Log analyze help.Crash 3.6.5

I have cube with 2xHere gps (blend) on dji S900 frame. Im on previous stable firmware (3.6.5?)
Battery 14000mah. Mauch power module and bec to power 1 and another Mauch bec for power 2.
I have been flying for a while now with this setup without gimbal/camera. Copter seems to fly ok and all functions are working as they should.
Copter is stable, but im not confident to install my gremsy gimbal with camera yet, To many bad experiences on my previous builds i quess :wink:
Its winter here, so there haven´t been too many chances for testing yet.
Went for a flight today, a bit windy, maybe around 5-7m/sec so i did not even try to get stable loiter for checking vibes or do autotune for roll and pitch, autotune is done for yaw.
I have had several pixhawk´s, but haven´t really understand how to do log interpretation properly in MP. I check´d vibes on log rewiew and did auto log analysis. I belive that vibes are too high and there was some motor balance issues, but i have understood that motor balance fail is not too serious, just something to monitor in future for possible mechanical issue on esc/motor ?
I will attach bin from todays flight. I would much appreciate if someone with more experience would have time to take a quick look at the log and give some feedback and suggestions for possible issues or actions to do for improvements.
If weather permits tomorrow, ill try to get autotune completed and get some stable loiter for log. Really would like to start installing the gimbal… :sunglasses
Thank you :slight_smile:

Motor channel averages = [1787, 1749, 1542, 1516]
Average motor output = 1648
Difference between min and max motor averages = 271
The problem is the disproportion of the race of engines or uncalibrated regulators. Apart from this, the ATT graph shows the lack of correct regulation.
Calibrate esc and check the logos again. what are your masses, engines, propellers and pids? Maybe you also need to improve your pids.
Vibrations are not a problem in this case. It seems that a copter can be too heavy to mount a gimbal, but it may be a matter of a small propellers.Is the firmware version of -rc5 stable?

just from a quick look:

  • vibration levels are a-ok (graph VIBE.x, y and z). around 15m/s/s on z-axis which is fine
  • attitude control is not great but I suspect an autotune will help with that
  • altitude control looks OK
  • compass messages have been turned off in the logs for some reason (LOG_BITMASK changed?) so can’t see if there’s interference from the motors. could be no problem though… just can’t be sure.
  • there’s a very significant motor imbalance.with motors 1 and 2 nearly hitting their upper limits which could lead to control issues. these are the counter-clockwise motors so perhaps a motor is tilted.
  • the vehicle is a little underpowered hovering at 60% throttle. If a gimbal is going to be added it may become worse. It will probably fly but I worry that it will lose it’s ability to control itself well as the battery voltage drops so perhaps bigger motors/props and/or higher voltage battery.

Hope this helps!

I have 400KV motors and 6S battery.Props 15"
Did esc cal.today and went for a flight.
Really calm day, so i decided to try autotune in alt hold.
I had to abort that due low bat. waisted some mah´s at the beginning with autotune on alt hold too high up where was too much wind…stupid mistake from my side. On landing i used auto land and there was a unusual bump, but i did not saw anything else alarming so i decided to go again with fresh battery.
Second flight, all motors started same time and were spinning fine, anyway right after takeoff copter started spinning and i noticed that one prop was hardly spinning at all…so, esc or motor failure, right?
I tried different modes to land spinning craft safely, got some EKF messages on my GCU, i was so busy to keep copter airborne that i did not really had time to pay attention on messages… Anyway, a crash happened, damages still under investigation…
Attatched both logs if someone is interested.
It must be faulty hardware, this build is made with lots of TLC and good quality components…really frustrated right now…well, not the first and probably not the last crash…part of the hobby i quess…$$$ :confused: