Need some experts on flat belts

Fritz Maurer · Mar 9, 2021

We are having repeated lacing failures on this
planer Ive been working on. Originally installed in
Cleveland, Ohio , it was disassembled and moved
across town to new location. No one left alive that
knows any details of the move. My question is, are
these pulleys properly assembled with the flanges
on the top? The belts will come off if either cutter
head is stalled, but in normal conditions they run as
the belt on the left is pictured. Any ideas? Thanks,
Fritz

[video play=false:654c4848f0]https://www.yesterdaystractors.com/cvvideos/cvvideo80931.mov[/video:654c4848f0]

Bret4207 · Mar 9, 2021

It looks liek your video won't load on this format. Way out of my knowledge field to fix that, but maybe you can ask the lady in charge for some help.

IaLeo · Mar 9, 2021

Lacing failures. Possible reasons.
1 Excessive tensioning putting too much of a load on the lacing.
2.Lacing elements too large (or for thicker belts) causing battering of the lacing over pulleys.
3.Belt carcas too (rotten?) to retain hooks or fasteners.
4.Related to #2: wrong kind of not flexible enough lacing. For example a plate-type versus a wire hook (Clipper?) type.
5.A circuit the flexes too much, requiring a heat bonded belt joint.
6.Is the belt tracking off the pulley(s) having the belt edge catching on something. Especially rough right at the splice join.

Are the pulleys and idlers smooth with slight crowns? Is there a frequent shock load to the driving system that is normal?

Steve@Advance · Mar 9, 2021

If the belt stays on as long as it doesn't slip, then the alignment must be good.

Flat pulleys are actually slightly crowned. The crown acts as a constantly self correcting ramp for the belt to climb up. Don't ask to explain it, it just does...

Stop the motion, and the self correction stops, so the belt slides off instantly. If it has to climb over a flange, that starts stressing the lacings, stretching the sides of the belt, reducing the driving surface to just the center or encouraging the belt to run off the edge.

If this has happened repeatedly, the belts may need to be cut and relaced, especially if the edge lacings are damaged.

Attack the slipping problems first though. Why is it slipping? Dull blades, loose or bad bearings? Feed too fast, too deep? Is something changing about the geometry when it is under heavy load?

You can try flat belt dressing, but sometimes that is more trouble. Anything sticky will attract dust and build up, making the problem worse.

I see raw linseed oil (not boiled) as a recommendation.

db4600 · Mar 9, 2021

I would agree with the input below. They listed several good points and it can be overwhelming where to start. I dont claim to be an expert on vertical driven planers or even planers in general, but this reminded me of a vertical driven shingle mill.

Youll notice the apron at the bottom of the drive pulley. On your assembly an adjustment of that sort might be an undertaking. The other comparison I can draw is with a small cast pulley sawmill I run at a show. In that case Ive noticed definite improvement with belt dressing. As stated below there are options on what to use. Ive used molasses, Dawn soap, and spray on belt dressing with success. If you feel your belting is in good shape and if you have correct size lacing this might be an easy first step. Clipper lacing should have a size and hp chart to guide you to correct size lacing. Your pulleys appear to have good crown to them, but a cheap experiment could be to wrap a couple layers of duct tape around the center of the pulley to increase the crown. Easy and cheap experiment to help single out possible problems.

Pete in Holland MI · Mar 9, 2021

Use any belt dressing sparingly. A little bit, and I mean a little bit, goes a long way.

IaLeo · Mar 9, 2021

Durn good way to get your hand or loose clothing caught while dressing a moving belt. Has been done safely many times...I know!

Tim in New York · Mar 9, 2021

Amen to that. Neighbor got run through the pulley of a threshing machine back in the early 60's because he was applying dressing. Got thrown onto the thresher. I worked for his uncle in later years and he told me the guy was not breathing when he picked him up. He shook him somehow to get him breathing again. The guys was never right after that. They quite using the thresher after that year and hired a combine.

Tim

Need some experts on flat belts

Fritz Maurer

Well-known Member

Bret4207

Well-known Member

IaLeo

Well-known Member

Steve@Advance

Well-known Member

db4600

Well-known Member

Pete in Holland MI

Member

IaLeo

Well-known Member

Tim in New York

Member