[Kevin Ray]

Dcollins
We've milled ours out of delrin rod (lucky enough to have a sponsor who gives us just about all we want). For those less fortunate, you could use schedule 40 plastic pipe with grooves cut, that's a common method. You could also use 1/2" shaft with plywood pulleys. It's simple enough to turn on a lathe or milling machine. There's lots of options.