centering servos, try this, turn on your TX then plug in the battery on the heli and let the servos move to their center position (make sure your TX trims are center) and once the servos settle into place (centered) make sure the servo horns are as close to horizontal as possible, one tooth off up or down is no big deal, these don't have to be level just horizontal. Adjust the pushrods until the swash is level with a bubble level (side to side, front and back) and then center the CG and you're done.