Never had a CG problem with either the ZDZ 40 or DA 50, just moved gear , battery around as needed. Plane does not care, flys very well with the ZDZ or DA. Its one of those that fly like they guys on the vidos, just with you at the controls. Be sure to ballance in all directions and get both halves of the elevator and ailerons working togeather. Had problems with my elevators until I made a template of the left side and transferred the horn on the right side to be exactly the same. Match boxes dont seem to work for me in this regard. ENJOY