9 inch South bend lathe

[Garyt]

I have an old model C 9 inch south bend lathe, the main issue I have is the flat belt drive. There is more slipping of the belt than I like difficult to make anything but light cuts. The belt is some sort of plastic, quite hard.
I have scrubbed the belt with a brass brush and different liquids (soap and water to solvent) no real improvement in traction. Any ideas what I can do to improve friction of the drive?
Gary

 

[terry_g]

I suspect you need to replace the belt. I had a 10K SouthBend that came without a belt.
I bought a belt that was made of plastic but had a rubber like coating on both sides and
once one side wore out you could twist inside out and use the other side. It also had a pin
you took out to thread it through the machine. I have seen people use serpentine automotive
belts on flat pulleys but you have to take to spindle out to install them.

 

[140mower]

The best I can suggest is to measure the length needed and put an automotive serpentine belt on it......

 

[Garyt]

The best I can suggest is to measure the length needed and put an automotive serpentine belt on it......

I have read that but it is a big deal the head would have to come apart

 

[Garyt]

I suspect you need to replace the belt. I had a 10K SouthBend that came without a belt.
I bought a belt that was made of plastic but had a rubber like coating on both sides and
once one side wore out you could twist inside out and use the other side. It also had a pin
you took out to thread it through the machine. I have seen people use serpentine automotive
belts on flat pulleys but you have to take to spindle out to install them.

We're did you source the belt?

 

[terry_g]

It came from a supplier in Vancouver BC over 25 years ago. I don't remember who
but it was made in Vancouver because the turn around time was very fast.

 

[140mower]

I have read that but it is a big deal the head would have to come apart

Pulling the spindle isn't that big of a deal, but you can also cut the belt and skyve the ends and glue back together, or sew the two ends back together with fishing line or similar. Several write ups should rise to the top with a Google search.
This is not mine, but definitely takes the serpentine belt to another level. I think I am going to try and groove a set of pulleys in this manner to see the difference....

 

[Former Member]

Use a grooved belt flat side in.

 

[140mower]

Use a grooved belt flat side in.

Why? I'm using one one my 13" South Bend, ribs on the pulley. It tracks beautifully and I can pull the 2hp motor down several rpm on a "test" cut, and with minimum belt tension, no belt slip.
I've heard it said before to run them inside out, just can't figure what the benefit might be.

 

[Former Member]

Why? I'm using one one my 13" South Bend, ribs on the pulley. It tracks beautifully and I can pull the 2hp motor down several rpm on a "test" cut, and with minimum belt tension, no belt slip.
I've heard it said before to run them inside out, just can't figure what the benefit might be.

Sorry mis understood thought it was slipping and didn't realize it was a grooved pulley.

 

[140mower]

Sorry mis understood thought it was slipping and didn't realize it was a grooved pulley.

That was just a picture I found somewhere and saved it to my phone, as it was in my opinion the slickest fix to the problem. My 10" South Bend is running a new belt that I picked up with a bunch of other parts, and it has been horrible since the beginning. When the 13" needed a belt I went with the serpentine belt that I knew I should have used on the 10". I have found that the ribbed side is extremely grippy, which is why I asked about the turning them inside out...

 

[Johnwa]

I agree with @140mower , it’s not that difficult to pull the spindle. The multi grooved belts can be found at auto part stores.

 

[DPittman]

There is a spray on belt dressing that makes belts less slippery and more grippy. I remember my dad using it on combine belts and I've know I have recently seen that it is still available.

 

[jcdammeyer]

About 10 years ago I pulled off the canvas/leather belt tied with a link fitting. On a SouthBend Heavy 10L the casting is in the way and so the drive belt has to be separated and threaded through the casting slot.

The old belt was in pretty sad shape. The replacement grooved belt is stitched together with MIG wire. The stitching is now starting to fail as the wire work hardens.

 

[Garyt]

OK it looks like a nice serpentine grooved belt is in my future.
Thanks everyone.
Gary

 

[historicalarms]

There is a spray on belt dressing that makes belts less slippery and more grippy. I remember my dad using it on combine belts and I've know I have recently seen that it is still available.

Pine tar, the same stuff ball player smear their bats with. We always had a jar of the stuff on every combine and spares in the shop. Stinks but sure does work on a slightly slipping belt that has a spring tensioner instead of a solid turn buckle.

There are also belt spicer tools available at most any farm supply store....use alligator teeth belt joining material, will "fix any width of belt, just use # of teeth for full width repair...crimp the teeth and cut a joining wire to correct length, will crimp any size alligator teeth you need.

 

[phaxtris]

I had a serp belt on my 9", stock cone pulleys, with the groves in, I didn't pull the headstock, just cut and glued the belt back together, worked good

If you hit the wrecker, the serp belt from the 2000+ silverado's are nice and long, and the right width, lots of room to cut and splice the belt to your desired length