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Just wondering what the purpose of the indexing pins or locking pins on a lathe are for?

Also, 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.
Jerry Bowen
 

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Just wondering what the purpose of the indexing pins or locking pins on a lathe are for?
Hi Jerry

From my own limited experience - indexing pins allow you to lock the spindle in place whilst screwing on a chuck or face plate, or installing a workpiece on a threaded nose piece (as stated elsewhere not all manufacturers recommend this). Another use is to lock the spindle and work piece when you are machining turned work with a router, e.g. making an octagonal spindle or turning flutes, although those two operations do require more equipment such as a lathe carraige or a follower mechanism. More complex faceting operations require the use of an indexing plate, frequently mointed outboard on the bowl turning spindle

Also, 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.
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 cases

Regards

Phil
 

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A 3 Phase motor provides true variable speed for an induction motor, which obviously is a huge advantage for turning. You can actually turn the speed all the way down to 0 RPMS. The lathe has a phase convertor built in so that it be plugged into a 220V Single Phase outlet.

As for the indexing pins, it is typically not advised to use them to lock the the spindle in place when loading the lathe. They are actually used for placement of the piece for doing things like cutting flutes, or other operations that need positioning.
 
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