Lathe Nomenclature

7HC

7HC

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There are a couple of lathe types, or maybe they're just loose descriptions, that I'm not sure I properly understand.

First, some lathes are described as 'Precision' models. Is this just marketing hype, or does it have a specific meaning related to a recognized standard of accuracy?

Second, some lathe models are described a 'Engine' models and I've noticed that many of these have a removable bed gap.
Again, is an 'Engine' model a recognized design and is the bed gap relevant to the 'Engine' descriptor?

Thanks,


M
 
Fair questions. Let's widen this discussion and toss in turret lathes and vertical lathes while we're at it. And speed lathes and chuckers. Let's keep this limited to manual machines though. CNC doesn't really fit this question.
 
Tony Wells said:
Fair questions. Let's widen this discussion and toss in turret lathes and vertical lathes while we're at it. And speed lathes and chuckers. Let's keep this limited to manual machines though. CNC doesn't really fit this question.
Click to expand...

Works for me, would you like to kick it off with a definition for one of them?


M
 
Many moons ago in a forum far far away (no name but it's initials are PM) there was a thread on just that question and many suggestions for the origin of engine lathe were given - all with supporting documents, but none that a consensus would agree on. Some said it could make all the parts of an engine, others said it was just a lathe powered by (originally before electricity) an engine. And others said it had to have a feed screw, or maybe a cross-slide, or pinstripes, or ???.

Turret lathe is, I think, a lathe with a toolholder that holds multiple tools and you can rotate from one to the next. Used for mass production of an item at one station.

I almost bought what was described as a "speed lathe" once. But when I showed up to examine it appeared to be missing a lot of parts. According to the encyclopedia (they still make those??) it might not have been:

TITLE: lathe (machine tool)
...in England the machine was adapted for metal cutting. The rotating horizontal spindle to which the workholding device is attached is usually power driven at speeds that can be varied. On a speed lathe the cutting tool is supported on a tool rest and manipulated by hand. On an engine lathe the tool is clamped onto a cross slide that is power driven on straight paths parallel or...


As far as I'm concerned there are only two types of lathes - the ones I have, and the ones I wish I had. :))
 
The word engine was in use long before what we consider a engine today. The old definition of engine is any machine designed to convert energy into mechanical work.

Here are my definintions. Others opinions may vary.

A screw cutting lathe is a lathe with a lead screw for cutting threads.

A engine lathe is a screw cutting lathe with power feed for the carriage.

South Bend defined a screw cutting lathe with a precision leadscrew, collet system and taper attachment as a tool room lathe.

A turret lathe has a rotating tool turret instead of a tailstock.

A speed lathes is a light duty lathe with out a lead screw used for hand work and normally don't have a carriage or tailstock.

Chuckers are like speed lathes with some form of a carriage, sometimes they have a tool turret.

Vertical lathes have a vertical spindle and can be quite large. A small may have a 24" chuck. I've ran them with chucks as large as 120".
 
Chuckers I believe have an auto feed that feeds stock into the chuck through the spindle and the chuck automatically opens and closes, I may be wrong or partially right:dunno:

There is a chucker/turret NC Hardinge for sale really cheap here in town. They have a very small capacity length & dia. but are really nice for high production small parts or first op cutting to size.
 
Everything posted up to this point is about right. Here's more.

A Gap bed lathe is a lathe with a removable section of ways under the chuck so you can chuck-up a big disk. In some cases, the carriage ways and assembly rides on another set of ways and the whole kaboodle can be moved "to the right" so to speak giving more room under the chuck to turn large plates.

A toolroom lathe is generally a higher precision machine that that has a wider range of everything like: Higher and lower speeds with more steps in-between and greater range of thread cutting ability. They often have multiple V's on the ways. They usually are supplied with taper attachments. Most do not require gear changes of any sort. They always have forward & reverse on both the chuck, carriage, crossfeed and compound and furthermore, you can run one thing in forward and another thing in reverse (and this usually requires two leadscrews). In general, they're better equipped and are tested/designed to hold tighter tolerances...

There's a screw lathe too. They're designed for cutting threads and most have the remarkable ability to stop on a dime, instantly reverse and backup to a known point so you don't need to eyeball the chaser like a hawk.

I'll post more if I think of them. In this day and age of marketing, terms like "high-precision" etc... -Doesn't mean a lot to me.
 
Yep, that's right.

Charley Davidson said:
Chuckers I believe have an auto feed that feeds stock into the chuck through the spindle and the chuck automatically opens and closes, I may be wrong or partially right:dunno:

There is a chucker/turret NC Hardinge for sale really cheap here in town. They have a very small capacity length & dia. but are really nice for high production small parts or first op cutting to size.
Click to expand...
 
What Joe_M says! Discussion is great but I have seen some pretty heated discussions on this topic with both arguments having supporting documents waving them in each others faces, and that is face to face. It IMO should be understood that the nomenclature came about over decades (or generations of machinery). Here is how I understand it from memory.

Engine lathe: Pretty much what you have in mind when you say "metal lathe" Sorta like saying Automobile, you got your hardtops, coupes, sedans, etc. Here we have:
Bench top, small lathes that can be bolted on a bench, stand is optional. 14x48 is large though not likely to swing 14" over saddle

tool room, kicked up from a bench top. Heavier and the stand is integral, usually smallish ~< 48" long 14x46" is large and is likely to swing 14" over saddle

Production, see commercial vehicle, could be a prious or a kenworth depending on the brand

precision, like "luxurious" Cadillac? BMW? Volare?

Die makers, big swing short bed say 24x24"

Gap bed, a section of the ways near the head stock can be removed for turning larger diameters.
Extension bed, the whole bed slides away from the chuck leaving a gap. Much more expensive and practical than a gap bed.

Turret lathe, setup to make a single part with extreme efficiency, else it is just a lathe with a turret in the way instead of a tool post. Never get sentenced to a turdent lathe else you brains evaporate. When other folk discuss root fillets, and c pitch of gears you can inform them "it pulls da leber and rolls the thingy" *note* anyone here who runs one for a living, I love you, because you really REALLY love your family and god bless you as a dedicated provider.

venerable dino, lathe that meets most needs or you know it is going to be expensive.

IMGP0741.JPG
 
Let's toss the Boring Mill in the mix. Basically a turret lathe on end. It functions like a vertical lathe, but called a mill. I ran a war production board era 54 in. Bullard for years, I never understood why they called it a mill. :dunno:
 
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