I recently had an opportunity to chat with a machinist who works for a shop that makes some parts for ASML’s machines. He showed me a picture of a couple of parts he finished that day. He said they weighed about a hundred pounds sitting there on the table, but at the acceleration they experience in the machine, they weigh roughy the same as a Toyota Tacoma.
I can't imagine that what I think of as a machinist - a human who picks up parts and places them into machine tools and adjusts settings - is who makes parts for semiconductor manufacturing machines. I'm guessing the title has a lot more to do with CNC/automation these days?
FWIW the Bridgeport milling machines could hit 1/10,000th of an inch which is 25 microns of accuracy many years ago. DRO and precisely controlled steppers on newer machines can do much better.
The main difference is the mill will be that accurate along each axis of motion independently, while the jig borer will hold that accuracy on all 6 degrees of freedom throughout the full workspace volume.
You kind of just described the job description of a modern "machinist". It's far more of a job regarding the machine itself (CNC in this case) and it's setup, versus the part itself being made. A mechanical engineer or manufacturing engineer deals moreso with that. Machinist is more synonymous with "operator" in my field.
