The bottom line really is how big a motor does it take to do the job? I have built the JGRO table design (rotozip router) and I plan to build the driver and controller around the motor; to do it the other way around doesn’t seem to make much sense to me. I have been doing some research on steppers: bipolar vs. uniopolar, half winding, whole winding, series and parallel wired. I am leaning towards a bipolar motor configuration with a current sensing resistor driver (L297/298) as opposed to unipolar motor with the same type configuration. I believe this would make better use of the power supply and be more efficient than a unipolar motor wired in bipolar configuration; ohms law really makes some tough choices for a DIY project. I want to maximize the (sweet rpm range) motor torque and efficency but am having difficulty deciding "how big a motor". I plan on using the router for light sign work, wooden clock gears and one off cut outs like yard ornaments or wirligig patterns. Also some plans for a few patterns of some "Gingery" projects I've been putting off.

Any input is greatly appreciated.

Whitney

Well....are you driving what type of leadscrew? Basically, just about anything in the over 200 oz-in torque as a stepper will work just fine.....

The plans call for 1/4-20 all thread, however since the bearings i already have will accept 5/16 with no modifications I will be using the standard 5/16-18 threaded rod.