Quote Originally Posted by Michael G View Post
Given that the centre of a sanding disc does (relatively) little work, using say a 15 or 20mm thick slab of Al and bolting that to a steel hub with countersunk screws would probably give an acceptable disc after a skim to true everything up.

Michael
When I made mine I used a disc of 20mm marine ply with a Taperlock hub bolted to it. Mounted it in the lathe & faced it off then saturated it in epoxy. Finished with one of the hook & loop backing discs. Been working fine for years now.

I drive it with a 1400 rpm 3 phase motor. It doesn't slow down regardless of how hard you press but you'd better keep a close eye on your fingers.

PDW