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11" south bend. Oddball lathe?

Jamesktm

Plastic
Joined
Mar 15, 2017
I recently came across a really good deal on an old south bend. The price was so low it was a no brainer I had to pick it up.

It seems to be in decent shape wear-wise.

Serial number J1044. I haven't been able to find any information about these lathes, It seems there were lathes produced between 1920 and 1921 with the "J" prefix. South bends website doesn't mention any 11" lathes whatsoever.

Its an 11" swing with a 4ft bed.

I'm working on cleaning it up and going through it, Not a full restoration or anything, I just want to get it operating.

One part I know I will need to repair or replace is the back gear, The large gear on the left has one tooth missing. There are used ones on ebay, but most are for 9 or 10" lathes. It appears these 11" lathes shared parts with the 9 or 10" models but I am unsure.

If anyone has any information, or owns one of these lathes. I would like to get any information I can.
 
While I don’t know much about the 11” lathes I do know that I’d love to get my hands on a worn cross feed and compound screw to use as references! If you want a couple new feed screws for your machine let me know and I’d happily make a trade.
 
Miller Machine and Fabrication makes replacement screws and nuts for the SB 11". The 11"s were made for quite a few years but were always the "redhead stepchild" of the line-up.

Here is some info from an old SB catalog:

SB11_30.jpg


SB11_31.jpg


SB11_32.jpg


SB11_34.jpg


SB11_35.jpg


Hope this helps,

-Ron
 
So the South Bend 13" back gear doesn't fit? You never replied or anything.

Its a small world! Sorry I hadn't responded, I've spent the past 2 days cleaning and inspecting the machine. And no the 13" back gear would definitely not be correct. It is much smaller in length then 15". I haven't measured it yet, But the large gear is "spoked" unlike what I have seen for the heavy 10's which appear to have a solid gear.
 
Thank you Ron! Although it looks very similar to the countershaft drivens series R, It does not have a double wall apron, It has the type with the "star" wheel to engage cross feed, and does not have a quick change gearbox. The badge on the gear cover says the catalog number is 27-A which I so far have not had any luck finding.
 
While I don’t know much about the 11” lathes I do know that I’d love to get my hands on a worn cross feed and compound screw to use as references! If you want a couple new feed screws for your machine let me know and I’d happily make a trade.

I may have to take you up on that offer! As I get further along on fixing this thing up it may be something I have to do. the cross feed screw has some visible wear in the typical high-use areas.

And to everyone sorry for the individual responses, I now see the main "reply to thread" icon...

I will try and get some pictures posted in the next couple days.

I may also be in the market for a new spindle... Digging into the machine today and found about .005" bearing clearance, and unfortunately there is some scoring on the spindle and bearings. I'm more accustomed to automotive engines, and not sure if this condition would still be usable, It definitely wouldn't pass if it was an automotive crankshaft...

I was suprised to find no shims whatsoever under the spindle bearing caps, the caps just clamp the bearing halves together, and when the bolts are tightened,its all bronze on bronze, no part of the casting actually touches the cap itself.

This led me to think I could possibly carefully lap the mating surface of the bearing to tighten up the oil clearance. I know this would not be ideal, but this is just a hobby machine after all. I would love to hear some feedback about that thought..

Also there were no felt wipers in the spindle bearings, long gone. The channels they should be in are about .080" wide, was going to order some felt, although it seems to be an odd size, I have never done any work with felt wipers, any tips about making new felts would be appreciated.
 
The machine in question is an early Series O, not one of the later R/S/T machines in those pictures. Parts are going to be basically unobtanium, you'll have to make or adapt. Fortunately, SB used pretty standard DP on all gears, 14.5 PA everywhere. So, take some measurements of the OD and tooth count, and we can probably help you find something to modify.

allan
 
This led me to think I could possibly carefully lap the mating surface of the bearing to tighten up the oil clearance

Common to "trim caps" in old car Babbitt bearing days - and was likely invariably done with something far more aggressive than lapping - to include Bastard files and angle grinders - which will do in seconds what hours of lapping might do

The issue with this process - at least in lathes - is that the spindle is lower. Some care or at least understanding should be applied to realize "tilt" is not a great thing in a lathe spindle.....the idea being to aim at getting both ends of spindle the same amount lower
 
Yes I do understand that aspect of it. Thank you. I really don't have the capability to machine new bronze bearings, both machining and cost wise. This kind of seems like my only option.

The way I see it, the bearings are already worn so much, by lapping the mating surfaces, the spindle won't necessarily sit any lower then it is now in relation to the ways, it just won't be able to deflect away from the ways as much.

I'm going to go ahead and carefully lap the bronze shells to bring the clearance down to a more respectable level. This machine seems more primitive then even the O series with the laminated shims (correct me if wrong, I am new to these old machines), It appears these bronze shells were hand fit to work without any shims.
 
yes, pics of spindle and bearings in particular.
dont do anything yet, cant unring that bell once you remove material, though it may prove necessary....if so you dont lap, use a fine file and proper filing tecnique to take a little off the edge of the shells without touching the casting.....we are talking just a few stokes here,

you might find it works just fine by just using a heavier oil- .005" isnt THAT far out of the park...and once that spindle starts spinning and the oil film distributes it becomes nearly uncompresible.
these things can look awful,yet still perform surprisingly well.
 
many times, the wear on the right bearing is worse than on the left, so the spindle points down. The fix might be to pull the lower bearing shell from the headstock, and apply a tapered shim under it. Don't rush in.

allan
 
IMG_20191029_221822746 (1).jpgIMG_20191031_083351648.jpgIMG_20191031_083310399.jpgIMG_20191031_083344844.jpg

The red stuff on the bearing was just some dye so I could confirm the casting didn't touch itself when the bearing cap was torqued down, And the blue stuff in the bearing cap is just plasti-guage.

I didn't have an issue removing the lower bearings from the head stock, they pop out somewhat easily by hand.

You can also see the back gear here with the damage. It looks different then all other SB back gears I've been able to find. It seems like most SBs have one solid casting that both gears are on while this one is 3 seperate pieces? Also having two screw holes for oiling seemed out of the norm.

I hope the pics show the bearing damage well enough along with the scoring on the spindle.
 
many times, the wear on the right bearing is worse than on the left, so the spindle points down. The fix might be to pull the lower bearing shell from the headstock, and apply a tapered shim under it. Don't rush in.

allan

Definitely makes sense the chuck side would wear more, I checked oil clearance with a dial indicator and plasti-gauge on both, and the chuck side has about .0005" more wear. This actually suprised me because by looking at it I would have expected much more on the chuck side.

And sorry I'm quite a newb when it comes to this stuff. What do you mean by "tapered" shim? I have regular shim stock. But nothing tapered, I am unaware of such a thing.
 
yes, pics of spindle and bearings in particular.
dont do anything yet, cant unring that bell once you remove material, though it may prove necessary....if so you dont lap, use a fine file and proper filing tecnique to take a little off the edge of the shells without touching the casting.....we are talking just a few stokes here,

you might find it works just fine by just using a heavier oil- .005" isnt THAT far out of the park...and once that spindle starts spinning and the oil film distributes it becomes nearly uncompresible.
these things can look awful,yet still perform surprisingly well.

Could you elaborate a bit? I don't disagree but to me it seems like if I were to go ahead and remove some material, that lapping would be more accurate then using a file. I wouldn't have to worry about hitting the casting as I would simply remove the bearings from the caps/headstock, lap on surface plate.
 
Well after much thought I decided to lap the bearings to reduce the oil clearance on the spindle bearings.

I took my sweet time, and went through a bunch of plasti-gauge, and I was able to get the clearance down to .0015" on both bearings. I also replaced the felt wipers that sit in the grooves formed by the bronze bearings. It all worked out well, There is a slight bit more resistance when spinning the spindle by hand, But I ran the spindle at high speed for 5 minutes or so and there was no appreciable warming of the bearings, everything stayed cool.

After that was all done it was time to address the spindle register area and the backing plate. Looks like a previous owner threaded the backing plate on and accidentally got a chip stuck between the backing plate and the register area. boogered it up pretty good.

I took a very light facing cut on the register area to clean that up, then machined a spacer on my other lathe so I could mount the backing plate backwards on the spindle and to the same to that.

I then re-mounted the backing plate, and I am very happy with the results. I now have roughly half a thou or less runout on the outer edge of the backing plate. When I brought the machine home it was running over 0.004" out.

At this point I don't really know if it would be worth re-facing the backing plate, not sure If it would really be able to improve more then it is now.

Although I am going to have to clock and re-drill the backing plate bolt holes, the person who did this originally did a pretty terrible job, not only are the holes enlarged to compensate for not being spaced properly, they are not counterbored with a flat bottom, just with a regular drill, so the cap screws when tightened are pulling the chuck around. (register is not a tight fit)

I found some other gremlins with the machine as well. Hoping it wont become a problem, but the half nuts have been "repaired" in a very different manner than one would hope. It looks like they cut the threaded parts of the half nut off, then took a regular acme hex nut, cut that in half and brazed that to the cast parts. It looks like whoever did it was pretty darn good at brazing as the repair looks like it was done well. Although it looks like I am going to have to go and remove some material from those halves. The side closest to the bed of the lathe, the half nuts touch themselves before the half nut has full thread engagement.

Wondering if anyone else has seen a half nut repair done this way. Comments?

I can post some pictures of the repair if anyone would care to see it.
 
many different cross feed screws

Hi as Ron said the 11" is an odd ball. Many years ago I had a customer contact me about making him a screw and nut. He had a copy of the factory prints. He had contacted South Bend before Leblond had bought them out. They didn't support the 11" any more but they gave him a copy of the print so he could have one made. The print I have is from the late 30s So i made hime the screw and nut.

Since then I have made 4 screw and nut combinations. Only 2 being the same. The others varied in screw and nut designed. Some nuts are counter bored for location others have bosses. The screws varied as well for the handle and dial mounting.

If you decided to have a new screw and nut made. I would send to who ever is making it and have them copy it and fit the dials. Because I am am pretty sure both have been worn and they will need them for proper fit.
Brian




Well after much thought I decided to lap the bearings to reduce the oil clearance on the spindle bearings.

I took my sweet time, and went through a bunch of plasti-gauge, and I was able to get the clearance down to .0015" on both bearings. I also replaced the felt wipers that sit in the grooves formed by the bronze bearings. It all worked out well, There is a slight bit more resistance when spinning the spindle by hand, But I ran the spindle at high speed for 5 minutes or so and there was no appreciable warming of the bearings, everything stayed cool.

After that was all done it was time to address the spindle register area and the backing plate. Looks like a previous owner threaded the backing plate on and accidentally got a chip stuck between the backing plate and the register area. boogered it up pretty good.

I took a very light facing cut on the register area to clean that up, then machined a spacer on my other lathe so I could mount the backing plate backwards on the spindle and to the same to that.

I then re-mounted the backing plate, and I am very happy with the results. I now have roughly half a thou or less runout on the outer edge of the backing plate. When I brought the machine home it was running over 0.004" out.

At this point I don't really know if it would be worth re-facing the backing plate, not sure If it would really be able to improve more then it is now.

Although I am going to have to clock and re-drill the backing plate bolt holes, the person who did this originally did a pretty terrible job, not only are the holes enlarged to compensate for not being spaced properly, they are not counterbored with a flat bottom, just with a regular drill, so the cap screws when tightened are pulling the chuck around. (register is not a tight fit)

I found some other gremlins with the machine as well. Hoping it wont become a problem, but the half nuts have been "repaired" in a very different manner than one would hope. It looks like they cut the threaded parts of the half nut off, then took a regular acme hex nut, cut that in half and brazed that to the cast parts. It looks like whoever did it was pretty darn good at brazing as the repair looks like it was done well. Although it looks like I am going to have to go and remove some material from those halves. The side closest to the bed of the lathe, the half nuts touch themselves before the half nut has full thread engagement.

Wondering if anyone else has seen a half nut repair done this way. Comments?

I can post some pictures of the repair if anyone would care to see it.
 
I will probably want new screws and nuts made at some point, atleast a cross-slide screw as it has more wear than the compound. Currently I've been using the machine almost on a daily basis, and it is still very usable as is, not too difficult to work around the excessive backlash but it is a pain. I have a couple dozen prototype parts I need to make in the near future for a customer so I would like to keep it together for now.

I do have access to a couple other machines, and I may or may not try to make my own screws in the future. If I were to make the screws myself, what would you guys recommend for material? I have 1144 on hand, I assume this would make an acceptable part. Although I would like to hear what others have to say that have already made and used their own screws in the long term.
 








 
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