Motor Saturation Problem?


I completed the maiden flight of my latest Octo (14kg weight without payload, 24" Props) recently. It seems to be quite well powered and hovers at THRO of ~ 0,15… actually better than I had calculated.

I completed autotune on all three axis successfully (still with the FLT setting at 20Hz) on one battery.

After that the flight performance subjectlively was a bit too twitchy on roll/pitch. I will retune with the 10Hz setting next time as suggested by Leonard earlier and maybe lower RC feel and autotune agressiveness - but I am happy with what I have already and I know what to do next on this.

Yaw behaviour was subjectively not quite as “tight” after the autotune so I had a look in the logs and was surprised to see that the motors (RCOUT) seem to go into “low end saturation” a lot during the whole fligh, i.e. they go to THR_MIN a lot of times during the flight.

The log can be found here: Flight Log Maiden Flight

Is this the reason for the subjectively a bit sluggish yaw performance?
Is this an indication of a more fundamental issue?
Any suggestions on how to improve the situation?

Thanks for any words of help or consolation :slight_smile:


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You have the same problem as this thread that was just posted and already solved. Please review my tuning results, 25Kg X8 with bad yaw

Your MOT_SPIN_MIN is set too close to hover. Try .06 and set MOT_SPIN_ARM to .05 and go from there.

Hi Keith,

Thanks - must have missed the other thread - will see if I can improve the situation wirh your suggestions.