Yes it's in number 17 of the workshop practice series. It's also about on the web usually missing mounting the buttons on a 5 degree slope to gain front clearance. A bit of back rake can be ground on the top as well. Or if the buttons are mounted flat around 5 degrees of back rake but make sure the cutting edge is very slightly below centre as there is no front clearance. These are then used to make the cutter. Simplest is a circular blank that then's gashed to make one cutting edge or by offsetting a blank in a jig several cutting edges.

When it comes to cycloids as used in clocks there are a number of standards. Like most things they are approximations so that cutters can be made. There is also one aimed at use with lantern pinions. These are I strongly suspect the main gain with cycloids as pinions with differing tooth counts need specific cutters.

Some links

**LINK**

and making the cutters

**LINK**

A search for David Creed Making Clock Wheel and Pinion Cutters will also find that.

John

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