One motor doesn't start with other 3 motors


I building s500 heli with apm 2.5mega with arducopter 3.2. I have problem that one of the motors does not start with all the other when i arm my quadcopter. Only when i raise the throttle a bit the motor start to spin with all the other 3. I calibrate each controller individually.
What can be the problem?

I’ve had this. I think it’s common.

Pretty well always a mis-calibration problem.

Just keep re-callibrating until it goes away. Try just the ‘bad’ motor first, directly from the receiver.


I think it is the minimum value. I will look at parameter that control the min value that the motors start.