RE: Balancing brushless outrunner motors
From what I can tell/guess is that the label itself on these smaller motors may be the cause of the imbalance. I am reluctant to remove the lable as this would make it guess work as to what the motor was sometime in the future.
There is an Appt for the Iphone that uses the inertial sensor within the phone to sense the vibration but, alas I dont have a smart phone. My balance detector is basically my hand lightly holding the shroud and spooling up the motor & fan to see if my taping has helped or hurt the balance. Not very scientific but it seems to help make the motor run smoother. Its the last little bit of vibes that I would like to eliminate.
Filing on the motor or grinding seems like a way of getting filing/grit into the magnets and causing a slow self-destruction of the motor.
Keep those cards and letters coming Folks!