1938 9" South Bend Lathe - motor replacement question

[jfk92]

Hey all,

I finally have in my possession the Atlas mill I posted about previously (using which - I intend on making very - very miniature parts with! ) - and the subject lathe. With it I received a brand new motor - I now need to hook that up - can someone point me to:

- where I would get a pulley for it
- what kind of belt would I get for it

Asking b/c the drive wheel is a large diameter flat wheel - the belt connecting the drive system to the lathe is a flat, leather type belt - thanks for advise- I'm 100% noob - with I think two very cool tools and no clue! I have the original documentation booklets for the lathe - very cool. And I have literally plastic bins - bins - of tooling for both the lathe AND the Atlas mill (which is a model MFB) - both very well maintained.

Thank you.

[MinnesotaDave]

Southbend was purchased some years back.

Parts likely can be found here: https://www.southbendlathe.com/older-machines/parts

Otherwise, ebay often has old parts for just about everything.

[M J D]

You probably need a V belt pulley on the motor and on the driven shaft. I'm guessing it was originally driven off of a line shaft, hence the flat belt drive. You would still use a flat belt on the step pulleys. I assume this is driven from the top and not from underneath. Picture would help

[jpump5]

Does it look anything like this?

[jfk92]

Yes similar but the large drive pulley that would connect to the motor pulley spindle is completely flat - there is no groove for the belt to ride in. Also the motor mounts in a small benchtop frame and sits directly behind the lathe - at least this was how it was run previously. I'm thinking I just need to buy some pulleys and belts and have a go at it...

[M J D]

Yes similar but the large drive pulley that would connect to the motor pulley spindle is completely flat - there is no groove for the belt to ride in. Also the motor mounts in a small benchtop frame and sits directly behind the lathe - at least this was how it was run previously. I'm thinking I just need to buy some pulleys and belts and have a go at it...

Yeah, remove that flat belt drive pulley and go with a V belt drive.

[idacal]

rather than changing pulleys on something like that I have run these https://www.gates.com/us/en/power-tr...00-000001.html
they are easy to find on eBay. my old lathe I had 2 v belts running on the flat pulley and a normal double belt v pulley on the motor. that was on a 16" lodge and shipley. It didn't slip until I was in the .150 per pass cutting range. on the motor you have you only have to transfer a horsepower or 2

[smithdoor]

I found the south bend 9 works great with 3/4hp sf 1.15
If you more data just let know .
This lathe I have for my shop today.

Dave

Hey all,

I finally have in my possession the Atlas mill I posted about previously (using which - I intend on making very - very miniature parts with! ) - and the subject lathe. With it I received a brand new motor - I now need to hook that up - can someone point me to:

- where I would get a pulley for it
- what kind of belt would I get for it

Asking b/c the drive wheel is a large diameter flat wheel - the belt connecting the drive system to the lathe is a flat, leather type belt - thanks for advise- I'm 100% noob - with I think two very cool tools and no clue! I have the original documentation booklets for the lathe - very cool. And I have literally plastic bins - bins - of tooling for both the lathe AND the Atlas mill (which is a model MFB) - both very well maintained.

Thank you.

[jpump5]

It hard to see in the pic that I posted, but that large pulley
has no groove for a v-belt. Pulley is driven only by inside of
belt. Looks like it’s meant to be used that way. I’ve never
had v-belt slip. I have stalled motor and had flat belt slip.

[smithdoor]

South Bend use glat belt so there no mark from gears.

Dave

It hard to see in the pic that I posted, but that large pulley
has no groove for a v-belt. Pulley is driven only by inside of
belt. Looks like it’s meant to be used that way. I’ve never
had v-belt slip. I have stalled motor and had flat belt slip.

[jfk92]

jpump5, idical, Dave - thanks so much for your input here - I think I know what to do - here are pictures of the lathe - going to ask my neighbor (who sold me - was his Dad's who recently passed) if he has the belt that seems to be in both pics off to the left. Have a brand new motor - but it's only a 1/4 hp - not sure why he bought a replacement as 1/4 hp when the original was 1/2 hp - I "think". I have the original in hand - need to search around for the pulley too - I can't imagine that was junked - the guy was meticulous with his equipment.

[smithdoor]

I found the 3/4 hp works better.
IMy first SB 9 came with 1/4 after about 10 years change to 1/2 hp .
The flat needs to be leather try rubber belts great slippage.
I just leather store and pickup a 1" and hang ithe belt shop with 20 pound weight for few months to stretch out belt.

I sold the first lathe after buying a large lathe and later found the 9" was great for small parts.
The does job that is harder to do on larger size.

Dave

jpump5, idical, Dave - thanks so much for your input here - I think I know what to do - here are pictures of the lathe - going to ask my neighbor (who sold me - was his Dad's who recently passed) if he has the belt that seems to be in both pics off to the left. Have a brand new motor - but it's only a 1/4 hp - not sure why he bought a replacement as 1/4 hp when the original was 1/2 hp - I "think". I have the original in hand - need to search around for the pulley too - I can't imagine that was junked - the guy was meticulous with his equipment.

[jmm03]

JFK, if you change the motor I would recommend you find a TEFC (totally enclosed fan cooled) motor that will keep chips and oil from becoming a problem as could happen with an open dripproof type. Also, if you did not already find this site, https://www.practicalmachinist.com/v...h-bend-lathes/ it will be a valuable resource. Jim

[12345678910]

jpump5, idical, Dave - thanks so much for your input here - I think I know what to do - here are pictures of the lathe - going to ask my neighbor (who sold me - was his Dad's who recently passed) if he has the belt that seems to be in both pics off to the left. Have a brand new motor - but it's only a 1/4 hp - not sure why he bought a replacement as 1/4 hp when the original was 1/2 hp - I "think". I have the original in hand - need to search around for the pulley too - I can't imagine that was junked - the guy was meticulous with his equipment.

If you want a new flat belt pulley, Al Bino (no joke) sells those laced flat belts.
https://albinoindustrialbelting.com/

Changing that from Flat to V is major surgery and not needed.


Manuals here free pdf's
http://vintagemachinery.org/mfgindex...?id=1617&tab=3

Join the email google groups, or Practical Machinist forum Southbend section ( don't post in any other section or you will be kicked out)
There are a couple of guys, -Ted (SBLatheman), and Steve Wells that are archives for anything.

They also sell on Ebay
Oils, the rebuild manual, parts,


The small pulley for the motor to the "horizontal drive unit" is available on ebay.
It's a V belt
If you read the manuals, OEM size is listed there. for the belt and the pulley


1/2 to 3/4 HP is all you need.

If you have the $, I'd go 1 hp and three phase with a variable drive VFD to get you variable speed.
Sometimes slowing down to a crawl is helpful.
ie, threading to a shoulder.


It's a Model C or some other Workshop model I don't' recognize.

[smithdoor]

Model A has quick change gear box.
Model B just a stack of gears with feed.
Model C uses half nut for feed.

The best belt is made from Buffalo hide.
I goto Tandy Leather and use cement for shoes.

Dave

If you want a new flat belt pulley, Al Bino (no joke) sells those laced flat belts.
https://albinoindustrialbelting.com/

Changing that from Flat to V is major surgery and not needed.


Manuals here free pdf's
http://vintagemachinery.org/mfgindex...?id=1617&tab=3

Join the email google groups, or Practical Machinist forum Southbend section ( don't post in any other section or you will be kicked out)
There are a couple of guys, -Ted (SBLatheman), and Steve Wells that are archives for anything.

They also sell on Ebay
Oils, the rebuild manual, parts,


The small pulley for the motor to the "horizontal drive unit" is available on ebay.
It's a V belt
If you read the manuals, OEM size is listed there. for the belt and the pulley


1/2 to 3/4 HP is all you need.

If you have the $, I'd go 1 hp and three phase with a variable drive VFD to get you variable speed.
Sometimes slowing down to a crawl is helpful.
ie, threading to a shoulder.


It's a Model C or some other Workshop model I don't' recognize.