Who can make this lead screw for me?

I'm in search of a replacement lead screw for a Clausing 6300 lathe that I'm rebuilding. This one is usable...just barely. It is severely worn
and SHOULD be replaced.
Clausing Service Center has one, but the price is...well, I paid half that much for the whole lathe!
To complicate matters, this is NOT a standard pitch for its diameter, and I can't find suitable lead screw blanks from any of the usual sources. I haven't found them ANYWHERE yet, actually.
The lead screw is acme thread pattern, of course, and it's 7/8ths inch in diameter, but rather than the normal 6 TPI, it's 8 TPI.
I need to see if someone can turn out a lead screw blank for me in this size, 7/8ths-8TPI, acme, and about 5 feet long, in decent steel.
Once I have the blank, I can handle the rest of the machining. But there's just no way that my only usable lathe (a tiny Smithy) is going to be able to make a five foot lead screw that's worth anything!
If you can help this hobbyist, (me), please let me know. Email me direct at cmjohnson(removethis)@cfl.rr.com.
CJ
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Chris Johnson wrote:

Of course, ALL American (Imperial threads) lathe leadscrews are 8 TPI. If you had a 6 TPI leadscrew, you would be unable to cut almost any standard Imperial thread! Look at the standard threads, 6-32, 4-40, 1/4-20, etc. They are ALL based on factors of 4 and 8, and only by accident do factors of 3 and 6 show up. The only standard I can think of is 12-24.

I know people have gotten Acme allthread from McMaster-Carr and such sources, and cut a keyway if needed. The 10 and 12" Atlas machines use a 3/4" - 8 leadscrew. I've NEVER, EVER, seen a 6 TPI leadscrew in a lathe. (Many use 10 TPI crossfeed screws.)
Jon
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Jon Elson wrote:

The issue is, I can't find any 8 TPI Acme lead screw stock in the diameter of 7/8ths of an inch. Other diameters, yes, but not in THAT one, which is the one I need.
If you or anyone knows of a source for that, please let me know.
CJ
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Chris Johnson wrote:

http://www.roton.com/acme.jsp
here is a place - try google.com
Martin
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Martin Eastburn, Barbara Eastburn
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Jon, As Ed McMahon used to say, "You are WRONG, sir!" My Rivett (as American as it gets) 1020S has a 6TPI lead screw, and far from being "unable", it will cut 84 different threads, from 2 to 240 TPI. Dan

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Are you telling me that my lathe can't cut 9tpi, 11tpi, 27tpi, 14 tpi, 13tpi, etc. etc... Because they are not multples of eight?!? The face plate seems to indicate that I can.
Even if you had an 11 or 14 tpi lead screw, you could still cut any thread you wanted to. _As long as_ the thread dial gear had the corresponding number of teeth.
Now, where the thread dial will re-align with the thread will matter depending on the relationship of the tpi of the lead screw and the thread being cut.
Since metric threads will have an irrational relationship to the lead screw, the half nuts cannot be disengaged. But, that is another facet of the same discussion...
Pete
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Noll Incorporated 390 Buckley Road San Luis Obispo, CA 93401 805-543-3821
Lists a precision rolled acme screw, 7/8-8.
I made a replacement lead screw for a friend's Atlas, I think it was 3/4" dia though. I looked for the literature from the source for that screw but can't locate it. Green-something or other, they sell lots of rolled screw stock, bronze and cast iron nuts, and other interesting stuff. Used a keyseat cutter to machine the slot. Take your time deburring here. If you don't, you'll quickly shave what's left of your half nuts into oblivion...
Jon
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<snip>

Tsk tsk Jon, maybe somebody should have told LeBlond about that? The TPI of the leadscrew will affect the number of lines on the threading dial, not what threads it will cut, that's just a matter of gearing. And what about 11 or 13 tpi (or 5.75 and 11.5, for that matter)? They're all on my changebox and I have a 6tpi leadscrew on my LeBlond Regal.
And of course you can cut metric threads with an English leadscrew, although the threading dial won't work in that instance.
Paul
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Contact Dave Sobel at:
Sobel Machinery 82 Herbert Ave. Closter, New Jersey Zip code 07624 Phone 201-768-9645
Or
Meridian Machinery at: Phone 610-656-0449 Mohnton,Pa. 19540 www.mermac.com
One of these to will have what you need from a donor machine.
Jim Vrzal Holiday,Fl.
Chris Johnson wrote:

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Here's one for the " buy used American group"- come on guys where can he get a leadscrew for his machine for a reasonable price? If the leadscrew is that worn out what about the rest of the machine? At least he has a Chinese ( Smithy) unit and I'll bet he could get a leadscrew for it same day for a real low price.
"Chris Johnson" > I'm in search of a replacement lead screw for a Clausing 6300 lathe that

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I have a brand new lead screw for an Atlas lathe. I'm sure its 8 TPI, but I think its 3/4. chuck
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