designed for high thrust cryo drives & he was limited to showing only non cryo thrusters that were not embargoed.

The unit he showed was 2008 vintage & a build prior to the Flight Thruster. At 80W Rf input, thrust was probably only 20mN, so a lot lower than say 100N for a cryo thruster.

A direct link to the video is here:
http://www.dailymotion.com/video/x3zqmo9#video/x3zqmo9

Phil

Let's look at this realistically not taking sides with a  open mind.


I also saw he pushed it on the air track and he did it both directions. I also realized that this might not have been a real test drive as it was covered in dust from not being used. Also there was no battery or inverter to drive the RF Amp so it wasn't even working.


I also noticed on the back wall sitting on a table a larger frustum that he made sure you could see.


With this video I'm left with two possibilities. 


1. He was prevented from showing a working model by NDAs and couldn't even power it up to show it working. Hence the drive that was obviously not a real working model.


2. It wasn't working and he just obviously  pushed it.


It seems like he would have hidden it better if he was perpetrating a scam and it didn't work. Doesn't It? He is no real dummy to be that obvious to push the darn thing. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/24/2016 01:21 pm
I noticed the Rf amp doesn't appear to have power applied & Roger is seen to be pushing the platform. Have emailed Roger to explain

He did tell me the air track was designed for high thrust cryo drives & he was limited to showing only non cryo thrusters that were not embargoed.

The unit he showed was 2008 vintage & a build prior to the Flight Thruster. At 80W Rf input, thrust was probably only 20mN, so a lot lower than say 100N for a cryo thruster.

A direct link to the video is here:
http://www.dailymotion.com/video/x3zqmo9#video/x3zqmo9

Phil

Let's look at this realistically not taking sides with a  open mind.


I also saw he pushed it on the air track and he did it both directions. I also realized that this might not have been a real test drive as it was covered in dust from not being used. Also there was no battery or inverter to drive the RF Amp so it wasn't even working.


I also noticed on the back wall sitting on a table a larger frustum that he made sure you could see.


With this video I'm left with two possibilities. 


1. He was prevented from showing a working model by NDAs and couldn't even power it up to show it working. Hence the drive that was obviously not a real working model.


2. It wasn't working and he just obviously  pushed it.


It seems like he would have hidden it better if he was perpetrating a scam and it didn't work. Doesn't It? He is no real dummy to be that obvious to push the darn thing.
Its difficult to judge given the typical industrial and/or military secrecy that floats about the planet. Rodal is invoking his privilege either personally or otherwise and we just have to accept that. Only a few of us are openly sharing what we're doing. We are the exception, not the rule.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/24/2016 01:37 pm
...Its difficult to judge given the typical industrial and/or military secrecy that floats about the planet. Rodal is invoking his privilege either personally or otherwise and we just have to accept that. Only a few of us are openly sharing what we're doing. We are the exception, not the rule.
Again, I am not building an EM Drive (a completely closed metallic cavity).  Anything else I or others may be doing is off-topic for this thread titled <<EM Drive Developments - related to space flight applications>>.

The statement <<Rodal is invoking his privilege either personally or otherwise and we just have to accept that. Only a few of us are openly sharing what we're doing. We are the exception, not the rule.>> is a non-sequitur, since it would be off-topic to discuss non-EM drive related subjects on this thread.  You might as well also write:

<<"Chris Bergin" [substitute any other name here] is invoking his privilege either personally or otherwise for not writing in this EM Drive thread about Chris's non-EM Drive related activities.>>  ;)

No reason for writing about me doing non-EM-Drive related things on the EM Drive thread.  Other NSF users are discussing other propellant-less projects in other NSF threads, for example Zen-In has a separate NSF thread on his interesting propellant-less space drive, patented invention US PTO 8575790, including building it, and his experiments:

https://forum.nasaspaceflight.com/index.php?topic=39204.0

that readers eager to know about other propellant-less space drive concepts are well-served to read.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: wallofwolfstreet on 03/24/2016 01:51 pm
Let's look at this realistically not taking sides with a  open mind.


I also saw he pushed it on the air track and he did it both directions. I also realized that this might not have been a real test drive as it was covered in dust from not being used. Also there was no battery or inverter to drive the RF Amp so it wasn't even working.


I also noticed on the back wall sitting on a table a larger frustum that he made sure you could see.


With this video I'm left with two possibilities. 


1. He was prevented from showing a working model by NDAs and couldn't even power it up to show it working. Hence the drive that was obviously not a real working model.


2. It wasn't working and he just obviously  pushed it.


It seems like he would have hidden it better if he was perpetrating a scam and it didn't work. Doesn't It? He is no real dummy to be that obvious to push the darn thing.

As I mentioned on (another forum-mod edit), the idea of an NDA here doesn't hold up at all. 

Looking at this realistically, there is no such thing as an NDA that lets you show the device, lets you tell the audience how you think the device works, lets you show what the device would do if it worked, but then not just turn it on and show it working.

Put yourself in the shoes of the counter party that signed this supposed NDA with Shawyer. You think they legitimately signed an NDA where he can show it off and talk about it on a BBC documentary, but just can't show it working? How would an NDA of that kind ever benefit the counter party?
Prevented from showing a working model (but allowed to show literally everything else) makes no sense from the NDA perspective.

The whole point of an NDA is to limit disclosure.  But everyone who watches that video just got disclosed to.  It's not hard to reverse engineer an oddly shaped metal cavity.  Seeing the thing in action wouldn't have changed the fact that it's trivial for any competitors to go build one now (as evidenced by the fact that multiple people can build them in their garages on a shoestring budget).

As to the possibility of a scam?  Consider other posts and your post even, where you admit that he pushed it, but are already coming up with justifications for why he wouldn't just show a working model.  It's easy to scam people who want to believe.  (not actually saying this is a scam of course, just pointing out that scaming is probably easier than you'd think once a good foundation has been laid)   
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/24/2016 01:55 pm
Having worked as VP R&D for a large multinational company, and having been involved with many lawyers in the Intellectual Property department, including intellectual property lawsuits, I fully agree with WallofWolfStreet that, to my knowledge:

Quote
there is no such thing as an NDA that lets you show the device, lets you tell the audience how you think the device works, lets you show what the device would do if it worked, but then not just turn it on and show it working.

Not just showing the device, but also showing the specific lab environment where the device is developed and tested (thereby showing the testing equipment and associated instruments) is usually a no-no as well for Non-Disclosure-Agreement (NDA) purposes, for obvious reasons (as we can tell readily in this thread by users trying to ascertain dimensions from looking at the pictures, the amplifier manufacturer, the testing device, even whether something in the ceiling is a fan or a winch, and other details one can gather from looking at these pictures).  Showing the device and the lab to anybody not involved with the project and covered by the NDA is already a no-no.  Allowing the device and the lab to be filmed and shown on a BBC program for everybody in the world to see and dissect would be very much against the NDA's I have been familiar with.   ???

Out of intellectual curiosity, it would be interesting to know the intellectual property justification behind such an unusual NDA that would allow all of this to be shown in a BBC program while specifically precluding showing that the device works.

Trade secrets have an advantage over patents that trade secrets (while being kept secret of course) have an infinite lifetime.  Under trade secret intellectual property protection one usually has the opposite of what is being discussed:

* the fact that something works is not kept secret: everybody knows that something "works"
* but the actual technology that allows it to work is kept secret
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/24/2016 02:44 pm
...Its difficult to judge given the typical industrial and/or military secrecy that floats about the planet. Rodal is invoking his privilege either personally or otherwise and we just have to accept that. Only a few of us are openly sharing what we're doing. We are the exception, not the rule.
Again, I am not building an EM Drive (a completely closed metallic cavity).  Anything else I or others may be doing is off-topic for this thread titled <<EM Drive Developments - related to space flight applications>>.

The statement <<Rodal is invoking his privilege either personally or otherwise and we just have to accept that. Only a few of us are openly sharing what we're doing. We are the exception, not the rule.>> is a non-sequitur, since it would be off-topic to discuss non-EM drive related subjects on this thread.  You might as well also write:

<<"Chris Bergin" [substitute any other name here] is invoking his privilege either personally or otherwise for not writing in this EM Drive thread about Chris's non-EM Drive related activities.>>  ;)

No reason for writing about me doing non-EM-Drive related things on the EM Drive thread.  Other NSF users are discussing other propellant-less projects in other NSF threads, for example Zen-In has a separate NSF thread on his interesting propellant-less space drive, patented invention US PTO 8575790, including building it, and his experiments:

https://forum.nasaspaceflight.com/index.php?topic=39204.0

that readers interested in other propellant-less space drive concepts are well-served to read.
Rodal, the sole reason to write is for clarification of, as you say, an incorrect statement made by a global science writer elsewhere. You clarified that you are working on a non-emdrive project (which you are not sharing here) and no one takes issue with that as far as I know. Its fully on-topic since another poster brought it to our attention, you clarified it and could possible share your experience with NDAs.

I've had a few NDAs in my day as well. They are all different and its not easy to categorize them as all-encompassing or permanent. Each is unique and each can allow for discussions outside of a specific product, design or technology. Depending on the language, an example could be a different frequency, material, size, mechanical configuration or any number of other distinct variations. An inventor NDA-ing an overall concept is ill advised. Also I've never seen an NDA that limits photographs of an inventor's test facility.

Seldom, in my humble opinion, is a overall concept protected by an NDA, it must be far more specific. None of us know shawyers limits or language on anything he might even have. All is pure speculation. In fact, the possession of an NDA itself often should not be divulged in most cases.

Since we're speculating here, I speculate that this first documentary from a reasonably reliable source (BBC) containing EMDrive will hasten the discussion, research and experimentation. Nothing wrong with that IMHO.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/24/2016 02:49 pm
... the sole reason to write is for clarification of, as you say, an incorrect statement made by a global science writer elsewhere. You clarified that you are working on a non-emdrive project (which you are not sharing here) and no one takes issue with that as far as I know....
Having already personally clarified it personally by me prior to your post, there is no reason for you to bring up my name again in this incorrect and off-topic context.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/24/2016 02:52 pm
Having worked as VP R&D for a large multinational company, and having been involved with many lawyers in the Intellectual Property department, including intellectual property lawsuits, I fully agree with WallofWolfStreet that, to my knowledge:

Quote
there is no such thing as an NDA that lets you show the device, lets you tell the audience how you think the device works, lets you show what the device would do if it worked, but then not just turn it on and show it working.

Not just showing the device, but also showing the specific lab environment where the device is developed and tested (thereby showing the testing equipment and associated instruments) is usually a no-no as well for Non-Disclosure-Agreement (NDA) purposes, for obvious reasons (as we can tell readily in this thread by users trying to ascertain dimensions from looking at the pictures, the amplifier manufacturer, the testing device, even whether something in the ceiling is a fan or a winch, and other details one can gather from looking at these pictures).  Showing the device and the lab to anybody not involved with the project and covered by the NDA is already a no-no.  Allowing the device and the lab to be filmed and shown on a BBC program for everybody in the world to see and dissect would be very much against the NDA's I have been familiar with.   ???

Out of intellectual curiosity, it would be interesting to know the intellectual property justification behind such an unusual NDA that would allow all of this to be shown in a BBC program while specifically precluding showing that the device works.

And really it doesn't even need to be a NDA for him not to show. How his actions are structured would depend on if it's with a corporation or a governmental agency. I've seen some pretty unusual requests from governments over the years. Just saying. I've sold machines to black operations just to end up seeing it listed in procurement data. Go figure.

This may not mean anything but...
Looking at a couple of other things in the video and knowing engineers ability to collect "stuff". I was struck at just how spartan his lab was, equipment that is critically needed to even test a EMDrive.  There are so many things just didn't fit right in this video. So many questions that are unanswered that could have been.


Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RERT on 03/24/2016 02:56 pm
The pictures didn't show Shawyer surreptitiously pushing an EMdrive which was purported to be working, it showed him obviously and deliberately pushing the thing up the air-track. Absolutely no claim at all was made that that clip showed the device working. Aside from anything else, to do so would have made liars out most of the program contributors.

What we saw was just some footage concocted to liven up shots of soundbites from an old guy. Like, we all gained some understanding by watching the physicist play boules in the desert, right?

What we saw neither confirms nor denies anything.

I think it's a bit fanciful to mull over what an NDA would/would not allow him to show: this is taken to be defense secrecy not SEC rules. To my knowledge no-one has as yet discussed any financial investors in SPR.

It's surprising at first that he would be allowed to participate at all if his later work is not allowed to be shown. However, given the earlier newsflow and the fact that the program was going ahead anyway, it may make some sense by way of damage limitation.

R.

Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/24/2016 03:00 pm
... the sole reason to write is for clarification of, as you say, an incorrect statement made by a global science writer elsewhere. You clarified that you are working on a non-emdrive project (which you are not sharing here) and no one takes issue with that as far as I know....
Having already clarified it previously, there is no reason as to why to keep bringing up my name up in this incorrect and off-topic context.
Except that if you choose to help the readership understand the intricacies of NDAs, which I believe you have done. By now, you probably have sensed what shawyer and others might have gone through regarding speculation, criticism and inquiry. It can be annoying. ;)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/24/2016 03:04 pm
Having worked as VP R&D for a large multinational company, and having been involved with many lawyers in the Intellectual Property department, including intellectual property lawsuits, I fully agree with WallofWolfStreet that, to my knowledge:

Quote
there is no such thing as an NDA that lets you show the device, lets you tell the audience how you think the device works, lets you show what the device would do if it worked, but then not just turn it on and show it working.

Not just showing the device, but also showing the specific lab environment where the device is developed and tested (thereby showing the testing equipment and associated instruments) is usually a no-no as well for Non-Disclosure-Agreement (NDA) purposes, for obvious reasons (as we can tell readily in this thread by users trying to ascertain dimensions from looking at the pictures, the amplifier manufacturer, the testing device, even whether something in the ceiling is a fan or a winch, and other details one can gather from looking at these pictures).  Showing the device and the lab to anybody not involved with the project and covered by the NDA is already a no-no.  Allowing the device and the lab to be filmed and shown on a BBC program for everybody in the world to see and dissect would be very much against the NDA's I have been familiar with.   ???

Out of intellectual curiosity, it would be interesting to know the intellectual property justification behind such an unusual NDA that would allow all of this to be shown in a BBC program while specifically precluding showing that the device works.

And really it doesn't even need to be a NDA for him not to show. How his actions are structured would depend on if it's with a corporation or a governmental agency. I've seen some pretty unusual requests from governments over the years. Just saying. I've sold machines to black operations just to end up seeing it listed in procurement data. Go figure.

This may not mean anything but...
Looking at a couple of other things in the video and knowing engineers ability to collect "stuff". I was struck at just how spartan his lab was, equipment that is critically needed to even test a EMDrive.  There are so many things just didn't fit right in this video. So many questions that are unanswered that could have been.


Shell

OK, this is an interesting discussion for people like me interested in intellectual property issues.  As I said:

Trade secrets have an advantage over patents that trade secrets (while being kept secret of course) have an infinite lifetime.  Under trade secret intellectual property protection one usually has the opposite of what is being discussed:

* the fact that something works is not kept secret: everybody knows that something "works"
* but the actual technology that allows it to work is kept secret

________

Now, there is another contradictory issue here: the fact that Shawyer has already obtained PATENTS.

The whole exercise (in time and money) of getting patent protection strongly argues against any intellectual property restricting to show that something works, while allowing to show why it works and what makes it work.

Patents have a finite lifetime: 20 years.

Some Shawyer patents have already expired.

The financial value of a patent exponentially decreases with time: as the life of a patent decreases with time.

The patent lifetime clock keeps on ticking: tick tack tick tack

Thus, in order to maximize the financial value of a patent, one normally does the opposite: one wants to show that something works, so that one can either sell the working units or otherwise sell the patents (and perhaps the company) to interested parties.

All entrepreneurs know this, as patents is just about the most valuable thing to own for a small company that does not yet have sales.  Entrepreneurs know that investors in a technology company and the whole financial structure of a small technology company is geared towards having sales of product as soon as possible.

BOTTOM LINE: I have yet to see any coherent reason why Shawyer would have a BBC program, showing his device and his lab, and yet not want to show his device working.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: wallofwolfstreet on 03/24/2016 03:10 pm
To my knowledge no-one has as yet discussed any financial investors in SPR.

I've actually discussed this at length.  You can look into my comment history just a few comments back and you will see it. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RotoSequence on 03/24/2016 03:14 pm
From my perspective as a hopeful but cautions observer, EM Drive (along with most of the other efforts) came off looking ridiculous in the Project Greenglow program.  :o
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/24/2016 03:20 pm
From my perspective as a hopeful but cautions observer, EM Drive (along with most of the other efforts) came off looking ridiculous in the Project Greenglow program.  :o
I'll be watching it tonight, could you give me a basic summary as to why?
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/24/2016 03:28 pm
...Except that if you choose to help the readership understand the intricacies of NDAs, which I believe you have done. By now, you probably have sensed what shawyer and others might have gone through regarding speculation, criticism and inquiry. It can be annoying. ;)
Off the mark.  Shawyer has just had a BBC program showing the whole world his lab and his EM Drive device, as well as a website and numerous reports through the years on what he is working on. Shawyer is the inventor of the EM Drive, which is the subject of this thread.

For the last time: please don't bring up my name in this thread regarding anything I may be working on that is not the EM Drive.  Doing so is 1) off-topic, 2) improper as I have repeatedly and explicitly asked you not to do so.  You might as well bring up the name of Chris Bergin [substitute any other name here] regarding what Chris or anybody else may be working on that is unrelated to the EM Drive.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: RotoSequence on 03/24/2016 03:32 pm
From my perspective as a hopeful but cautions observer, EM Drive (along with most of the other efforts) came off looking ridiculous in the Project Greenglow program.  :o
I'll be watching it tonight, could you give me a basic summary as to why?

Charitably speaking, the science content was light, much of the footage that accompanied the narration was trite, and each and every effort explored follows the same pattern of yanking the viewer's chain. "This would be so great if it worked. We explored this idea, and here's the tantalizing thought about what it might be" before saying, in a sort of narrative footnote that it doesn't actually work. The whole narrative of Project Greenglow is built on the angle of pursuing a dream, while establishing that the entire field has no sense of credibility.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: tchernik on 03/24/2016 03:33 pm
From my perspective as a hopeful but cautions observer, EM Drive (along with most of the other efforts) came off looking ridiculous in the Project Greenglow program.  :o

Not my feeling. I agree the presentation of the Emdrive done by Mr. Shawyer wasn't very good, because he is seen pushing it over the air cushioned track with his own hands. That was worse in terms of PR than not showing it working at all. He should have avoided it or explain that he is testing it over an air cushioned track, because well, this was his chance to make this known to a broader public than his regular bunch of Internet followers (including me).

However the words of Dr. Tajmar had the feeling of being overall positive about it, even if his papers themselves are much more cautious. That part I liked.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/24/2016 03:36 pm
From my perspective as a hopeful but cautions observer, EM Drive (along with most of the other efforts) came off looking ridiculous in the Project Greenglow program.  :o
I'll be watching it tonight, could you give me a basic summary as to why?

Charitably speaking, the science content was light, much of the footage that accompanied the narration was trite, and each and every effort explored follows the same pattern of yanking the viewer's chain. "This would be so great if it worked. We explored this idea, and here's the tantalizing thought about what it might be" before saying, in a sort of narrative footnote that it doesn't actually work. The whole narrative of Project Greenglow is built on the angle of pursuing a dream, while establishing that the entire field has no sense of credibility.
Can't argue with that, but it was nice to see Tajmar and Shawyer in their working envinronments.

Would have preferred that more time would have been devoted to active participants like Tajmar and Shawyer and the project using quantum mechanics to sense gravitational fields and less time to presently inactive people, and people that were involved in projects that did not work out.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Notsosureofit on 03/24/2016 03:54 pm
Still, Tajmar's comment that self-accelerating photon systems are accepted and demonstrated was interesting.  But, he ascribed it to photons with negative mass rather than that the photon is its own antiparticle.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: rfmwguy on 03/24/2016 04:17 pm
From my perspective as a hopeful but cautions observer, EM Drive (along with most of the other efforts) came off looking ridiculous in the Project Greenglow program.  :o
I'll be watching it tonight, could you give me a basic summary as to why?

Charitably speaking, the science content was light, much of the footage that accompanied the narration was trite, and each and every effort explored follows the same pattern of yanking the viewer's chain. "This would be so great if it worked. We explored this idea, and here's the tantalizing thought about what it might be" before saying, in a sort of narrative footnote that it doesn't actually work. The whole narrative of Project Greenglow is built on the angle of pursuing a dream, while establishing that the entire field has no sense of credibility.
Looks as though they had to moderate it with "entertainment" and ditch the over-your-head science stuff so not to lose the average Joe watching it. I produced a direct-to-DVD documentary about the old west a few years back. While the participants were long dead, the re-enactors had to entertain AND provide historical facts. Its a fine line on entertainment and historical content...it all depends on the target audience. BBC is targeting a mass market with general science interest. Thanks for your summary...look forward to viewing it.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/24/2016 04:40 pm
The pictures didn't show Shawyer surreptitiously pushing an EMdrive which was purported to be working, it showed him obviously and deliberately pushing the thing up the air-track. Absolutely no claim at all was made that that clip showed the device working. Aside from anything else, to do so would have made liars out most of the program contributors.

What we saw was just some footage concocted to liven up shots of soundbites from an old guy. Like, we all gained some understanding by watching the physicist play boules in the desert, right?

What we saw neither confirms nor denies anything.

I think it's a bit fanciful to mull over what an NDA would/would not allow him to show: this is taken to be defense secrecy not SEC rules. To my knowledge no-one has as yet discussed any financial investors in SPR.

It's surprising at first that he would be allowed to participate at all if his later work is not allowed to be shown. However, given the earlier newsflow and the fact that the program was going ahead anyway, it may make some sense by way of damage limitation.

R.

I found it interesting that anything he showed was off the shelf common equipment.

Shell
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: knowles2 on 03/24/2016 04:44 pm
The pictures didn't show Shawyer surreptitiously pushing an EMdrive which was purported to be working, it showed him obviously and deliberately pushing the thing up the air-track. Absolutely no claim at all was made that that clip showed the device working. Aside from anything else, to do so would have made liars out most of the program contributors.

What we saw was just some footage concocted to liven up shots of soundbites from an old guy. Like, we all gained some understanding by watching the physicist play boules in the desert, right?

What we saw neither confirms nor denies anything.

I think it's a bit fanciful to mull over what an NDA would/would not allow him to show: this is taken to be defense secrecy not SEC rules. To my knowledge no-one has as yet discussed any financial investors in SPR.

It's surprising at first that he would be allowed to participate at all if his later work is not allowed to be shown. However, given the earlier newsflow and the fact that the program was going ahead anyway, it may make some sense by way of damage limitation.

R.
Actually all the shareholders information is here

https://companycheck.co.uk/company/04097991/SATELLITE-PROPULSION-RESEARCH-LIMITED/group-structure

Also found this document,

http://ind-tech.com/wp-content/uploads/2014/11/Investment-Memorandum-final.pdf


More interestingly there seem to be no one helping Sawyer develop this engine in the lab. He an old bloke, I don't think it reasonable for him to still be working alone on this project if he planning on scaling it up any time soon.


As to the documentary, the thing that disappointed me the most was that there wasn't more information on project Greenglow, a project that seem to ran for at least a decade and apparently all it did was Sawyer research and they didn't even have the funds to recreate the Russians research, seem strange to me that BAE Systems would let a project run for that long with nothing to show for it.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/24/2016 04:53 pm
Able to get TE013 at 2.44889Ghz using Shawyer's flare-shape geometry, but with different dimensions. Units are in cm. It's about twice the size as the c-band unit shown on BBC.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: SeeShells on 03/24/2016 05:01 pm
Able to get TE013 at 2.44889Ghz using Shawyer's flare-shape geometry, but with different dimensions. Units are in cm. It's about twice the size as the c-band unit shown on BBC.

It looks about the size of the unit on the bench in the background. Interesting.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/24/2016 05:04 pm
Able to get TE013 at 2.44889Ghz using Shawyer's flare-shape geometry, but with different dimensions. Units are in cm. It's about twice the size as the c-band unit shown on BBC.
Please observe that mode shape TE013 is very different from mode shape TE311, which -from my memory- (please correct me if I'm wrong) you emphasized in your experimental setup. 

Have you compared the Q's for these mode shapes ?

It will be interesting to see your experimental results for force and Q.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/24/2016 05:06 pm
The pictures didn't show Shawyer surreptitiously pushing an EMdrive which was purported to be working, it showed him obviously and deliberately pushing the thing up the air-track. Absolutely no claim at all was made that that clip showed the device working. Aside from anything else, to do so would have made liars out most of the program contributors.

What we saw was just some footage concocted to liven up shots of soundbites from an old guy. Like, we all gained some understanding by watching the physicist play boules in the desert, right?

What we saw neither confirms nor denies anything.

I think it's a bit fanciful to mull over what an NDA would/would not allow him to show: this is taken to be defense secrecy not SEC rules. To my knowledge no-one has as yet discussed any financial investors in SPR.

It's surprising at first that he would be allowed to participate at all if his later work is not allowed to be shown. However, given the earlier newsflow and the fact that the program was going ahead anyway, it may make some sense by way of damage limitation.

R.
Actually all the shareholders information is here

https://companycheck.co.uk/company/04097991/SATELLITE-PROPULSION-RESEARCH-LIMITED/group-structure

Also found this document,

http://ind-tech.com/wp-content/uploads/2014/11/Investment-Memorandum-final.pdf


More interestingly there seem to be no one helping Sawyer develop this engine in the lab. He a old bloke, I don't think it reasonable for him to still be working alone on this project if he planning on scaling it up any time soon.

That's the third clock ticking, tick tack tick tack, arguing for showing the device working so that he can either sell working units, scale up or sell the company (intellectual property).

Already discussed the other two clocks:

1) the clock of financial value of his patents: it decreases exponentially with time.  It behooves the patent holder to show a working device as soon as possible to extract financial value out of the patents (that demanded time and money to get patented in the first place)

2) the clock of a leveraged small entrepreneural company: such a small company has to borrow money that has to be repaid back with interest as well as dilution of the company shares if also stock is given to entities providing financial capital.  It behooves the owner or CEO of a small entrepreneural company to show a working device as soon as possible to sell working units or to sell the company as soon as possible before further dilution of shares and running out of money.

The third clock you are referring to:

(https://s-media-cache-ak0.pinimg.com/736x/e4/f4/c5/e4f4c50cfa23650f0e894b66172df70b.jpg)

3) Our human lifetime clock.  Unfortunately none of us humans have an infinite life.  Our life is limited to an unknown age.  Our human life clock keeps on ticking.  The older we get the more that it behooves the aging owner or CEO of a small entrepreneural company (a company of one ? or few ?) to show a working device as soon as possible to sell working units or to sell the company.  Is there somebody (family member or company associated) prepared to take over and continue Shawyer's efforts?

Here of course, one presumes that the reason for the enterprise was always to have a working unit and commercialize such invention, as for example so well done by inventors like Edison, Ford, Steve Jobs, etc.

All of this discussion motivated by the recent, much anticipated, BBC program featuring Shawyer.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: A_M_Swallow on 03/24/2016 05:31 pm
{snip}

As to the documentary, the thing that disappointed me the most was that there wasn't more information on project Greenglow, a project that seem to ran for at least a decade and apparently all it did was Sawyer research and they didn't even have the funds to recreate the Russians research, seem strange to me that BAE Systems would let a project run for that long with nothing to show for it.

You are assuming the Project Greenglow was a full time job rather than say a once a week meeting in the back room of the sports & social club.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Monomorphic on 03/24/2016 06:13 pm
Please observe that mode shape TE013 is very different from mode shape TE311, which -from my memory- (please correct me if I'm wrong) you emphasized in your experimental setup. 

You are correct. The copper frustum I have fabricated already is designed for TE311. I was able to find TE311 in the flare-geometry as well at around 2.5Ghz. I'm seriously considering fabricating a flare-geometry emdrive deigned for TE013 at 2.45Ghz as well. The flare-shape is much easier to fabricate than the frustum, and it will only take a little extra copper than what I already have. I would probably use thicker copper for the end-plates. 
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Rodal on 03/24/2016 06:16 pm
Please observe that mode shape TE013 is very different from mode shape TE311, which -from my memory- (please correct me if I'm wrong) you emphasized in your experimental setup. 

You are correct. The copper frustum I have fabricated already is designed for TE311. I was able to find TE311 in the flare-geometry as well at around 2.5Ghz. I'm seriously considering fabricating a flare-geometry emdrive deigned for TE013 at 2.45Ghz as well. The flare-shape is much easier to fabricate than the frustum, and it will only take a little extra copper than what I already have. I would probably use thicker copper for the end-plates.
Thanks  :)

Comments on calculated Q would be appreciated when you have a chance.  I expect that the Q for TE013 should be higher than for TE311.

As I understand the choice between mode shapes TE013 and TE311 (TE=transverse electric; subscripts TEmnp number of half-wave patterns in m=circumferential, n=radial and p=longitudinal directions):

1) TE013: higher Q (Q is the most important parameter in Shawyer's, McCulloch's and Notsosureofit's equations).  Also TE013 has the Energy Density concentrated near the small end (which is important for White's QV theory).

2) TE311: as I understand (please correct me if I'm wrong) you would like to test this mode shape because of the electromagnetic field being closer to the metal, as in a Whispering Gallery Mode (albeit the fact that is is a sextapole mode: 2*m=2*3=6 poles).  But that fact should result in a lower Q as well.  This mode shape also has p=1 which results in the Energy Density being closer to the big end (compared to p=3 in TE013).  p=1 may result in a self-acceleration towards the big end instead of the small end ? (As per Minotti's theory and perhaps White's QV theory - not sure-).

Therefore it would be interesting to see the force (magnitude and direction) in your experiment.  :)
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: FattyLumpkin on 03/24/2016 07:44 pm
Where SpaceX and Elon Musk are concerned (a multi-billion dollar business), He/they do not file patents on a good deal of their tech. Hence, trade secret(s). How and to what extent the individuals that are privy to said secrets are bound is anyone's guess, but I'd suggest that disclosure of any of the aforementioned "tech" would result AT MINIMUM in Federal incarceration, since the security associated with the big US rocketry business falls within the realm of Nation Security. So Elon gets to have his cake and eat it too.(But the Feds have their hooks in him)
Enter Emdrive and I'd suggest the same "controls" might be placed on it (or at least attempted to be.)
When queried about positive Emdrive results, the few who had achieved this although not being able to provide an acceptable theory for their peers, have indicated that their "gut" is telling them that there is an effect there that they themselves cannot account for. Those who capture the Emdrive effect in a reproducible way know well that it also will be a multi-billion dollar affair. In a way I'm glad for the fact that there is (a least for now) no peer reviewed theory with a concomitant working prototype. I'd assert this leaves DIYs with the freedom of the Wright brothers. Cheers and best of science and results to you here at NSF!   F.L.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: Chrochne on 03/24/2016 09:05 pm
Where SpaceX and Elon Musk are concerned (a multi-billion dollar business), He/they do not file patents on a good deal of their tech. Hence, trade secret(s). How and to what extent the individuals that are privy to said secrets are bound is anyone's guess, but I'd suggest that disclosure of any of the aforementioned "tech" would result AT MINIMUM in Federal incarceration, since the security associated with the big US rocketry business falls within the realm of Nation Security. So Elon gets to have his cake and eat it too.(But the Feds have their hooks in him)
Enter Emdrive and I'd suggest the same "controls" might be placed on it (or at least attempted to be.)
When queried about positive Emdrive results, the few who had achieved this although not being able to provide an acceptable theory for their peers, have indicated that their "gut" is telling them that there is an effect there that they themselves cannot account for. Those who capture the Emdrive effect in a reproducible way know well that it also will be a multi-billion dollar affair. In a way I'm glad for the fact that there is (a least for now) no peer reviewed theory with a concomitant working prototype. I'd assert this leaves DIYs with the freedom of the Wright brothers. Cheers and best of science and results to you here at NSF!   F.L.

Not to mention increasing rumors of testing at JPL. Pepole will always speculate :D.
Title: Re: EM Drive Developments - related to space flight applications - Thread 7
Post by: knowles2 on 03/24/2016 10:35 pm


You are assuming the Project Greenglow was a full time job rather than say a once a week meeting in the back room of the sports & social club.
May be I think that because the documentary made it sound like it was more than that.
Title