Originally Posted by MisterHeavy

I only own two TB cutters. One's a 1/2" pattern, the other a jig-fitting dovetail.
Both bearing retaining sleeves have either been loose or worked loose in use. The pattern bit threw its grub screw into a parallel universe somewhere and last ninght the DT bit suddenly "felt funny" so I stopped ASAP and saw the bearing had slid up the shaft to the collet.

I don't bottom bits out in the collet, but if I did, the bearing retaining ring would sink a mm or two below the collet nut edge.
The T9 has a deep collet, and most bits would "bottom out" on the collet face before the shaft hit the motor spindle but I always back the bit out a smidgeon
The DT is long-shafted and I had the bit backed out a lengthy smidgeon - maybe 1/3" to give me a little more bit height (smidgeons aren't metricated yet ) so there's room on the shaft for the bearing to slide if it becomes loose.

It did.

QUESTION:
If I packed the bearing retainer-to-collet distance with two or three 1/4" washers, would that cause any problems? It seems to me that it wouldn't, as the cutter would only be "rigidified" against the collet, not the arbor, but I'd like to avail myself of correct wisdom before doing anything potentially blood producing.

I know an O ring would be better in some ways, but the washers are more easily available.
Thanks