Lathe options - 12x36 up

[Mitch Alsup]

I would be curious how the torque works out - going back to my first post here. When run in low gear the input RPM from the motor can be higher for any given spindle speed, so long as the target speed of the spindle lies in the range of what ever gear or belt selections there are. So the higher input RPM would equate to higher torque,

There is a speed below which TQ drops off, and there is a speed above which TQ also drops off. To a large measure these speeds are about 1/2 rated RPM (30 Hz) and 1+1/2 rated RPMs (90 Hz). I am not sure why TQ drops off towards the slower RPMs*, but TQ drops off at higher RPMs due to motor inductance.

(*) possibly due to not enough pulses per second at really low speeds.

I'm sure. I suppose that may even be able to be adjusted beyond spec on what ever machine by changing the gear ratios. That may be pretty far out there and not necessary, but having all the modification ideas floating around there on how to upgrade these machines I'd bet there are ways to do that. Though, the principal of the variable speed drive is to eliminate, or at least vastly reduce, the need to change gears/belts in the first place.

I only change speeds on my mill about once a week.