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View Full Version : Where do leather machine belts come from?



dp
09-19-2010, 12:05 AM
Jerry's question about belt end joiners sent me off on a search for the answer n the subject line - I had not idea what the answer would be, but I found a great old book on the subject at Google:

http://books.google.com/books?id=W53mAAAAMAAJ&dq=how%20are%20leather%20machinery%20belts%20made&pg=RA1-PA31#v=onepage&q=how%20are%20leather%20machinery%20belts%20made&f=false

It's also a free PDF download, so it's already in my eLibrary.

Evan
09-19-2010, 12:13 AM
Cows.

I had one cut for me for my SB at the local saddlery. Cost me $10.

gwilson
09-19-2010, 12:40 AM
In Hampton,Va. is a useful place called Hampton Rubber. While the name isn't exciting,they sell all kinds of belting. Leather too,I think. They also have a great assortment of dust collection hoses. Just all kinds of things. Is there a rubber supply near you?

dp
09-19-2010, 01:18 AM
Cows.

I had one cut for me for my SB at the local saddlery. Cost me $10.

Well, yeah :) But not just any old contented cow. It was fun to read how it was done in 1900. It turns out there is a lot of science and art that goes into making repeatable belts from leather. One thing I was trying to discover is where very long belts come from and half expected to find a link to whaling. I'm left thinking they just splice the ones they make from cows.

Arcane
09-19-2010, 01:48 AM
One thing I was trying to discover is where very long belts come from and half expected to find a link to whaling.



Very long cows.....:D

Black Forest
09-19-2010, 02:16 AM
Longer belts/straps are cut from the hide in a circular manner. In these times the hide is put on a vacuum table which is rotated. The knife is cnc'd. One just punches in the desired width and presses start. I know a place close to me that does this sort of thing. They make lace for me out of Kangaroo. Out of one hide I get around 50 meters of one continuous lace and it is beveled on both sides of the flesh side. Lots of farmers here still use leather belts to drive different machines off their tractors here in Germany.

Forrest Addy
09-19-2010, 03:49 AM
I missed out on an old belting handbook (Page, I think) that used to reside, utterly ignored in the shop library. In it was a detailed description of leather belting from selection of the hide, how it was graded, tanned, taken from the hide, assembled, etc. This book was written in the 1920's when most of US industry was driven by line-shaft. Leather belting came in several qualities but belting as I've read about it machine belting was never taken from the hind in a spiral. Lacing, strip, and straps, yes, but not machine belting.

Leather stretches in different ways in use depends on where it was taken from the hide and its orientation. As I recall the best leather for belting came from a foot on either side of the spine omitting the center 6" or so and the length runs from the withers to the haunch. Further, the hide has a natural taper and if split parallel it still tends to bow in use. In multi-ply belting the leather is selected and laminated so the tapers. flaws, bows etc cancel. Good belting tracked well on its pulleys, was more tolerant of slippage, and lasted for a long time. Back in the 1890's leather belted power transmissions ranged up to several thousand HP. Look at the old Edison Electric photographs. When I was a pup, I've been in line shaft shops where some belting in daily use was generations old.

The belting is laminated, scarph jointed, and laid up to form long spools and sold in trade widths and thicknesses. By the 1920's, leather belting, horse harness, etc had become a highly optimized and sophisticated product. From this I conclude that the 150 ft long belts used with steam traction engines to drive threshing machines, sawmills etc were enormously expensive. Stop and think about it: a 150 ft belt 10" wide and 5/8" thick - maybe 600 lb (wild a$$ guess) the equivalent of 40 or so full size tanned hides. Ever priced leather? Look at the Tandy website.

Lesser removes from the hide is used for belting of lesser size and quality and the remander used for shoes, cheaper saddles, etc.

That's about all the belting refinements I can recall from several readings 30 years ago. I wish I had stolen that book. It was a real resource.

Evan
09-19-2010, 05:20 AM
Yep, long belts are made by spiral cutting. I've done a fair amount of leather work over the years. Just lay out some hide on a board with a screw in the middle that has a bushing on it of the right diameter. Use a non stretch cord like whipping twine to the knife that wraps around the bushing as you cut.

For making laces you can use odd scraps and a cutter that has a spacer on it to automatically cut the right width. Just keep going around the edge until it gets too tight. It can be hard to find good leather around here though since the cattle here are all raised for beef and the ranchers don't care about wire scars. This isn't dairy country and most fences are barbed wire, including mine. If you raise your own cattle and use smooth wire, pipe and or board fence there are several local meat cutters that will do a good job on the hide and we have several local tanners that can still do chrome tanning.

Your Old Dog
09-19-2010, 08:49 AM
When I got my SB 9, the leather belt was shot. I went to a Industrial Belt making company here in buffalo and the guy said they were using a high tech product now-a-days. My belt is leather on the inside with some kind of plastic like material glued to the outside of it for strength. It came in the mail with a serious scarf joint and two bottles of chemicals to be mixed to join the scarf. I made a wooden jig with a ridge in it to hold the belt in alignment, glued the joint and then C clamped it between the two pieces of wood while it dried.

I am forever forgetting to take the tension off the belt but still it nearly refuses to stretch. It worked out fantastic and I didn't have to take my Model A SB apart to get it on! Cost me something like $120.00 12 years ago. If I had to do it again I'd do the serpentine belt like Evan did.

BigBoy1
09-19-2010, 10:07 AM
Tandy Leather had a sale a while back on half cow hides. The leather was about 1/4" thick. I bought one half hide and used it to make belts for the two SB lathes I was restoring. One of the belts I was able to get out of the hide was 80" long! I still have enough leather left to make several more belts.

becksmachine
09-19-2010, 01:17 PM
I can believe that round leather belts might be cut from the hide in a spiral, but for flat leather belts Forrest has it right.

Quoting Machinery's Handbook, 11th edition;
"The leather for the best grades of belting is taken from the central part of the hide along the back of the animal. If the leather is taken too far down the side, it will be flexible and lack strength and closeness of grain. If the strips are cut too long, the ends will be taken from the neck of the animal, which is also inferior stock."

Dave

clutch
09-19-2010, 07:45 PM
I noticed that there are some here that know leather. I'd like to make a holster for a firearm. I looked at Tandy Leather and didn't have a clue as to what type of leather to buy.

Anyone care to enlighten me?

Thanks,

Clutch

Weston Bye
09-19-2010, 09:19 PM
I can believe that round leather belts might be cut from the hide in a spiral, but for flat leather belts Forrest has it right.

Quoting Machinery's Handbook, 11th edition;
"The leather for the best grades of belting is taken from the central part of the hide along the back of the animal. If the leather is taken too far down the side, it will be flexible and lack strength and closeness of grain. If the strips are cut too long, the ends will be taken from the neck of the animal, which is also inferior stock."

Dave

So that's why they didn't use giraffes.

whitis
09-19-2010, 10:57 PM
At Field Day of the Past this weekend there were lots of machines running on flat leather belts. Long belts. Wide belts. One belt, that ran the main saw mill was almost two feet wide. That is a lot of cow.

Evan
09-19-2010, 11:00 PM
I just found another very useful book on the subject.


Power Transmission by Leather Belting

http://www.evenfallstudios.com/woodworks_library/power_transmission_by_leather_belting_1916.pdf

According to this book, which is filled with practical information, tables and calculations, the 1" belt on a South Bend 9" lathe is capable of transmitting up to 1 hp.

Liger Zero
09-19-2010, 11:08 PM
I hear machine grade leather comes from specially bread mechanical cows, and that's no bull my friends.

Evan
09-19-2010, 11:22 PM
A noble gesture I would say...

planeman
09-20-2010, 11:26 AM
Shucks, You guys should see some of the long leather belts we use on our farm machinery down here in Georgia where we grow Naugas. When a Nauga dies we wait until he's good and stiff, then we mount him in a large lathe with the tailstock center in his ass and his nose in the chuck and set a knife in the tool holder. Then we set the lead screw change gears for a coarse thread and peel 'em like a potato. Works every time. That Naugahide is tough stuff!

Planeman

Evan
09-20-2010, 11:56 AM
First liar doesn't have a chance. :D

During the recent forest fires here a lot of ranchers were ordered to evacuate on very short notice. They didn't have time to deal with the herds so the just opened all the gates and put steel sheets across the cattle guards so the cattle could hopefully escape the fires.

Most did but there are some animals missing. Some people are out right now looking to make a lot of money on the pine mushrooms that always grow right after a big fire. I have heard that they are finding very good eating along the way as some of the cattle ended up being roasted in the blaze. If the conditions are just right the steers will be cooked right through and the residual heat as the fire dies out will produce a very tasty smoked beef jerky. The only problem is that the hide toughens up so much that you need a fine toothed chain saw to get at the beef. The local saw shops have brought in special Teflon lubricated straight cut saw chains so that the jerkey isn't contaminated by chain oil.

They aren't permitted to sell the product because it hasn't been inspected but I also hear there is a thriving business going on by word of mouth since beef jerkey made this way is obviously a rare and uncommon delicacy.

dp
09-20-2010, 12:48 PM
Nothing I like more than a mouth full of dead cow I've found laying in the debris of a forest fire. Mmmm mmm!

Al Messer
09-20-2010, 02:03 PM
I noticed that there are some here that know leather. I'd like to make a holster for a firearm. I looked at Tandy Leather and didn't have a clue as to what type of leather to buy.

Anyone care to enlighten me?

Thanks,

Clutch


If you are at the store, just tell the clerk what you are going to make, if on line, choose a good grade of Saddle Leather.

camdigger
09-20-2010, 02:22 PM
Forest's post has me wondering when the longer machine belts switched from leather to fabric filled with rubber. The folks have an antique threshing machine that was OLD in the '30s that had that type of belts. The belts range from 1 1/2" wide X 42" or so long on assorted drives to the main drive belt that has to be 6" wide and 100 feet long. Personnally, I've never seen a leather belt used in an outdoor application. I have seen canvas belts on assorted pieces of farm equipment from 1 1/2" to 48" wide in assorted lengths.

FWIW, the widest belts were essentially conveyors joined with 4 or more straps across their width. The drive belts were initally endless belts, but were/are often joined with a product called "alligator lacing" if a bad (burnt) spot had to be cut out. The belts were known to slip if overloaded, and would get hot and literally burn the rubber and char the fabric of the belt if allowed to slip too long.

Edited P.S.

On drives that had some sheltering from the elements and had need of long belts, some used hemp rope spliced into a continuous loop. I've seen examples of rope up to 2" in diameter used on occaision.

Mike Burdick
09-20-2010, 02:49 PM
camdigger,

When I was very young I remember my dad taking me over to a fellow that lived in our same valley that used a belt drive to power his "stationary" baler. As I recall, the belt was about 6-8-inches in width and the man used an old John Deere tractor for power. He would park the tractor about 50-feet away and connect what I thought was a tightly woven cotton belt, about 1/2 inch thick, to a pulley that was about 6-feet in diameter on the baler. The reason the belt being so long was that it provided sufficient "weight" so the belt would not slip. By the way, two men stood at the baler and would feed cut lengths of wire around each bale and hand tie before it was ejected! As one would expect, the baler didn't turn very fast but it turned out bales that weighed in excess of 200 lbs depending on what material was being baled.

Baling hay is sure easier now!;)

TGTool
09-20-2010, 03:37 PM
So that's why they didn't use giraffes.

The old timers did a lot of things but one wonders why in this part of the country it didn't occur to them they they could make gear belts from armadillo hide.

camdigger
09-20-2010, 05:39 PM
Mike

That sounds a lot like the flat rubber/canvas/cotton fibre flat or endless belts I've seen on threshing machines, stationary balers, sawmills, cordwood saws, feed grinders, and miscellaneous other farm and light industrial equipment. 40 years ago, Dad had a 3rd party made pickup on an old John Deere combine that used 1 1/2" flat rubber belts with natural fibre core in the center between the spring teeth to pick the swathed crop up off the ground.

The flat belts belts I've seen are usually gray, pink/orange, or black in color. The gray and pink/orange ones may or may not have a black stripe down the centre of the belt.

The agricultural tractors up to about the early '70s had flat belt pulley drives as an option. Typically, the belt pulley was designed to run at the same time as the PTO. Depending on make, the belt pulley could be cast iron (like John Deere adn Massey Harris), wood, or pressed paper (like Farmall/McCormick/International). The largest tractors with belt pulleys were about 65 HP. Some spec sheets listed belt HP separately from BHP, traction HP, and Brake HP.

The Fixer
09-20-2010, 05:46 PM
It comes from Cows.

Liger Zero
09-20-2010, 07:35 PM
The old timers did a lot of things but one wonders why in this part of the country it didn't occur to them they they could make gear belts from armadillo hide.


They didn't have carbide tooling back then that's why. :rolleyes: