I have a tarot quad frame using apm 2.6 with external 3dr compass/gps and cannot get the quad to stop yawing throughout the flight in either stabilze or loiter. Running auto it will be steady for about the first 3 or 4 minutes then you can tell its trying to fight it and ultimately ends up unable to correct. Ive replaced all blades, compass, gimbal (went back to a lighter frame thought CG might have been off), recalibrated accelerometer and compass without any luck. Besides changing out motors and/or esc’s I am completely unable to figure this one out. The yaw is not anything erratic- it slowly starting to creep in late last year (was great for upwards of 100 flights)- but has not gotten better and interferes with the flight plans I’ve made for imaging and this is the only platform I have capable of carrying our IR camera. If anyone has ideas on where to go from here it would very much help us out.