APM 2.6 yaws clockwise - can trim it out but then can't arm!

hello

any help appreciated

I have an APM 2.6. On take off it just wants to yaw clock wise. Not terribly fast - probably 1 rev / 30sec.

I can trim it out but then when I land/disarm I can not rearm as the trimmed yaw axis will not allow me to get enough “right” to initiate arming.

I have tried calibrating everything / changed compass / even put it on an entire new frame but problem persists.

Any solution would be most appreciated

Al.

See copter.ardupilot.com/wiki/autotrim/
Set all your trims to center first. Do not try to trim with with radio trims.

I have tried all that - but auto trim only helps with roll and pitch? Or am i wrong?

I have a similar problem. I increased the RATE_YAW_P to 0.32 from 0.2, and I am currently experimenting with RATE_YAW_I. I can get it to hold, but not very tight, if you know what I mean.

My homemade quad frame yawed badly. I solved it by tilting my motors slightly in opposite direction to offset the yaw. It flies fine now.

If your copter won’t stop yawing, then likely cause is your motors being tilted slightly. You really should fix the problem at the source.

However, you should also have a look at your Rate_Yaw_Imax value. It’s probably set at the default of 500 or 1000. I normally use much more than that. Try increasing it to 2000. However, be aware that, again, the root cause of this is probably mechanical, and you should fix the problem at the source. Imax is a band-aid, particularly on Yaw, and really should not be required.

I had this exact same infuriating problem.

When I looked at the Rate Yaw I valkue it was zero! I increased mine to 0.1415 (your value may be different). I noted also that the Rate Yaw IMAX value was 10. I increased this to 100. The tricopter holds heading well now!

Scott

What rob said! Have aligned motors is key to the performance of multi copters. You will have more lift, better battery life and it will fly nicer.

Yes having the yaw tuned properly is required. But don’t mask mechanical issues with I. Use rcout to determine if clockwise motors are at the same level as anticlockwise in hover.

Seen a few people have unexpected landings that wouldn’t have happened with a correct torque balanced setup. As the battery dies the motors working harder to fight any torque ran out of head room and the copter starts spinning harder and the other motors need to reduce to keep it level.

sent from my phone so apologies for any typos