EM Drive Developments - related to space flight applications - Thread 7

[Monomorphic]

After properly calibrating the precision 3-axis compass and reattaching it to the torsional pendulum beam, I confirmed that the beam wasn't aligned perfectly N-S. I knew this already based on crude measurements with a cheap compass. You can see in the image how much I had to move the entire rig to get the alignment correct. My strong suspicion is this "geomagnetic misalignment" was the source of the anomalous "reverse thrust" seen for both emdrives tested so far.

[Bob Woods]

After properly calibrating the precision 3-axis compass and reattaching it to the torsional pendulum beam, I confirmed that the beam wasn't aligned perfectly N-S. I knew this already based on crude measurements with a cheap compass. You can see in the image how much I had to move the entire rig to get the alignment correct. My strong suspicion is this "geomagnetic misalignment" was the source of the anomalous "reverse thrust" seen for both emdrives tested so far.

Can you expand on how you think the misalignment would reverse the thrust vector?

[bad_astra]

Yes. If a cubesat could not be tracked, why would anyone send one up?

https://en.wikipedia.org/wiki/CubeSat

Well yes by the people who sent it up, I meant a 3rd party.  My point is just that verification of results is key here.  The more third parties that can do it the better.

Hams do it every day.

[Monomorphic]

After properly calibrating the precision 3-axis compass and reattaching it to the torsional pendulum beam, I confirmed that the beam wasn't aligned perfectly N-S. I knew this already based on crude measurements with a cheap compass. You can see in the image how much I had to move the entire rig to get the alignment correct. My strong suspicion is this "geomagnetic misalignment" was the source of the anomalous "reverse thrust" seen for both emdrives tested so far.

Can you expand on how you think the misalignment would reverse the thrust vector?

Basically the EM fields inside the frustum, current flowing through wires, or perhaps the magnetron itself, makes the entire torsional pendulum beam act like a compass. During all powered tests the pendulum moved in the inverse direction that aligned North-south.

[SeeShells]

After properly calibrating the precision 3-axis compass and reattaching it to the torsional pendulum beam, I confirmed that the beam wasn't aligned perfectly N-S. I knew this already based on crude measurements with a cheap compass. You can see in the image how much I had to move the entire rig to get the alignment correct. My strong suspicion is this "geomagnetic misalignment" was the source of the anomalous "reverse thrust" seen for both emdrives tested so far.

Can you expand on how you think the misalignment would reverse the thrust vector?

Basically the EM fields inside the frustum, current flowing through wires, or perhaps the magnetron itself, makes the entire torsional pendulum beam act like a compass. During all powered tests the pendulum moved in the direction that aligned North-south.

Did you ever get a USB O-scope?

As it would take a DC component in the power to the magnetron to make field that the device would align too. Your heater is AC as well as the pulsed HV DC.

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magfor.html#c1

[Monomorphic]

Did you ever get a USB O-scope?

Not yet. The extra Laser Displacement Sensor (LDS), 3-axis multi-sensor, mini-computer and Li-ion battery wiped me out budget-wise this month.  I'll have to wait a couple of weeks.

[WarpTech]

After properly calibrating the precision 3-axis compass and reattaching it to the torsional pendulum beam, I confirmed that the beam wasn't aligned perfectly N-S. I knew this already based on crude measurements with a cheap compass. You can see in the image how much I had to move the entire rig to get the alignment correct. My strong suspicion is this "geomagnetic misalignment" was the source of the anomalous "reverse thrust" seen for both emdrives tested so far.

Can you expand on how you think the misalignment would reverse the thrust vector?

Basically the EM fields inside the frustum, current flowing through wires, or perhaps the magnetron itself, makes the entire torsional pendulum beam act like a compass. During all powered tests the pendulum moved in the inverse direction that aligned North-south.

I don't know about that. The Earth's magnetic field is at most .6 Gauss and the current in the wires is not very large either, and the current is bidirectional. So any force on the wires due to the Earth's magnetic field should oscillate at 60 Hz, and not produce a NET force in one direction or the other.

[aero]

Just a curiosity question, but do you know? What is the beam wattage of your laser displacement sensor?

[Bob Woods]

Was looking at this describing the LENZ effect on aluminum. A moving magnetic field, or aluminum moving close to a magnet, can induce motion because aluminum is para-magnetic. It might not be the earths magnetic field alone.


http://terpconnect.umd.edu/~wbreslyn/magnets/is-aluminium-magnetic.html

[Monomorphic]

The magnetic field strength at my location is 0.49 Gauss. There is a line conductive noise suppressor in the filter box of the magnetron (shown at bottom of image here).

I'm not sure about the LDS laser strength without looking it up. I would wager it is no more than 100mW, if that.

[D_Dom]

Thread is informative, interesting read. Thanks to all contributing to this effort. Started next in the series, thread #8.

https://forum.nasaspaceflight.com/index.php?topic=40959.0