Folks should understand that most of the lathes that come out of China are really "lathe kits." They have most all the parts that would make a lathe already put together, but once you know something about machining, the Chinese-made machines will drive you to distraction, because you will find X,Y and Z on the machine that need to be addressed before you can really use it. Things like burrs and casting dross on some parts (pieces of the taper attachment are famous for being barely ground before being slapped together), seals that leak because mating surfaces are not true, etc.

I have a Taiwanese lathe (a "Sharp", 13x40 with a variable speed drive), and while they're a step up from the ChiCom lathes, it still isn't a "ready to really work as delivered" lathe. I use mine for gunsmithing and light machining, and it works OK - just OK. I've used a lot of different lathes at gunsmithing schools, community college shops, other gunsmith's shops, you name it. I now have opinions about lathes, and most of my opinions about the ChiCom lathes run towards "when you get them, you need to really go through them and finish what the ChiComs started..." The Taiwanese lathes are better in fit, finish and quality, they cost about 2X what the ChiCom lathes do, and they still need finishing.

The way I tell that the Jet lathe above is from China is the price: If you see a 13x40 or 14x40 lathe in the under-$6K price range (new), it's from China. If you see a 13x40 or 14x40 lathe more than $7K, and under $12K, it's probably from Taiwan. There's only a couple of companies actually making the castings and lathes in China - the different machines you see for sale are just different badgings and paint schemes on the same basic lathes from China. The amount of quality in these machines is usually what the company that sells the machines here "inspects into" the machine.


Now, if you asked my opinion of a good lathe for a farm shop, my first choice would be a LeBlond Regal. These are, hands-down, one of the most rugged, no-nonsense, reliable, easy-to-fix lathes out there. We have one in the college shop here, and it withstands use and abuse for 15 years by students that has literally taken apart four brand-new Taiwanese lathes in three years.

When you say "threading gun barrels," I assume you mean threading the muzzle. If you meant threading the breech end, then you'd need to be chambering. Lots of people will tell you that you need a short headstock so you can put the gun barrel through the headstock. That's not so - you can thread gun barrels easily if you have a stead rest and know how to use it. I vastly prefer a steady rest that uses brass "fingers" on the workpiece, not the roller bearings. The roller bearing steady rests will emboss a groove on softer steels so quickly, you will wonder why anyone uses them. The solid brass steady rest fingers work on just about anything, and they don't leave a mark on the finish.

OK, judging a used lathe:

- turn it on, listen for bearing noises, gear lash in the headstock. Make sure the longitudinal feed and cross-feed work. Make sure all the gears in the gearbox are there.

- look for wear on the ways - dings, nicks, etc. Look for a step on the ways near the headstock - many lathes that have been used hard will have a mark on the ways where the carriage has been used up close to the headstock, and the ways were not oiled.

- make sure the tailstock is there, and functional.

- make sure that the lathe comes with all the tooling - the steady rest, the follower rest, the centers for the headstock and tailstock, faceplaces, dogs, toolpost, etc. 

Many Regals go for less than the price of that Jet lathe.

If you really want a new lathe, but are constrained as to your budget to the price of that Jet, have a look at Grizzly's offerings. Grizzly has many machines that are made in China, but Grizzly inspects them better than Jet does (IMO), and Grizzly has better support. Another outfit selling Chinese import lathes is Precision Matthews.

Your budget for a lathe should include tooling. The cost of the lathe is just the start of the budget it takes to actually make chips and get something useful done. 

Just remember that you will spend about three quarters to 100% of that amount in tooling.

I can not only recommend Noga, I can tell you that using just about any other indicator holder is a waste of time and money. Every other indicator holder I've used has broken, sooner or later. Noga's indicator holders just keep on working.

Suburban Tool is VERY nice stuff - at a VERY NICE price. 

The Cadillac of American lathes was either the American Pacemaker, or the Monarchs, and I'd lean towards the Pacemaker. These machines were built to very exacting standards, they were built from very high quality materials, with exceedingly good bearings in the headstocks. If I could find a Monarch 15" lathe, I'd be on it like stink on a cowpie. They're awesome lathes.

For a gunsmith, I think the Clausing 5913/5914's are pretty nice lathes. The South Bend "Heavy" 10 (aka model 10L) is a good (and almost too-well-known) gunsmith lathe. The 10L is very short through the headstock, which makes it easy to put a barrel through the headstock for chambering or threading. The 10L is also a rather light lathe, making it easy to move in/out of tight spaces (basements, workshops, etc).

For many farmers who want to tinker with guns and make parts for farm equipment, I'd recommend looking around for a South Bend "Heavy 13" lathe. These can be found with 60" beds, so you can work on longer shafts and such. The Heavy 13's only downside is that it is low - tall men will end up stooping over the thing and getting a backache, or you'll end up building up a platform to raise it by about 8 inches. But they're a very good "all round" lathe, with very reasonable prices in the used market.

For people who want/need to make lots of little screws/pins/bits/bobs, the Monarch 10EE and Hardinge HLV-H are the ticket. These lathes were used to make very precise workpieces - the bearings on both of these lathes were significantly better than the bearings on most all other lathes; the 10EE's TIR (total indicated runout) was 50 millionths of an inch, and the HLV-H's bearings were good for 25 millionths of an inch TIR (that's 0.00005 and 0.000025" respectively). Most lathes have headstock bearings that are good for 0.0002" TIR - and that includes modern CNC lathes as well.  Neither the 10EE nor the HLV-H (or the even more useful variant, the HLV-H-EM, which had English & Metric thread gearing) will come cheaply. If I saw either one listed for less than $9K, I'd ask "What's wrong with it?"

To be able to have a three-jaw chuck with no runout requires an adjustable back-plate. There are chucks called "Adjust-Tru" chucks that are three jaw (or six jaw) that then have two additional screws on the backplate to allow you to take out all the runout - so you get the best of both worlds: a scroll chuck for quick chucking/unchucking, and the accuracy of a four-jaw to dial it in to perfection. In my shop, I use the four jaw chuck 95% of the time, a collet holder 4% of the time, and a three-jaw 1% of the time.

Where you are in IL, you're so much closer to good, used American machines than we are here in Wyoming. Here, I can locate a half-dozen used lathes that you could use to turn a 25" diameter axle shaft, but it is very, very rare to see a lathe smaller than 15x60" come up for sale. 

BTW - if people have questions about "how to do XYZ?" on a lathe, please ask and I'll try to answer. There are at least three different ways to do most any gun work on a lathe. Too many people tell you "you have to do it THIS way" and that just isn't the case. If I could have only one machine in my shop, it would be a good lathe. A mill is optional most of the time - a lathe is not.

If you have questions about doing gun work on a lathe, please just ask.

BTW - when you are putting threads on a barrel for a suppressor, you will need to be able to judge class 3 threads accurately. This isn't as easy as it sounds. I use thread wires and a mic, and my thread wires are held in specially cut holders that slip over the anvil and rod on a mic.

There are several books that are essential for a machinist to have in his library, foremost among these is "Machinery's Handbook." The MH contains an incredible amount of information, and the book's sections on threading, taps, dies, drills, etc are worth the price all by themselves.

http://new.industrialpress.com/machineryhandbook

You don't need to buy a new copy. The information you need is available in any of the editions from about the 20th edition forward. What changes every few years from about the 25th edition to now is more modern machining stuff, 3D printing, EDM metalworking, etc. For someone seeking to have access to the most commonly used machinist material, a 25th edition would work fine.

Now, how to run a lathe:

http://www.vintagemachinery.org/pubs/1617/3789.pdf

This is a book by South Bend from 1914. I'm pointing to the older edition, since they had so much more information about grinding HSS tooling back then. Most people (including me) will tell you that modern machinists barely use HSS tooling any more, and they're right. Inserted carbide tooling is probably the single biggest return on investment any machine shop can make. I use inserted carbide tooling - but I still grind and use lots of HSS tooling as well. The early "how to run a lathe" books also cover lots of mechanic's operations on a lathe, which makes it useful for farmers/truckers/etc.

Threads: I could write a whole dissertation on threads here, but I won't. I'll refer you to read the Machinery's Handbook. You'll need a little knowledge of trig and general math to completely understand threads. I'll take pictures of my thread-checking tools tonight and post them in a thread on machining tools for people to see. The subject of threads is a huge expanse of knowledge now, and MechE PhD could (and some  ave) written their PhD dissertation on esoteric issues in threading. When I say "Class 3" threads, I'm referring to how much engagement the thread has. A class 3 thread is the tightest fitting thread there is in the Unified thread system. Most bolts/nuts are Class 2 fits, and some really coarse bolts will be Class 1, designed to be screwed in with dirt, muck, etc on the threads and still fit. Class 3 threads demand that the threads be clean, clean, clean in order to get screwed together without messing up the threads or jamming the fit so tightly that you won't get them apart again.


Note: the MH has two editions: the "compact" edition that has remained the same size for over 100 years now, and the large print edition. Since I suffer from presbyopia just as most people do as we age, I now have the large print edition in addition to my small edition. If you wear bifocal safety glasses, you can read the small edition. I don't have any Gerstner toolboxes that have the handbook drawer in them, so most all of my MH's from here on out will be the large print edition.

For those who are wondering "What the ??? are you talking about Dave?" here, allow me to explain:

The top-end machinist's toolboxes are/were made by a company called Gerstner, made of American Oak, with felt-lined drawers, and these toolboxes have been the ultimate machinist's toolbox for over 100 years. The machinist version of their toolboxes has a drawer specifically designed for the Machinery's Handbook:

http://gerstnerusa.com/made-in-usa-products/chests-and-bases/2610-chest

See that odd-shaped drawer smack in the center of the toolchest? That's for the MH. Has been for 100+ years. The company that published the MH changes the information in the MH - taking some older stuff out, and putting newer stuff in, to keep the toolbox edition of the MH the same size it has been in order to fit into that drawer. The print size on the toolbox-sized edition is very small, but the quality of the printing is superb, and the pages are as thin as most Bible pages are. MH's have now become collectable of their own accord, with early editions fetching hundreds of dollars.

See the mirror in the lid of the box? Most folks are probably thinking "Those machinists must be a pretty vain group of guys." No, that's not why the mirror is there. In the days before safety glasses, when a man got a chip in his eye, he's use that mirror and a magnet to get the chip out of his eye. I suggest you use the mirror for vanity's sake and wear safety glasses instead. Gerstner toolboxes and bases are very, very nice. They make a great gift for someone who is a machinist, and they're very, very well built. The company has been owned/operated by the same family for four+ generations now, making high-quality toolboxes for craftsmen, machinists, woodworkers, etc.

The 10EE's had several generations of variable-speed drives. 

The very earliest variable speed drive was a hydrostatic drive coupling. This was changed during WWII to a variable-speed system that was a AC motor -> DC generator -> DC motor, and they'd vary the field on the DC generator to change the output on the generator to vary the speed of the motor. These were also the least efficient variable speed drive systems, and they were noisy and heavy as a load of lead bricks.

These early machines are known as "round dial" machines. The speed/feeds indicator operated in a circular fashion, and the indicator swept over a beautifully machined round brass plate. It was terribly sexy from the standpoint of visual appearance.

The next variable-speed drive was based on vacuum tubes, tube rectifiers, "thyratrons," tube voltage regulators, etc. These machines now had the "Square Dial" speed/feed indication - it looked more like an early shortwave radio dial. To me, the vacuum tube control is the sexiest system, but then I'm a EE and a ham radio nerd from back in the days when I built my own tube equipment & amplifiers. To most machinists, this was the system that scared the crap out of them. If you opened up the door to the motor drive system (which was on the front of the machine, below the chip bin), you'd see this multi-colored glow out of the tubes - which were about as big in diameter as a beer can, and twice as tall. The voltages in the "WiaD" drive cabinet were high - lethally high. Those who didn't understand tube circuits were wise to open the door, lose all of their bravery, and then close the door again. It was like open a small portal into a very scary mad scientist's lab.

By 1961, I think most of the tubes were gone, replaced by solid state devices. There were several re-spins of variable speed drives based on solid state circuits.

Today, if you slap a 5HP three-phase motor into a 10EE and a VFD, you've pretty much got the power issue licked.

The HLV-H's are much simpler - and also much less powerful. I think a HLV-H has a 0.75HP motor. The 10EE has it all - precision, accuracy, gobs of power to take heavy cuts. The HLV-H is a beautiful little machine, made for taking light cuts, making absurdly fine threads, etc.

Hydrashifts: These machines are basically just a hydraulically-controlled variable-ratio pulley set coupling the motor to the spindle via a belt. If you've seen how the snowmobile transmission setup works with those two large pulleys that smoothly change the ratio as the speed of the sled picks up? It's sort of like that. So what happens on lots of the hydra-shift lathes is that the seals on the little piston that compresses the sheaves on the pulley(s) starts to leak. This is messy, and when it gets bad, you have quite the mess on the floor on a regular basis. Fixing these machines is right up farmer/mechanic alleys - it's just hydraulics and seals. Most machinists don't want to screw around with these, because they don't like tearing into their machines to fix hydraulics - because lots of machinists don't really "get" hydraulic systems.

Bridgeport Series I mills use the same sort of variable-ratio pulley sheave system, only their open/close mechanism is the speed crank on the right side of the mill head. Don't fiddle with that speed crank unless the motor is running - changing the speed on a Series I-style mill is a formula to needing to tear down the mill head and fix the pulley and possibly the belt.

Today, most of the variable-speed issue is done with 3-phase motors and VFD's. Both my Sharp lathe and mill use a VFD and a 3HP 3-phase motor. They're pud-simple by comparison.

Yes. I won't delve into the electrical theory on single vs. three phase motors here.

Single phase motors, under load, can produce a pattern on the finish. Three phase motors, run on real three phase power (whether from a rotary, solid-state, VFD converter or a real three-phase power source) produce smoother finishes. If you're using a static phase converter, you might see a pattern on the finish if you load down the motor to the maximum ability produced by a static phase converter (66% of full power).

I think a three phase motor with a modern VFD is the way to go anymore. My shop doesn't have 3 phase power - only 230 1 phase. The VFD's in my machines can accept either three phase or one phase input power - the result is the same: 3 phase power of variable frequency to allow me to control the speed of the motor.