trim with ACM

[sglynn55]

What might be wrong with trim indicator?

I have HDX on a Quick Panel with the ACM and I'm configuring my trim motors on ACM. I'm on Version 15.3.3. The pitch trim works great and indicates smoothly on the screen.

But the aileron trim works, but the indicator jumps from full right to full left back and forth. It doesn't move smoothly like the pitch trim indicator. What might be wrong? I'm hoping it is a setup, and not a bad wire.

thanks

 

[Dynon]

Did you do an end-to-end trim calibration on the aileron axis?

 

[sglynn55]

Mark
Well, assuming you mean Trim Motor #2 calibration with ACM so that it can couple to the autopilot, YES and it passed. I did same things to both trim motors.

Motor moves fine and in the correct direction, although I did have to switch the two white wires to change its direction.

But I'm inclined to do this calibration again. By the way, prior to calibration the little triangles on the trim axis did not show. After calibration they appeared on both axis.

Or if you mean something else by your question, please clarify.

Also tonight I unplugged the trim motor and measured voltage. 5 Volts between wht/oragne= wht/blue. And 5V Orange+Green. But 0V between blue and orange. Any clues here? I have not yet dismantled big connector at ACM to check wiring. That will be messy. Your help is appreciated.

 

[DBRV10]

If it is the indicator that is jumping around you may have a faulty linear pot in the trim motor. Solution to that is buy a new one.

 

[sglynn55]

David
Yes, that is plan B if the wiring and setup are correct. I'm trying to determine if the wiring from the ACM is sending the right signals to the trim motor. I may have messed up mapping a couple pins. Shocking I know; But possible.

 

[GlennB]

I had a similar problem with a recent install.  The raw data from the trim servo stopped incrementing at about 3/4 travel, and the indicator was similarly erratic.

As David suggested, it was a faulty linear pot.  Before giving up on the servo, it might be worth opening it up and squirting some contact cleaner into the pot. That worked for me.

 

[sglynn55]

Did you do an end-to-end trim calibration on the aileron axis?

FIXED, After disassembling both connectors and testing them and testing the servo I final found the end to end Aileron trim calibration. It is under SETUP>HARDWARE>EMS>Aileron Calibration. Why I don't know because TRIM doesn't even connect to EMS. It connects to ACM. But after doing this calibration the indicator works great.

Thanks Much