motor numbers slowly fall in GUI

[nelsons]

Morning guys, I'm noticing in the gui that when I give full throttle my motor values go up to:
Front L 1828
Front R 1850
Rear L 1800 - then slowly start to fall to 1622
Rear R 1800 - then slowly start to fall to 1574

What would cause this? How can I fix this?
The quad is sitting on my kitchen table nice and level.
In the air the quad does tend to drift as I hover, is this why?
THanks for any suggestions, still new to this, but have some flying time with this quad nd board and loving every minute of it!
Steve

[PatrikE]

Probobly the gyro or acc values isn't 0 and the controller starts to compensate for that.

/Patrik

[nelsons]

THanks Patrik for the quick reply,
So again, I'm still new to this - to set the ACC values to 0 - is this done by recalibrating the ACC? So onTx throttle full down/left, and elevator full down? or is this done in the GUI??
THanks again
Steve

[mr.rc-cam]

I don't think this is a fair test if you are trying to troubleshoot drift. With the model sitting on the table the PID's are not operating in the intended close-loop state. That is to say, as hard as the PID's try to compensate the model using the motors, it cannot correctly react (because it is stuck on top of the table). So the overall result is that the corrections are invalid even as the PID's try harder to compensate. Long story short, the model has to be in a close loop state (flying) for the PID compensation magic to work correctly.