# Needed: Atlas Model 3996 Lead Screw



## bobby light (Aug 5, 2014)

Like the title says, have an Atlas 12" Model 3996 Lathe and it has a bent lead screw. Looking for a replacement.

Thanks.

Here is the Lathe


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## kd4gij (Aug 6, 2014)

Ebay is your best bet. You may be able to straighten it. If you have a couple of V-blocks and a press.


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## Charles Spencer (Aug 6, 2014)

Is that the same diameter/thread as the 10" models?

Charles


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## Charlie5683 (Aug 8, 2014)

Should be. I was understood a lot of the 10" parts will fit 12". But the I'm just a newbie.


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## iron man (Aug 8, 2014)

I purchased an acme threaded rod and made my own there is not much to it.

http://www.hobby-machinist.com/showthread.php?t=18159

http://www.hobby-machinist.com/showthread.php?t=18061


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## Pops (May 20, 2015)

I put two beds together on my 12" Craftsman lathe and needed a lead screw 8' long. Bought a piece of 3/4" acme threaded rod, cut the 1/8" keyway, did some minor machine work on both ends and it worked great. Did have to do a little straightening on it too.


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## wa5cab (May 21, 2015)

All Atlas built 10" and 12" lathes Model 10D or 101.07402 and earlier have 5/8" dia. lead screws threaded 5/8"-8.  All Model 10F, 101.07403 and 3965 and later have 3/4" dia. lead screws threaded 3/4"-8.

The lead screw on the 3996 is 49-9/16" LOA.  It is also 3/4" dia. all the way to the left end.  The ones on the Atlas 10F, the Atlas 12" models up through 3991 and Craftsman models from 101.07403 up through 101.28910 are 5/8" dia. at the left end.  The 3/4" dia. lead screws on the earlier 12x36 models can be converted to fit the last version 12x36 (or 12x24) by cutting off the f/8" dia. portion.  According to what I have been told by several owners, the 10" 3/4" diameter lead screw's 3/4" diameter portion is 5/16" too short to convert.


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## spongerich (May 23, 2015)

Pops said:


> I put two beds together on my 12" Craftsman lathe and needed a lead screw 8' long. Bought a piece of 3/4" acme threaded rod, cut the 1/8" keyway, did some minor machine work on both ends and it worked great. Did have to do a little straightening on it too.



Well, it's just not nice to say something like that and fail to include a picture. 

What sort of work do you do with such a long bed?  Are you into pole vaulting?


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## Pops (Jun 3, 2015)

I had several 1" diameter shafts that were 6' long that my customer needed turned down a few thousands and polished up. Since then I've done quite a few of those pieces for him. Do have pics that I need to put on here. 


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## Pops (Jun 3, 2015)

Here's a couple pics of my long lathe.


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## wa5cab (Jun 4, 2015)

Neato.


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## Pops (Jun 5, 2015)

It took quite a while to get it all lined up but it is within .005 from end to end. I have turnbuckles on it in several places to anchor it to the wall. Cutting the keyway in the lead screw was a challenge too. 


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