im having the same problem with a harmonic vibration between the pinion and the main rotor gear

it is not the gear mesh, it happens with the mesh all the way from almost too loose to too tight, and it happens only at high rpms

ive replaced the main gear and the same thing happens with the new one so i guess i will try replacing the motor or pinion

one thing ive noticed is that the main rotor gears both seem to be less than perfect circles, meaning the mesh will get tighter and looser at different points around the gear

not sure if this is just a product of bad luck or cheap production, is there a different rotor gear that will work on the AxeCP?