View Full Version : Flat lathe belts

11-17-2012, 08:00 PM
I have rebuilt a SB Heavy 16. The old belt was missing. I have tried cutting , skiving, wrapping and super gluing an automotive serpentine belt. The first try didn't hold very long. The second try is now running but I have little confidence that it will survive the first hard job. I see ads for replacement belts in HSM. Has anyone tried one. I am not totally clear on how the ends are fastened together. Do any of you guys have any experience with this?
Thanks Jim

11-17-2012, 08:21 PM
Some folks have success with more modern "link belts," glued serpentine belts, and other methods, but frankly I prefer to keep old machines looking mostly period correct and by this I mean - I LOVE GENUINE LEATHER FLATBELTS! You can buy flat belting of various lengths and widths from TSC, Rural King, and other "country" stores around these parts. Not sure where youre located, but I would seriously consider that an option. Flatbelts are "laced" together using several laces that are similar to big steel staples, but this requires a lacing tool to crimp them. Google or search on youtube for "belt lacing" and you will probably find quite a bit to read/watch/learn.

Here's one for example.

11-17-2012, 08:24 PM
I have made my own flat belts, but fairly small ones. I machined a form on the lathe, filled the groove with tool handle coat, ground it smooth, added a fresh layer of the compound, wound on some cord, smoothed it over, added more compound and smoothed that over. When it was cured, I ground it again- enough to smooth but not get into the cord.The form was in two halves so it could come apart to release the belt. Worked pretty well actually. Some other belts were made by first laying a layer of rubber into the groove- I think what I used was tire patch material that came on a roll. I believe there's a sensitized side on that, and it works well with goop or shoe-goo. For cord I've used what used to be called 1/2A flying line, which was dacron, and also dental floss.

The belts I made were all around 6-8 inches in total length, but on my lathe I could have made one up to about 24 inches long.

I have not made one using leather, but there's no reason why you couldn't first stick one together, then give that the goop and cord treatment. Not only will that add strength, it will also keep the join from ever coming apart. I don't know if the leather belts were butt-joined before stapling, but there's no reason why you couldn't use a tapered splice instead. If you did add the goop and cord backing, that would let the leather act as one loop of strength also, without the weak spot at the join.

I suppose at the same time you can splice together any number of lengths of leather belt to make your final belt as long as it needs to be- otherwise you'd have to look for a particularly long cow :)

11-17-2012, 08:25 PM
http://www.ebay.com/itm/SOUTH-BEND-DRIVE-FLAT-BELT-CUSTOM-CUT-LATHES-MILLS-ANY-OTHER-MACHINES-/300816743452?_trksid=p2047675.m1850&_trkparms=aid%3D222002%26algo%3DSIC.FIT%26ao%3D1%2 6asc%3D48%26meid%3D3535841976957895735%26pid%3D100 011%26prg%3D1035%26rk%3D1%26sd%3D290810238599%26

11-17-2012, 08:30 PM
There is a method listed in the SB Lathe book. I've scanned it and posted it below.


11-17-2012, 08:30 PM
I've spliced belts many times and have never had a failure. You mentioned Super Glue. Don't use it. Use Barge Cement. If you cannot find it anywhere else, try a shoe repair shop. I've never found one, yet, that did not handle it.

I have the best luck skiving the ends by using a razor-sharp wood chisel. Don't try to make the cut all at once; just nibble away at it in an easy, controlled fashion.

To make sure the splice is straight, mill a channel in a piece of scrap aluminum that is the exact same width as the belt. I generally make the channel deeper than the belt is thick.

Make a trial fit of the belt. Make sure the raw edge of the splice in contact with the pulleys is on the trailing end. In other words, do not let the raw edge approach the pulleys, let it follow.

Follow the directions for the Barge Cement. Apply it to both surfaces and let it dry for 15-20 minutes. Apply a second coat, if necessary; but, I've never found it necessary.

Lay one end of the belt in the channel, then carefully lay the other, being careful to make the lap "just right." Wrap a layer of aluminum foil around a thin strip of wood (do this as a preparatory step) and use it as a backing-piece to clamp down over the splice. Use several clamps so that the wood will bend to follow the irregularities of the splice (if any).

Leave it clamped for a full day to allow the barge cement to obtain full strength.

The aluminum foil will keep the wood from sticking to the splice. Remove the clamps and wood and you are in business. Your splice will be permanent and if done carefully it will never let you down.


11-17-2012, 08:34 PM
I have always used alligator style clips. (http://www.lathes.co.uk/flatbeltclips/)

11-17-2012, 09:38 PM
www.mcmaster.com also sells leather belting.

Dr Stan
11-17-2012, 11:24 PM
I've made flat belts using automotive serpentine belting and gluing them together with Loctite Plastic Bonder and they held up very well. You can get it here: http://www.bigpaintstore.com/hen-01-82565-02.html?cmp=googleproducts-wiz&kw=hen-01-82565-02&utm_source=google+shopping&utm_medium=cse&utm_term=hen-01-82565-02&gclid=CLWngdTV17MCFc5cMgodCnUAVw but I bought mine at one of the local big box stores.

11-17-2012, 11:26 PM
www.mcmaster.com also sells leather belting.

As well as the lacing:

Paul Alciatore
11-17-2012, 11:40 PM
I have a SB 9 and had to replace the old leather belt. I purchased a serpentine belt from a local auto parts store and disassembled the spindle and the counter-shaft to assemble it. No splices. It runs very quiet. And it will probably outlast me. If you can do it this way, I highly recommend it.

You say you have already rebuilt yours, but in my case the disassembled had an additional plus as I discovered that the oilers were well worn and starting to scratch the spindle. I also replaced them.

11-18-2012, 12:00 AM
I broke my leather drive belt on my 9" SB wanted to get job finished, took belt to Car Quest and asked for a 6 groove 1" wide serpentine belt as long as this. Got back to my shop cut the belt (if not in a rush could have tore down lathe to install) clamped both ends 1 up 1 down on a piece of aluminum bar and belt sanded a taper on the ends, put a board between the flat pulleys, cleaned the ends of the belt with acetone clamped the ends to the board and aligned them straight, now this is what I had gel instant glue and what I used, smeared it on, clamped the ends together let it set for 15 Minutes, cleaned up the mess adjusted the tension and finished the job . So gel acc (instant glue) is usable, after awhile I tried to turn the belt over and run the smooth side, no go the belt then was about 2"s to long. Been running for 3 months now.

11-18-2012, 12:42 AM
I bought my new belt here. http://www.flatdrivebelts-anysize.com/
Fast friendly service and a great price.

The laced belt is simply held together by a pin that you install. Really easy to remove if necessary.

11-18-2012, 08:50 AM
You can get leather belting and adhesive from Tandy Leathercraft. Pricing will probably be better than most of the above-listed companies. If you want a laced belt, they also sell synthetic sinew, which is ideal for lacing.

11-18-2012, 09:32 AM
If nobody has mentioned this guy already, check him out for flat belts:


This is the cottage operation of one Mr. John Knox who operates the Sheldon Yahoo groups. He is a great guy and former engineer who worked at Sheldon Lathe back in the day. He is a wealth of first hand knowledge about all things Sheldon and is an all around nice guy. Worth your consideration when you are deciding where to spend your money.

All disclaimers apply: I have no interest in company, nothing in it for me, no relation, not even a customer, some settling may have occurred during shipment, do not point at the sun, etc.

11-18-2012, 10:06 AM
Orrin, thanks for the good description, tucked away in case i ever need it.

11-18-2012, 10:18 AM
Since the OP was about an automotive serpentine belt, I'll have to agree that I had no luck whatsoever with any kind of tapering, gluing, clamping, etc. It had a short life. Finally settled on butting the ends together and lacing with 18 gauge copper strand wire. Being copper, it was easy to solder the ends of the lace to the adjoining stitch to hold it in place. It's not a permanent method. Have to stop and re-lace when the wire begins to wear. Re-lacing is not as frequent as I think, but it always seems to occur at the worst moment. Guess that's true of a lot of things.

11-18-2012, 10:33 AM
I use belts from Tandy Leather they also have a good glue [ Barge AP Cement ]
The best way is to hang the belt a few weeks or more be for installing on the lathe for a 16 lathe belt use a 30 pound weight. Use a sander for the ends of the belt and over lap [ but gluing will not work ]


I have rebuilt a SB Heavy 16. The old belt was missing. I have tried cutting , skiving, wrapping and super gluing an automotive serpentine belt. The first try didn't hold very long. The second try is now running but I have little confidence that it will survive the first hard job. I see ads for replacement belts in HSM. Has anyone tried one. I am not totally clear on how the ends are fastened together. Do any of you guys have any experience with this?
Thanks Jim