Just an idea for parabolic holes in watch pinions

[Okapi]

It's a very simple holder very usable when you have to make a clock or watch pinion with inside divisions.
You can modify the diameter simply with the screw on the center, if it's necessary to be very precise, just use a dial gauge.
http://www.lecollectionneur.ch/_Media/_dsc2300_med.jpeg

[kbalch]

Thanks Okapi! I've added your Watch Pinion Holder to our Machining category, as well as to your builder page: Okapi's Homemade Tools. Your receipt:

Watch Pinion Holder by Okapi

tags: lathe, clock movements, watchmaking, pinion