Just Picked Up A New (to Me) Craftsman 12" Lathe

[nwarcade]

Hello All,
I recently picked up my first decent lathe (my previous being an ancient Barnes 4 1/2). The plate on the back of the bed lists the part number as 101.07380. From what I've read it seems to be an earlier 12" with babbitt spindle bearings and no power cross feed. It does have a few issues that I'm hoping to remedy.

There is a decent chip out of the top of the saddle, the gib for the cross-feed is fairly hammered and causes it to bind, and most importantly it looks like I've ran out of shims for the spindle. I've been watching eBay for a replacement saddle with the same 10D-9 casting mark and possibly a replacement gib for the cross-feed but I'm not sure what to do with the spindle. Once you run out of shims is it the end of the road for a babbitt headstock? Would I be better off finding a timken bearing headstock from a later Craftsman 12" lathe and swapping it over?

Thanks in advance for the info everyone. After using the old Barnes for several years I look forward to getting some time in on a slightly newer machine. Pics of the new Craftsman will follow here in a bit.

 

[coffmajt]

Hello All,
I recently picked up my first decent lathe (my previous being an ancient Barnes 4 1/2). The plate on the back of the bed lists the part number as 101.07380. From what I've read it seems to be an earlier 12" with babbitt spindle bearings and no power cross feed. It does have a few issues that I'm hoping to remedy.

There is a decent chip out of the top of the saddle, the gib for the cross-feed is fairly hammered and causes it to bind, and most importantly it looks like I've ran out of shims for the spindle. I've been watching eBay for a replacement saddle with the same 10D-9 casting mark and possibly a replacement gib for the cross-feed but I'm not sure what to do with the spindle. Once you run out of shims is it the end of the road for a babbitt headstock? Would I be better off finding a timken bearing headstock from a later Craftsman 12" lathe and swapping it over?

Thanks in advance for the info everyone. After using the old Barnes for several years I look forward to getting some time in on a slightly newer machine. Pics of the new Craftsman will follow here in a bit.
J

Have you measured your bearing clearance with a dial indicator on each end? How much did that show? Making a new gib should be pretty straight forward - Glad to hear about the new machine to you == Jack

 

[Randall Marx]

Congratulations! Looking forward to pics and more info. We'll be glad to help in any way we can!

 

[wa5cab]

101.07380 is the first version of the 12" 16-speed machines that Atlas built for Sears. It was sold for about one year, in 1936. Please report serial number.

Did you remove shims or were they already all removed when you got the machine? In either case, to evaluate their condition, remove, clean and oil the bearing cap bolts. Assuming that they are I think 3/8"-16 (none of the parts lists give that), tighten to a torque figure of about 35 lb-ft. Assuming that there is no discernable drag when rotating the spindle, position a dial indication as required and measure spindle movements at both ends in both the horizontal and vertical planes. I don't think that there are any factory figures ever listed for this but I would say that the limit is about .0015".

The same 10-56 Gib was used on the cross slide (AKA Compound Swivel (Lower)) on all 10" and on all 12" up through about 1977. So you shouldn't have any problem finding one.

The same 10D-9 one-piece carriage casting was used on 10D and 10E and all 12" from 101.07360 through 101.07383 and 101.07400 through 101.07402. The later two-piece carriage (separate saddle and apron, and with power cross-feed) will also fit your bed but requires a lot of other parts, too.

If your spindle bearings are too worn, I would recommend replacing the headstock with a Timken bearing model. But there are other parts that you would also need, although the headstock casting itself will bolt right up. I would first check the condition of the babbit bearings and if usable, use them until they become too loose.

 

[nwarcade]

Wow, thanks for all of the info. I'm enjoying researching all of the little changes that occurred in the production run of these lathes. To clarify when I received the lathe there were no shims under the front or rear caps. I just got done running the lathe for a bit and checked the play on both ends of the spindle.

Unfortunately I'm seeing .003 at the front and .002 at the rear of the spindle. There is no measurable end play and after torquing down at 35 lb-ft there was no noticeable drag on the spindle either.

I've attached some pictures of the lathe as I received it. It did come with some extra odds and ends and some tooling. I am a little bummed about the spindle situation though. Would it be possible to do a really light cut on the bearing caps and re-shim to get a few more miles out of it or would that lead to bore no longer being concentric? The babbitt still looks good in the headstock and caps and the spindle is darn near perfect on the bearing surfaces.

 

[wa5cab]

Well, as far as I can see, you've nothing to loose by trying taking a few thou off of the bearing cap faces. But you'd better have someone with a good mill and an operator who is a competent machinist do it. I would probably go with about 0.005" off of the cap faces.

Actually, there have been people who reported having re-poured the babbit. But getting it line bored to adequate accuracy would probably cost more than you probably paid for the lathe.

You will probably find that your tailstock center line will be a little higher than the spindle's. Fortunately, the diameter error that would cause if you were turning a part between centers decreases rapidly as the part diameter increases. The diameter error from end to end of a 1/2" diameter part with a tailstock to spindle height difference of 0.010" would be 0.0016". It increases or decreases as the square of the diameter so 1/4" would be off by 0.0064" and 1" dia. would be off 0.0004". Your height error will probably be less than 0.010", which will decrease the error directly. And this only applies to parts held between centers. It would have no effect on a short 1/4" diameter part held in a chuck or collet.

 

[wa5cab]

I forgot to add that the small block with a dovetail on the bottom shown in your next to last photo is the drawbar guide for a taper attachment. But I didn't see any other pieces in your other photos.

And don't forget the serial number.

 

[nwarcade]

Thanks for the reply Robert. I might just start searching for a timken headstock. I assume the headstock will need to be shimmed or ground to line back up with the tailstock. Will the bull gear, back gears and pulley work on a newer headstock or should I look for a complete unit? Also the only number I can find is 3858S stamped on the tailstock end of the bed. Would that be the serial number?

 

[wa5cab]

!@#$%. I was so busy looking at the bits that came with the lathe, I missed the photo of the right end of the front way showing the 3858S. Yes, 3858 is the serial number. Usually shown in lists as 003858. No one still alive seems to know what the S stands for. It doesn't stand for Sears because some of the Atlas 10" also have it. The earliest production didn't. Then it was on everything. Then around VJ Day it disappeared.

 

[wa5cab]

Could you post a photo of the compound taken from a point in front of the headstock? I'm trying to confirm that it's the later version, as it should be since it has a crank instead of a knob on its feed screw.

Theoretically, the two headstocks should be perfectly interchangeable on the bed. In practice, they usually are.

The bull gear and the spindle pulley, small spindle back gear and three bushings are the same in both type headstocks. As is the 32T gear and collar on the left end of the spindle and the entire back gear assembly and countershaft assembly.. But the spindle, spindle bearings, a collar that goes just to the left of the small spindle back gear, four bearing dust covers, and the spacer between the left bearing and the 32T gear are not on your spindle. Plus the 12" Timken bearing headstocks all had a full belt and gear cover and the holes for the screws attaching your two gear guards probably won't be either drilled or tapped.

Read the DOWNLOADS usage instructions at the top of this forum and then go to DOWNLOADS and get the parts manuals for 101.07403, 101.07383 and 101.07381. We don't have a parts list for 101.07380 but the 07381 is almost the same and I suspect yours has the later compound anyway. So the main difference will be the gear guard over the change gears.

With the Timken headstock, if you get the belt cover and mounting bracket, yours becomes equivalent to 101.07400 except for the change gear guard and maybe the compound. For the change gear parts, carriage, and most other parts, refer to the 101.07381 parts list. They are the same as on the 101.07380.