I made the arbor that you see with the washers stacked on it. It fits in a 3/8" C-5 collet the the spin jig will hold. You can't see the hand crank that operates it on the far end of the spin jig. The arbor is two pieces, one end goes in the collet , the square shimstock with a .096" hole in the middle fits on the other end that screws into the half that is in the collet.