I have a 600N that flys very well, no vibration and copes well with 3D.
I was able to pick up a 500 scale fuselage from our hobby shop. Modification to the tail servo was straight forward. The model looked the part.
Test flight, start up normal, on the ground all smooth with all working as it should. As I lifted into the hover the tail started to seriously vibrate ending in a messy pile on the ground.
Damage to the mechanics all ok the shell a bit broken.
Later that day the shell was removed and the old skids installed together with a new set of tail rotor blades. The helicopter flew perfectly without any hint of vibration.
Has anyone got any thoughts on what the cause may have been with the shell fitted. I will get spares and try again with the 500 shell, it looks to good to give up.

Thanks