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View Full Version : Belts for Unisaw 36-945. Length? Harbor Freight Link Belts Good?



Patrick Irish
02-06-2017, 11:33 PM
What are the signs of bad belts on a Unisaw?

The belts on my used 1999 3hp Unisaw I think are fine. I get a little rattle but I think that's the extension table I made without a leg. The saw did sit for about a year not being ran the seller told me. I figured, changing the belts wouldn't hurt.

Been reading about needing matched sets, matched sets are a waste, get link belts, link belts arent good on a Unisaw etc. Is there a consensus?

What's the length of these belts? 24"? I was about to order some AX24 then saw that Harbor Freight has the green linked belts. They sell a 5 foot section for $40. Is that long enough? Are they good belts?

Cary Falk
02-07-2017, 12:50 AM
I have heard the link belts from HF are fine. I have heard that link belts rub on the underneath side of the table. Some people just run a single belt.

George Makra
02-07-2017, 5:50 AM
If you want to do it right go to a bearing supply house and get a matched set.
Here is what a matched set is when a belt is made the put it in a jig and measure the amount of stretch in tenths of an inch and mark each belts amount of stretch.
On the belt will be a stamped marking smaller than the rest of the writing, in the old days it was a numeral, now it seems that everyone has their own system.
So get a belt that has the same identifiers and they will be the same length.

Linked belts originally started out as temporary belts to get a piece of machinery going with out having to get the correct belt.
Marketing and fad have made them popular but IMHO they are just a temp solution at best.

Look at your existing belts and see if you have any rubber cracking or glaze on the belt sides if so replace if not quit worrying about it and make some saw dust.

Larry Edgerton
02-07-2017, 7:55 AM
I use Optibelt in matched sets. Perfect belts, no hump, made for machinery. Not a fan of link belts.

David Pascoe
02-07-2017, 8:07 AM
I would say definitely NOT to link belts, they stretch and slip. The Unisaw belts are very short, hard to get on and off, plus there is only an inch or less of adjustment with the motor. That means that belt length is critical BUT three belts are only necessary for high HP motors (3 & 5 HP) and very heavy loads. Most of us don't really need three, so matched sets are not critical. I don't have matched set and they are clearly not equal, are all of unequal tightness but I don't put heavy loads on it and don't have a problem.

OEM belts can last a very long time. If they are not grooved, cracked, or glazed, I'd say leave them be. Cracks indicate age deterioration and nearing the end of life. You'll have to remove the extension table and possibly the top -- depends on if you have adequate clearance between upper pulley and gimbal arm. This can be a very difficult job for one person and removing the top makes it a lot easier. Easiest way to do that for one person is to place a table or platform next to saw and slide top over and onto it. I add some legs to my extension table and slide top onto that. You can increase the gap to get belts on)by loosening the single bolt in the raising arm and sliding it over on the shaft. Be sure to realign pulleys if you do this, which you should check the alignment in any case.

Mark Wooden
02-07-2017, 9:18 AM
A set of belts for a Uni are easy to get , you should shop around, even Amazon has them.
DON'T use link belts, in that short of a belt length,m they'll groove the pulleys and you'll end up replacing them(the pulleys)

Chris Hachet
02-07-2017, 10:30 AM
A set of belts for a Uni are easy to get , you should shop around, even Amazon has them.
DON'T use link belts, in that short of a belt length,m they'll groove the pulleys and you'll end up replacing them(the pulleys)Likewise, running just one belt will cause the pulley to wear unevenly. I learned the hard way about link belts when running one weakened a cheap pulley on one of my Asian machines...pulley was a cheap pot metal pulley and came apart violently and set shrapnel through the shop. tension was not that high on the pulley, just apparently wearing unevenly and under stress.

Having serviced HVAC equipment and industrial equipment with link belts on them...I don't like what they do to pulleys.

glenn bradley
02-07-2017, 10:32 AM
Is there a consensus?

Well, obviously no. I'm not sure where the anti-link-belt thing comes from. They are used in industrial settings for a lot of reasons . . . although not usually the reasons a home shop enthusiast might use them for.

Link belts set high in the sleeve. The right hand pic below shows this well. If one does not account for this there could be consequences that would be convenient to blame on the belt. The belt is simply part of your power transmission system and many folks just run a single belt on a Uni.

353398353399

I have link belts that have been in service for a decade or so without issue so I have not gripe about them. The HF link belts are 'name brand' oddly enough; Fenner IIRC. I run Power-Twist and Fenner sections combined without issue but, there is certainly nothing wrong with a high quality 'standard' V-belt.

Bill Adamsen
02-07-2017, 10:52 AM
I bought a set from a supplier on Ebay (a matched set of 3 for a 40 year old Unisaw) and they were inexpensive and arrived quickly, but they were too long to adjust to the proper tension. I used them anyway and no noticeable issues. When I searched the forum there were cautions about exactly that issue and recommendations for reputable suppliers. I would suggest searching this forum for those suppliers and sticking with them.

lee cox
02-07-2017, 10:56 AM
I have been running the Gates Premium AX24 belts since last summer without any problems. The Premium AX belts are made so well and precise no matched belts are needed. The little cog on the belt allows them to run freely on the small Unisaw pulleys without taking a set. I bought mine AX24 belts from O'Reilly Auto Parts.

Rick Potter
02-07-2017, 1:30 PM
You say your belts look fine, why not just use them. Mine are from 1983 or so, and run smooth. Running them for a while should smooth out the set they may have taken.

My 2 cents.