[balsaman]

I took a chunk of 1/2" steel round stock, turned it in my 4 jaw and make a 3/8" "cam". I then put it back in my 3 jaw and turned the end down to 1/4". I drilled and tapped the end for 4/40 for a retaining screw. In the picture there is a spacer and a 1.5" round peice that the handle screws into.