Atlas Frankenstein Lathe

I didn't purchase the lathe from the person who combined the lathes so I'm not sure where any of the drive components that would have been in the cabinet may have ended up, but it has been converted into a storage area.

The black nob is to lock the side cover in place. Those components we're home made, but whomever built them did a very nice job.

Is there anywhere on the headstock casting I could look to determine it's year of manufacture? Also does it use the timkin tapered roller bearings? I assume it does.
 
First, the lathe that supplied the bed, carriage, etc. was a 3986, which is a bench model with a countershaft assembly quite different from the one on the 10". The cabinet, on the other hand, came from yet a third group of models that ended with the 3996.

There was considerably more to this "conversion" than would be obvious to someone familiar with the later two 12" version groups and the 10" and early Craftsman 12". As I wrote earlier, the last two 12" version groups had the back gears mounted under the spindle. Whereas the 10" and all of the early 12" had them mounted behind the spindle. That means that he couldn't use the 3986 countershaft assemble, which is smaller. Assuming that the person doing the conversion was able to source the 2-groove spindle pulley used instead of the 4-groove cone spindle pulley used on all earlier Atlas lathes except for the 6" and 9", the conversion would have been far simpler. The 2-groove spindle pulley will fit all of the 10" and early 12" spindles. But in any case, he didn't do it that way.
 
What did that conversion entail?
I'm thinking of converting mine to underneath with either VFD or treadmill motor.

kcoffield said:
I converted an older 12" Craftsman from rear to underneath countershaft installed on a 3996 style cabinet. It took considerable effort so it's sort of strange to see a 3986 style lathe converted the other way. Unless the original headstock was lost, I would have thought it far easier to just fix whatever the problem was with the original headstock rather than the effort to swap the 10" HS onto the lathe. With the degree of parts interchange, the 10" could likely have been the repair donor. Is the drive hardware inside the cabinet still present. Any chance the take off parts are available?

Best,
Kelly
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Jlwright3,

We were apparently writing at the same time.

No, as far as I know, the only castings that Atlas/Clausing made that have a casting date cast in are the headstocks for the MK2 6". My estimate of the manufacturing date is probably the best that you are going to get. And as to when the 10F headstock was actually made, the best that I can say right now is sometime between 1939 and 1957. I have asked several people at Clausing about paper documents and all have told me that except for the drawings, they were all either lost by accident or destroyed by the Clausing hands.

All of the lathes that Atlas and then Clausing made after 1945 except for the 6" used the same part number Timken bearings.

As to when the 10" headstock was made, if you have any other reason to pull the spindle, odds are about 3:1 that the spindle bearings will have dates engraved into them. That practice stopped around late 1952. So if there are no dates, late 1952 to mid 1957. If there are dates, then the latest of the dates -0+1. If you pull the drum switch and find that the original 10" motor switch was mounted in a round hole, then 1939 to 1942. If the hole was originally square or rectangular, the late 1942 through the Summer of 1957.
 
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aaronrumple said:
What did that conversion entail? I'm thinking of converting mine to underneath with either VFD or treadmill motor.
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It depends on whether you have the late model headstock that was introduced with the models with 1/2" thick ways. If you do, it's a lot easier. If not, as in my case, it's much more involved. It's detailed in this thread with the meat of it starting here.

www.hobby-machinist.com

New Caretaker of Two 12” Craftsman Lathes

Well, I'm back at it. I commented earlier about building a stand and a possible under drive countershaft conversion. I located the parts to do the conversion and a complete Craftsman lathe cabinet with drive assembly for a reasonable price, so off I go. It was my Grandfathers, Father’s, and...
www.hobby-machinist.com www.hobby-machinist.com

Best,
Kelly
 
Actually, as I wrote earlier, if you have the late model cabinet and the drive components that are attached to the cabinet, but have any Atlas built bench model lathe except a 6" or 9", the only other things that you need to make it a bolt-together conversion are the 2-groove spindle pulley and two A42 belts. The 2-groove pulley is a drop-in replacement for the 4-groove conical pulley used on the spindles of all of the bench model 10" and 12" lathes, whether 3/8" or 1/2" bed.

I will also mention that Atlas built in very small numbers a model 12700 which is identical to the 3996 and 101.28990 except that the cabinet and door are wider, with the two 4-groove conical pulleys mounted inside of the cabinet instead of on the outside of the left cabinet wall under the external swing-out cover. It was apparently intended for use in schools with the students not being able to chop off their fingers without an instructor with key standing by. It had the misfortune of being introduced at about the same time that most four-year high schools in the US were dropping all of their Shop and Home Economics classes in the interest of "saving money" and "college prep". So very few were made or sold.
 
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wa5cab said:
Actually, as I wrote earlier, if you have the late model cabinet and the drive components that are attached to the cabinet, but have any Atlas built bench model lathe except a 6" or 9", the only other things that you need to make it a bolt-together conversion are the 2-groove spindle pulley and two A42 belts. The 2-groove pulley is a drop-in replacement for the 4-groove conical pulley used on the spindles of all of the bench model 10" and 12" lathes, whether 3/8" or 1/2" bed.
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I'm probably misinterpreting what you're saying here but unless you mean the entire lathe when you say and the drive components that are attached to the cabinet, I acquired the cabinet and drive components separately and I can tell you with certainty that there is no way my late 1940s era 12" is Craftsman (101.07403) could be converted to under drive with just the 2-groove pulley. There's absolutely no way the headstock casting could accommodate bottom exit of the belts, and certainly not placing the back gears underneath the spindle if that is part of the desired conversion. Also, near as I can tell the spacing between the bed ways is not wide enough to allow that belts to pass through under the headstock. I had to mill mine wider in that location to clear both the back gear and the belts. Weren't these features on the bed introduced around the same time as the first cabinet models?......and 1/2" ways?

The other thing I don't fully understand is the need for the two grove pulley......of course you don't need the other three steps but why two instead of one groove? The two groove pulley is the same diameter as the smallest step on the 4-groove pulley step at 3" so you already have several drive combinations that have the same belt/pulley contact area with a single belt but when you put two 3" pulleys you need two belts???

Best,
Kelly
 
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OK. First, for many years, I used to every now and again ask for a bottom view photo (from outside, inside or both) of the headstock castings from various models of the 10" and 12" Atlas and Craftsman lathes. I quit asking a few years back but No One ever responded with any photos. But, I never said that there wouldn't be any modifications that had to be made to either the headstock casting or the bed, just that the parts were all usable. I also did not say that there would be no hole drilling and/or hole plugging required in order to bolt the bed legs to the cabinet and oil pan. There will at the very least be one hole to plug as the left leg on the Atlas 3991 and 3996 (equivalent to 101.28970 and 101.28990) has three mounting holes for attaching to the cabinet and is different from the right leg. Whereas the 10F at least uses the same leg on both ends. I also do not know whether the four holes equivalent to the four in the 10x36 10F and Craftsman equivalents are in the same relative locations (although that would probably have been easier if they would fit than putting them somewhere else). So it is at the moment unknown exactly how many holes might have to be drilled and/or plugged.

As to why the 4-groove cone pulley was replaced by a 2-groove pulley for two of the same belts instead of a single belt and groove, I don't know. But three possible reasons are (1) both grooves obviously had to be the same diameter if they were going to have two belts in place, (2) The pulley had to be the same LOA as the 4-groove in order to replace it without having to add several additional parts. The hypothetical spacer would have to be keyed to the 1 or 2-groove pulley in order for the direct drive pin to work which would have cost more, (3) having only one belt on such a long pulley looked funny, (4) your guess is as good as mine but I'm voting for #3. I will mention that it was good for me that they did have two belts as my 3996 was incorrectly assembled at the factory with the right-hand belt rubbing up against the wall around the belt pass-through cutout in the oil pan. I did not notice it until several months later, by which time one belt was about to fail. I moved the 2-groove jack shaft pulley all of the way to the left so that the right jack shaft groove lines up with the left spindle groove and the belt was well clear of the sharp edge of the hole in the drip pan. And it has been working that way for the past 39 years.

Anyway, I will post another request for photos of the bottom of the Atlas 10" and early Craftsman 12" headstock.
 
If I didn't make it clear, look at the bed page in the 3996 manual in Downloads. It clearly shows the cutouts in the front and rear ways to clear the belts. Otherwise, the only other significant difference between the early and late bed castings is the thickness of the ways. The distance between them and probably the total width is all the same. The later tailstock is different and the base is different but the two pairs are the same width. You could if you needed to run the early 12" tailstock on the late bed or vice versa. I have both the early lever operated tailstock and the early turret tailstock and both fit the late bed.
 
wa5cab said:
Anyway, I will post another request for photos of the bottom of the Atlas 10" and early Craftsman 12" headstock.
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I still have the old headstock. So as not to Hijack this thread, if you post a call for headstock pictures I'll detail the differences I'm referring to. As far as the bed casting mods, post #15 of this thread has a link to my build/conversion thread that shows the milling necessary. The belt reliefs need to be milled in both the top and bottom webs of the older style bed castings. Since I converted to the modern headstock casting with the back gear under the spindle, the larger gear on the back gear protrudes below where the headstock casting lands on the lathe ways so an even wider relief needs to be machined in the older style bed casting to accommodate that feature. These mods are clearly pictured in the link. When I bought the cabinet, I also acquired the bed feet/risers from the cabinet 3996 style lathe. If I hadn't done so I would have also had to mill belt reliefs in the older style bed feet and if I recall correctly they may have a different mounting location to the drip pan.

If you look at the very first post of the thread in the link, there is a picture of both lathes, and I think they were manufactured within a year or two of each other. I've seen a few Atlas/Craftsman lathes but never paid close attention to them. These are the only two I've ever owned and the only one I've had apart. I also had modern headstock part and am familiar with the differences between those two models but don't know squat about the rest. The 54" bed lathe I still own is complete and completely original and a nice example. It has the same headstock as the 42" bed lathe I modified......

For the Original Poster of this thread, I guess my lathe is now a Frankenstein as well, but it's my Franky and I can assure you "it's quite alive" and will perform well by the time I'm done. I wouldn't worry too much about the mix of parts if it performs well.

Best,
Kelly
 
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