Servos not at 1500us in manual mode

When setting up a flying wing using the TBS Caipirinha airframe preset in QGC the servos are not at zero trim level (1500us) for pitch in manual mode.


Logfile is here:
http://logs.uaventure.com/view/kiFw3qPAGjM2ajWxe5bux3

Anyone know why?

Cheers!

There’s an offset in that mixer. https://github.com/PX4/Firmware/blob/master/ROMFS/px4fmu_common/mixers/caipi.main.mix#L27

Thank you very much!
Why would it be an offset in the mixer? And how is the correct way of removing it? Do I really have to change the mixer directly to get the servos centered?

Cheers

you can try using the new PWM_MAIN/AUX_TRIMn parameters to recenter, but I’m not sure how that interacts with a mixer offset
IIRC, the parameters override the offset