Artificial horizon leans to the Right
« on: August 19, 2016, 10:58:00 pm »
Hi there,

Because of calibration issues, my Revo is out of the plane and back on the testbed. The problem I have is that the artificial horizon leans to the right, making believe the plane (or testbed) leans to the left as it is horizontal (after spirit level verification) on the all wood bench. Actually, if I do the "Board Level Calibration" with the board aligned on a North-South axis (2 calibrations 180° apart), only East and West headings show the AH leaning some 5° to the right. North and South Headings are OK (AH is horizontal). Of course, any heading in between leans in between.

Now, if I do the Board Level Calibration with the board aligned on an East-West axis, North and South headings show the AH leaning some 5° to the LEFT (yes, left) this time.

I did that part of the calibration many times (omitting to redo the much longer accelerometer and magnetometer calibration) and the result is more or less the same leaning between 4° and 5.5° right or left depending whether I use a North-South or East-West axis for calibration.

Any suggestions ?


Thanks for your help

West

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Re: Artificial horizon leans to the Right
« Reply #1 on: November 27, 2016, 05:11:11 pm »
Happy Thanksgiving Bizuth_74!
I will just throw in some brainstorming to move this along and respond for support...do you have another of the same FC to prove that it can be leveled/done on your bench exactly as the first? If so do it.

Also, is the FC in question installed/seated into a case that is completely snapped closed on all four corners?
How do you hold it down to the bench? Finger hold, mounting tape, loosely/not fixed?
What is the distance between the FC and the closest iron/metal object/s, speakers, transformer, power supply, monitor, PC?
ISOLATE at least 24" placed on surface/structure of non-metallic material. 24" Not a magic number just insurance.
Could be a bad gyro/thingy.
Do not be discourage, only challenged.

Good problem solving to ya,
West

Re: Artificial horizon leans to the Right
« Reply #2 on: November 27, 2016, 07:29:04 pm »
First of all, never change your transmitter trims after running the transmitter wizard.  If it drifts in Attitude mode, there is a different way to fix it correctly.  It should never drift in Rate mode.

Be aware that some copters aren't level when they are hovering motionless.  A misaligned motor (crash damage, etc.) is the most common cause.

I would first of all hover in Attitude mode with Basic "Attitude Estimation Algorithm".  Adjust Attitude -> Settings -> RotateVirtual to correct the drift
  if it is drifting forward you subtract from pitch
  if it is drifting left you subtract from roll

Then hover in Attitude mode with INS13 "Attitude Estimation Algorithm".  Adjust Attitude -> Magnetometer -> BoardRotation to correct the drift.
  if it is drifting forward you add to pitch
  if it is drifting left you add to roll

This should make it stop drifting in Att INS13.  It should then be level in the HUD unless you have a misaligned motor, etc.  It will still be motionless if you switch back to Basic.  If you want to tweak it more, you can just adjust (a few degrees at most) mag boardrotation to make the HUD do whatever you want.

Re: Artificial horizon leans to the Right
« Reply #3 on: November 28, 2016, 10:45:44 pm »
I had similar issues (constantly up/left 5-10 degrees) until I did the temperature calibration procedure.  Now it's "very close" but still off a little on pitch.

Thanks for the the tips on how to manually adjust!  I knew there had to be some place to do this.