The stock for the cam ring was a piece of heavy-wall 4142 tubing, 3.25″ x 2.0″ in the annealed condition. You can used pre-hardened material, but if you do, you’ll need to anneal it before re-hardening and tempering.
I turned a stub arbor with a 1/4″ thick aluminum washer to mount the brass gear for machining. You want a good tight fit on the ID of the gear. Continue reading