[artdutra04]

Using a lathe, you can just buy pulley stock and make your own 1in bore pulleys. For example #A 6A24M024TM20 from SDP-SI is 24t 5mm HTD aluminum pulley stock. From this you drill in the ID of your choice and then wafer off individual pulleys with a parting tool.

If you go this route, always try to design around sprockets with a multiple-of-three number of teeth; this way it'll be much easier to clamp the pulley stock into a 3-jaw chuck since the soft jaws will all align to the same phase of the pulleyteeth.