# Another South Bend 9 Newbie - Slipping flat belt



## phrodo (Jul 27, 2013)

Hi All,
Although not a newbie to lathe work I am still learning the ins and outs of my SB 9X36 I picked up a few years ago. One thing I am having trouble with is the flat belt from the countershaft to the spindle. Under medium to heavy loads it tends to slip quite a bit. The previous owner had fitted an automotive timing belt (flat side in). Is there a better belt I could be using? Or do I just need to apply some good belt dressing.


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## stevecmo (Jul 27, 2013)

*Re: South Bend 9... newbie... help!*



phrodo said:


> Hi All,
> Although not a newbie to lathe work I am still learning the ins and outs of my SB 9X36 I picked up a few years ago. One thing I am having trouble with is the flat belt from the countershaft to the spindle. Under medium to heavy loads it tends to slip quite a bit. The previous owner had fitted an automotive timing belt (flat side in). Is there a better belt I could be using? Or do I just need to apply some good belt dressing.




To address your belt question, all installations of automotive serpentine belts that I've seen (including my own) use the ribbed side of the belt against the pulleys.  I believe you will get better grip that way.  Having said that, your issue may just be the tension of the belt.  There should be a means of adjustment somewhere.

Hope that helps.

Steve


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## woodtickgreg (Jul 28, 2013)

I use an automotive serp belt on my heavy ten, it is just stitched together and works well. I do not tension it so much that it puts stress on the stitching, it is rib side down or to the pulley's. These belts are very grippy and do not need to be super tight. In my experiments with the belt and a heavy cut, it will slow or stall the 3/4 hp motor before the belt slips. Now I just run light tension and take light cuts and enjoy the smooth quiet action of the belt and lathe running.


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## Rick Leslie (Jul 28, 2013)

I went through a few flat belts before going to a 'link' type belt. These belts are universal and can be made any length. They separate at each individual link and are virtually indestructible. I run mine inverted with the flat side down. It will still slip if I really load the machine (.100" + cuts) but I have yet to break the belt or a tool. The best part is you don't have to disassemble the spindle to install or change belts like with a one piece auto belt.

http://www.ebay.com/itm/ACCU-Link-V...148?pt=LH_DefaultDomain_0&hash=item27b7891224


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## ScrapMetal (Jul 28, 2013)

Is it a benchtop or under-drive model?  I know on a benchtop that there should be a turnbuckle you can use to increase tension on the belt.  I am not familiar with the underdrives but I'm sure there is also a way to do it.

If it's a problem with the belt itself, many of the guys here do well with serpentine or automotive belts.  I prefer to keep it "old school", sort of anyway.  I went with a belt from Al Bino Machining and Custom Flat Belts. 

I went with his "Ploy nitrile laced belt" and have been very happy with it.

-Ron


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## Bailey (Aug 6, 2013)

Rick Leslie said:


> I went through a few flat belts before going to a 'link' type belt. These belts are universal and can be made any length. They separate at each individual link and are virtually indestructible. I run mine inverted with the flat side down. It will still slip if I really load the machine (.100" + cuts) but I have yet to break the belt or a tool. The best part is you don't have to disassemble the spindle to install or change belts like with a one piece auto belt.
> 
> http://www.ebay.com/itm/ACCU-Link-V...148?pt=LH_DefaultDomain_0&hash=item27b7891224



Rick,
I use the accu link v -belt for my small Atlas 618 and it works fine. 
I will need a flat belt for the sb9 I am getting, it will not have a flat belt provided, normally 1 inch wide ( I've read)
So what you do is just flip the belt over (invert) where the v groove is facing upward?
What is the width or the belt you use? Are there any issues with the belt tracking off center when under tension on the flat drive pulleys?
No doubt this would depend on the condition and alignment to the pulleys.
Sounds like a good idea to me thanks for the information. 

Regards


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## Retired1997 (Aug 20, 2013)

Can you loosen the serpentine belt and turn it over so that the ribs are facing down, that is against the pulleys?  If so, I would try that and see if this stops the belt from slipping.  Of course, I may be way off track too.:nuts:


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## Bill C. (Aug 20, 2013)

phrodo said:


> Hi All,
> Although not a newbie to lathe work I am still learning the ins and outs of my SB 9X36 I picked up a few years ago. One thing I am having trouble with is the flat belt from the countershaft to the spindle. Under medium to heavy loads it tends to slip quite a bit. The previous owner had fitted an automotive timing belt (flat side in). Is there a better belt I could be using? Or do I just need to apply some good belt dressing.



Might try some belt dressing if adjusting the tension doesn't help.


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## george wilson (Aug 20, 2013)

Leather never seems to get done stretching.. I use "Belt Traction" spray can on my V belts when they start slipping. I'd suggest using one of the non leather belts mentioned above.


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## McGuyvers shop (Sep 7, 2013)

I bought one of the standard belts from ebay and under some heavy loads I can hear it and detect it slipping some, but this has always been my gauge to slow down a little or lighten the cut, otherwise I may break something expensive.


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## george wilson (Sep 8, 2013)

I use "Beltraction" aerosol. Not sure of the spelling. Could be Belt Traction. If it is used on V belts(yours isn't) make sure you get it equally on both sides of the belt. I do this by spraying it into the revolving groove of the pulley,and let it distribute it itself. Powdered rosin is good ,to. Get some violin rosin and finely powder it. sprinkle it on the belt on the bottom(inside side)  of the belt as it exits the pulley. You might try dissolving it in some turpentine and brushing it on. It,or belt traction will take some time to dry. Then,it will grip like mad. Rosin can be messy unless you dissolve it in some media so it will stay on surfaces. Turpentine should work,but so much sold is not the real stuff. The can needs to say "From the living pine",or it is crap distilled from ground up stumps and is not the same. As a last resort,get a little bottle of artist's turpentine for a few bucks. It will be real. Best thing is to find a commercial non slip substance like Beltraction. Google it.

P.S.: I Googled it. It is BELTRACTION.Must be sold on Amazon.or some such place. A can will last forever,mine has. Just not used that often.

Go to an automotive store. See what they have for slipping belts. This is likely your best bet. Bear in mind: leather belts NEVER seem to get done stretching. They always get loose. Probably best to replace with a serpentine belt as others often have.


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