Author Topic: EM Drive Developments - related to space flight applications - Thread 5  (Read 940263 times)

Offline aero

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How would one implement a Q-switched EM drive cavity?

I wonder if the EM drive effect is dependent on pulse output power in some way other than linear with Q. Reading wikipedia, I noticed that some Q-switched cavities use wavelength in the 10 cm range, which is our frequency of interest.
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Offline Ender

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Here's a question:

Why are all the calculated predictions for the Emdrive's thrust so far off the mark?  In many of the papers I've read on the subject (ex. Mcculloch 2015), the author speaks as though his results match with the data "generally" or "more accurately" - basically scientist speak for "balllpark."  Why are they even publishing such organized speculation?  Their theories don't line up with the data but they still continue on about those same theories. 

I get the difficulty in determining this very important piece of information.  I've had tons of trouble with it myself.  Best I can figure, there isn't a relatively large set of consistent data from similarly formed cavites, but I'm no expert.  What am I missing?

Offline SeeShells

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How would one implement a Q-switched EM drive cavity?

I wonder if the EM drive effect is dependent on pulse output power in some way other than linear with Q. Reading wikipedia, I noticed that some Q-switched cavities use wavelength in the 10 cm range, which is our frequency of interest.
Waveguides for power and add additional Insertion antennas, "like a modified loop" to provide the "seed".

It's a thought.

Offline SeeShells

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Here's a question:

Why are all the calculated predictions for the Emdrive's thrust so far off the mark?  In many of the papers I've read on the subject (ex. Mcculloch 2015), the author speaks as though his results match with the data "generally" or "more accurately" - basically scientist speak for "balllpark."  Why are they even publishing such organized speculation?  Their theories don't line up with the data but they still continue on about those same theories. 

I get the difficulty in determining this very important piece of information.  I've had tons of trouble with it myself.  Best I can figure, there isn't a relatively large set of consistent data from similarly formed cavites, but I'm no expert.  What am I missing?
Good Question!

I'll throw out the first ball here and then have to get back to my build.

Thermal instabilities will ruin a drive. When the thermal expansion with materials "thickness of a piece of paper" can cause you to drift out of resonance. You could almost hold your hand on the frustum and cause it to expand that much.

Shell

Offline Tellmeagain

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And their data are being vetted by a peer-reviewed journal.

Where did you get that? I read and re-read star-drive's 10/09 post and I did not see this statement.

Offline Blaine

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And their data are being vetted by a peer-reviewed journal.

Where did you get that? I read and re-read star-drive's 10/09 post and I did not see this statement.

Its actually from 10/12 post here:
There is still that elephant in the room that everybody sees but does not want to talk about. The rotary test R.Shawyer made and the test results of Dr. Yang. It is a good right to doubt their results and ask for those tests to be reproduced. but both these tests DID reproduce thrust signals well beyond the background noise. It can mean 2 things: either their tests were wrong, or all the other tests do not understand what's needed to make "it" work.

The latter is the reality. Yang doesn't, AFAIK, communicate. Roger has offered a trail of useful bread crumbs but is largely ignored or worst. EWs has stopped discussing their work.

Which leaves Roger as a source of "how to make it happen at a level well above the noise / thermal effects and snowflake equivalent Force generation".

Anyone listening to what the man is sharing?

BTW it was Roger who helped Prof Yang to understand now to make it happen.

Phil,

Please realize when we are testing an impossible drive it's going to require virtually unquestionable results from a test bed and drive. That's in itself is impossible. Even when thrusts are out of a noise level or error.  Every test is going to come under question regardless of the quality of the test or level of thrust gained. You could lift a car and they will say it's a trick with hidden wires. You launch a ship and they will say it's a Hollywood trick... like the moon landings.  ::)

Even after a hundred years have passed Einstein's theories are questioned and tested and the same thing will hold true if this device works the way many claim it does. That not only goes for the theories, but the test beds and the actual devices tested.

It's our nature to question and choose sides. It can be our greatest strength or our greatest weakness.

So why do I do it and fight for my right to?

"Because I choose to dream.

I believe we are at a cusp of our growth on this ball of mud and if we don't evolve from this tiny seed called earth we may perish and never know the glorious heights that await us, or the true challenges of a universe that has no bounds. Yes, I dream, for humanity. Michelle Broyles"


Michelle:

Bravo girl, way to go!!  We are in this business because we are dreamers that see the light on the distant hill that we want to be part of.

Now back to how to get there. 

BTW, Tetrakis is right to be very concerned about accounting for the thermal effects in these EmDrive experiments for they can make an otherwise straight forward thruster test into a nightmare of conflicting results.  Been there, done that.  However we've found that going to vacuum operations just changes one set of thermal effects for another set that still have to be analytically accounted for and subtracted from any impulsive signal that may be present in the experimental data.

Phil:

The Eagleworks (EW) Lab ultimately works for the taxpayers of the USA and the data we are accumulating and vetting will be made public, but only after its been further vetted in a known peer reviewed journal, which is happening now, but sadly that process can take months to accomplish, so please be patient.  We are also preparing to test our copper frustum in another NASA test facility as part of an Independent Verification & Validation (IV&V) requirement mandated by JSC management, but again that is several months off, so it will take even more time to divulge those test results, pro or con. 

All:

In the meantime I cheer on all the DIY experimenters who are pursuing these EmDrive replications either in-air or in-vacuum for both approaches brings illumination to the dark-estate we are exploring.  I also suggest that all of us should look deeper into how Roger Shawyer designed and built his 2nd generation, 100kg rotary copper frustum test rig.  Why?  Because I think Roger's use of spherical end-caps in his 2nd gen copper frustum and on, AND the use of resonant mode frequency tracking and active feedback driven tuning of the frustum RF system, either mechanically and/or electronically, are the key elements needed to produce large impulsive thrust signals that measure in the hundreds of milli-Newton (mN).

Best, Paul March
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Offline Tellmeagain

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Where did you get that? I read and re-read star-drive's 10/09 post and I did not see this statement.

Its actually from 10/12 post here:


Thank you! Got it.

Offline SeeShells

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Needed to fuel up so I'm taking a break. For your inquiring minds some pics...

Then back at it.

Shell

Offline zen-in

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great to see Paul March's post, although I guess NASA is still controlling what Eagleworks may or may not say.

...

My memory is not that good, but I remember there was a talk of the americans here writing their representatives to tell NASA to not block info from Eagleworks. If this memory is correct, did anyone proceeded with writing their representatives?

My guess is that NASA is just enforcing its ITAR policy as interpreted by the NASA Inspector General.   When I worked at a NASA center even something as innocuous as presenting a paper to an SPIE conference required approval of the contents.   This took over a week.    It is even worse if a NASA contractor is a foreign national; Canadian, British, or other nationality.   They have to be escorted everywhere they go and are scrutinized by the FBI every 2 years.   There is a lot of paranoia there.   If Paul March wants to keep his job he will have to toe the line.

Offline TheTraveller

We are not the first to see a tunable frustum as a interesting device to discriminate and select the modes needed to operate in.
Shell

Photos looking good.

Please share your frustum build dimensions. Will then do analysis runs on mode versus resonance and report back.

BTW have heard running regulated DC on the maggie heater reduces freq splatter versus using AC. If your spectrum analyser is up and running, might be interesting data to share.

Would also suggest installing 5kv filter caps and inline 2.5ghz capable ferrite filter at the maggie DC feed point might again reduce freq splatter and stop the DC feed lines back to the PSU acting like antenna.

I suspect every little bit helps tighten up the system.

Phil
It Is Time For The EmDrive To Come Out Of The Shadows

Offline glennfish

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Needed to fuel up so I'm taking a break. For your inquiring minds some pics...

Then back at it.

Shell

SeeShells.   I know of some under 14 folks who are following this.

Do you think that if you put some stickers of Barnie on the outside it would affect the resonance?  :)

Just kidding.

Offline Prunesquallor

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great to see Paul March's post, although I guess NASA is still controlling what Eagleworks may or may not say.

...

My memory is not that good, but I remember there was a talk of the americans here writing their representatives to tell NASA to not block info from Eagleworks. If this memory is correct, did anyone proceeded with writing their representatives?

My guess is that NASA is just enforcing its ITAR policy as interpreted by the NASA Inspector General.   When I worked at a NASA center even something as innocuous as presenting a paper to an SPIE conference required approval of the contents.   This took over a week.    It is even worse if a NASA contractor is a foreign national; Canadian, British, or other nationality.   They have to be escorted everywhere they go and are scrutinized by the FBI every 2 years.   There is a lot of paranoia there.   If Paul March wants to keep his job he will have to toe the line.
You are correct. ITAR is brutal and the regs are in flux. Anything to do with propulsion is problematic.
Retired, yet... not

Offline TheTraveller

Unless I'm missing something, it really looks bad when you conflate radius and diameter. What else do we have to guess at to understand your approach? Is the center of curvature for the endplates a radius? What is its origin? Be clear. Be concise. Be careful. No handwaving allowed. None. If you choose to publish drawings, they should be of sufficient quality that another person, "schooled in the art", can replicate your device and results.

Roger made that clear quite some time ago. End plates radius from the frustum vertex.

My design is 2nd image.

But that's exactly my point. In the figure TTEMDriveMark2-1.jpg what appears to be the diameter of the frustum is labeled as the radius. Which is it? It may appear obvious, but it's sloppy. If the drawing purports to be an attempt at an assembly drawing, it doesn't pass muster.

It is a schematic, not a build plan.
It Is Time For The EmDrive To Come Out Of The Shadows

Offline SeeShells

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We are not the first to see a tunable frustum as a interesting device to discriminate and select the modes needed to operate in.
Shell

Photos looking good.

Please share your frustum build dimensions. Will then do analysis runs on mode versus resonance and report back.

BTW have heard running regulated DC on the maggie heater reduces freq splatter versus using AC. If your spectrum analyser is up and running, might be interesting data to share.

Would also suggest installing 5kv filter caps and inline 2.5ghz capable ferrite filter at the maggie DC feed point might again reduce freq splatter and stop the DC feed lines back to the PSU acting like antenna.

I suspect every little bit helps tighten up the system.

Phil
The center length starts at 210 mm can extend additional 125 mm
Bottom Plate 295 mm
Top Plate 165 mm

My plan is to turn the heater off entirely after a few seconds of on time. I'm using an inverter instead of the normal power supply for the maggie and there will be filter caps and a couple ferrite beads on the HV out. When I get over to the maggie and power supply maybe by weeks end or this weekend I'll post a SA of it.

Offline SeeShells

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Needed to fuel up so I'm taking a break. For your inquiring minds some pics...

Then back at it.

Shell

SeeShells.   I know of some under 14 folks who are following this.

Do you think that if you put some stickers of Barnie on the outside it would affect the resonance?  :)

Just kidding.
You think it would be less attenuation than SpongeBob SquarePants?  ;D

Offline TheTraveller

We are not the first to see a tunable frustum as a interesting device to discriminate and select the modes needed to operate in.
Shell

Photos looking good.

Please share your frustum build dimensions. Will then do analysis runs on mode versus resonance and report back.

BTW have heard running regulated DC on the maggie heater reduces freq splatter versus using AC. If your spectrum analyser is up and running, might be interesting data to share.

Would also suggest installing 5kv filter caps and inline 2.5ghz capable ferrite filter at the maggie DC feed point might again reduce freq splatter and stop the DC feed lines back to the PSU acting like antenna.

I suspect every little bit helps tighten up the system.

Phil
The center length starts at 210 mm can extend additional 125 mm
Bottom Plate 295 mm
Top Plate 165 mm

My plan is to turn the heater off entirely after a few seconds of on time. I'm using an inverter instead of the normal power supply for the maggie and there will be filter caps and a couple ferrite beads on the HV out. When I get over to the maggie and power supply maybe by weeks end or this weekend I'll post a SA of it.

Thanks for the dimensions. Will check them out.

Try to put the filters as close to the maggie power input as possible. Use the maggie outer shell for the ground for the caps. Ensure the caps and ferrite are rated to handle 2.5ghz noise filtering.
It Is Time For The EmDrive To Come Out Of The Shadows

Offline rq3

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Unless I'm missing something, it really looks bad when you conflate radius and diameter. What else do we have to guess at to understand your approach? Is the center of curvature for the endplates a radius? What is its origin? Be clear. Be concise. Be careful. No handwaving allowed. None. If you choose to publish drawings, they should be of sufficient quality that another person, "schooled in the art", can replicate your device and results.

Roger made that clear quite some time ago. End plates radius from the frustum vertex.

My design is 2nd image.

But that's exactly my point. In the figure TTEMDriveMark2-1.jpg what appears to be the diameter of the frustum is labeled as the radius. Which is it? It may appear obvious, but it's sloppy. If the drawing purports to be an attempt at an assembly drawing, it doesn't pass muster.

It is a schematic, not a build plan.

But you've dodged the question. Is that a diameter or a radius? Even a schematic should be labeled correctly, unless you are attempting intentional obfuscation.

Offline SeeShells

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We are not the first to see a tunable frustum as a interesting device to discriminate and select the modes needed to operate in.
Shell

Photos looking good.

Please share your frustum build dimensions. Will then do analysis runs on mode versus resonance and report back.

BTW have heard running regulated DC on the maggie heater reduces freq splatter versus using AC. If your spectrum analyser is up and running, might be interesting data to share.

Would also suggest installing 5kv filter caps and inline 2.5ghz capable ferrite filter at the maggie DC feed point might again reduce freq splatter and stop the DC feed lines back to the PSU acting like antenna.

I suspect every little bit helps tighten up the system.

Phil
The center length starts at 210 mm can extend additional 125 mm
Bottom Plate 295 mm
Top Plate 165 mm

My plan is to turn the heater off entirely after a few seconds of on time. I'm using an inverter instead of the normal power supply for the maggie and there will be filter caps and a couple ferrite beads on the HV out. When I get over to the maggie and power supply maybe by weeks end or this weekend I'll post a SA of it.

Thanks for the dimensions. Will check them out.

Try to put the filters as close to the maggie power input as possible. Use the maggie outer shell for the ground for the caps. Ensure the caps and ferrite are rated to handle 2.5ghz noise filtering.

I know. Thanks for covering it anyway.

Shell

Added...
You may want to step through the distance between the end plates and see the resonances. It will be interesting to compare. Also did you see the parts bins in the pictures of the shop, that's just part of all of them... ::) yes I have spares parts and beads
« Last Edit: 10/14/2015 12:31 AM by SeeShells »

Offline zen-in

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great to see Paul March's post, although I guess NASA is still controlling what Eagleworks may or may not say.

...

My memory is not that good, but I remember there was a talk of the americans here writing their representatives to tell NASA to not block info from Eagleworks. If this memory is correct, did anyone proceeded with writing their representatives?

My guess is that NASA is just enforcing its ITAR policy as interpreted by the NASA Inspector General.   When I worked at a NASA center even something as innocuous as presenting a paper to an SPIE conference required approval of the contents.   T
...
You are correct. ITAR is brutal and the regs are in flux. Anything to do with propulsion is problematic.

I am a Canadian citizen and worked at NASA's Ames Research Center for about 12 years.   I never thought there was any consequence to being a foreign national but over time the restrictions got worse.  Eventually my manager decided the extra paperwork was not worth his time.   He was already getting flack from the FBI because a co-worker was accused of being a Chinese spy, despite being a US citizen.   I suspect I was the unescorted foreign national that didn't have a security plan for 3 years mentioned in the NASA Inspector General's report on ITAR compliance at NASA's Ames Research Center.   Maybe I should have kept quiet about my Tory ancestors who left the US after the revolution. I think it's just as well I am no longer working at a NASA center.   I do not have the security clearance required to do the research I have been doing since leaving NASA.

https://oig.nasa.gov/Special-Review/Ames_ITAR.pdf

Offline aceshigh

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great to see Paul March's post, although I guess NASA is still controlling what Eagleworks may or may not say.

...

My memory is not that good, but I remember there was a talk of the americans here writing their representatives to tell NASA to not block info from Eagleworks. If this memory is correct, did anyone proceeded with writing their representatives?

My guess is that NASA is just enforcing its ITAR policy as interpreted by the NASA Inspector General.   When I worked at a NASA center even something as innocuous as presenting a paper to an SPIE conference required approval of the contents.   This took over a week.    It is even worse if a NASA contractor is a foreign national; Canadian, British, or other nationality.   They have to be escorted everywhere they go and are scrutinized by the FBI every 2 years.   There is a lot of paranoia there.   If Paul March wants to keep his job he will have to toe the line.
You are correct. ITAR is brutal and the regs are in flux. Anything to do with propulsion is problematic.

That seems to imply that NASA management believes EM Drive may be a real effect (if so, it could be used as a kinetic weapon), but my impression has been much more on the line that NASA just wants to avoid negative light and mocking of the science it does, which would explain why the firewall on the info from EagleWorks was erected only after Eagle Works experiments became "mediatic" appearing EVERYWHERE and also being criticized everywhere.

If was just protection against foreign espionage, NASA would have acted long before the EM Drive and Warp Drive appeared on Forbes...
« Last Edit: 10/14/2015 12:50 AM by aceshigh »

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