There is now several month that i try to optimize the tuning of a big octo-quad (carboncore cortex).
Carboncore use mn4010 motors and tmotor carbon 15" on the top, 16"on the bottom. This set up is working well with DJI Naza, but i never had a perfect attitude with my pixhawk. It constantly overshoot and begin to wobble, worse in loiter mode.
These lasts month i used smaller cheaper (less stiff) props, and it was acceptable (with a low P, High I and D). Now i wants to put the big props and start over. I got back to default PID's and tried with 20.000maH battery.
The setup is 8kgs. I was trying to adjust P with ch6 knob method. On this first flight, i had the feeling that somebody put my sticks (i'm french, and i feel that it will sound funny in english), as the copter made some movement on roll/pitch and yaw, all alone.
Finally, the copter falled on a side as was trying to land it... 4 props to the trash (160€...)
-Could i try an autotune with that kind of setup? anyone has experience with it?
-Generally, what kind of PID's should be applied on heavy copters
-Could anyone analyse the log, i checked all but i didn't find anything. Maybe mag or imu problem?
Thanks for your help!