For the third wheel in my reconstruction of the Dominy’s wheel cutting engine, I again used the manual dividing plate, but this time with an indexing arm instead of a compass.

In cutting out the teeth, I decided to just use files, foregoing the jeweler’s saw. The file I used to remove most of the material is a ‘bastard’ cut with a nice wedge-shaped profile. Interestingly, it is similar to this “Chisel” owned by the Dominy’s that I found in storage at Winterthur:

Although it is labeled “(for wood) (Chisel),” the edges have file type teeth cut into them and the profile is a deliberate gear-tooth-esque wedge shape:

Furthermore, it has a a thumb rest relief cut out on the handle near the ferrule, very much suggesting it is meant to be held with the edges pointing up and down – the way I used a similar file in the video.

I also relied on a similar file for the bulk material removal when I cut the pinions to the engine, see this post.

Stay tuned for the finished engine, and eventually my master’s thesis on this research, where I will discuss the Dominy’s tools in more detail and context.