Cutting some ratchet wheels.

Apprentice here. This is my first official post to the blog, and I thought I'd share with you one of my more interesting - yet minor - undertakings here in the workshop.

A while back a chiming mantle clock that was recently serviced came in for repair. It seemed the customers couldn't wind it properly. After dismantling it, the problem was obvious; two of the ratchet wheels were damaged. One had broken off two teeth, and the other had bent teeth. I apologise for my lack of photographs... back then I hadn't thought to document it further for a blog post.

There is so much spring tension on these wheels, it is not entirely uncommon for them to be damaged, especially when broken mainsprings are involved.

After a bit of horological mathematics, the right P.P Thornton gear cutter and stock brass was ordered for the job.

Example ratchet wheel pictured here, not the one from the job.

Once I had all the parts I needed, the brass was faced off in the lathe and prepared for cutting in the milling machine. Everything had to be aligned and centred correctly, and the Z and Y axes fixed into place.

If you've followed the earlier posts, you'll know about the Sherline rotary device (which unfortunately I couldn't recall the name of, and is henceforth referred to as the 'little computery thing') which was used in the milling of the Breitling case-back opener. I set this up to have twenty divisions/rotations, and got to work cutting the teeth.

Snip snip. It's hard to get a good angle on this one, but I'm sure you get the idea of what's going on.

Little computery thing did its divisions, and all I really had to do was crank the X-axis of the milling machine back and forth till my arm felt like it was going to fall off, or at least until the divisions were complete.

After that, the brass was put into the lathe, drilled, and with a noise most terrible, the two ratchet wheels were parted off.

After and before.

So here are my wheels next to the old, damaged ones... you can clearly see how they would have been causing problems in the clock!

All that was left to do was the filing, greasing and fitting, and hopefully that clock lived happily ever after. Time will tell.(Get it? Clock puns. I'm simply a comedic genius.)

(I'm sorry.)

Till next time. Hopefully I'll have something a little more interesting, and more photos to boot! Perhaps I'll bother to slightly further my horology humour, but my hopes aren't high for that dead horse.

Bronte.