Author Topic: EM Drive Developments - related to space flight applications - Thread 7  (Read 1665977 times)

Offline Monomorphic

  • Full Member
  • ****
  • Posts: 1725
  • United States
  • Liked: 4364
  • Likes Given: 1403
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.


Offline Bob Woods

  • Full Member
  • ***
  • Posts: 380
  • Salem, Oregon USA
  • Liked: 515
  • Likes Given: 1564
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?

Offline bad_astra

  • Full Member
  • ****
  • Posts: 1920
  • Liked: 311
  • Likes Given: 541
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.
"Contact Light" -Buzz Aldrin

Offline Monomorphic

  • Full Member
  • ****
  • Posts: 1725
  • United States
  • Liked: 4364
  • Likes Given: 1403
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.
« Last Edit: 08/18/2016 08:18 pm by Monomorphic »

Offline SeeShells

  • Senior Member
  • *****
  • Posts: 2442
  • Every action there's a reaction we try to grasp.
  • United States
  • Liked: 3186
  • Likes Given: 2705
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


Offline Monomorphic

  • Full Member
  • ****
  • Posts: 1725
  • United States
  • Liked: 4364
  • Likes Given: 1403
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.

Offline WarpTech

  • Full Member
  • ****
  • Posts: 1406
  • Do it!
  • Statesville, NC
  • Liked: 1452
  • Likes Given: 1923
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.

Offline aero

  • Senior Member
  • *****
  • Posts: 3617
  • 92129
  • Liked: 1136
  • Likes Given: 358
Just a curiosity question, but do you know? What is the beam wattage of your laser displacement sensor?
Retired, working interesting problems

Offline Bob Woods

  • Full Member
  • ***
  • Posts: 380
  • Salem, Oregon USA
  • Liked: 515
  • Likes Given: 1564
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
« Last Edit: 08/19/2016 03:03 am by Bob Woods »

Offline Monomorphic

  • Full Member
  • ****
  • Posts: 1725
  • United States
  • Liked: 4364
  • Likes Given: 1403
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.
« Last Edit: 08/19/2016 01:16 pm by Monomorphic »

Offline D_Dom

  • Global Moderator
  • Full Member
  • *****
  • Posts: 620
  • Liked: 417
  • Likes Given: 139
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
« Last Edit: 08/19/2016 07:39 pm by Chris Bergin »
Space is not merely a matter of life or death, it is considerably more important than that!

Tags:
 

Advertisement NovaTech
Advertisement SkyTale Software GmbH
Advertisement Northrop Grumman
Advertisement
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
1