What is it

catmechanic

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I obtained these pieces in an auction, with some unrelated stuff, and don't have a clue what machine they go to. Each one is a different thread pitch from 4tpi to 40tpi, including at least one being a left hand thread. I imagine they are to facilitate cutting threads on some kind of machine, but thats my guess. Can any body help me with this? IMG_1136.JPG
 

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Each one is marked indicating the pitch, but that is all. Found no indication of a makers mark.
 
If nothing else, a lot of nice bushing material. Mike
 
I seem to remember seeing a miniature lathe many years ago that didn't have a powered carriage, but instead had some kind of follower and several cylinders (turned by or in sync with the spindle?) with different pitches on them. This is admittedly a bit obscure, but maybe it'll give you or somebody else the germ of an idea.
 
They look to be for fitting drive shaft threads and coupler nuts for multi section pump drive shafts, I made a few similar
pieces for my use at an irrigation pump shop in which I was the duty machinist before retiring, though they were nearly all
left hand threads, could be for well drill shaft sections or other specialty industrial shafting as well, My $,002
 
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I seem to remember seeing a miniature lathe many years ago that didn't have a powered carriage, but instead had some kind of follower and several cylinders (turned by or in sync with the spindle?) with different pitches on them. This is admittedly a bit obscure, but maybe it'll give you or somebody else the germ of an idea.
We may both be wrong, but we are on the same wave length. I have been imagining something on line with a Hardinge, something without a lead screw.
 
@hman and @catmechanic ,

That's an interesting idea!

I went searching for such a beast.....

First I found a "homemade" version here:
http://www.cartertools.com/brooketh.html

And then a description of "Chase Screw Cutting" on lathes.co.uk here:
http://www.lathes.co.uk/chasescrewcutting/

that page says:
In its simplest form, a master thread (or hob or leader) is attached to or made to rotate with headstock spindle and a guide, held in contact with it, transmits the motion to an adjustable cutting tool engineered so that it can slide along a arm and impart a copy of the thread to a workpiece held in a chuck or between centres.

They give a few examples of lathes using this system:
http://www.lathes.co.uk/waltham/index.html
http://www.lathes.co.uk/karger/page2.html (with a sliding spindle!)
http://www.lathes.co.uk/ames/page3.html

-brino
 
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