I changed the 10" disc on the sander and the plastic knob disintegrated when I was putting it back together. I decided to try to make one out of wood but the splined ring was .715" and I had no Forstner bit that size so it had to be bored on the lathe. That came out fine and then I put in 2 1/8" dowels along with epoxy to contain the ring and hold it up to the torque needed to tighten it.. It is made out of mesquite and finished with Danish oil and clear lacquer.