Did you heat the chuck before installing it?
I have had them fall off of the conical fitting and onto my hand before.... not fun... ever.
The vibration may also be a loose conical bearing, or some shavings somewhere where they shouldnt be. I had to clean out my drill press before using it because of this problem. Tighten everything up and be sure the belt is good and tight.
__________________
I have a nice computer.
|