Hi all.

Along my life, I have seen some variety of manufacturing machinery. Never had the luck to see how mechanical wristwatch parts are made. Not even pictures. And they have been built since at least 1700. How were the parts made then ? The tooling is a mystery to me.

 

And beyond this, who makes and how is the machinery to make wristwatch parts ? The entire factory fits in a suitcase, right ?

 

There is a hidden universe there. What do you know about ?

Parts were cut by machine. Here's some old drawings of an antique gear-cutting machine.

 

Gear Cutting Machine

When electronic wristwatches nearly suppressed mechanical ones, manufacturers in Switzerland converted to other precision machining activities, one being small electric motors - meanwhile bought by US companies, whose motors presently run exploration robots on Mars for instance. I used some on rockets and a satellite, and:

- They're made by machines, definitely.

- On a 3mm shaft, the doc gave a tolerance of +0 -1µm.

- Downstream a planetary gear, hence with a short shaft, you couldn't feel any play at all.

Just a PS to the antique machine image reference I gave, which is that I knew what to look for because the process was shown and explicated on PBS program in the last year or so. Alas I can't recall the show name, but it was a part of a series that followed scientific advancements throughout history. Maybe that's enough to jog someone's memory and we can get the name of the show. While the drawings may be a bit vague as to the actual operation, seeing it done makes all quite clear.