Hi JerryJust wondering what the purpose of the indexing pins or locking pins on a lathe are for?
It generally just means that the single-speed three-phase induction motor is controlled by a variable speed inverter. Three phase motors do not require a capacitor to start them and so are easier to control (start and stop) as well as developing more torque at low speeds when operated thriough a frequency inverter. The speed the motor runs at is governed by the frequency of the AC electric supply, so motors in this sort of application are generally either 2-pole (or 3600rpm @ 60Hz) or 4-pole (1800rpm @ 60Hz) designs which can be slowed down to 1/4 of their rated speed by reducing the frequency to 15Hz. as frequency drops, so does the torque of the motor, hence the need to retain pulley sets as well in most casesAlso, I see a Grizzly lathe that says that it has a three phase motor but the power required is single phase power supply, I"m, as usual, confused.