Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1876633 times)

Offline kml

I have started conducting tests on my linear EmDrive.   The test assembly is fully untethered using a battery power source and IR remote control for RF on/off.  Forces are measured using an AND MC-10K 10.1kg x 0.001g scale. 

...

Only the dummy load test did I not see any change in scale output.   The output of the isolator is directly connected to the dummy load that normally takes the output of the sampling port, thus bypassing the RF cavity:
Most likely there is an RFI problem with the scale.[/b]  I'm going to attempt to shield the scale with the unit suspended above it to prove that it is RFI.


That is very interesting.  Can I make a constructive suggestion?   Why don't you put the dummy load (or a suitably sized resistor for DC power) inside the cavity and collect data with that configuration?   This was my criticism of the Eagleworks lab tests going back to thread 1.    Have you posted a picture of your apparatus?  videos?   Good work!

The feed ports are removable so I can find a way to test with a dummy load inside.

Here is a picture of the setup:

http://kl.net/20150621-setup-fullsize.jpg


Offline SeeShells

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I have a 7 ton car lift in my shop that is buried in over 3 feet of bedrock and concrete so I figured I would use that as it's stable.

The fulcrum is a laminated plywood beam with a SS cable attached to the ends with a turnbuckle to keep it taunt and straight.

The critical issue I've seen id getting power cables to the Drive without having to worry about the power cable causing issues. I have the power box under the fulcrum in a shielded cage. The power line from it goes up to connect to a point above the center of the beam. *see drawing and never touches the beam which could cause deflection.

The damper is a small 1 gal can filled with 30 weight oil and is connected to the end of the fulcrum and should provide damping in the X and Z directions.

The end of the beam opposite of the drive is a laser pointer to monitor any disturbances. (thrust hopefully) Still looking at scales so I've not put one into my layout.

Thoughts? Questions?

Shell


Offline SeeShells

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Roger Shawyer kindly sent me a copy of his EMDrive paper that is currently under peer review. All I can say is WOW. All doubt will be removed. Apologises but can't yet share it.

SNIP

Still in bed, recovering slower than desired, damn old age, but getting there. My build start still looks like 4 to 6 weeks away but the design steadly improves. Force measurement system will follow what Shawyer did in the Flight Thruster demo setup as attached. Hang it from a spring and measure the generated forces on a digital scale. Typical KISS enginerring.

Please get well soon, getting old is not for wimps.

Honestly I hope he shakes up the community and the world with earth shattering news better than discovering fire. He has been like a dog with a bone stubborn working on this and sometimes that is what it takes.

Get better, ok?

Shell

Offline zen-in

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The feed ports are removable so I can find a way to test with a dummy load inside.

...

Here is a picture of the setup:

Very good!  I remember seeing that waveguide earlier.   I don't think the dummy load would fit inside it so you would have to use a power resistor.   Maybe one with a lightweight Aluminum heatsink suspended near the bottom of the cavity and not touching the walls would do.  Another similar test would be to heat the outside of the cavity with a heat lamp.    If the metal inside the cavity is heating up uniformly the heat transfer to the air inside would happen quickly; hence the underdamped response you are seeing on the longer RF on times.  How well sealed is the cavity?  Are there o-rings at each end or just metal to metal seals?   Some air may be escaping from one end.   From a theoretical perspective what determines the directivity of this cavity?

Offline Prunesquallor

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And even with the unit suspended by a wood stand just above the scale (to prevent contact), with ceramic flooring tiles placed on the scale tray for similar loading:


So let me understand. The rig wasn't even ON THE SCALE and the scale regestered a weight change?
Retired, yet... not

Offline Rodal

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...Still in bed, recovering slower than desired, damn old age, but getting there. ..
Take all the time you need to build up your strength and spirits. Your job right now is to relax and recover. Wishing you a prompt recovery.

Offline Rodal

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@Rodal - I have:
 BIG DIAMETER = 0.27246 m
 SMALL DIAMETER = 0.068115 m
 LENGTH =  0.4890240258390259 m
Pardon the extra digits from the calculation.

Running in 3-D with bandwidth opened up to 0.5 * drive frequency (drive = ~1.95GHz), Meep finds 4 frequencies:
1.58530024E+009
1.83409637E+009
2.08402579E+009
2.33698507E+009 Hz
 Q - in order
620.675008923
133.4147313913
1211.3296422825
141.0133154386

This is electric excitation with antenna = 0.2 * wavelength, perpendicular to and centered on the central axis of rotation.


OK - I just read the rest of your post. I'll look for the location of the antenna in the Brady cone, and put it there. But as I recall, that was for exciting a TM mode?

Those dimensions

 BIG DIAMETER = 0.27246 m
 SMALL DIAMETER = 0.068115 m
 LENGTH =  0.4890240258390259 m


have lots of natural frequencies around that range.  Here are just a few, for flat ends:

Mode     frequency (GHz)
TE011   1.73146
TE012   2.0553
TE013   2.3431

TM211  1.9874
TM212  2.40296
TM213  2.72512

TE111  0.965122
TE112  1.24641
TE113  1.50459

TM111 1.51277
TM112 1.89759
TM113 2.20088
« Last Edit: 06/23/2015 03:12 AM by Rodal »

Offline Prunesquallor

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I have a 7 ton car lift in my shop that is buried in over 3 feet of bedrock and concrete so I figured I would use that as it's stable.

The fulcrum is a laminated plywood beam with a SS cable attached to the ends with a turnbuckle to keep it taunt and straight.

The critical issue I've seen id getting power cables to the Drive without having to worry about the power cable causing issues. I have the power box under the fulcrum in a shielded cage. The power line from it goes up to connect to a point above the center of the beam. *see drawing and never touches the beam which could cause deflection.

The damper is a small 1 gal can filled with 30 weight oil and is connected to the end of the fulcrum and should provide damping in the X and Z directions.

The end of the beam opposite of the drive is a laser pointer to monitor any disturbances. (thrust hopefully) Still looking at scales so I've not put one into my layout.

Thoughts? Questions?

Shell

My thoughts?  I lust after your shop.
Retired, yet... not

Offline TheTraveller

...Still in bed, recovering slower than desired, damn old age, but getting there. ..
Take all the time you need to build up your strength and spirits. Your job right now is to relax and recover. Wishing you a prompt recovery.

Thanks.

My wife ensures I stick to doctors orders. Does allow me to do fat finger typing on my phone. :)

Bonus is I get to mentally build my 3 frustums and go through the testing process at least once a day.
« Last Edit: 06/23/2015 02:22 AM by TheTraveller »
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.
Herman Melville, Moby Dick


And even with the unit suspended by a wood stand just above the scale (to prevent contact), with ceramic flooring tiles placed on the scale tray for similar loading:


So let me understand. The rig wasn't even ON THE SCALE and the scale regestered a weight change?

Something shooting out the back perhaps?  Would love to see this setup inversed

Offline demofsky

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I have a 7 ton car lift in my shop that is buried in over 3 feet of bedrock and concrete so I figured I would use that as it's stable.

The fulcrum is a laminated plywood beam with a SS cable attached to the ends with a turnbuckle to keep it taunt and straight.

The critical issue I've seen id getting power cables to the Drive without having to worry about the power cable causing issues. I have the power box under the fulcrum in a shielded cage. The power line from it goes up to connect to a point above the center of the beam. *see drawing and never touches the beam which could cause deflection.

The damper is a small 1 gal can filled with 30 weight oil and is connected to the end of the fulcrum and should provide damping in the X and Z directions.

The end of the beam opposite of the drive is a laser pointer to monitor any disturbances. (thrust hopefully) Still looking at scales so I've not put one into my layout.

Thoughts? Questions?

Shell

In my own speculative experimental design I also have thought about using a very large beam with a laser pointer. 

Question.  Does something as massive as that beam really need any additional dampening?   Without doing the math, I envisaged that any changes would happen slowly, the mass of the beam dampening most artifacts. 

Also, because it will be slow, you need to be mindful of cooling since everything will need to run for long periods of time.

Offline Rodal

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....

Let's try to work through this.  The standard convention is to take z as the axis of symmetry (the longitudinal axis of the cone) but the way you labeled them, it looks like x is your axis of symmetry, is that correct?

If x is the axis of symmetry, then y and z are perpendicular to it. 
On the trapezium-looking cross section with axis y perpendicular to it, the axis of the trapezium are x and z, is that correct?

OK, if the answer is yes, on your y plot, what are you plotting:

Ex ?

Ez?

Hx?

Hz?

X is the axis of symmetry. The antenna is to the +Y edge of the cavity. Z completes the coordinate system.

I am plotting a snap shot of the x, y and z corrdinate values of the Ez field. More than that you'd have to ask a physicist.
Can you plot the Absolute Value of the E field:

for example, for the cross-section with normal y

instead of Ez, can you have contour plot Sqrt[(Ex)^2 + (Ez)^2]
« Last Edit: 06/23/2015 02:42 AM by Rodal »

Online aero

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I have a 7 ton car lift in my shop that is buried in over 3 feet of bedrock and concrete so I figured I would use that as it's stable.

The fulcrum is a laminated plywood beam with a SS cable attached to the ends with a turnbuckle to keep it taunt and straight.

The critical issue I've seen id getting power cables to the Drive without having to worry about the power cable causing issues. I have the power box under the fulcrum in a shielded cage. The power line from it goes up to connect to a point above the center of the beam. *see drawing and never touches the beam which could cause deflection.

The damper is a small 1 gal can filled with 30 weight oil and is connected to the end of the fulcrum and should provide damping in the X and Z directions.

The end of the beam opposite of the drive is a laser pointer to monitor any disturbances. (thrust hopefully) Still looking at scales so I've not put one into my layout.

Thoughts? Questions?

Shell

How massive is that beam? I see a lot of inertia but maybe it's not as massive as it looks.

Still, you can measure the response time using weights as rfmwguy did.
« Last Edit: 06/23/2015 02:47 AM by aero »
Retired, working interesting problems

Online aero

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....

Let's try to work through this.  The standard convention is to take z as the axis of symmetry (the longitudinal axis of the cone) but the way you labeled them, it looks like x is your axis of symmetry, is that correct?

If x is the axis of symmetry, then y and z are perpendicular to it. 
On the trapezium-looking cross section with axis y perpendicular to it, the axis of the trapezium are x and z, is that correct?

OK, if the answer is yes, on your y plot, what are you plotting:

Ex ?

Ez?

Hx?

Hz?

X is the axis of symmetry. The antenna is to the +Y edge of the cavity. Z completes the coordinate system.

I am plotting a snap shot of the x, y and z corrdinate values of the Ez field. More than that you'd have to ask a physicist.
Can you plot the Absolute Value of the E field:

for example, for the cross-section with normal y

instead of Ez, can you have contour plot Sqrt[(Ex)^2 + (Ez)^2]

That is not an option that I see in the h5topng manual. Maybe HDFview has that option but I think you're asking for some MatLab data processing. If so, then no, I can't, maybe someone else would like to accept the challenge. I know that Meep users commonly reduce data using MatLab programs so it's likely possible.
Retired, working interesting problems

Offline kml

Most likely there is an RFI problem with the scale.  I'm going to attempt to shield the scale with the unit suspended above it to prove that it is RFI.

I have to say that these are very intriguing results!  While we are all waiting to see if you can eliminate RFI interference on your scale as the cause for these results, I would like to point out a couple of notable things:

1). The performance with and without dielectrics reflects Shawyer's and Yang's experience.

2).  Much more interesting from my perspective are the declining lows in your first experiment with the dielectrics.  This is a very similar pattern to the Eagleworks tests With a dielectric insert.  It was speculated at the time that this might have been due to out gassing but I can't see that happening with a ceramic dielectric!!

So what the heck is happening with the dielectrics?

There is a more subtle pattern of declining lows without the dielectrics, but it is more pronounced with them present. 

So either there is some type of ongoing electrical (electrostatic?) interference with the digital scale once the power is off, significant out gassing from somewhere, or we are looking some very interesting theoretical issues here folks - and evanescent waves are just not going to cut it...

Edit:  After checking the scale,  it is apparent that the unit is getting lighter and so we have to add ballooning to the possible effects, with the dielectrics thermal mass sustaining the effect.

Don't read too much into the overall declining slope.   It takes a while for the scale to fully stabilize after placing the unit on it.   The faster I start the test the steeper the slope is, usually.   I have learned to wait longer before starting as you can see from the later test #'s.

Keep in mind the "suspended" test is without any contact between the test unit and the scale.  There should be absolutely no force registered in this configuration.   The weight on the scale is from several ceramic flooring tiles used to simulate the weight of the unit. I did test with very little weight on the scale with the unit suspended above it and there was no change in weight indicated:

20150621-test-42-nod-up-suspended-paper.png



This indicates that the RFI induced error may be related to the dynamic correction system used to offset heavy loads.:

http://www.scalenet.com/and/gx/sensor.html

Also, the tests done in the "down" orientation show much less force, though still in the "weighs less" direction.  This may be due to the better RF sealing on the fixed end which is down in the "down" orientation.

Offline rfmwguy

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I have a 7 ton car lift in my shop that is buried in over 3 feet of bedrock and concrete so I figured I would use that as it's stable.

The fulcrum is a laminated plywood beam with a SS cable attached to the ends with a turnbuckle to keep it taunt and straight.

The critical issue I've seen id getting power cables to the Drive without having to worry about the power cable causing issues. I have the power box under the fulcrum in a shielded cage. The power line from it goes up to connect to a point above the center of the beam. *see drawing and never touches the beam which could cause deflection.

The damper is a small 1 gal can filled with 30 weight oil and is connected to the end of the fulcrum and should provide damping in the X and Z directions.

The end of the beam opposite of the drive is a laser pointer to monitor any disturbances. (thrust hopefully) Still looking at scales so I've not put one into my layout.

Thoughts? Questions?

Shell

there will be 4 wires needed for magnetron, 2 bias and 2 filament. Make a liquid "wire splice" for the 4 wires. Basically 4 test tubes of conductive mercury. An electrode from power supply wire goes in at bottom of tube. Another electrode from fulcrum drops down into mercury. The mercury conducts the voltage regardless of the depth of the fulcrum side electrode, it simply swims in it. Depth of mercury and length of electrode should allow Moment arm displacement without breaking contact (fulcrum side electrode rising out of mercury).

A non scientific description of a near frictionless wire splice...hope I explained it well enough.

Offline SeeShells

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I have a 7 ton car lift in my shop that is buried in over 3 feet of bedrock and concrete so I figured I would use that as it's stable.

Thoughts? Questions?

Shell

In my own speculative experimental design I also have thought about using a very large beam with a laser pointer. 

Question.  Does something as massive as that beam really need any additional dampening?   Without doing the math, I envisaged that any changes would happen slowly, the mass of the beam dampening most artifacts. 

Also, because it will be slow, you need to be mindful of cooling since everything will need to run for long periods of time.
Good points. I worried about the pendulum effect that I've seen on other tests and the slow movement of other outside forces is a concern. I remember setting up anti-vibration tables in a lab and watching cars and trucks drive by a 100 foot away. Even when we would set up our semiconductor equipment in a lab with a concrete floor we could detect the bending movement of the floor and into our machines by someone walking next to it. Very small movements, but a issue when they were expecting submicron accuracies. 

Cooling is a issue and I hope the holes in the Copper Frustum help, free hanging with holes I should get away from a hot air balloon effect but still need to worry about hot air eddie currents from the frustum. Turning the drive around should give me subtracting data for the total deviations.

The lasers are great to monitor deflections and vibrations of the beam, plus they are very cheap.

I hope by putting the beam between the 2 stainless steel cables I can reduce movement in one direction and the oil damper should help with any others... hope.

Thanks for your input, I don't feel so alone in doing this.

Shell

Offline kml


And even with the unit suspended by a wood stand just above the scale (to prevent contact), with ceramic flooring tiles placed on the scale tray for similar loading:


So let me understand. The rig wasn't even ON THE SCALE and the scale regestered a weight change?

Yes! which is why I susped RFI of the "hybrid super sensor" in the scale:

http://www.scalenet.com/and/gx/sensor.html

Though my experience with RFI is that it is usually much more dramatic/noisy/unpredictable.    This is a remarkably consistent and reproducable effect.

Offline maciejzi

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splad posted this great video on Reddit:

https://www.youtube.com/watch?v=L5fVFA2sWt4&feature=youtu.be

Acoustic Propulsion

[...]

You must have mass/energy coming out of the EM Drive to have any propulsion, as well.

This is a great test to show that Shawyer is wrong (justifying the EM Drive on resonance, and claiming that no esoteric physics is needed to have propulsion without anything coming out): if you put a cap on the bottles, they will not spin, as there is no air coming out, it is an ASYMMETRIC RESONATOR.  It needs to have an open end for it to work.

EDIT: Acoustic propulsion works because the exhaust of gas (due to compression of the plastic bottle during acoustic vibration) occurs in well-directed vortices while the intake of gas (due to the expansion phase of the plastic bottle during acoustic vibration) is not as axially directed but instead it sucks air from a large range of directions, including the direction perpendicular to the axis of axisymmetry of the bottle.   In other words, acoustic propulsion works due to the difference between ejection flow and intake flow.


I think that EmDrive is in many aspects similar to such acoustic propulsion, only tuned for microwaves and energized by electromagnetic wave (not sound wave).

There is no sound in vacuum, but the microwaves may still work and generate thrust in vacuum as well. No end needs to be open, microwaves can escape with the whole resonator closed.


Offline SeeShells

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The critical issue I've seen id getting power cables to the Drive without having to worry about the power cable causing issues. I have the power box under the fulcrum in a shielded cage. The power line from it goes up to connect to a point above the center of the beam. *see drawing and never touches the beam which could cause deflection.
Thoughts? Questions?

Shell

there will be 4 wires needed for magnetron, 2 bias and 2 filament. Make a liquid "wire splice" for the 4 wires. Basically 4 test tubes of conductive mercury. An electrode from power supply wire goes in at bottom of tube. Another electrode from fulcrum drops down into mercury. The mercury conducts the voltage regardless of the depth of the fulcrum side electrode, it simply swims in it. Depth of mercury and length of electrode should allow Moment arm displacement without breaking contact (fulcrum side electrode rising out of mercury).

A non scientific description of a near frictionless wire splice...hope I explained it well enough.
Very well indeed! I'll look into it. I think I have some old home thermostats that used mercury. I need to be very careful of it.

Shell

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