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#3260
by
otlski
on 01 May, 2018 23:50
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Mono,
With all that foam insulation in close proximity to your UUT and measurement structure, you might want to treat with an antistatic or dissipation spray to reduce electrostatic attraction.
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#3261
by
D_Dom
on 03 May, 2018 16:25
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With a brief exposure to fiber optic based instrumentation many years ago (OK decades) I consider this technology when thinking about force measurements at this scale. Here is a paper addressing this, many thanks to the fine folks at Luna Inc.
http://lunainc.com/wp-content/uploads/2014/01/LT_TD_EN-FY1324_MeasuringSmallStrainsWODB.pdfReason I find this so compelling is when using a wavelength of light as your measurement standard you have an ability to measure very small forces. I remember back in the day (eyeroll) seeing full page ads in Lasers and Electro-Optics describing the deflection of a manhole cover caused by a dime set on it. Another memorable claim was to measure change in shape of a glass of wine when filled as opposed to empty.
These sensors are lightweight, low profile and can easily be installed within challenging environments. The sensors are EMI immune and use no electrical signal. A single strand of fiber can be used for both temperature and strain. I realize this is not a low-cost solution, integrating a test rig sized to cubesat experiments is on my wish list. Lurking this forum helps me understand the challenge.
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#3262
by
otlski
on 04 May, 2018 00:01
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With a brief exposure to fiber optic based instrumentation many years ago (OK decades) I consider this technology when thinking about force measurements at this scale. Here is a paper addressing this, many thanks to the fine folks at Luna Inc.
http://lunainc.com/wp-content/uploads/2014/01/LT_TD_EN-FY1324_MeasuringSmallStrainsWODB.pdf
Reason I find this so compelling is when using a wavelength of light as your measurement standard you have an ability to measure very small forces. I remember back in the day (eyeroll) seeing full page ads in Lasers and Electro-Optics describing the deflection of a manhole cover caused by a dime set on it. Another memorable claim was to measure change in shape of a glass of wine when filled as opposed to empty.
These sensors are lightweight, low profile and can easily be installed within challenging environments. The sensors are EMI immune and use no electrical signal. A single strand of fiber can be used for both temperature and strain. I realize this is not a low-cost solution, integrating a test rig sized to cubesat experiments is on my wish list. Lurking this forum helps me understand the challenge.
I went to their website I saw where you can integrate a fiber into your own mechanism. Do they also have prepackaged optical strain gages?
What properties do you wish your rig for cubesats to measure?
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#3263
by
Chrochne
on 04 May, 2018 04:32
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I am glad to share that Mr. Mike McCulloch confirmed to me he and Mr. Tajmar received funding for their project. They have detailed technical plan to test it. Now only facing some negotiation difficulty with university. I hope they will be able to over come it!
Also Mr. McCulloch pays a visit to NSF sometimes and check on the progress here.
Great to see so much progress lately on the EmDrive (and other propellantless fields).
I also see that many testing projects are recieving more funding lately. That is a good news as we hope to see more testing data
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#3264
by
X_RaY
on 06 May, 2018 19:05
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#3265
by
Monomorphic
on 07 May, 2018 21:59
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The final version of the liquid metal contact system is up and running!
I completed the last of the wiring this morning and then used an eye-dropper to add ~7 ounces of liquid metal to the 8 reservoirs. If you look closely, you can see the liquid metal through the clear PLA used to 3D print the part.
Everything went smoothly except the USB connections didn't work at first. A USB signal can only travel 16.5 ft in the best of circumstances, and with all the wiring and twisted pairs, connections, and extension to the main computer, that came very close to 16 ft. This was solved by adding a $20 four-channel powered USB hub between the liquid metal contact and main computer. Now it works like a charm. I had no problem accessing the Windfreak SynthNV signal generator on the pendulum through the liquid metal USB connection.
I also found out that the SynthNV software was written in LabView. This should save me untold amounts of heartache as I figured writing a LabView virtual instrument for the signal generator would be the most challenging part of the scripting.
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#3266
by
D_Dom
on 08 May, 2018 03:47
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With a brief exposure to fiber optic based instrumentation many years ago (OK decades) I consider this technology when thinking about force measurements at this scale. Here is a paper addressing this, many thanks to the fine folks at Luna Inc.
http://lunainc.com/wp-content/uploads/2014/01/LT_TD_EN-FY1324_MeasuringSmallStrainsWODB.pdf
Reason I find this so compelling is when using a wavelength of light as your measurement standard you have an ability to measure very small forces. I remember back in the day (eyeroll) seeing full page ads in Lasers and Electro-Optics describing the deflection of a manhole cover caused by a dime set on it. Another memorable claim was to measure change in shape of a glass of wine when filled as opposed to empty.
These sensors are lightweight, low profile and can easily be installed within challenging environments. The sensors are EMI immune and use no electrical signal. A single strand of fiber can be used for both temperature and strain. I realize this is not a low-cost solution, integrating a test rig sized to cubesat experiments is on my wish list. Lurking this forum helps me understand the challenge.
I went to their website I saw where you can integrate a fiber into your own mechanism. Do they also have prepackaged optical strain gages?
What properties do you wish your rig for cubesats to measure?
Still discussing possibilities, they have a wide experience with this measurement capability..
I think about setting an experiment capable of thermal and vacuum testing. No budget for any of that so it is just a mental exercise at this point.
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#3267
by
Chrochne
on 09 May, 2018 07:12
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I am glad to share that Mr. Mike McCulloch confirmed to me he and Mr. Tajmar received funding for their project. They have detailed technical plan to test it. Now only facing some negotiation difficulty with university. I hope they will be able to over come it!
Also Mr. McCulloch pays a visit to NSF sometimes and check on the progress here.
Great to see so much progress lately on the EmDrive (and other propellantless fields).
I also see that many testing projects are recieving more funding lately. That is a good news as we hope to see more testing data
Additional news today. Mr. McCulloch will have a speech at Plymounth University (UK) tomorrow (10.5.2018) on the topic of (quote from Twitter)
" 'Rocket propulsion from Quantised inertia'. ie: how to launch satellites without chemical rockets, as #QI suggests can be done. "
Trying to contact the University if it will be streamed or if video will be made, or presentation on the topic...ect. If answered will share here.
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#3268
by
SeeShells
on 09 May, 2018 14:04
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The final version of the liquid metal contact system is up and running! I completed the last of the wiring this morning and then used an eye-dropper to add ~7 ounces of liquid metal to the 8 reservoirs. If you look closely, you can see the liquid metal through the clear PLA used to 3D print the part.
Everything went smoothly except the USB connections didn't work at first. A USB signal can only travel 16.5 ft in the best of circumstances, and with all the wiring and twisted pairs, connections, and extension to the main computer, that came very close to 16 ft. This was solved by adding a $20 four-channel powered USB hub between the liquid metal contact and main computer. Now it works like a charm. I had no problem accessing the Windfreak SynthNV signal generator on the pendulum through the liquid metal USB connection.
I also found out that the SynthNV software was written in LabView. This should save me untold amounts of heartache as I figured writing a LabView virtual instrument for the signal generator would be the most challenging part of the scripting.
Just a note on passing through and catching up. You might want to provide a ground return the metal wrap you added on your wires for the liquid metal contacts if your other end isn't grounded. It can be a source of noise and cross talk.
Beautiful work.
My Very Best,
Shell
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#3269
by
Monomorphic
on 09 May, 2018 15:32
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Just a note on passing through and catching up. You might want to provide a ground return the metal wrap you added on your wires for the liquid metal contacts if your other end isn't grounded. It can be a source of noise and cross talk.
I was wondering who was going to notice that.
It is definitely planned. I will either solder a small wire to each shield and ground that or use small clips.
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#3270
by
Monomorphic
on 10 May, 2018 00:33
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More images.
I now have everything working as designed. This includes getting full power from the main amplifier over the liquid metal contacts. I had some interference problems with the ADC, but that was solved with ferrite cores. I've also continued covering everything I can in insulation. I hope to have a video out in the next few days detailing the setup and all the improvements.
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#3271
by
The_Optimist
on 11 May, 2018 15:12
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Amazing work! I’m in awe and very much hoping you measure something anomalous!
Stu
Sent from my iPhone using Tapatalk Pro
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#3272
by
Monomorphic
on 14 May, 2018 00:53
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More progress this weekend. While testing the main amplifier and phase change heat sink, I discovered a small leak in one of the petroleum jelly reservoirs. This is after taking special care to make sure everything was sealed as when I visited Paul March at NASA, they were having the same problem. Melted paraffin will flow through the tiniest hole! A generous application of high temperature epoxy seems to have sealed the leak.
I also moved the main amplifier to the center of the pendulum and completely encased it within a foam insulation box. This allowed me to remove several lbs of counterweight and further decrease the noise from convection. I can still view the petroleum jelly as it melts through a double-pane acrylic window at the top.
I was also able to use the last remaining liquid metal contact for the MOSFET temperature sensor on the main amplifier. So while tests are running, the temperature of the amplifier transistor can also be monitored and recorded.
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#3273
by
Monomorphic
on 15 May, 2018 21:27
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Intel ISEF Public Day is this Thursday, May 17, 2018 in Pittsburgh, Pennsylvania. This year the Emdrive Polish group headed up by Jakub Jedrzejewski will be presenting their findings. This is the group I have been advising on their experiment and test rig. They have some interesting test results to report (which I have already seen). If anyone is in the area, it is open to the public from 9:00 am to 9:00 pm.
https://student.societyforscience.org/intel-isef-2018-public-dayI have asked Jakub to post their results here after their presentation on Thrusday, but with them traveling, it may take a few days. Their chosen resonant mode (TE013), amplifier, signal generator and laser displacement sensor are the same as I am using, so it will be interesting to see if my tests replicate their findings.
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#3274
by
WarpTech
on 16 May, 2018 23:56
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#3275
by
RotoSequence
on 17 May, 2018 03:40
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#3276
by
ThinkerX
on 17 May, 2018 06:51
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And so it remains infuriatingly ambiguous. 
To me, it looked like a lean towards the negative, especially with the reference to earths magnetic field.
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#3277
by
Chrochne
on 17 May, 2018 07:47
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Intel ISEF Public Day is this Thursday, May 17, 2018 in Pittsburgh, Pennsylvania. This year the Emdrive Polish group headed up by Jakub Jedrzejewski will be presenting their findings. This is the group I have been advising on their experiment and test rig. They have some interesting test results to report (which I have already seen). If anyone is in the area, it is open to the public from 9:00 am to 9:00 pm. https://student.societyforscience.org/intel-isef-2018-public-day
I have asked Jakub to post their results here after their presentation on Thrusday, but with them traveling, it may take a few days. Their chosen resonant mode (TE013), amplifier, signal generator and laser displacement sensor are the same as I am using, so it will be interesting to see if my tests replicate their findings.
Thank you on reporting this Monomorphic. I hope for some interesting data. Can you share any details on their setup?
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#3278
by
meberbs
on 17 May, 2018 08:15
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And so it remains infuriatingly ambiguous.
To me, it looked like a lean towards the negative, especially with the reference to earths magnetic field.
To quote the paper:
This clearly indicates that the “thrust” is not coming from the EMDrive but from some electromagnetic interaction.
People should read the paper for details, but basically, they did a good null test that showed comparable thrust. Looking at the data in the paper, it looks like out of the 2 mN/kW that they measured, if there was a hidden real signal I estimate it would be below 0.5 mN/kW. Keep in mind that 0.003 mN/kW is a laser pointer, by which point an experiment would have to account for all forms of emitted and incident radiation.
They make a good point in the conclusion, which I agree with and is one reason I continue to read this thread:
At least, SpaceDrive is an excellent educational project by developing highly demanding test setups, evaluating theoretical models and possible experimental errors. It’s a great learning experience with the possibility to find something that can drive space exploration into its next generation.
The accurate measurement techniques they are developing and ways to control various errors can have a variety of potential applications.
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#3279
by
Monomorphic
on 17 May, 2018 12:49
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Thank you on reporting this Monomorphic. I hope for some interesting data. Can you share any details on their setup?
They have asked to keep specific details confidential until they've published. I can say that their setup is very similar to mine, with a few small differences, such as the length of the pendulum and torsion wire and the exact LDS model. So their setup is technically more sensitive than mine, but that difference is not so huge at the scales we are dealing with (<3uN). They are also still using a wifi signal and batteries for their experiment while I have switched to liquid metal contacts. That's about all I can share at this point.
I completed the last of the wiring this morning and then used an eye-dropper to add ~7 ounces of liquid metal to the 8 reservoirs. If you look closely, you can see the liquid metal through the clear PLA used to 3D print the part. 
It is definitely planned. I will either solder a small wire to each shield and ground that or use small clips.
