I am not so sure where to post - here or in Arducopter, but let's try here first . . .
I fly a Tarot 680 Pro hybrid (longer arms) hexacopter, using APM 2.5.2. in X Frame configuration. I was running on Arducopter 3.1.3, then went to 3.1.5, and then back to 3.1.2 - and the problem persists.
I noticed that my CCW motors (2,4, and 5) were running considerably hotter than the CW motors, and the logs showed that they are getting quite a bit more power from the APM compared to the CW motors
I swapped out props with a set that did not exhibit this problems in AC 3.1.3 - see 2nd log attached. I fell back to 3.1.2, and no luck. I swapped out motors, no luck. I reversed the APM 180 degrees (so nose now points to the rear) and exchanged motor leads accordingly. After this, arm/motor/esc #1 now becomes #2, and #2 becomes #1, and so on for 3 - 6. The problem stayed with the CCW "new" motors 2,4, and 5 and did not follow the original arms. So this at least tells me that it is not an ESC/motor/frame/alignment issue.
What makes this even more strange is that it flies very well. No yaw or drift, in stabil, alt hold, and loiter - no complaints/worries what so ever.
This CCW motors taking more power and running hot has me concerned though, and I would want to figure out what is causing it. So any suggestions would be greatly appreciated. Do I have a possible APM that's gone bad?
Two log files attached - one showing the persistent problem after APM reversal, and the other not . . . .
Tarot 680 Pro Hybrid
APM 2.5.2
Sunnysky V3508 - 580kv
iPeaka IQ HV 40A ESC with SimonK
Tarot 15" TL2831 CF props
2 x Zippy Flightmax 8,000 mah 4S batteries
Replies
sounds like one or more arms is "twisted" some some thrust is slightly horizontal trying to spin the copter. the apm will fight this by adding power to the opposite spinning motors to hold a heading.
it doesn't take a lot of misalignment in my experience.
I did level all the motors before tightening the motor mounts. Also, you will note that I had turned the APM around 180 degrees. So all the arms "reversed": 1<>2 ; 3<>4; 5<>6. The problem remained on the CCW arms 2, 4, & 5. If indeed it was a frame alignment problem then surely the issue would have remained with the problematic arms - which after the reversal are now numbered 1,3, & 6. This did not happen . . . .
Not so sure, if one is twisted it will try and spin the copter the same way regardless of the twisted arms motor direction.
or you have a weak motor esc, but I think that would swap to CW assuming you swapped all the motor directions when you turned the apm around so that the directions of spin matched what is stated in the manual.