Babbit bearings? help

M

Mikecolt20

Registered
Registered
Joined
May 20, 2020
Messages
6
I just bought a craftsman 12in lathe 101.07383 after reading through some articles about the history of atlas craftsman lathes I determined it must be about a 1939
As it has the bronze "babbit" bearings in the head stock and a 12 in swing 42 in bed measured end to end and no power cross feed
seemed to be in very good condition just going over it and noticed a bit of play in the headstock and cross slide screws I believe the play in the cross slide may have to do with the brass nut I have tried taking slack out with the nuts near handles but when it feels good it has a few spots that seem to get tighter making it very difficult to apply even pressure while facing also seen the headstock bearing cap bolts are loose but can not find the proper way to adjust them for the "babbit" bearings
Ps I have worked with metal for years (cutting grinding and welding)and am currently a heavy truck mechanic but am new to machining.never worked with a lathe prior to buying this one .
 
Ok would you happen to know what the spec is for clearance I do have some plastigauge like what is used for checking engine bearing clearance
Also any suggestions where I might be able to find the shims do they need to have a hole to go all the way around the cap bolt and doing shim both sides of both caps thanks for the quick reply
 
I would shim them as tight as I could without binding or significantly heating under use; generally it is best to have the bolt hole in the shim, the shims should be metal, like brass, you could get a kit of different thicknesses, a thing good to have on hand. shim stock may be available at a bearing house locally, an industrial supply like MSC or McMaster Carr. I made a punch setup by taking two pieces of cold rolled flat steel, and drilling and reaming two holes in one end for hardened dowel pins for guides and then drilling and reaming various size holes in the other end and making the punches out of dowel pins ground to a shallow angled peak on the cutting end; sandwich the plates over the shim slide in the punch and hit the punch with a hammer.
 
The original shims in the babbit bearings consisted of five 0.002" thick rectangular shims laminated together with a hole for the cap screw more or less in the center. If there was nothing there when you pulled the bearing caps and the spindle spun freely with the screws torqued to about 25 lb-ft, then the bearings and/or the spindle journals are already worn beyond usability.

If you can find a 10-31T Timken spindle which we recently learned is the same as the 10-31 except for lacking the hole for the anti-rotate pin and the pin to use as a go/no go gauge, you can determine whether or not the bearings would still be usable for a few more years. Simply lay the 10-31T in the babbit in the headstock and tighten down first one and then the other of the two bearing caps. The spindle should be locked when either cap is tight. If so and if the 10-31T is otherwise in good condition, have someone bore the hole for the pin, install the pin and file its top until the thrust bearing will slide into place against the shoulder. You will most likely have to make the pin.

And if there weren't any under the bearing caps when you first removed them, you will need to make some shims because you can't run the lathe with the bearing cap screws loose or with the spindle locked.
 
I have not removed a bearing cap yet but will check when I get home today . I believe the bearings may be ok still since it had play due to loose bolts when I snugged bolts up a bit the spindle would not turn and back of till it would then had no play so I may only need shims for it so that bolts can be tighted properly
 
Also would anybody know the correct name for this lathe if I look up the 101.07383 I get very limited results but if I look up craftsman 101 series I find a bunch of stuff about the atlas 618 but when I have ordered parts for atlas 618 or craftsman 101 they are all for the 6 in lathe and mine is 12 in
 
The correct identifier for your lathe is its Sears model number, which I think that you said wsa 101.07383. The Atlas Model 618 is a 6" lathe with 18" nominal between centers. As far as I can recall, the only two 6" parts (aside from miscellaneous nuts, washers, bolts and keys) that are used on the larger lathes are the two locking cylinders for the tailstock ram. Why you got no hits when searching for "101.07383" I don't know. But probably because wherever you were looking had none or maybe did but doesn't know it.

You really shouldn't try to order parts from someone who knows nothing about any of the Atlas lathes (which group includes most eBay sellers) unless you know the correct part number. Part numbers for the 101.07383 will be found in either the Sears parts manual (mostly a flat file listing with a photograph of all of the parts spread out on a flat surface) or in the Illustrated parts list for the 101.07383 that I adapted mostly from the Sears parts list on the 101.07403. Both versions may be found in Downloads. However, access to Downloads requires that you be a donor, (any level) because maintaining Downloads is a significant part of the monthly bill for keeping this site online. Before going to Downloads, be sure that you read the instructions for using it that are in the Sticky area of this Forum plus a few other places on the site.

From 1932 until 1957, Atlas assigned part number with the first one or two numbers or letters identifying the first machine that used that part. For some unknown reason 6" part numbers mostly begin with M6 instead of just "6".Most of the parts on the 101.07383 begin with 9 or 10 because the Craftsman 12" was adapted from the Atlas 10", which carried over some of the 9" parts. Parts unique to the 12" for whatever reason mostly begin with the letter "L" and a single digit followed by a hyphen and then the same one, two or three digits ending the part number for the equivalent 10" part.

Also, I have know idea why a search for "101" would have turned up anything about the Atlas 618. "101" happens to be the Sears Contractor Code for Atlas Press Co. and later Atlas-Clausing and Clausing-Atlas. Sears never sold anything made by Atlas under the Atlas Model numbers. Although they did use all of the various Atlas part numbers when selling parts for any machine made by Atlas. But when they started selling the Atlas 618 in 1957, they called it the 101.21400.
 
Last edited:
You must log in or register to reply here.
Back
Top