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Serpentine belt question...

FlyinChip

Aluminum
Joined
Dec 20, 2017
hey all,

loving my 'new' heavy 10. but, the belt slips and it seems an cut and glued automotive serpentine belt is popular. I installed a 1hp replacement motor so it would be nice to get all of that power.

my belt is about 63" so I found this one, a Dayco #5080750 8 rib 1.1" wide and 75 inches long. That should allow for plenty of overlap.

question, is what is the latest glue solution? I've seen reference to glues that have an "activator". Just wondering what is the latest and greatest. Many of the posts I found are several years old.

thank you
 
While it's true some of the serpentine belt threads are old, most of the information is still valid. The serpentine solution is a really good one. The glued splice is a "maybe." Some folks seem to have success with gluing but it's a difficult splice to make and align because you have to do it with the belt in place. Also getting the correct glue can be difficult as well. The belt I have on my 10L is 7/8" wide. 1.1" width may be OK although some report tracking problems with wide belts. Compare prices between the Dayco and some of the automotive belts that are 62-63 inches long. But make sure what length you need before you buy something.
 
I just did this upgrade on my Heavy 10L. I used an 8-rib belt, which is approx. 1.12" wide. I tried to glue it with Dr Bond, but it didn't want to stick (temperature may have been too low). I had ground a 6" overlap and ended up using 6 hog rings like large staples thru the overlap. Haven't used it much yet, but it will stall the motor before it slips. I have a slight misalignment at the lap, but the belt tracks well anyway. I cut my belt 66" (with 6" overlap). If I do it again, I'll cut the belt and inch longer. I bought my belt off Amazon for $19. D&D PowerDrive 7K8 Simplicity Manufacturing Replacement Belt, Poly, 8 -Band, 7.75" Length, Rubber: Amazon.com: Industrial & Scientific

Several people have laced thru the overlap with heavy fishing line. One recommended using small eyelets/grommets (like the ones for shoelaces) to prevent tear-out, and lacing with stainless safety wire. In all cases, the lacing or hog rings are placed in the grooves of the belt and crossed over or crimped on the back to prevent contact with the pulleys. I don't recommend simply butting the ends of the belt, the reinforcing fibers run parallel to the belt and the lacing will likely tear out. This includes the clipper style splices used for conventional flat belts. If you decide to lace, I would recommend aligning the ends and punching the holes before putting the belt on the machine.
 
Check out "Al Bino Industrial Belting", I used one of his belts and was very pleased. The only problem I had was of my doing-I didn't follow the instructions and got the splice backwards which caused it to fail.
Karl
 
thanks guys. all great info. I'm still hoping to hear about the latest glue ideas... maybe will glue and stitch.
 
You could cut the belt, butt the ends and stitch it. Then, if you aren't sold that it will hold, glue a thin "strap" over the stitching a few inches on either side. A good glue would be loctite 406.

I posted this the other day:

"I did the exact same. Bought a serpentine belt from the auto parts store for $15, and picked up 150 yards of 50lbs braided fishing line for ~$11. I found I had better luck without crossing over and lacing it; each set of opposing holes I drilled in the belt get their own loop, maybe passing the line through each pair of holes 3-4x."


 
I think the varying levels of fsilures and success have to do with the belts...some are "different" and will take to glue some won't...some will tear with stitching some won't...it just isn't theur intended use so YMMV.

Mine was the same as Dobermans...punch and lace a traditional pattern in a 6 rib K section belt.
 
thanks guys. all great info. I'm still hoping to hear about the latest glue ideas... maybe will glue and stitch.

I did this a few months ago. In the past I've had limited success with both glueing and lacing - the glue eventually failed, or the lacing tore out - all with serpentine belts of various manufacture. The recent one was done with a Dayco belt and Loctite plastic bonding system (two part) and with a 4" overlap splice. I carefully ground the rubber away down to the reinforcing cord on one side on both ends of the belt, and did the same with a 4" long piece to overlap the splice, then glued the exposed reinforcing cord areas together with clamping jig to assure a straight splice. The spliced area is roughly the same thickness as the rest of the belt and only marginally stiffer. So far there is absolutely no indication that the glue is failing after several months of daily use, my best result by far. FWIW - good luck.
 
I did a trial and error method of removing the headstock and installing an intact serpentine belt. It took me about 3 tries total to get the right sized belt. And I just went to autozone and purchase their basic belt. Little bit of a pain but not that bad on a 9" with a rear countershaft. I'm guessing it would be harder on the underbelt. That said, there's no glue and I'm guessing this will be on this lathe long after I'm dead and gone. Any auto belt has to go through much more abuse than a lathe. Anyway... It has been working great.
 
I used the loctite activator and glue on my automotive belt. 3 years going strong.
John
 
ordered the d&d belt and that locktite from amazon... we'll see how well I can get it to hold. would be nice to have no belt slip!
 
OK I cut the belt at a 45 degree angle allowing for a 6 or so inch overlap. then I ground the serpentines off to flat for the overlap section. lightly grinded the back side that would glue on to. and made a nice taper at both ends. did the grinding with my makita 4" mini grinder and a coarse grinding disk maybe 36 grit.

the "activator" seemed to just soak in. but I applied the glue and joined them. I noticed that there was almost NO adhesion at the end (it just peeled apart). I suspect this glue will not work (locktite plastic bonding system) or possibly I needed to grind away all the rubber which I didnt, just grinded it flat. If this doesnt hold I will try to stitch it next, or possibly pop rivet it with the flush end of the rivets on the inside, with a washer on the outside.

the 8 rib belt seems just the right width for this application.

I'm also open to other glue suggestions.
 
I only lapped about 3” on mine. Then I clamped the belt and let it set overnight before using it.

John
 
well, I found out that the belt was 1/2" too short even with the adjuster all the way up. that gave me an excuse to do some "destructive testing". It had in fact bonded in a few places as strong as the rubber itself (tore the rubber apart). I sanded it down again, and will buy more glue (it was only $3.77 at home depot) and use all of it including a little I have left from today. I'm guessing it's about how much you use.
 
I think the issue you're having is that you didn't grind all the way down to the reinforcing cords. The Locite system is for plastics, not rubber. Grind all the way down to the cords, glue, clamp and leave overnight.
To make it easier to get the correct length, I just butted the ends together and then glued a 4" long strip across the butt joint, grinding all the rubber away where the splice is. Either way, the trick is to get the glue onto the reinforcing cords.
 
OK re-did it. Learned a couple of lessons. I did grind to the fibers on one side, left a thin layer of rubber on the other. It did bond the rubber last time, where there was enough adhesive.

I found out that you have to be careful not to over heat the belt when grinding, or it will warp. That happened.

Also, do a dry run with the clamping. My lathe is a Heavy 10 with the iron motor base. NOT enough room to work in there when clamping. Takes practice. Took me too long to bond it, so it may be weak from that.

We'll see if it holds but may take a second belt and this experience to get it right.
 
OK re-did it. Learned a couple of lessons. I did grind to the fibers on one side, left a thin layer of rubber on the other. It did bond the rubber last time, where there was enough adhesive.

I found out that you have to be careful not to over heat the belt when grinding, or it will warp. That happened.

Also, do a dry run with the clamping. My lathe is a Heavy 10 with the iron motor base. NOT enough room to work in there when clamping. Takes practice. Took me too long to bond it, so it may be weak from that.

We'll see if it holds but may take a second belt and this experience to get it right.

Keep at it and you'll get it fixed. It took many of us more than one try. My 10K is an underdrive so I understand what you say about no room to work when clamping. To make it easier I rigged up a jig with some angle iron to hold the belt straight and had the clamps, clamp bar and all ready to go. If your iron base is tighter quarters than mine, you'll need to be a contortionist to get it done. :-)In the end it's worth it - completely fixed my belt problems and requires very little tension to get the job done. Good luck!
 
OK it's been THREE YEARS.. and the used serp belt I picked up off the ground at a junkyard finally has started to fail. BUT not the glue joint! Belt seems to just got dried out and has started to tear. Thats why I came back here, to find out what I did! LOL

This time will use a new one, but shopping for a serp belt by length (and width) - not easy! if I get a belt number I'll post it for others who also have a Heavy 10

20210407_160126 (Medium).jpg
 








 
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