Parametric Ball Chain Sprocket

Parametric ball-chain sprocket.

Should be customisable to work with pretty much any variety of ball chain.

Supports round and "D" shafts, with or without a grub screw, with or without a hub.

The OD of the sprocket is auto-generated based on the requested number of ball pockets, when compiled OpenSCAD will echo the generated sprocket diameter for reference.