After ESC calibration motor start spinning not at same time


I have done some trouble shooting on my drone but can not found a way around.
The issue is that after ESC calibration on a quad copter the motor start spinning not at the same time when I push the throttle stick. One motor start spinning way before the other.

I have done both manual calibration without the arduino and one with the automatic calibration with the arduino board.

It is always the same motor that start spinning before the others.

I have the old APM Atmega base arducopter board.

I have been doing the calibration several time.

Thanks for the help

is it level? Does the hud show level? are the motors that dont spin up together and opposite those that do?

The calibration sets the end points for the range for the escs, not so they are equal. If one spins before another it maybe due that motor having bearings that more free than the others. In any case, it’s probably insignificant. The copter adjusts power based on keeping itself level, not by ‘value’ so it will all work as expected.

Ps: I am assuming that you have done accel calibration as well

Ok I see so the accel shoud compansate for the offset. Make sense. So I have a issue.

Whenever I push the throttle stick the copter seems to tilt nose up. I have done the accel calibration a dozen of time. :frowning:

Did you take off? Or did you stay on the ground?

Nop the prop touch the ground before taking off

Maybe post a log file for analysis. Ideally with rcin rcout (motor) outputs and attitude logs enabled.

sent from my phone so apologies for any typos

Ok I will enable logging. In the mean time do you think that I should enable the sensor filter as describe in the old manual :

Oh my… are you really using an APM1.4? I didn’t think that was even supported anymore.

I think what you might want to do, is increase your MOT_SPIN_ARMED and/or your THR_MIN. On the Octocopter I just built, for some reason the ESC’s need the MOT_SPIN_ARMED at about 200. Not sure why.