Stabilize Mode Yaw during takeoff

I have a very strange behavior: right after the landing legs lose contact with the ground, the copter turns to the left. Does the compass play a role in Stabilize Mode? Or an obstacle sensor forward? Otherwise I can’t explain the behavior, it seems to be “intentional” as the RCOUT values on motor 1 and 2 and motor 3 and 4 are different… would be very grateful if someone would take a look at the logfile!

some info about the quadcopter:

Cube Orange+ with Copter 4.3.5
MAD Motors 5005 280KV
17" - 5.8" Props
HerSi 30A CAN Bus ESCs
LiIo Samsung INR21700 50E 5000mAh 6S2P Smart Battery
Take off weight 3Kg

According to the messages and the RCOUT you have a serious physical yaw bias.
CCW motors are working way hard than CW motors to try to maintain yaw/direction.
This would be twisted motor mounts or frame.
Maybe even motors/props are spinning the wrong way.

Check that all motors and props are perfectly level/straight/true/aligned (however you want to say it :slight_smile: )
and use the MissionPlanner motor test to verify this:
image

Unrelated but you can also set these for general improvements:
INS_ACCEL_FILTER,10
INS_HNTCH_ENABLE,1 ← set this then refresh params to see the rest
INS_HNTCH_MODE,1
INS_HNTCH_REF,0.2
INS_HNTCH_FREQ,50
INS_HNTCH_BW,25
INS_HNTCH_FM_RAT,0.7
INS_LOG_BAT_MASK,1
INS_LOG_BAT_OPT,4

The harmonic notch filter values will need to be reviewed after you have a successful stable flight, just hover for a while, nothing special.

@xfacta
Thank you so much for your input! I check the direction and sequence of rotation several times before each first flight. I can rule that out. However, 2 motor mounts on the arms were indeed slightly twisted (by 1-2°). I have never had such an extreme effect. I suspect that the controller on motor 1 is not working properly. But I will immediately test again whether the corrected alignment of the arms make a difference.