# New member with Atlas Craftsman QCGB 12” and a few questions



## DaveInHouston (Jan 1, 2019)

I bought this old lathe a couple of weeks ago and, after reading a few posts here, am wondering what I really have. The old gentleman that I bought it from had owned it for thirty years and only used it for occasional wood working! I cleaned, lubed, adjusted and tuned it and it seems to be running pretty good. I assumed it was an old Babbitt bearing lathe but not sure. I ‘d like to know the approximate date of manufacture. Got 40 gears with it but 15 are steel gear with “Boston” and the tooth count on them. Not sure why I would need all those gears with the QC. Photos attached. Any information, advice, recommendations etc. would be appreciated.
Thanks,
Dave


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## dparker (Jan 1, 2019)

Dave:  I have a bench mount 12x36 Craftsman/Atlas, (bought new in 1968)   model # 101-28910 SN 104454.  It has Timken bearings.  The other lathe is a Craftsman Commercial 12x36 Model # 101-28990, SN 105937 that my Dad bought used and it also has Timken bearings.  Your lathe has a very much earlier Serial Number but the headstock and oil cups look just like both of mine leading me to think you also have Timken bearings.  The things on mine that have shown the most wear have been the half-nuts and the lead screw, I bought replacements for both from Clausing many years back and still have one set of half-nuts and the new lead screw in reserve.  With the QCGB I am wondering if the gears you received might be for another lathe, but they may come in handy for mounting them on the outboard of the spindle and use them for indexing purposes.


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## DaveInHouston (Jan 1, 2019)

I appreciate the reply and the information. I wish my lathe were a 12x36 or a Commercial cabinet model but they don’t come along very often around here. I bought this one to “play” with and get back into machining. The gentleman I bought it from couldn’t tell me much about it even though he had owned it for thirty years. Clearly some of the items I got with it didn’t belong as there was a box of forty odd 3/4” carbide cutting bits! The gears may well have come from another machine too. There was a nice, complete collet set with it. Again, thanks and Happy New Year!
Dave


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## westsailpat (Jan 1, 2019)

Hi Dave , nice score and welcome to the group . Do you have any projects in mind ?


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## DaveInHouston (Jan 1, 2019)

Thanks. I have tons of projects in mind, just not sure where to start! I’m the farm hand on my wife’s little horse farm, so have almost limitless opportunities between the tractors, barns, welding machines, etc. I’m actually looking forward to putting it to use, understanding it’s size and power limitations. Thanks again!
Dave


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## thomas s (Jan 1, 2019)

Dave,Welcome to the forum.


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## wa5cab (Jan 1, 2019)

Dave,

Your lathe is a Craftsman 101.07403.  It has Timken tapered roller spindle bearings.  If it had babbit bearings, first it would have a model number that began with either 101.0736x or 101.0738x.  And second, the parts of the headstock casting that the spindle fits through would be split horizontally and each would have two hex head bearing cap bolts.

As originally sold, it was a change gear lathe.  When Atlas first offered the QCGB for the Craftsman 12" lathes circa 1950, they could be retrofitted to any of the 48 different earlier models from the 12x36 101.07403 back to the 12x18 101.07360.  The loose gears that you have with 3/8" faces, 1/2" hubs and two keyways are the change gears that presumably came with the lathe and were used before the addition of the QCGB,  What the other gears are, I don't know.

I don't see the serial number in any of your photos nor in any of your posts.  It should be stamped into the top of the front way near the right end.  If you will post that, I can tell you within probably 2 or 3 years of when it was originally made.

You didn't say what the bed length or the nominal maximum distance between centers is.  Up until 1948 or late 1947, Atlas made and supplied Sears with four beds of different lengths, 36" (12x18), 42" (12x24), 48" (12x30) and 54" (12x36).  From the one side view photo, I would guess that your machine is a 12x24, but you could confirm that when you give the serial number.


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## kd4gij (Jan 1, 2019)

Your model # 101.07403  is a 12x36 change gear lathe. The quick change gear box was a add on Some one add later in it's life.
I have the same lathe. I added the qcgb after I got it.
Nice score and welcome to the site.


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## DaveInHouston (Jan 1, 2019)

thomas s said:


> Dave,Welcome to the forum.


Thank you!


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## DaveInHouston (Jan 1, 2019)

wa5cab said:


> Dave,
> 
> Your lathe is a Craftsman 101.07403.  It has Timken tapered roller spindle bearings.  If it had babbit bearings, first it would have a model number that began with either 101.0736x or 101.0738x.  And second, the parts of the headstock casting that the spindle fits through would be split horizontally and each would have two hex head bearing cap bolts.
> 
> ...



Thank you so much. Although I was okay with babbit bearings I would prefer Timken bearings. The serial number is 11998 S. I assume the S is for Sears? And you are correct that it is a 42” (12x24) lathe. I suspect the owner prior to the one I bought it from accumulated the extra gears and parts. I put a new belt on it and lubricated everything and it runs very smoothly.


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## DaveInHouston (Jan 1, 2019)

I suppose the next question is do I even need that stack of extra gears since it has the QCGB?  I did see a YouTube video showing how to slow the feed screw down even slower than the GB would allow by changing out a couple of gears on the banjo. I’m having a blast with the old lathe. I’ve contemplated re-painting it but I think I’ll wait. It appears to be really tight. I’ve been running all over the place looking for potential projects. Thanks again. The Timken bearings upgrades my view of the old girl! I attached a photo of the collets and drawbar that came with it.


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## pontiac428 (Jan 2, 2019)

Dave, you got yourself a heck of a great lathe!  One tip, your link belt will run quieter if you reverse it- the tails of the links are supposed trail in the direction of travel.  Happy turning!


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## DaveInHouston (Jan 2, 2019)

Pontiac, Thanks for the heads-up on the belt. I'll reverse it when I get home this evening. I've never used a link belt and wasn't sure on the orientation. When I got the lathe the drive belt was in good shape but much too long, to the point that the pulley was so far back that you couldn't close the drive belt cover. In fact someone had broken one of the drive ears off the cover. Repairing that cover and fabricating a hinge replacement was my first project on the lathe. I didn't want to remove the head-stock to install a new conventional belt so bought a link belt. Thanks again!


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## pontiac428 (Jan 2, 2019)

I ran mine "backward" for almost 2 years before I realized it.  Still smooth, just runs quieter and grips a little better in the "forward" direction.

Again, great lathe!


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## DaveInHouston (Jan 2, 2019)

Thanks again. I'm looking forward to getting familiar with it and using it.


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## Bi11Hudson (Jan 2, 2019)

Although a newer model than your's, a 101.27440, I have acquired a set of change wheels in addition to the QC mechanism. I do a lot of (electrical) coil winding, and other "non-standard" feeds. It could well be that the "extra" gears are for this purpose. There are several charts for this, some on this site. This is in addition to the above comments, not in opposition to.  
Bill Hudson​


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## DaveInHouston (Jan 2, 2019)

You could be right. Thanks


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## WallyEmm (Jan 2, 2019)

There is a paragraph in the Atlas/Craftsman Manual of Lathe Operations that says:



> Between the coarsest thread, 4 threads per inch, and the finest feed, .0018 inch or 553 threads per inch, over a thousand threads and feeds have been charted by Atlas engineers.  Tables I, II and III, pages 128-133, give proper gear set-ups for a wide variety of special threads and feeds.  (MOLO, part 7 "Thread Cutting", page 125 in this PDF copy)



I noticed some of those settings require extra copies of the gears included with the original lathe.  Since you have the gears you might want to keep them for the day you might need an unusual thread or feed, or need to wind a coil as Bill Hudson does.  They are not cheap on ebay, and not all sizes are readily available.

Wally


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## DaveInHouston (Jan 2, 2019)

Wally,
I think that’s good advice. Having too many gears doesn’t really present a problem. And you never know, I may need them some day.
Thanks,
Dave


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