Hi all,
I switch from loiter to autotune (pitch only)… copter dived directly to the ground, despite aggressiveness reduced to minimum. I flew the same copter before for 30 minutes without any problems
Not really sure what happened. I’m sharing the log in case anyone can help me:
log
Thanks
Did you take a look at the tuning guide prior to flying? Looks like things were not set. Did you perform a radio calibration?
thanks for taking a look at it. yes radio calibration was done. I first flew the quad to test his autonomy. landed , then I set up auto tuning… mind telling me what are the things they were not set ?
This is probably the most often shared link in this entire forum … but here you have it … again 
https://ardupilot.org/copter/docs/tuning-process-instructions.html
thanks for you response.
I’m familiar with that link, but I haven’t touched those parameters since the quad is 18inch props (I assumed the default value will be same as 20inch’s params) , I’ve had successfully performed autotune on the same frame without changing them. But I will go back and change the MOT_ parameters, I maybe missing something else. I’m having concern since it’s the board that had to be grounded recently as instructed by hex folks. thanks again