Originally Posted by
NC Cams
IT is a VERY rare 3 jaw chuch mounted to anything that will hold the same tolerance when clamped to a 1" part as it will when clamped to a 3" part.
My G4003 Grizly lathe had specs provide when it was certed at the factor and they were better than 0.001 BUt as soon as you move it, all bets are off.
Unless the lathe is reset, leveled and recerted/aligned properly on a solid stand and level floor, you'll never see the same specs it saw on the floor when certed as opposed to just being dropped off the truck at your shop.
I'd be inclined to rank the ascending quality as Harbor Freight then Grizzly then Jet. WIth care, most of anything they sell will match or outperform a tired Atlas, West Bend or other domestic long out of production lathe.
For a cheap starter, go Harbor. For an affordable hobby and light/moderate duty shop use item, go Grizzly. For a true commercial shop, go Jet or better.
A "grand daddy" that is operational is worth the cost to refurbish as they are true, kick A$$ commercial, tool room quality lathes designed and built for 100% plus duty cycles.
The "tool room" lathes from Hardinge are true jewelry - with a cost to match.
Tiger's explanation is about as clear and consise ans one could ask for.