I just put this in another post but, i smoked my dremel that i have had for about 20 years the other day trying to cut lite ply with the abrasive wheel. it melted the coupling between the motor and the head of the tool. it was toast when i opened it up. it kind of looks like a small plastic version of a slipyoke on a driveshaft. I just put what was left of it back together after a good cleaning of melted peices out of the case and used some jb weld. works good again. who knows how long it will live. but like i said this thing has seen 20 years of hard use. I think i already got my money's worth out of it!!! maybe it needs a blowproof bellhousing like they use in drag cars now in case it frags itself again? oh and the clencher is i looked at the parts breakdown in the manual attached in this thread and that is the one piece that is not listed. it is shown, but no listing for it.