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9" South Bend Lathe - need to identify parts and where to find them

spctravis

Plastic
Joined
Nov 14, 2021
IMG_20190209_165258608.jpg

I bought the above metal lathe. It needs some love. It has some parts that are worn out. I am trying to figure out what they are and where to get them. I know I need a cross feed nut. I can't figure out what the other parts are though or where to acquire them. Any feed back is appreciated!

I put yellow circles around the parts that need replaced. The threads are trashed. Repairs had been done but I don't know if I should look at getting it repaired again or if it's possible to get a new part.

IMG_20211114_164335476.jpg


This is my SN:
IMG_20190512_121412429.jpg
 
"New" parts for a 1940's lathe, LOL! Nuts for cross and compound can probably be sourced here, or ebay, take note, sometimes slop that appears to be the nut is actually slop in where the screw goes thru casting, investigate fully. Looking at the pics and parts you have circled, I'm not seeing why they are unserviceable, maybe we need better pics. You can probably source some used gears here, or on ebay. I suspect "new" gears will exceed value of the lathe. If this is a first lathe, the best advice might be to clean it up and use as-is to learn on, when you are ready move on to something nicer.

Edit: Do a google search for "How to run a lathe", its an old South Bend publication, it will help you with nomenclature.
 
Series "O" - and indeed from around a hundred years ago. Forget "finding" parts until you acquire yourself a duplicate donor machine

The "big tooth" gear is the rack pinion. The "little" tooth gear is the worm wheel for the power feeds - engaged by the left hand "knob" on face of apron

Here is the "O" apron assembled

Series O Apron.jpg

As can be seen, "O" South Bends did not feature double wall apron

I'd guess from the four step spindle cone pulley that it is at least a 13"

Here is a slightly later handy pub

http://vintagemachinery.org/pubs/1617/5795.pdf

have fun
 
Do you have any ability to cut gears, such as any kind of milling machine?

Your best bet here might be to attempt repairs to the parts in question. Not sure how bad the worm wheel is based on that photo, but it looks like
the gear mated to the pinion (pinion being the gear that engages the rack directly) might be missing teeth which could be an easy repair if not too many
are gone. The pinion looks pretty rough but was it working when you took it out?
 
Don't get too discouraged. Last time I looked there were something like 50 pages of South Bend parts on ebay. Even with a lathe that old you might get lucky.

Also, depending upon what is wrong with the gears they may be repairable. People often fix teeth by brazing.

Some parts like cross slide nuts and change gears are available on ebay from people who manufacture replacement parts for South Bend lathes.
 
Thanks all for the feedback. I don't have a way of making parts for this lathe. Just trying to figure the model of this lathe has been difficult. I will look on vintagemachinery org for 13" model O pre 1930s. I would like to make this machine work, but if it's too far gone. I can move on. I do love old tools so I would like to fix it if it's reasonable to do so.

I took some more photos and put a 1/8 bar for reference. The teeth on most things look like they been used for 100 years, and at someone wasn't always good with oil.
This is my split nut:
IMG_20211206_195342151.jpg

This is the cross feed nut. I tried to get a good view down. I think I can get a new one of these in bronze The acme thread is basically gone:

IMG_20211206_195719294.jpg
IMG_20211206_195746281.jpg

Worm Wheel (If I am not using the correct term please correct me), I tried to take a better photo showing how little is left of the teeth:
IMG_20211206_195513595.jpg

Pinion gear set, Pinion gear is worn but the bottom gear is in bad shape. I don't know if it's worth saving. I am open to advice:
IMG_20211206_195430047_HDR.jpg

As for it working. It ran, but I could move the cross feed about 1/16 inch back and forth just from the feed nut. Made testing everything else hard. There was so much play just from the one piece being so worn.
 
Actually the half nuts look pretty good. Leave those alone for now. The crossfeed screw and the crossfeed nut are probably both pretty well worn, and those should be your first task for the machine. You can get the existing crossfeed screw replaced on the handle and crossfeed gear by one of the services associated with members here. The nut may be a special but can be re-done without too much trouble.

The pinion that mates with the rack looks more or less OK, the larger gear would benefit from a repair. Just one example of a repair:

SF_gear01.jpg
 
Just one example of a repair:
SF_gear01.jpg

On Jim's example, the teeth are removed, holes drilled and tapped (or just drilled for press fit) and then pins threaded / pressed in and filed to shape.

An alternate method is to build up weld and file it down.

Luckily all your gears are steel, unlike some lathe that used zinc alloy.

Using a gear cutter would result in a better tooth profile, but these fixes can work.

Your best bet may be to look for a complete apron or cross slide. Don't use the cross slide, if you get a complete unit - just use the apron. The cross slide is hand-scraped to match the bed.

Steve
 
never seen that before. wish i had prior to searching the world for a few metric threading gears for my 52 9A.
 
Using a gear cutter would result in a better tooth profile, but these fixes can work.

Filing is sort of self reporting as to progress

If the gears are in their assy - the filed tooth will either go past its undamaged mate or not

When you get far enough along to RUN those assembled gears - the CLUNK will tell you you need to finesse the filling a bit:D
 
On Jim's example, the teeth are removed, holes drilled and tapped (or just drilled for press fit) and then pins threaded / pressed in and filed to shape.

An alternate method is to build up weld and file it down.

Luckily all your gears are steel, unlike some lathe that used zinc alloy.

Using a gear cutter would result in a better tooth profile, but these fixes can work.

Your best bet may be to look for a complete apron or cross slide. Don't use the cross slide, if you get a complete unit - just use the apron. The cross slide is hand-scraped to match the bed.

Steve

I can mig weld. I thought it had to be brazed. The pin method is interesting. I am thinking I personally might have a better time mig welding and filing then pin method.
 
I can mig weld. I thought it had to be brazed. The pin method is interesting. I am thinking I personally might have a better time mig welding and filing then pin method.

I'm pretty sure that the gears are made out of cast iron, so if you build up the broken teeth with weld, use a nickel rod or wire.
 
I see lots of wear, but no teeth are completely missing. If it were my lathe I'd put it back together and run it as is, until a parts machine eventually pops up on ebay. How is the bed wear?
 
Like others have said the compound & crossfeed screw nut's are available from members here . Look in the wiki's in the first handful of post's in this forum . There are also a few guys selling them on ebay . The gear shown in your first pic (brain fart is keeping me from telling you what gear it is ) is supposed to be a concave gear for lack of better term right now .SO from here that gear unless it's missing any teeth looks good from here , but YMMV .
animal
 








 
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