Having more of a problem with the threads and the adapter gripping properly to the motor shaft. I had to machine my current adapter to accept the bolt for the Tru-turn spinner. Seems Tru-turn and others make the right adapter for up to 6mm motor shafts; I have an 8mm motor shaft.

I was wondering if you guys were using steel adapters (seems logical) and if any came pre-tapped to accept a tru-turn bolt.