The "Quality" v-belt thread

[John Coloccia]

That's exactly what I use on my 3hp bandsaw. I drive a 1" Resaw King through 10" of hardwood with no slipping, stretching, fluttering or anything else. It really makes me wonder why there's so much variation in experience with these belts.

[Jim German]

That's exactly what I use on my 3hp bandsaw. I drive a 1" Resaw King through 10" of hardwood with no slipping, stretching, fluttering or anything else. It really makes me wonder why there's so much variation in experience with these belts.

Lots of variables involved besides just the belt. Alignment, Pulley finish and dimensions, power being transmitted. Can you stall the motor on your saw? Or does the belt slip? Could be that your carbide blade only needs 1hp to resaw.

[John Coloccia]

I've never stalled the motor or slipped the belt. I can slow down the motor if I'm ridiculously aggressive...far more aggressive than anyone would ever want to do.

[Rich Enders]

To review:

A 7 year old jointer V-belt failed, so I decided to replace the V-belt on the Ridgid bandsaw since it was similar in age.

The process:

-Based on suggestions in this post I replaced the Fuju A-980 with a Gates A38 (from Amazon). The result was significant vibration even after a 15 minute run in.

-Re-alligned the motor and saw pulleys with no improvement. Resawed some 7 inch maple for 30 minutes, and no change in the vibration.

-Re-installed the original Fuju, and the vibration disappeared.

-Installed a link belt (Power Twist Plus) and it vibrates somewhat more than the Fuju, but far less than the Gates.

-Larry suggested Optibelt so I left them a tech support request. Surprise, surprise their tech rep out of Wheaton, Illinois called me the next day. After reviewing the situation he recommended trying a HVAC A38. I failed to explore why an HVAC belt because until then I didn't know there was such a thing.

So maybe my Gates A38 Hi-Power II (from Amazon) should have been an HVAC A38??? I am confused.

For now I am going to stick with the Fuju A-980. I will keep the link belt as a back-up until I find something better.

[Doug Ladendorf]

Thanks for sharing your experience Rich. Sorry to hear about the trouble. I done know the High Power-II belts just the Gates AX series. Not sure what the difference is but the AX belts slightly reduced vibration on my 20" bandsaw. I hope you can get it sorted out to your satisfaction.

[John Gornall]

Back a number of years I worked in a large factory with automated production lines. A standard drive unit was used to run the hundreds of conveyors. There were problems with vee belts so we brought in an engineer from Goodyear. He explained how a vee belt works. When the belt wraps around a pulley the sides of the vee belly out and grip the pulley. A vee belt should never bottom in the pulley. The main reason vee belts vibrate is having them too tight. The vee belt grabs the pulley as it wraps around and the sides belly out and lets go of the pulley when the belt straightens out after the pulley rotation and the vee sides go back to being straight. But there is a transition from grip to free and if the belt is too tight it holds in the pulley for a moment. You can watch the vibration on the slack side of the belt. Most time reducing the belt tension will eliminate the vibration. I bought a Delta 17" drill press from a guy that had given up on it because of vibration - took it home and slackened off the belt - ran smooth as silk from then on. Great drill press for 50 bucks!

[Allan Speers]

Throwing yet another monkey into the wrench:


I recently read an article from some major industrial belt manufacturer, which said that having too much grip can actually be a bad thing. This article said that for systems without a soft-start circuit (which probably means almost all 1-ph induction motors) a little belt slippage under starting torque is actually designed into the system. Even for machines that don't start under high torque, the same design consideration goes for bogging down the motor: Better to have a little slippage in such a situation than to damage your belts.

I dunno, but it's something to consider. My 5 HP Grizzly band saw only uses two belts, and they are regular "A" types. Granted, this machine has a reputation for being slightly hard to adjust the belts "just right," but I doubt the Grizzly engineers decided to use an inferior system just to save about $2 on a $2300 saw.

I'm still looking to use AX instead of A or 4L belts on my PM 10 and maybe the Grizzly BS (or something even better, if I can figure out what that might be) but more because it should theoretically give less vibration.

- Or should it?

[Rich Enders]

John, and Allen

Thanks for sharing your experience on V-belt tightness. It sounds logical, and worth a try.

[glenn bradley]

The fact that a 2008 thread can breath new life into a discussion is impressive

The general consensus on link belts is:

Allan is taking some heat here but, it is possibly well deserved. The info in this general consensus does not fit with what I have been reading for years. I must have missed it the last decade of discussions on the forums I participate in . I do recall a member here smoking some link belts on a shaper but, he did chastise himself for trying to take wayyyy too big a bite out of a long section of material and stated that the foolish act would have smoked anything.

1: They are not rated for more than about 1/2 hp per belt.

-- I have belts on 2HP and 3HP machines that see a reasonable amount of use. I'm a one man shop but, I'm busy.

2: When used at higher HP, they tend to stretch, flutter, and "bloom out," losing grip.

-- I have never had to adjust a link belt once installed. My 3HP jointer is nothing close to a soft-start and the belt is still under correct tension.

3: When used in pairs, they can stretch at uneven rates, causing a mis-match.

-- I cannot speak to this, no experience there.

4: They are often used to compensate for a problem that really should be corrected at the source.

-- This is indeed the way I first started using link-belts but, the yard sale contractor saw I was trying to smooth out was just built wrong; no fixing cheap-o. Since trying them on properly operating, decent machines and finding good service I just started installing them on new machines from the git-go

5: Pink? Are you kidding me?

-- Well, red actually but, Fenner has Green and Gray as well if that's a problem .

I imagine, like anything there are knock-offs of name brand link-belts; Fenner, Jason Industrial (Jason Ind. makes the Harbor Freight belts), there may be others. There are probably also inappropriate places to use them and like anything used incorrectly, they could have failed to perform well. I do have a mix of HF and Fenner on a tool . . . speaking of colors mattering, I intermixed green and red sections because the belt is visible and I wondered what it would look like; it wasn't all that impressive . Anyway that's been my experience with them over a decade or so.

It is important to remember that we are all entitled to our opinions. Different viewpoints are what add value to forums like this. If we all agreed on everything, there wouldn't be much point in visiting now would there? I appreciate Allan's comments, they just don't match my own experience.

[ian maybury]

Must say it's not a field i've looked at closely in the woodworking context, but i'm kind of bemused at the way these discussions go.

Belts are engineered components made to stock sizes, and like most engineered components (bearings, chains etc) there's a requirement to work through the test data based selection process in the catalogue or data sheets to verify suitability. This for good quality stuff, less so for cheap rip offs where the quality is highly variable. When the latter is the case and there's no reliable data about then all bets are off. Dimensional errors, cheap materials, material variations, kinks, absence of reliable selection information and everything are in the mix in that case.

The straightforward route is to replace like with like - go for a quality belt with the same section and length which if the machine was correctly engineered day one should work fine. (lay a good one side by side with an Eastern cheapie, and the difference is generally pretty obvious)

If you're of a more sceptical mindset (and there's plenty of machines - especially drills and mill drills with e.g. pulley blocks where on some settings there are problems with use of too small pulleys to get enough grip to transmit the torque, and which bend a stock solid belt more tightly than is advisable at a given RPM) - then it's a case of sitting down with the catalogue and working through the selection procedure. It's quite likely in those cases that a notched belt will do better, as it'll handle a tighter bend.

It's important to verify that the pulleys are in good shape - not worn/the belt dropping down too low (if it bottoms out in the groove then it can't 'lock in' and must slip), dimensionally and shape wise correct (a good belt is the simplest method of checking), are clean and have regular surfaces, are running true etc.

If the belt and pulley selection checks out for the worst case situations (max HP, max torque, potential for impact/shock/start up loadings etc, max/min RPM, pulley diameters etc) and hopefully has some spare capacity then just buy the belt in a good make. If it's not correctly engineered, then there may be some options to upgrade to a better spec of belt on the same pulleys - but it's again a case of taking a supplier suggestion or whatever and verifying it by working through the relevant data based selection procedure. There's no magic or hocus locus - it's a straightforward case of the belt either being suitable or not.

Depending on budget, space availability etc there may be the option in the event of serious problems with the engineeering of the existing drive to switch to a totally different pulley and belt type - maybe. Again to be verified by working through the selection procedure. (it's even more important given the high cost to get it right this time)

You may find in the end that there's a fundamental design problem with the drive, but working through the procedure will at least mean that you know what the probelm is and what you need to fix it. The alternative is to keep throwing belts on the machine, and never know why they are failing. The land of myth and magic....