Edit/Note: This is NOT "the X/Y problem". The question I have asked here is exactly the question I need an answer to.
I'm not asking how to selected the correct RPM for a given situation (that's irrelevant to the current problem, and besides I already know how to do that), but rather asking about what RPM settings are available on machine and how standardized those settings are from model to model.
I have a project I'm working on where one of the parameters is spindle speeds on manual machine tools that that only run at discreet speeds. For example gear head lathes or Bridgeport clones with step pulleys. Part of the project would work much better if the numbers I pick, happen to exactly match what's offered by the machine tools other people are using. Is this even remotely possible? Are there a few standard sets of speeds offered or does each machine more or less end up with a different selection?
As a starting point; I have a Bridgeport clone that lists it speeds of: 80, 135, 210, 325, 660 1115, 1750 and 2720rpm. I'm also finding a number of images online that list the same numbers, so that seems to be at least one standard.
Are there other common sets of speeds for other kinds of mills? What about for geared head lathes? Etc?