Leather vs synthetic flat belts

[Just a Sparky]

Looking to order a new flat belt for my 13" South Bend. The one I've got in it now is a bit long and I've run out of adjustment to take up the slack.

Before I re-order from the same supplier as before, I'd like to learn a little more about the different material options available out there. Right now I'm running a three layered composite Nycor belt. The fact that it doesn't stretch and I will never have to chase it is nice, but it's hard, textured surface is not very grippy on a smooth, polished flat belt pulley. I find that it takes considerable tension to prevent the belt from slipping when taking a reasonable 50+ thou cut in 6061. Yes, it's only a 1 horsepower machine, but I know the motor's got a little more grunt in it than that. Big heavy Century machine tool motor with a 1.25 service factor.

Are leather belts any tackier than the synthetics? Are there grippier options out there to choose from?

Thanks.

 

[sfriedberg]

Heh. I don't know if it works on synthetics, but try "belt dressing". Failing that, lightly scuff the belt surface and spread some Coca-Cola over it (thin film) and let it dry. That's a trick used by dance companies to get some grip on slick surfaces.

 

[JST]

Leather, hair side in, on a polished pulley pulls like crazy. Absolute crap on a rough pulley though.

Plastic slips on anything that is not rough.

Some softer rubber compositions with a shiny surface will grip well on polished pulleys.

 

[dundeeshopnut]

Rubber baler belting doesn't stretch and bites real well! In fact if it does slip you WILL hear the "laying rubber" chorus.

 

[michiganbuck]

Definitely leather.
That way they will not be able to outlaw cows because of flatulence

Likely leather will last a very long time and to me, it seems to grip better than some synthetics.

 

[M.B. Naegle]

Each has pros and cons. A stretched belt just needs to be shortened to the right length. If either belt is cracked and rotten, it's time to go. Synthetics are "maintenance free", in that you don't have to mess with them for awhile, until they break down and then you have to replace them. Leather requires more frequent attention (treating with conditioning oil and/or belt dressing), but will last and last and last if you take care of it.

 

[Darren McCarley]

I may end up regretting this but..... I chose synthetic for my Wade rebuild. Granted, I did so knowing it was never going to be a production machine. Also, I'm JUST now testing it and, if needed, will turn a new drive pulley. Also, I have a custom belt tensioner. e.g. Ford serpentine belt tensioner. I went with these folks. https://albinoindustrialbelting.com/
Decent write ups, quick shipping, and accurate length. Gluing was simple and is working well so far....
Just my opinion.

 

[metalmagpie]

Before you buy new, trim your belt an inch or two shorter. Then punch and lace it. Then tighten it way up. Nothing to lose.

 

[Jim Christie]

One method of lacing a belt is shown here .

How to Run a Lathe (1934) : South Bend Lathe Works : Free Download, Borrow, and Streaming : Internet Archive

How to run a geared screw cutting lathe. No Copyright renewal found in Stanford or LOC online databases. Book provided by Bay Books & Prints of Bigfork,...

archive.org

Other methods of using alligator clips and scarfed and glued joints have been covered on the forum too .
If you don't have enough length to allow for a scarfed joint the lacing shown in the link or the alligator clips might be workable options .
Jim

 

[Darren McCarley]

WHICH ... of the synthetics that source offers, did you choose?

https://albinoindustrialbelting.com/

Sorry thermite, I didn't read your post properly.... I went with.... (Will update in a moment)

The NyCor

Ordered the 1.25" x custom length from this page
I liked them because it seems they prefer a phone call. I will say this, don't let the glue sit for more than a couple of weeks w/o using it. As advised on their web page, and documentation, the glue will set up in the bottle. Industrial contact cement + their nylon glue works well. So far.

 

[Just a Sparky]

That's the exact belt material I'm having trouble with, from the exact same supplier. Al's response when I asked him if he has any alternative synthetics available that might work better for the polished, oily pulleys present in a South Bend was more or less that I could try another option but that none of the synthetics he offers can be expected to perform well under those conditions.

Considering the pulleys in the average South Bend are burnished nice and shiny, and the fact that the only time the bronze bearings in these lathes won't leak oil all over them is when said bearings run dry... that just ain't gonna fly.

What I'm gathering here is; textured belt for a textured pulley, smooth belt for a smooth pulley. So, leather or rubber it is then.

Just have to debate whether I want another glued belt or if I should switch to a clipper belt. Just a matter of how much the constant 'ticking' is or is not going to annoy me. I appreciate a quiet, well-tuned machine, but being able to remove a leather belt in order to condition and maintain it might be useful.

 

[MrStretch]

The ticking of a clipper belt has never bothered me and It's nice to have the ability to disconnect the belt. I would go with a leather clipper.
I've been lucky to have been able to reuse the leather belts on my Starks, but needed a replacement for my old flat belt High Speed Hammer drilling machine. Ended up using a leather belt from a thrift store that I stitched into a loop. I like it because it slips before any real trouble occurs.

 

[DanASM]

I have screw machines with flat leather belting. I have recently been looking at replacing some of them and came across the same info you have been seeing.

I can tell you that my smaller machines that spin up to 7k rpm have smaller narrower belts with nylon fibers in the middle. They are for higher speeds with less torque. The bigger machines use a thicker, wider flat leather belt with no composite filler. They tend to grip better and have more surface area to grip.

I found the belts at Mcmaster for sale in all types and thickness, and widths.

A 1 HP machine, I would go with 1.5-2.0" wide and around 1/4" thick.

 

[JST]

That's the exact belt material I'm having trouble with, from the exact same supplier. Al's response when I asked him if he has any alternative synthetics available that might work better for the polished, oily pulleys present in a South Bend was more or less that I could try another option but that none of the synthetics he offers can be expected to perform well under those conditions.

Considering the pulleys in the average South Bend are burnished nice and shiny, and the fact that the only time the bronze bearings in these lathes won't leak oil all over them is when said bearings run dry... that just ain't gonna fly.

What I'm gathering here is; textured belt for a textured pulley, smooth belt for a smooth pulley. So, leather or rubber it is then.

Just have to debate whether I want another glued belt or if I should switch to a clipper belt. Just a matter of how much the constant 'ticking' is or is not going to annoy me. I appreciate a quiet, well-tuned machine, but being able to remove a leather belt in order to condition and maintain it might be useful.

"polished" is ok.... "oily", not so much. No belt works very well when oily, except toothed timing belts. For this, oily means lube oil, because obviously belt dressing can seem oily, but when applied correctly on leather is ok.

A composition belt with a shiny and "grippy-feeling" surface, or a good leather belt hair-side in, should work best on polished pulleys.

Some say polished pulleys cannot work, but leather polishes them and works very well

 

[animal12]

I've been running a synthetic belt on my South Bend 9A for years now . California Industrial Rubber is the guy that made mine . Works great . I'm sure that they ship also .

California Industrial Rubber | Agricultural, Industrial

Trust California Industrial Rubber to meet all of your rubber and plastic needs. Call us for more information.

www.cir.net

animal

 

[Peter from Holland]

I had a synthetic belt covered on both sides with split leather In my case where it was a major PITA to disassemble the shaft it came witht the ends shaped and glue applied I had to align it in a heating element and keep it on a certain temperature for some minutes
Worked really well

Peter

 

[Just a Sparky]

Trying a leather belt. So far it's slip city. The smooth hair side can't even get enough of a bite to crack the spindle bearings loose. Throws itself off almost immediately unless the chuck is given a starting push. Will take two inches off and try again but have a feeling that won't be enough.

How to condition the leather for better grip? Am told linseed oil works well. Can anyone corroborate? Boiled vs raw? Warned away from dressing by the old timers I buddy up with who spent their careers running 130+ year old Niles planers, 36" G&Es, big Cincinnati mills, etc. Only get to see them once in a while so I figured I'd ask around here in the mean time.

 

[JST]

Trying a leather belt. So far it's slip city. The smooth hair side can't even get enough of a bite to crack the spindle bearings loose. Throws itself off almost immediately unless the chuck is given a starting push. Will take two inches off and try again but have a feeling that won't be enough.

How to condition the leather for better grip? Am told linseed oil works well. Can anyone corroborate? Boiled vs raw? Warned away from dressing by the old timers I buddy up with who spent their careers running 130+ year old Niels planers, 36" G&Es, big Cincinnati mills, etc. Only get to see them once in a while so I figured I'd ask around here in the mean time.

Linseed is a drying oil, so it will harden up. What you want is something more like "neatsfoot oil". Not sure what that really was, but it never hardened up, and kept the leather flexible.

The smooth side is the grippy side. But it needs to be in that "barely damp" condition.... like your hand when it is almost dry from washing, but not quite. Just like your hand when like that will grip polished metal to near the point of tearing your skin off, the leather wants to be in somewhat the same condition, which will cause it to grip smooth polished pulleys very well.

If dry and somewhat hard, which is a normal condition un-treated, it won't do anything but slip. I'd not do the linseed, but neatsfoot, or something like it should work. it needs to soak into and condition the leather, but never harden.

When right, the belt should hold and pull well, without much tension.

 

[Peter from Holland]

Handballplayers spray their hand with a tackie substance to get a better one hand grip on the ball That stuff is also used on leather belts

Peter

 

[projectnut]

Back in 1999 I inherited a 1916 Seneca Falls lathe. It was passed down from my wife's grandfather to her father, and most recently to me. I'm not sure how long the first belt lasted, but when it went to my wife's father the belt on it was purchased in 1954.

It powered the machine for at least 45 years before I got it. I decided it had served its purpose, so I bought enough new belting and lacing clips for a replacement and a spare from McMaster. It's 23 years later and the new belt is still working fine and shows little signs of wear. At the rate it's wearing I'll have to replace it sometime around the year 2060 or so.