Different issue every time , but haven't seen this one yet. I got motor number 2 spinning on and off after arming (and after minor crash). Do you think this motor to be replaced or ESC failed ?

See video here https://vimeo.com/manage/videos/854196694

That behaviour isn't typical of a motor issue. If that wasn't happening prior to the crash then my money would be on a damaged MOSFET on the ESC board.

Try swapping motors 1 and 2, and see which doesn't work then. That will tell you if it's motor or esc. Which one the problem follows.

Guess what, I followed someone advice "Is it an f4 or f7 fc? If you have the newest betaflight and you are running an older f4 board, switch to dshot300 and don't run bidirectional" and it is looking just fine now ... I wonder how did he know . I did run BF 4.4 on F4 with bidirectional

I run bidirectional on f411’s and f405’s, with no issues- but I do also run dshot300 on f4 boards.

I don’t necessarily agree with his entire statement, but, I’m glad your issue is resolved.

Hm..that one motor stopped to spin off and on after arming, but ...when I tried to take off it didn't , kept spinning lol

I said it is fine...but it looked fine after arming only, I've tried to fly

I would still put my money on it being a faulty MOSFET on the ESC. Changing those Betaflight settings to fix the issue makes no sense to me. If the MCU on the FC was being overloaded with trying to process DSHOT600 or bi-direction RPM data it would affect other things on the FC, not just a single random ESC output.

Personally I wouldn't risk flying the quad with that issue unless you are willing to potentially lose your whole quad if/when it drops out of the sky during a flight. If you do decide to fly it, just make sure you do so well away from any people with that unresolved issue.

(15-Aug-2023, 08:06 PM)SnowLeopardFPV Wrote: I would still put my money on it being a faulty MOSFET on the ESC. Changing those Betaflight settings to fix the issue makes no sense to me. If the MCU on the FC was being overloaded with trying to process DSHOT600 or bi-direction RPM data it would affect other things on the FC, not just a single random ESC output.

Personally I wouldn't risk flying the quad with that issue unless you are willing to potentially lose your whole quad if/when it drops out of the sky during a flight. If you do decide to fly it, just make sure you do so well away from any people with that unresolved issue.

Sure, appreciate. I always fly away from any people

Finally I noticed ESC f/w to be lower version on motor 2 comparing to all remaining three...looks good after flashing that one now. So I guess not equal ESC versions on all motors was just waiting for the issues

I'd have to say ESC as well, especially since it seems to be stopping in a specific pattern. If it was more random I'd bet on the motor.

It happened again, now with motor number 3...it is showing 32.8 instead 32.9 . Why is this happening ?

I built a 5" early last year and I noticed a similar twitching but not stopping like yours on my #1 motor but it only ever seemed to be on whatever the default arm RPM is. When I give it throttle, there is no indication that the motor is spinning any different than the other motors. Even tried another motor, same thing so it's coming from the stack that way. Kind of forgot about it since there is no sign of an issue in flight and it's had many flights and crashes on it. I ended up moving the build to another frame when I got an o3 air unit and have flown that a bunch. Flew it a couple weeks ago and only remembered it again since I armed it while out of the goggles.

T-Motor Velox ESC but the FC is whatever their newer iteration is.