Here is a picture of my Am. Watch Tool Co. No. 1 watchmaker's lathe. The collet body measures 4.96mm so is a nominal 5mm. The overall length of the bed is 8". Serial number is 3838. I believe this dates to the later 19th century.
Maurice, that's a really nice looking lathe! I notice that the finish is in excellent condition. I wish the same could be said about my Rivett. How does your lathe perform? Is the headstock-tailstock alignment pretty good?
Hi Tony! Wow, are you still putting together your own watchmaker's lathe? Pictures when you finish, PLEASE!
Your drive system will depend on what you want to do with it. For traditional pivot work you'll want to simply use a length of belting directly to a motor, with a foot-operated rheostat controlling the motor's speed. The motor should have a 3-step pulley so at least you'll have torque options. You could also use a countershaft (aka jackshaft or a variety of other names). For myself, I use my lathe two ways. I leave my lathe coupled to my countershaft at all times. If I'm doing a machining operation, I disconnect & remove my rheostat. But if I'm doing pivot polishing/burnishing I put the rheostat back into the equation. For pivot burnishing there's a little move I make at the end when I'm sure the pivot has been burnished and sufficiently work-hardened. The move involves getting the pivot work-hardened, and then instead of lifting my sapphire burnisher off the pivot I take my foot off the rheostat and let the burnisher ride the pivot to a complete stop. This seems to make a difference in the final hardness of the pivot, but I'm not entirely sure why.
Yes, I am, Doug....and using some stainless to avoid plating problems (more heresy), but perhaps I can be forgiven because this is my first foray into watchmakers lathes. Seeing as I am scratch building some of these parts anyway, I may just put my own brand name on it lol