My MM had worn out the shaft hole on the last gear of the castle gate drive train. Not available as far as we can tell, so we made another out of Delrin. These parts are laser cut; the tooth design holds up reasonably well, despite the laser kerf. We made two and sandwiched them together to get the right shaft catch. The original uses a cluster gear, but the smaller gear is unused.
Delrin is hard to glue, so the parts are held together with dowel pins and cyaonacrylate.
The replacement gear works perfectly. I figure that I can probably do the gear clusters with a small hub by using smaller pins. Therefore, we should be able to reproduce most pinball gears.