Dear Dr, after racing today I followed your instructions and unassembled the motor, I found that my arm had not been balanced properly, there seems to be parts where a drill has been used, I beleive this to be the clamping method when wrapping. I need some advise in what to use to fill the holes, they are 1mm and quite deep. Sellys need it work? after filling the holes how do I go about re ballancing I've tried several different flat/level surfaces sometimes it falls left then sometimes right??