Rough out a piece of plywood, screw it to the faceplate and turn the OD of the wood right there in place.
Draw a "timing mark on the OD of the plywood and the lathe spindle. This way the plate will turn deadnuts true each time you set it up.
Sorry about the mistatement on the 9" drill press. I was mistaking it for the throat dim on a bandsaw.
Threaded Mode