Re: rod-mill project - "mains" electric motor advice

"Richard Smith"  wrote in message news:m1ldsc42kf.fsf@void.com...

If using flat-belts (or any other belt drive) that needs 2
countershafts, for a 3-stage speed reduction?

https://woodgears.ca/big_bandsaw/pulley.html
You could also round the pulley blank on an H/V bandsaw set upright. Wood needs a coarse blade, 6/10 TPI at 200 FPM works on mine for 6" thick timbers. My sawmill is a bandsaw too, 3/4" tooth pitch at 5000 Feet Per Minute. When cutting it drops to 50 MPH on the ex-motorcycle's repaired speedometer.
The groove angle varies with diameter, since a large bend radius widens the inner rubber less.
https://www.masterdrives.com/engineering/groove%20dimensions.pdf
A flat and vee pulley doesn't, but a drive with two flat pulleys needs them crowned to keep the belt running centered on the high spot, like a bandsaw blade.
https://www.smokstak.com/forum/threads/making-flat-belt-pulleys-and-their-crown.77493/
If the belt runs off the crown the conical side surface deflects the approaching belt sideways in the direction that leads it back on. A belt or bandsaw blade doesn't have to stretch, when off the crown the less tensioned outer edge buckles out of line to allow the blade to curve sideways.
I carved the crown on the unworn front motorcycle tire with an angle grinder, by hand and eye. The rear had been worn to the cords and was fine as-is for the bandsaw.
A millwrights guide, preferably older to cover vintage and replica tech, explains how to design and set up belt and other drives.