Pulley repair

[Tundra Twin Track]

[QUOTE=nickel-city-fab;n1880308]

I don't know what the proper terminology is, but my last employer had a similar situation. Belt was going onto a 50-hp motor on a VFD to spin a 30" dia steel plate that weighed ~250lbs. The supplier informed us that Gates Rubber makes a type of belt where all 4 of them are joined into one really wide belt. But I forgot the trade name for it. I'll never forget bench-pressing that sheave though... (vertical application)

Just as you described where there joined into one wide belt,Banded is what I've allways called them.You can order how many ribs you want and it will be matched.

[Tundra Twin Track]

[QUOTE=754;n1880212]Here is something most are ignoring the flange you want him to cut off contains the balancing holes, cut it off, it's out of balance.
second I have like 3 or 4 pulleys on my lathe, bought a matched set of replacement belts, a few years later they are not all as tight, only two pulling, not so good, cut one row off 4 leaves 3 if one belt slacks more than the others, good luck with heavy cuts.. .. but hey it's fixed now, all belts can be in place.


Most machines are way over kill with number of belts IMHO,I have 2 separate Grain augers each with 10hp with 1 B width belt and have thousands of hours on them.

[The Metal Butcher]

Don't K&T motors run really slow? 6 or 8 pole motors? I can't imagine that that small of a pulley would cause that much of a fuss even unbalanced. Anyone with a surface grinder wheel balancer could have that static balanced in a jiffy.

[754]

The point I was trying to make was. .. he is closer to original balance the way he did it, than he woukd be, had he cut the flange right off.

[nickel-city-fab]

The point I was trying to make was. .. he is closer to original balance the way he did it, than he woukd be, had he cut the flange right off.

True, that is true. I am simply pointing out that his repair is not that far off. At least its a lot better than cutting the flange right off.

[754]

True, that is true. I am simply pointing out that his repair is not that far off. At least its a lot better than cutting the flange right off.

Yes that is exactly what I meant, it's a no lose scenario, if it for some reason does not work, then you have the unbalanced options. Why go to the point of no return right away..

[nickel-city-fab]

Yes that is exactly what I meant, it's a no lose scenario, if it for some reason does not work, then you have the unbalanced options. Why go to the point of no return right away..

True. Even if it was unbalanced, the inherent stretch in the belts would probably make up for it. On the other hand, I bet the motor bearings would get eaten for lunch.

[garyhlucas]

A couple of things about belts. The reason for having many belts is to reduce slip when they are loose, because they stretch. I have measured power loss through slipping belts and it is way higher than you might think, as much as 50%. Those banded belts must run on perfectly aligned pulleys. If they aren't they will make a noise that sounds exactly like bad bearings! I've seen this more than once, just recently at my job.

[754]

I keep thinking back to that elevator motor the guy posted with a 4 belt sheave, I surmised it was a reliability issue, it is after all an elevator.
as in if one of 4 belts loses tension, its a far safer scenario, than having a belt lose tension on a 2 belt sheave..
we have choices, they went 4 belts for a reason. .

[outlawspeeder]

I was worried about the balance because how far out the pulley is from the motor and when I put the pulley on the motor it rotated to the missing part up. With the repair it is close enough. Yes the balance hole are out on this end but there are more down in one of the grooves. With that many holes that is why I was really worried.

I think I mention that I don't think I will ever need the four belts to drive a cutter. I never thought about "matched belts". Is there such a thing? Do I really have to worry about match belts? How do I check that. Maybe Atom79 has a youtube video I can watch to understand what a matched belt are? Only joking. haha

Just to pass information these belts do have a setting. With a 3/4 flex of the belts I am not sure if I really need matched belts or a four belt linked / banded... Most likely any cutting I do will only need one belt.

[nickel-city-fab]

I think either banded belts or matched belts is probably a good idea. Reason being, I've seen guys put unmatched belts on jobs like this and within days only one belt is doing all the work. Then you get to have the joy of re-adjusting everything , every week, forever until they finally break.

[754]

I have 3 belts on my lathe, replaced them once with matched ones, and now i think something is slipping. I suspect it needs adjusting and one belt may be looser.. it's 7.5 hp.. and its funny, my buddy has a 12 or 15 up lathe, and when he ran mine he said it was gutless,..lol.

[PStechPaul]

I wonder if segmented link V-belts might work better for multiple sheaves?

https://www.fennerdrives.com/nutlink/

https://sawsonskates.com/adjustable-link-belt/

[old mart]

I did read in one manufacturers info, that their link belts could be used in multiple sheaves. I assume it would have to come from the same batch. Trouble is I haven't been able to find the source. Matched multiple belts are easy to get hold of, but everything depends on the pulleys being matched and parallel.

[754]

The segmented belts on my Herbert Lathe, had at least one loose one you could see it bobbing around , sharing little of the load.
to all those guys that say just cut that flange off, when a sparkplug or cylinder goes in your vehicle , do you just leave it that way because you only travel at 60 percent of top speed ?