# Atlas lead screw dimensions



## iron man

Hi I have ordered a new 8tpi acme screw to make a replacemnt lead screw for my 10 inch Atlas lathe I was just wondering if anyone had one apart or an extra screw laying around. If so if you could give me the dimensions at each end so I could machine the new one before I pull the old one out??? Just the dimensions to the shoulder and the diameter at each end should do it. Mine is the long Atlas lathe probably what would be called a 42" bed the whole lathe is about 5 foot long but that probably does not make a differance.. Thanks Ray


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## pdentrem

I have an old one. Hope these do the job for you. Mine was off a 10F24.
Pierre


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## iron man

Thanks a bunch the distance to the shoulder might be different since I may not have the same caliper as you. Thanks Ray


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## aforsman

Ray,

I'm guessing you're paying a pretty penny for the long acme screw.  Before I fooled around and made a mistake, I would remove the one from your lathe and measure it carefully (twice) at all points to be machined.  The leadscrew can be removed from the machine in less than five minutes and reinstalled in about the same time.  Position the apron near the center of the bed (to help support the screw) and remove the two nuts at the tail end of the screw.  Then remove the two 1/4" bolts in the bearing at the tail end.  As long as the half nuts aren't engaged, the leadscrew should just slide right out toward the tail end of the lathe.

The only other thing to note is that when you reinstall it, you need to rotate it in the apron until the keyway lines up with the pin that drives the power crossfeed gear.  You'll have to do the same as it enters the drive gear box at the headstock.

Allen


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## iron man

aforsman said:


> Ray,
> 
> I'm guessing you're paying a pretty penny for the long acme screw. Before I fooled around and made a mistake, I would remove the one from your lathe and measure it carefully (twice) at all points to be machined. The leadscrew can be removed from the machine in less than five minutes and reinstalled in about the same time. Position the apron near the center of the bed (to help support the screw) and remove the two nuts at the tail end of the screw. Then remove the two 1/4" bolts in the bearing at the tail end. As long as the half nuts aren't engaged, the leadscrew should just slide right out toward the tail end of the lathe.
> 
> The only other thing to note is that when you reinstall it, you need to rotate it in the apron until the keyway lines up with the pin that drives the power crossfeed gear. You'll have to do the same as it enters the drive gear box at the headstock.
> 
> Allen



 I did not think it was that bad McMaster Carr was rather high but a company called Roton out of MO. was about half the price for the same item.


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## pdentrem

I bought my replacement from Clausings back in the early 90s. Was not cheap back then. I think it was near $260 if not more. 

Removing the leadscrew and reinstalling is not a real issue. Just a bit finicky to get the key ways lined up, also you do not need to remove it completely, just far enough to get your measurements, about 4 to 6" will do.
Pierre


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## iron man

Senna said:


> The brand of caliper should have no effect on the dimension.
> 
> Pdentrem is using his caliper correctly and the distance to the shoulder is just what his caliper (and yours will too) shows.



Thanks for the info on that I just was not sure if it would make any differance or not. I always use the tail of the caliper like a depth gauge to check a shoulder..Ray

- - - Updated - - -

Cutting that long keyway should be a hoot!! I will have to make some sort of jig to hold it straight all the way. Here is the Acme threaded rod I purchased I will probably just add a solid piece to one end and machine it straight.

http://roton.com/Mating_Components.aspx?family=7059433


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## wa5cab

Ray,

The longest Atlas lathe has a 54" bed. Bed length is defined as the total length of the ways. Nominal, or rated, distance between centers on the Atlas 10" and Atlas or Craftsman 12" is 18" less than the bed length. So a 42" bed machine would be a 10x24. Up until about 1948, Atlas sold 10" and Sears sold 12" with bed lengths of 36", 42:, 48" and 54". The 36" and 48" beds were dropped around 1948. The 42" bed was dropped in the late 1970's (I haven't gotten around to pinning down the exact year).

Robert D.



iron man said:


> Mine is the long Atlas lathe probably what would be called a 42" bed the whole lathe is about 5 foot long but that probably does not make a differance.. Thanks Ray


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## iron man

Thanks for the info if it is the total length of the ways mine is a 54" Thanks Ray


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## Privateer

Ray.

I'm in the process of upgrading my 10D to a 10F, namely replacing the original saddle with the one that has the crossfeed. In so doing, I'll be needing to do what you're about to do. I'd be very keen on learning how you go about it, and what difficulties you ran into cutting that supremely long keyway. Incidently, the supplier you used was the one I've been looking at too. Though there is a 3/4 leadscrew on fleabay atm for less than $100 USD, while it would work for me, (I have the 42" bed), it wouldn't do you much good.

Regards,
Terry


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## iron man

As soon as I get the Acme threaded rod I will start to work on it and I will keep you updated. I think I have figured out a simple way of keeping the key straight and I plan on making a pair of brass half nuts while I am at it.. Ray


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## Privateer

I've been contemplating how to go about making those too. Making replacement brass nuts for the compound and crossfeed seem trivial by comparison. In looking at the piece to be made, I'm wondering, do I cut the block to size, then cut out the half thread and then mill the final shape? Or, and I'm leaning in this direction, use a rectangle that will have the thread cut in the middle, mill the ends to match the half nut configuration, then cut it in half with a bandsaw. Not having much experience with a vertical mill the most expedient solution doesn't jump to mind. 
    Then there's the question of where to obtain the appropriate size acme thread tap. I ran across an idea utilized by someone else, where they took the screw which matched the thread pattern they wanted, tapered the end slightly, cut in two furrows with a bit of a rake on the cutting edge, and used that. Fed it in as if it were a boring bar and claimed the results were perfect. As ACME thread tappers are hardly what I would call inexpensive, and add to that I would need three different sizes. That being said, I happen to have a few bits of pristine ACME threaded rod in 2 of the required sizes already, and will happily experiment to see if that method is viable.

Terry


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## iron man

There is several ways you could go about it one way is to take a round piece of brass bore an under size hole through it then split it in half solder it back together. Make sure you do it to a longer piece than you need. Chuck it back up turn the outside and the inside to the proper dimension and I always just thread it on the lathe brass threads nice. After your done warm up the brass till the soft solder releases and you have two perfect halves. Now just take some Foss Copper and braze them onto a couple of brass plates and mill them till everything is square and flat. Foss Copper is a rod similar to silver solder but with no flux it is just as strong as the brass and is easy to use. Ray


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## wa5cab

Ray,

I wouldn't waste my time trying to make half nuts.  It's cheaper to buy them.  Remember that contrary to what some people apparently think, the fact than you CAN make something on your lathe does NOT mean that you MUST make it.  And if I for some reason had to make them, I definitely would not use brass.  While brass wears pretty well, it scarrs easily, too.  It's OK for the compound and cross-feed nuts because they are always engaged.  But not for half nuts.  

Robert D.


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## iron man

wa5cab said:


> Ray,
> 
> I wouldn't waste my time trying to make half nuts. It's cheaper to buy them. Remember that contrary to what some people apparently think, the fact than you CAN make something on your lathe does NOT mean that you MUST make it. And if I for some reason had to make them, I definitely would not use brass. While brass wears pretty well, it scarrs easily, too. It's OK for the compound and cross-feed nuts because they are always engaged. But not for half nuts.
> 
> Robert D.



 My experiance has been brass makes an excellent bearing surface for just about any steel and it is a lot tougher than Zink base metal. New half nuts will cost anywhere from $50 on up with supplies I have I can make them for nothing in my spare time. I spent all this time setting up a nice home shop then I sit around wondering what to make this is a good project for me!!


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## wa5cab

I always have at least a dozen things that should have been completed last week, last month or last year.  I don't have recent cost on half nuts for any of the 6" machines and haven't checked price on the 10"/12" to see whether or not they've gone up.  But last year when I bought a set, price from Clausing was $33.01 plus shipping.  I'm pretty sure that, starting with all materials and necessary tooling on hand, I couldn't make a set in 40 minutes.  

As I wrote earlier, brass or bronze wear pretty well against steel and are good choices for the compound and cross slide nuts.  But they are relatively soft against scratching and scarring and I wouldn't consider them a very good choice for half nuts.  

Robert D.


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## Privateer

As it happens, I'm awaiting a response from Jo Olds at Clausing right now, having sent a RFQ for a list of parts I'm needing to complete my retrofit. I'll happily post a copy of the cost for parts when I get it.


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## iron man

Brass is still tougher all the way around than Zink base it will not scratch or gall any easyier than Zink plus I have worked on lathes with both brass or cast iron half nuts on bigger lathes and they come that way from the factory they work for years with no problems.

http://www.tools4cheap.net/proddetail.php?prod=nutatlashalf


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## Privateer

Ray,
I had forgotten to update on the half nuts from Clausing.  The 10F-12 Half Nuts come as a pair for $34.63. The 10F-19 Brass Nut (Carriage location) is $76.96. And the 9-306 Brass Nut (Compound location) is $44.72. So the half nuts to me would be cost effective to purchase from them. 

Other items on the list include the felt oilers 547-004 were $1.00 each, and the wipers 938-003 @ $4.00 each.

For the entire quote all the parts I had requested prices on, it would cost me $813.34 plus tax and shipping, if I order through them. And that amount was not including a lead screw, which I anticipated either purchasing used or fabricating one of my own using the threaded rod from Roton.

Terry


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## iron man

Privateer said:


> Ray,
> I had forgotten to update on the half nuts from Clausing.  The 10F-12 Half Nuts come as a pair for $34.63. The 10F-19 Brass Nut (Carriage location) is $76.96. And the 9-306 Brass Nut (Compound location) is $44.72. So the half nuts to me would be cost effective to purchase from them.
> 
> Other items on the list include the felt oilers 547-004 were $1.00 each, and the wipers 938-003 @ $4.00 each.
> 
> For the entire quote all the parts I had requested prices on, it would cost me $813.34 plus tax and shipping, if I order through them. And that amount was not including a lead screw, which I anticipated either purchasing used or fabricating one of my own using the threaded rod from Roton.
> 
> Terry



 Thanks for the info I am just about ready to cut the keyway this should not take long I just have to find time this weekend to do it. I dont think I will ever buy stock parts again I can usually make them from a better material at a quarter of the price and it makes a good project. Ray


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## iron man

The shipping from Roton is rather high I am told McMaster Carr has better rates. Ray


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## Privateer

I just had Roton quote me aproximately 31 to ship my order which comprised of 1 3/4"-6 LH ACME thread @ 48", 2 1/2"-10 LH @ 12", and 1 1/2"-10 RH @ 12".  Total with shipping just over $100. McMaster wanted $77 for just the 3/4"-6 part at 72". Their options were limited to pieces at 12", 36", and 72". At least according to my quick tour of their website. It's entirely possible I could get more exact dimensions if I phoned them as I did with Roton.

Terry


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## iron man

Roton has a minium order I think its $60 I think my shipping for one piece 6' of 3/4 x 8tpi was $22 not too bad I guess. I dont know the grade of steel the roton one is for sure..  McMaster's has three grades the roton one will work just fine it machined a little rough with high speed steel but machined really nice with carbide.


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## pdentrem

pdentrem said:


> I have an old one. Hope these do the job for you. Mine was off a 10F24.
> Pierre



No pictures? What happened? I reloaded a couple back in.
Pierre


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