Did you calibrate your ACC while having the copter standing still on the floor?
did level calibration within APM Planner.
do you mean when you press forward its flying sideways or when you try and hover it just goes side ways ?
sometimes when i yaw right it yaws left...
- but the problem is solved by aligning the motors straight.
I had the same problem and did inflight leveling..hold throttle 20 seconds to the right just like arming, then fly and hold it stable then land.
after aligning the motors i did inflight leveling. It flyes super stable now, but loitering is a catastrophy.....
APM2 same problem :
got a carbon frame, motors are straight. Setings standard.
when yaw cw it torns cw o.k, but ccw nearly no reaction....
any help appreciated :-)