Motor drive pulley diameter for south bend 9" lathe

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DICK CARLSON

Plastic

Joined

Dec 11, 2017

• Feb 3, 2018

• #1

I am assembling a 1946 south bend model 9a. I have a 3/4 hp 1725 rpm motor with no pulley. I need to know what diameter i need to get the desired speed for the 10" driven pulley. Sure would appreciate any advice -- thanks

carlson

 

C

Christian James

Aluminum

Joined

Sep 26, 2016

• Feb 4, 2018

• #2

I reckon you may get a few different answers to your question. (May not be original pulley)
Anyway,the motor pulley on my 9" SB is ~2.43" OD, uses a B type belt and drives a 10" countershaft pulley.

Cheers
CJ

 

Yan Wo

Stainless

Joined

Jan 22, 2014

Location

Highland, Utah, USA

• Feb 4, 2018

• #3

The (assumed) original pulley on my 1948 9A is two speed: 2.090 and 3.410 inch OD. The large pulley diameters are 9 1/8 and 10 inches. The smaller pulley has V grooves and the larger is flat.

 

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Technical Ted

Cast Iron

Joined

Dec 31, 2017

• Feb 4, 2018

• #4

Don't know if this will help or not...

Ted

 

D

DICK CARLSON

Plastic

Joined

Dec 11, 2017

• Feb 4, 2018

• #5

Thanks to all. Think i will try a 2.5 inch.

Ted, your picture came out so small and i guess i am not smart enough to get it zoomed so i can read it clearly. Looks like good info though. What reference book/manual did you get this from?

Thanks so much for your help

 

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iwananew10K

Diamond

Joined

Sep 12, 2010

Location

moscow,ohio

• Feb 4, 2018

• #6

Without knowing the exact model you have, it's hard to say....

But to be on the safe side, 2" pulley, and use a 5L belt.

 

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Erich

Hot Rolled

Joined

Apr 4, 2017

Location

Poway, CA (from Location field)

• Feb 4, 2018

• #7

Right click on thumbprint.
Choose open in new tab.
Press the Ctrl button and roll the middle mouse wheel to zoom in or out.

 

T

Technical Ted

Cast Iron

Joined

Dec 31, 2017

• Feb 4, 2018

• #8

DICK CARLSON said:

Thanks to all. Think i will try a 2.5 inch.

Ted, your picture came out so small and i guess i am not smart enough to get it zoomed so i can read it clearly. Looks like good info though. What reference book/manual did you get this from?

Thanks so much for your help

Click to expand...

You can do what Erich suggests, which works great by the way, or I just left mouse click on them and they open right up full size.

Ted

 

D

DICK CARLSON

Plastic

Joined

Dec 11, 2017

• Feb 5, 2018

• #9

Worked great -- thank you so much. I do surely appreciate your help.

Dick

 

C

CWC(4)

Cast Iron

Joined

Jan 2, 2017

Location

North Central MA

• Feb 5, 2018

• #10

Dick,
Just recently got a similar 9A lathe (1947) back together after refurbishing.
I believe the motor & pulley arrangement on mine to be original. The smaller step on the motor pulley measures about 2.100 O.D. for the flange and 1.100 for the I.D. or arbor. The larger step measures about 3.400 O.D. by 2.400 I.D., this takes a 5/8" wide belt. The large countershaft step pulley measures about 9" and 10" I've attached a couple of pictures. Hope this helps.
CWC(4)

 

D

DICK CARLSON

Plastic

Joined

Dec 11, 2017

• Feb 5, 2018

• #11

THANK YOU, CWC. IT'S NICE TO SEE OTHER CONFIGURATIONS. MY COUNTERSHAFT PULLEY IS 10" (SINGLE ONLY) . I MOUNTED A 2"OD MOTOR PULLEY THIS MORNING AND AM USING A LINK BELT. SEEMS TO TRACK OK. THIS IS THE FIRST TIME I HAVE HAD THE LATHE RUNNING. SEEMS NICE AND SMOOTHE BUT THE COUNTERSHAFT BELT TO THE LATHE ( ALSO A LINK BELT) DRIFTS AND SOMETIMES COMES OFF,

BEING A NEWBE, I DON'T KNOW WHAT THE RPM's ARE OR WHAT THEY SHOULD BE. I FEEL THAT I AM MAKING HEADWAY -- BUT HAVE A LOT TO LEARN.

THANKS AGAIN FOR YOUR REPLY.

DICK

 

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iwananew10K

Diamond

Joined

Sep 12, 2010

Location

moscow,ohio

• Feb 5, 2018

• #12

Ditch the link belt....a 5L of the right length will run SO much better.

 

M

MGMarriam

Plastic

Joined

Apr 24, 2021

• Apr 28, 2021

• #13

This was the information I was looking for. I had Form 921F (Motor Pulleys) but had no idea which Style 2A pulley to use. Now if I can just find one.

 

C

chipss

Cast Iron

Joined

Jul 19, 2020

• Apr 29, 2021

• #14

let's see if this helps.

 

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NewtonSquare

Plastic

Joined

Aug 23, 2004

Location

Toronto, Ontario

• May 1, 2021

• #15

Don't know if this will help, I have a couple of 9 inchers and they all have 2 1/2" motor pulleys with both 9" and 10" pulleys on the counter shaft. Note the cone pulleys are different diameters too. The smaller ones came from school lathes.

 

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