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  1. SouthBendLathe9
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9" 1925 South Bend Lathe

 

Hi John,
That picture shows what apparently used to be a line shaft countershaft unit. You can see the brackets for the fast/loose pulley shifter.
If you look on eg this page, you can see an example of what I mean about the vee belt onto flat pulley setup;
Both my old lathes have original setups which use this arrangement. One from 1929, the other from 1940-ish.
Of course it's possible to use a flat belt from the motor, but it's not as efficient, requires higher tension, and is no more 'correct' or 'original' than the vee belt setup. Personally I wouldn't recommend changing to a flat belt in this application.
 

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All the lathes I've seen go from V-belt pulley on motor to Non V as the Driven pulley on the countershaft .

On 1/29/25 4:56 AM, James Thornton via groups.io wrote:

It was very normal to have a vee belt pulley on the motor, driving a vee belt, that then ran on a flat pulley on the countershaft. This was true even on original lathes from the 1920's.
They work much more efficiently, especially around a small pulley, and over a short span.
Why would you want to go to a flat belt? You would have to tension it like mad to stop it slipping, probably distort the countershaft which won't be designed fornthe load.
 

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That's the first one I've seen with a flatbelt from motor to counter shaft . Looks like the countershaft is out on alignment in that second pic . Is that a 9B or one of I think a " O " model ? That apron has one m ore knob the I've seen on other 9"s . Yea I just looked at the first pic closer & that one has the 2 bolt bearing caps . it also looks like it may have a brake internal to the countershaft pulley ?

thanks for posting

animal


On 1/29/25 8:42 AM, John Walker via groups.io wrote:

There are some pictures of a 1925 SB on vintage machinery. ?It uses a flat belt from the motor. ?It could easily have been driven by a line shaft which might explain the flat belt.?
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John
 

Thanks John, I will look thought the and see if I can see what the Motor pulley looks like and of course save to file, thanks, Joe



On Wed, 29 Jan, 2025 at 11:13 AM, John Walker via groups.io <johnwa27@...> wrote:
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Joe
I found this catalog at .
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Do any of these look like your lathe?
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John
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Thanks John, that looks very similar to mine, I have the change model and all the gears, yes at that date (1925) it probably was a line shaft machine, I have a Sidney that was just changed over it was a line shaft (1890-1910)



On Wed, 29 Jan, 2025 at 10:42 AM, John Walker via groups.io <johnwa27@...> wrote:
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There are some pictures of a 1925 SB on vintage machinery. ?It uses a flat belt from the motor. ?It could easily have been driven by a line shaft which might explain the flat belt.?
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John
 

ok, wrong place, yes my large pulley on the counter shaft that goes down to the motor is a single pulley, would have to use back gear if I want to thread slow, thanks, Joe



On Wed, 29 Jan, 2025 at 8:05 AM, Rick via groups.io <vwrick@...> wrote:
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On Wed, Jan 29, 2025 at 07:04 AM, Joe Guidry wrote:
Rick, guess I did not explain what I was asking correctly, let me explain what I have and the question that I organelle asked, the one that I have has a "V" belt pulley on the motor, the belt goes up to a larger pulley that is a flat belt drive and has the three strep counter shaft? pullies, all flat drive, I was just trying to find out if anyone would have known the size of the flat belt pulley on the motor that all., thanks, Joe
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Joe, that wasn't a reply to you. It was a response to Animal, the post I quoted. He said he never uses the slow speed pulley. I use that every time I thread.?
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That said, the 2 step flat pulley on my 1947 SB9A is 10" on large side, 9" on small side.
 


James, the machine came with flat belts, I will say again that the large drive wheel that is on the counter shaft that lines up or goes on the Motor side pulley is a flat belt, it would stand to reason that there would be a flat drive on the motor, all I was trying to find out if anyone had one or knowledge of the size of the flat drive that goes on the motor, guess I will make several to see which one would be the best, thanks, Joe

On Wed, 29 Jan, 2025 at 6:56 AM, James Thornton via groups.io <exupjim@...> wrote:
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It was very normal to have a vee belt pulley on the motor, driving a vee belt, that then ran on a flat pulley on the countershaft This was true even on original lathes from the 1920's.
They work much more efficiently, especially around a small pulley, and over a short span.
Why would you want to go to a flat belt? You would have to tension it like mad to stop it slipping, probably distort the countershaft which won't be designed fornthe load.
 

Hi Joe,
Ok, maybe I misunderstood a bit. I thought you were proposing to move from a vee belt arrangement to a flat belt for some reason.
Although it would seem natural that you would run a flat belt over a flat pulley, this often isn't the case. Maybe because most countershafts of the time were originally designed for overhead lineshafting, they retained the flat pulley but this was paired with a vee belt when the setup was adapted for an electric motor. The motor has a vee pulley, but the flat pulley on the countershaft remains as is.
Here is my Hansen lathe setup. The motor isn't original, and I have since sorted the loose wires, but the vee belt running over a flat pulley is original:
It works really well with no slip.
 

Joe
There is a 1934 edition of “How To Run a Lathe” on the internet archive.
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It lists the countershaft speed as 255 rpm for a 9” lathe.
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John

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