Quite a few years back there were several post on making an adjustable drive for an item which is hollow such as a log (not on SMC as far as I can find)
It was basically similar to an Elio drive but shop made.
Your faceplate attached to 3/4 plywood and the ply could be 6", 9", 12" diameter....whatever you need.
Screws then went through the ply into the work piece.
Anyone remember those or have a link to a picture.... or a name of the chuck/drive I can search for?
Thanks