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View Full Version : Belts tearing on my wide belt sander


dirk martin
07-10-2010, 12:46 PM
I've got a 15" wide belt sander. Grizzly. Model G9983.

This problem I'm having has been getting progressively worse. A thin strip will tear off of the belt on the left hand edge. The strip that tears off is very even all the way around, it usually remains in the round form, and the rest of the belt is in very good condition. The tearing never happens while we are sanding. It happens just with the sander running, with no stock going through. The feed belt will be a few inches below the sanding belt and the tearing will occur. On one occasion, the tear was not so clean and complete, and the whole belt ended up really getting mangled. The last couple of belts that have torn had not been used much at all.

At first I thought it was maybe the brand of belt and there was a deformity with that brand. But then we recently loaded up a different brand and it shortly occurred again. When you are facing the sander, the tear always occurs on the left edge of the belt.

At one point we were having a problem with the sanding belt tracking too far to the right and pushing against the lever that shut the sander down. So I had to do some adjustments regarding the belt tracking. I did these adjustments following the instructions in the booklet step by step. I did get that problem fixed. Before I did this adjustment, we did have a belt that tore on the left edge, so I don't think my adjustments to the tracking have anything to do with the tearing problem. But the tearing of belts is occurring more and more often, sometimes we've hardly used the belt.

So right now, we are shut down on sanding until we can find out what the problem is and get it resolved.

I am attaching 3 pics of two different belts. The first 2 pics are of the same belt, just different angles of it. The third pic is of a different belt and the piece the tore off of it.

Can anybody offer any assistance on this?
glenn bradley
07-10-2010, 1:05 PM
On the cleaner belt I don't see any sign of abrasion past the tear on the outer surface (lower right hand part of the pic). This makes me think the offending projection is between the belt and the platen / rollers. With the belt off can you get a good look at the entire path? Its like there is a something-or-other caught in there or out of position(?).
Travis Porter
07-10-2010, 1:20 PM
Does this unit have a platen? If so, do you have the same issue with the platen removed?
Bruce Koch
07-10-2010, 2:16 PM
Does the belt move to the right and left for tracking? It seems like it going left and not returning to the right. Does it have an electric eye and does it click when you put your hand in front of it?
Ed Hazel
07-10-2010, 3:18 PM
Is it tracking to far to the right?

I have never had this problem with my 9983.

I know if I open the dust collector blast gate it will suck the sanding belt up against the the dust collection opening (if the compressed air is not turnned on to tension the sanding belt) maybe their is a sharp edge on the metal duct? It might be just enough to cut the belt when starting.
Rick Fisher
07-10-2010, 4:43 PM
You should inspect the contact drum .. is it rubber ? if its damaged, it could cause this to happen..

Damage to a rubber drum can cause a small bump to protrude.. A mushroom effect..

If there is a platen, it could easily be causing the same thing..

I would strip off as much sheet metal as I needed too, to inspect all the rollers.

Make sure the support rollers spin freely as well.

You should also ensure your belt tension is right.. if the tension is not right, you could get slippage on start up.. I have had this exact problem.. trying to find the picture of my stripped belt.. The problem was a small gouge in the rubber on the contact drum.. when touched up .. it went away..
dirk martin
07-12-2010, 6:06 PM
Does this unit have a platen? If so, do you have the same issue with the platen removed?

Is it ok to run my sander w/o te platten?
I wasn't sure tat was ok to try....
Mike Hollingsworth
07-12-2010, 6:27 PM
Is it ok to run my sander w/o te platten?
I wasn't sure tat was ok to try....

Sure

I never used the platen when I had my Powermatic
http://www.muellerco.com/images/portfolio/powermatic/17-1632-WideBeltSander.jpg
When I traded up to a 20" with motorized elevator and DRO, No Platen was No Big Deal.
http://tool-corral.com/shopsite_sc/store/html/media/W1709.jpeg
Mike Hollingsworth
07-12-2010, 6:32 PM
BTW

make sure you unhook all the air fittings and blow everything out. I found that the tiniest piece of dust will clog the system.
dirk martin
07-12-2010, 11:15 PM
If it's no big deal to run without the platten, then why is when I read up here about people shopping for a wide belt sander, I see so many replies say make sure you get a model with a platen, and other replies that'll say to make sure you get a platen for finish sanding?
Shiraz Balolia
07-13-2010, 12:07 AM
Dirk - there are a couple of things that could be happening:

1) When you load the belt it may not be inside the air eye fork (figure 22, page 27 owner's manual). This is probably the biggest cause of belts running off the edge and ripping.

http://cdn1.grizzly.com/manuals/g9983_m.pdf

2) The little white "finger" that sits on both sides of the machine and trips the oscillation so that the belt starts moving in the other direction - could have broken or may have a groove cut into it. These need to be replaced from time to time. Figure 23, page 27 shows the finger I am talking about. There is one finger on each side of the belt.
Mike Hollingsworth
08-30-2010, 12:30 PM
If it's no big deal to run without the platten, then why is when I read up here about people shopping for a wide belt sander, I see so many replies say make sure you get a model with a platen, and other replies that'll say to make sure you get a platen for finish sanding?

Dirk

I don't use my wide belt for finishing. If you do, I'd suggest a machine with a platen.



Dirk - there are a couple of things that could be happening:

1) When you load the belt it may not be inside the air eye fork (figure 22, page 27 owner's manual). This is probably the biggest cause of belts running off the edge and ripping.

http://cdn1.grizzly.com/manuals/g9983_m.pdf

2) The little white "finger" that sits on both sides of the machine and trips the oscillation so that the belt starts moving in the other direction - could have broken or may have a groove cut into it. These need to be replaced from time to time. Figure 23, page 27 shows the finger I am talking about. There is one finger on each side of the belt.


Is this incredible or what?
Shiraz, I am in awe when it comes to your Customer Service.
Grizzly's website is the best
Perry Bowen
08-30-2010, 8:47 PM
The only time I have made a wide belt rip like that is when I did not install the belt correctly.
dirk martin
08-30-2010, 8:59 PM
Once we made sure it was "inside the forks", all has been good.

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