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9" 1925 South Bend Lathe
开云体育Yer lookin for the pulley size for the " flat pulley on the counter shaft " or the 2 slot pulley on the motor ? I thought the 2 slot motor pulley was in the files section . animal On 1/25/25 9:22 AM, Joe Guidry via
groups.io wrote:
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开云体育Are you talking about the belt from the motor to the countershaft or the belt from the countershaft to the spindle? If the countershaft assembly is mounted to the bench separately
from the lathe, then the flat belt size would depend on where the
countershaft is mounted. I'm guessing here since I haven't seen a 1925 9", but based on many of the countershaft assemblies that SB used, the motor mounts directly to the countershaft? In that case the v-belt length will be fixed. If you have pulleys with two grooves on the motor and two flats on the countershaft, I believe the v-belt should work in both locations without changing the length or using a tensioner. The image in my head is based off of my 10K with horizontal drive. In any case, if you get a seamstress tape measure (tailor's tape)
you can directly measure the flat belt size from the countershaft
to the spindle. For the v-belt from the motor to the countershaft, I would suggest using a piece of 1/2" diameter rope wrapped around the pulleys, mark the rope then lay it out flat for a measurement. OR. if you have an old belt from something else that is longer, cut the belt and then wrap it around the pulleys, mark and measure. I am pretty confident that the v-belt will be an "A" series which means that it is 1/2" wide on the top of the belt. It should fit entirely into the groove of the motor pulley. Ideally it does not stick up above the groove nor should it bottom out in the bottom of the Vee. This assures that the belt sides make complete contact with the pulley. The motors were most likely only 1/4 to 1/2 HP on those early lathes, but I have no direct knowledge of that. The oldest documentation I have is a catalog from 1966. There
were lots of different motor options in that catalog. Have you looked on the vintagemachinery.org web site? If you would like, I can take some screen shots of that catalog and email them directly to you, in case that might help. Would that be an "O" series lathe in 1925? Stuart On 1/25/25 11:22, Joe Guidry via
groups.io wrote:
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Ok, so your motor pulley is flat, (slight ovel) to it and they are 2.100 thousand and 3.400 thousand, Joe? On Sun, 26 Jan, 2025 at 12:05 PM, John Walker via groups.io <johnwa27@...> wrote: ? My measurements
Motor pulley OD of flanges
Small sheave 2.1”
Large sheave 3.4”
counter shaft
large pulley 10”
small pulley approximately 9”
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John
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开云体育Looks like a standard countershaft pulley .? I've had & used my 9A for many , many years & have never moved the belt to the smaller pulley on the motor . animal On 1/28/25 7:54 AM, John Walker via
groups.io wrote:
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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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I am talking about the Pulley that is on the motor shaft that belt would turn a single flat drive pulley that on the opposite end is the triple drive (counter shaft" that goes to the three shives on the lathe spindle, yes if you have anything that can help, jguidy@...? |
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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. |
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On Wed, Jan 29, 2025 at 07:04 AM, Joe Guidry wrote:
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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. |