This set of steel quadrants bolts onto the jaws of the chuck and provides secure mounting for home-made wood jaws. Just mount the roughly shaped wood pieces with wood screws, fit to the chuck, lock the jaws solid and turn the wood jaws to shape. They will run true if turned on the chuck.
The bottom picture shows a typical set made to reverse-grip a bowl or platter for cleaning up the other side or the bowl base. One wood quadrant removed to show the chuck at rear.
Supplied with fixing screws for attaching the plates to the chuck. You supply the wood and wood screws for attaching the wood to the plates