APM Quad precesses then crashes on takeoff

Hi There,

I’ve recently changed all the ESC’s on my quad to SimonK ones to improve it’s handling and responsiveness. But now every time it takes off it rapidly starts precessing and inevitably crashes within a few seconds. I’ve tried tuning it using the extended tuning panel in Mission Planner with no success.
I’ve had a look in the log file and the gyros and accelerometers seem to be giving the correct readings.
Has anyone seen anything like this before when changing to SimonK ECU’s. What could cause it and can be fixed by tuning parameters alone?

The firmware is : ArduCopter V3.1.5 (3c57e771)
Here’s a link to a video showing the behaviour:

Thanks in advance

Thanks for sharing the video, and sorry about the long delays in anyone getting back to you.

It looks like your motors are not connected in the correct order, or your ESC’s are not calibrated correctly.

What you should do is open up mission planner and connect via the terminal and run the motor setup. This will help you to double check if the motors are connected in the correct order and to the correct APM output. The video itself is kind of old but stil very helpful.

Hope that helps :slight_smile: