Image from: http://upload.wikimedia.org/wikipedia/commons/archive/2/2c/20080518200048!Terms_involute_gear_engagement.PNG
Rotary Table
For the rotary table we will be making a gear cutter, worm, and worm wheel. I just "figured out" an equation for calculating TPI, and worm gear teeth. Starting with S=r(theta) I derived:
60/TPI = r(2*pi)
Where 60 is the gear ratio of the worm gear to the worm wheel. Referenced below (in the previous post) is what lets you calculate the resolution that will give you on your table. The 'r' in the equation i suspect is the diametrical pitch, or namely the diameter where the force of the gear is being transmitted, not the OD of the gear. Anyways with this equation I can adjust my TPI for the cutter, and worm gear till I find a TPI that matches what the lathe is capable of cutting. Now in my research i did find that 40' was common for this application no the 60' degrees you typically see. So I need to do some more research or simply "test" it out with an ACME cutter that i already have. (I'd prefer to take the simple route)
An example calculation yielded:
8 TPI, would yield a 1.1936 radius worm wheel.
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