3.5-rc7 loiter problem

Installed today 3.5 rc7 on a new build 900mm quad pixracer

first test flight went pretty well second one switching to loiter total mess
copter maintains altitude and position though motor sound like a race car
ch3 out very strange going from 1700 to 1000 every second or so

some expert opinion might help!


You have a lot of vibrations, X axis especially.
The copter has plenty of power, maybe a bit too much, as some of the motors are literally stopping to maintain attitude and altitude.
There is a lot of overshoot on the Desired versus actual in Attitude control.

So I would suggest
reducing vibration
Adding some load and
Doing an autotune

1 Like

Thanks a lot, added weight worked. Going for tunning.

Sorry for the slow reply. Definitely it’s working a little too hard. I think with the little copters the gains can be a lot lower so perhaps reduce the rate roll, pitch and yaw P,I,D values by 30% each would help. I think the ACCEL_Z_P and ACCEL_Z_I could be reduced as well.

From the logs it looks like it’s bucking forward and backwards so the Pitch gains in particular probably need to be reduced.

Thank Randy, it is a 900mm or 90cm quad. I am waiting for good weather for autotune.