Lathes, what’s the difference between the different types of lathes out there?

[MrRage]

Precision or high precision, one was more refined than the other I take it – but I saw no numbers to support that.

Bench, tool room, engine, Gap bed, Machine shop, second operation lathes. The second operation lathe looks noticeably different, its purpose I’m still not grasping but I’m sure there is a good reason why they are so expensive. The rest of those lathes on the other hand look the same to me, at least on grizzly’s site they look the same. So what are the differences between all of these types of lathes?

Link - http://www.grizzly.com/products/cate...spx?key=460000

[WhiteTiger]

I have no idea if the terminology has morphed over time, but precision used to refer to tolerances of .001, high precision meant .0001, and super precision was .00005 or less. At least that's how the machine and tooling grades were explained to me.

With lathes the differences are mostly in the spindle runout and the straightness and parallelism of ways, and whether and how the ways are hardened.

Bench lathes are self explanatory, tool room are generally more rigidly built and to tighter tolerances, machine shop can be as robust as toolroom but not built to as close tolerances. Gap bed are just that, they have a removeable bed section just in front of the headstock to make room for turning large short pieces without having to have a much bigger lathe.

As you noticed, a lot of the differences aren't visible to the eye. You can't tell by looking what class bearings are in the spindle or whether the bed casting is extra beefy or has high precision ways.

Second operation and turret lathes tend to have small fast high precision spindles in relation to their swing, and most use collets for the majority of their work. They also usually have infinitely variable spindle speed and very short working travels compared to the bed length.

There's a whole lot more to be said on the topic, but that's enough maunderings from me. The current pros can flesh things out and no doubt correct me on some points

Tiger

[Mcgyver]

good description Tiger, there's as you move from tool -> engine -> bench, price and weight drop substantially.

The toolroom lathe is the grand daddy, Rivett, Monarch, Hardinge etc. they'll weigh in at 2-3 times what a similar sized engine lathe will and fetch 15-20k or more in good shape, even if they are old. Replacing a set of bearings in one of these might be just less than buying one of everything in the grizzly catalogue

here's a link to a grizzly product, which advertises a class 7 bearing. dollars to donuts its NOT an ABEC 7 bearing, in fact this came up on another forum and several guys who had the spindles apart testified they they are crap bearings, not even recognized brands. very misleading imo calling them class 7 - who's classification system??.

http://www.grizzly.com/products/G3102

anyway, bearings and alignment and flatness of bearing surfaces is some of the stuff you pay for in a good machine. you could use a car analogy, yugo, chev & merc sort of thing. if you have a yugo and are good, you can do some nice work, but you'll always pining for a use chev, next step up. etc, nothing wrong with that. just don't get tricked on what you think you're getting

[ViperTX]

Last time I talked to Grizzly about tolerances on their lathes.....the tech guy mentioned a TIR of 0.001 as the best they could do.

southern-tools.com (I believe that is their addy..) sells Jet Lathes and he will send you a copy of the tolerance certificate that is included with each Jet Lathe.

[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.

[MrRage]

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.

Where would Enco sit in this scale you think? Jet, Grizzly, Enco, HF?

[lakeside]

ENCO is owned by MSC.

[chineguy]

Tiger hit the nail on the head. Second Op lathes are High precision lathes meant for accurate finish work on blanks usually produced on some other machine. They are great for making alot of the same thing. They are a pain to set up and adjust. Those old Hardinge lathes are great. They are very solid. Just don't buy a new one unless you are buying the manual toolroom lathe. We bought a CNC swissturn from them. Nice heavy construction. Then you can start re-engineering it so it will actually run. They discontinued swiss turns. Go figure, pretty obvious why. One big warning the older machines and indeed most of the newer ones are designed for cutting oil. If you use water base soluable coolants expect to put bearings in often.

[MrRage]

Originally Posted by lakeside ENCO is owned by MSC.

Does this put it above the others or below? Others being Grizzly, Jet, HF. I heard Enco lathes were quite good

[WhiteTiger]

I'm not directly familiar with Enco lathes, but their mills I know well and I'd rate them closely behind equivalent Jet models for the most part. I'd expect their lathe line to pretty much follow suit.

The budget machinery from MSC I'd rate at about as high as it gets without going to a pricey name brand, then Jet, then Enco, Grizzly, HF then all the small competitors in a general lump with the best of the lump being pretty fair, and the bottom end being paper weights

All just personal opinion, of course.


Tiger