I'd advise going to a bicycle shop instead. Or converting over to timing belts. Or buying Eagle V-Belting from Fenner Drive and using V-sheaves so that you can choose your custom lengths and make much simpler rotating parts.
However, if you want (or need) to make your own sprockets, I would recommend downloading the Martin catalog PDFs (
http://www.martinsprocket.com/suppor...atalog-online). The materials and dimensions of the sprockets should all be in there. You should be able to fabricate your sprockets from there.
One recommendation would be to use a hardenable steel and flame-harden the teeth. A lot of sites abound on the web that can advise you how do do it properly. As always, safety first ...
