This bolt hobbing jig should allow for either a 8mm, or 5/16" bolt (or rod with nut) to be indexed to 19 positions.
It's a derivative of Fred Latesta's original work.
In general all you need to do is load up hobbing_jig_plate.stl and print that one time. If you prefer to do two prints then print ratchet_gear_4.stl followed by block_4.stl
- Place a bolt into the ratchet gear so that the bolt head sits flush with the gear.
- Insert the bolt into the jig block.
- if you have one, insert a 608 bearing into the jig, and snug it in with a nut and washer
- secure the jig in a vice, or clamp. (or hold it if you feel brave)
- use a rotary tool to grind your first tooth into the bolt
- rotate the bolt clockwise one notch
- use a rotary tool to grind tooth into the bolt
- rotate and repeat