Band saw belt slips?

[Al Willits]

Haven't had much of a chance to look at it, but my 14" Delta bandsaw has started to have the belt slip under even light loads, the wheels and blade seem to turn easily, but when I try to cut something it starts to bog down and then the drive belt will slip.

Any suggestions where I should start looking, saw can't have more than a couple hours of cutting on it and everything is box stock.
tia

Al

[David Rose]

Al,

What do you call a "light load"? I would call that ripping 3/4" hardwood at a moderate (what do you call "moderate"?) speed a "light load". And this is with a carbide tooth blade. If you are getting slipping with something like this, I would check the belt tension first. I don't know how much flex at what pressure, but when I ran a standard "V" belt, I kept it feeling fairly tight with the short distance between pulleys. I'm running a link belt now and tension seems less critical.

You could also have something dragging like a wheel bearing. Just take off the band and try spinning the wheels. They should be smooth and spin with no gritty feel.

David


Haven't had much of a chance to look at it, but my 14" Delta bandsaw has started to have the belt slip under even light loads, the wheels and blade seem to turn easily, but when I try to cut something it starts to bog down and then the drive belt will slip.

Any suggestions where I should start looking, saw can't have more than a couple hours of cutting on it and everything is box stock.
tia

Al

[Al Willits]

1/2" plywood or 3/4" pine, are what I was cutting, this saw cut this stuff just fine untill this weekend, I thought maybe sawdust or wood pieces had maybe gotten jamed somewhere, but it doesn't look like it.
I can spin the blade without any noticable drag.
Belt tension seems to be loose, but it appears the weight of the motor is all that keeps tension on the belt.

I'll check all the bearings tomm, thanks.

Al

[Norman Hitt]

Al, you might also check the belt itself and feel of the inside, (the part that runs in the pully), and see if it seems soft and pliable or hard and has a glazed look. It is possible that the belt could be old (long time since mfr) even though it came new on the saw. The other thing is that even though it appears that the tension is only from the weight of the saw, it's possible that you can tighten the bolt that the motor's mount swivels on and if so, press down on the motor until the belt is tight, and tighten the bolt until the motor won't swivel up and down and see if the slipping stops then.

Oh, I forgot to ask, when you say it starts to bog down, do you mean the motor seems to bog down, or does the blade just start slowing down? If it's the motor that seems to be bogging down, then the problem is NOT with belt tension being too loose.

[Al Willits]

Norman, its the blade that bogs down, motor keeps running fine.
I'll get a new belt today and see what happens, plus take a closer look at the pulley's, maybe somethings got on them or the belt and glazed them, or like you said, its a old belt.

Thanks.. :)

Al

[Mark Singer]

Al,
If you have been cutting oilly wood it may be slipping between the tire and the blade. Lightly hand sand the tires and blow the dust out

[Al Willits]

Mark, its the motor pully that slips, I did clear a lot of sawdust off the wheels and should get some of them brushes that help keep the wheels clean anyway, but there's not any slipage that I can see on the wheels.

I'll replace the belt and clean the pully's and see what happens.

Al

[Al Willits]

OK, got a chance to look a bit closer, cleaned belt and pulley and while doing that I noticed that there is a adjustment for belt tension....except the nut that's welded to the chassis is no longer welded...pretty poor welding..not close to enough heat to penetrate.


Anyway got that temp repaired and reset the tension and it cut better, but now it cuts to the right badly and still cuts slow, thinking blade may be dull for the slow cutting, but I have to figured out how to get it to cut straight.

I've got the 6" extension and may just install that and order a set of blades from Timberwolf, need to do it anyway and nows as good a time as any.

Al

[Lee Schierer]

I thought my saw motor was either way too small or was failing. Everytime I cut something thicker than 3/4" it would bog down and the saw would smell hot. The belt tension on a 14" Delta bandsaw is set by and adjusting screw opposite the pivot for the motor mounting plate. The weight of the motor does not work to apply tension, you have to adjust the two nuts on the stud that goes through the motor mounting plate. A few turns should be all you need.

Your saw will behave like a totally different saw once the belt is tight.

[Al Willits]

Lee that was one of the problems, the nut that was welded onto the plate had come undone, weld broke.
I'm looking for my manual now to see how tight that belt should be, not sure what to do about the cutting to the (my) right, really bad..blade seems straight but when cutting it almost looks like me and my Golf driver its so bad. :)

Once again, thanks all.

Al

[Lee Schierer]

Check your saw set up. If you are wandering significantly and you are sure the blade isn't dull, the problem is probably adjustment of the upper wheel. It has to be coplanar with the bottom wheel. When you put the blade on and lightly tension the band, turn the wheels by hand a couple of revolutions. The blade should center itself on the upper and lower wheel. Wrap a dollar bill around the blade where it goes through the blade guides and tighten the guides against it. The clearance between the back of the blade to the back up rollers should be 2 standard playing cards . Tension is a bit more tricky. I find that on my Delta if I tension to the next size blade according to the scale provided on the saw I get good results (1/4" blade gets tensioned to 3/8).

Either Wood or Workbench magazines recently did a big article on bandsaw tune up.

[Al Willits]

Thanks Lee, band saw set up is next on my list of things to do in the garage, I might as well put the extension on and get new blades and do it all at the same time...

Al