Lathe Difference

[1hand]

Some one explain the difference be a Engine Lathe and a Tool Room Lathe? I look at the specs and don't really see a difference myself other than the way they are listed. And does a gap bed lathe have a removeable section so you can turn large things without hitting the ways, or what does this mean?

Matt

 

[Deanofid]

Hi Matt;

Yes, a gap bed lathe has a piece of the bed (ways) that can be removed. It sits right under the chuck. You can take it out so the jaws on the chuck can be opened up all the way, or to put a larger chuck or face plate on the spindle. It also lets you do larger diameter flat pieces on what is basically a regular sized lathe, (whatever "regular" size is). Like, normally a lathe may be able to turn only 9" diameter, but if you have a gap, you could turn a 14" flywheel for a car. Things like that.

An engine lathe is what you will usually find in a job shop, where all manner of work will come in. It does all the regular chores at a good level of accuracy.

A tool room lathe is similar, but generally made to tighter tolerances and often have specialized chucking options for making somewhat more specialized items. If you are making tools that will be used to make other tools, like the Starrett company does, you use a tool room lathe. They can be set up to do very accurate work in batches. They are often setup to do very fine threading that an engine lathe operator would have a hard time duplicating. Usually the machine will be held to a tighter tolerance in the areas of the spindle, ways, leadscrews, and like that. They often have a rapid threading option, and the ones I've seen are kind of scary to watch. They will zip through a thread really fast, right up to a shoulder, then stop immediately and return to the start position.

An engine lathe can do most of the things a tool room lathe can, but the engine lathe would be considered the jack of all trades, where the tool room lathe would be the specialist.

There are a number of differences I'm leaving out, but you should get the idea.

Dean

 

[1hand]

Thanks for the info.

 

[Tin Falcon]

IIRC the tool room lathe will have some exras like a taper attachment and a collet closer and collet set. Although engine lathes can have collets as well.
Tin

 

[Richard1]

It basically comes down to weight, accuracy, accessories and price. A tool room lathe will have significantly more of all of them.

 

[steamer]

I days gone by, the Toolroom lathe was exceptionally fitted (alignment) and outfitted ( accessories). With this the lathe was better suited to a wide variety of precision work. As the lathe got older and more or less worn, it would be moved to the production floor of the shop and a new Toolroom lathe replaced it....or it was rescraped and or overhauled.

Just remember when the sales add says "Toolroom" lathe, a worn clapped out lathe is still a worn clapped out lathe....regardless of who its "Papa" was.

A 60 year old Toolroom lathe probably ain't no more.....mythical barns aside 8)

Dave

 

[Deanofid]

Also, remember when you see a new Wang Dang 10 x 24 lathe on ebay for $1499, and it says "tool room lathe", it isn't. Putting a "turbo" sticker on a Chevy Vega doesn't make it an Indy car, etc...


DW

 

[RICHARDDV]

This tool room lathe discusion brought back some old memories when I was in college at East Texas State University in '69 when I was taking metal processes for the Industrial Arts teacher program. We had 16 lathes in the metal lab of various sizes from 4 ft. SBends to a 20 foot Drummond. We got our machine assignments for the semester by drawing a number form a hat. I drew a 10 ft. Pratt&Whitney tool room lathe. It was identical to another in the shop except it still had the brass war department tag attached certifying it for the production of war material in 1898 and it was equipted with feeds and leads marked in .0001 instead of .001. I ran this machine for 2 semesters for an instructor that required a tolerance of +1/-0. He told me that if I could hold that tolerance on a machine with and excess of .065 backlash and worn ways I could teach anyone to run any new machine that the high schools or trade schools would have. Richard

 

[jack.39]

.... It was identical to another in the shop except it still had the brass war department tag attached certifying it for the production of war material in 1898 Richard.........

Your story reminded me of one told by my Dad about a War Production lathe (WW-II) bought by his employer. It seemed that lathe had been used to make one part, over and over, and the section, short, of ways which were traversed so many zillions of times were worn considerably, but the rest of the ways were brand new. It was impossible to turn a part extending beyond the worn portion, and keep it from having "steps" in it! jack

 

[steamer]

This tool room lathe discusion brought back some old memories when I was in college at East Texas State University in '69 when I was taking metal processes for the Industrial Arts teacher program. We had 16 lathes in the metal lab of various sizes from 4 ft. SBends to a 20 foot Drummond. We got our machine assignments for the semester by drawing a number form a hat. I drew a 10 ft. Pratt&Whitney tool room lathe. It was identical to another in the shop except it still had the brass war department tag attached certifying it for the production of war material in 1898 and it was equipted with feeds and leads marked in .0001 instead of .001. I ran this machine for 2 semesters for an instructor that required a tolerance of +1/-0. He told me that if I could hold that tolerance on a machine with and excess of .065 backlash and worn ways I could teach anyone to run any new machine that the high schools or trade schools would have. Richard

YUP A machinist is always better than their equipment...you just need to know how to ask nicely... ;D

Dave