Belt Sander Question

Dopic1

Dopic1

Irredeemable wood purveyor
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Guys,

I have a LB Wilmont 72 grinder with a 2hp 3 Phase VS Baldor Motor and love it, however I cannot get the belts to run true. At almost any speed they oscillate from side to side, some more than others. It doesn't matter what brand of belt or how it's tensioned ect. I am scratching my head on this one since I cannot get it to run true in any configuration. I've check and rechecked and still cannot figure this out. I also spoke with Chris at Wilmont and his recommendation was to change the brand of belts which really didn't help. Any help would be greatly appreciated.
 
First off are your drive wheel and front ones if you have a flat platen in alignment and are there screws in these that might be loose?
Where is the tracking wheel? is it pretty much running in the center of the belt assuming the others are in alignment? Now place a bunch of layers of masking tape on the idler wheel at about center and adjust this. I hope this helps.
Frank
 
Frank, I have checked the alignment over and over and do have a flat platen, the tracking wheel is on top below is a stock photo. I'm scratching my head thinking I'm missing something. I'll try realigning it again with the masking tape.

Grinder_zpsm8b0qves.jpg


Thanks Scott
 
Have you manually applied more tension? Is this a new grinder? Did this just start or has it done it since new?
 
I've had it for about 8 months and it has done it since new. Some belts more so than others, by manually applying tension I assume you mean pulling the steel tube with the platen out further? Yes I have tried all sorts of different tension settings. I can usually figure something like this out but it starting to drive me nuts.
 
Here is what I can add:

1) make sure all wheel shafts are at 90 degrees to the belt. Even 1 degree of bend in a shaft can make the belt want to track left or right. This will make the idler wheel corrct it, and then it will track off again - over and over and over.
I would take a good look at the idler shaft bolt, as it could have easily been bent in assembly.
It is possible that in the drilling and tapping of one of the wheel shafts is nit straight.

2) make sure the drive wheel is aligned directly in line with the idler and contact wheel.
Question - does the tracking problem exist with a single contact wheel???

3) check all bearings and sleeves for any play.

4) If the problem can't be found or solved, ask Chris if you can ship it back for a replacement or repair.
 
if all your wheels are in line,none are wobbly or loose and you have good belt tension it should run true. a few things come to mind 1. you have a weak or worn out air spring 2. the platen is too far out from the wheels. 3. the crown on the tracking wheel is not even all the way around the circumference. i think Matt R. is suggesting that you manually pull up on the tracking arm while the grinder is running and see if the belt wobble goes away, if it does you need a new air spring.
 
Stacy E. Apelt - Bladesmith said:
Here is what I can add:

1) make sure all wheel shafts are at 90 degrees to the belt. Even 1 degree of bend in a shaft can make the belt want to track left or right. This will make the idler wheel corrct it, and then it will track off again - over and over and over.
I would take a good look at the idler shaft bolt, as it could have easily been bent in assembly.
It is possible that in the drilling and tapping of one of the wheel shafts is nit straight.

2) make sure the drive wheel is aligned directly in line with the idler and contact wheel.
Question - does the tracking problem exist with a single contact wheel???

3) check all bearings and sleeves for any play.

4) If the problem can't be found or solved, ask Chris if you can ship it back for a replacement or repair.
Click to expand...

Thanks Stacy, maybe Ill take it apart and re-assemble to ensure everything is true and check the items you pointed out. I thought I had aligned everything correctly but something has to be out of kilter. A side note Chris was very helpful and responsive when I did contact him.
 
mike-E said:
if all your wheels are in line,none are wobbly or loose and you have good belt tension it should run true. a few things come to mind 1. you have a weak or worn out air spring 2. the platen is too far out from the wheels. 3. the crown on the tracking wheel is not even all the way around the circumference. i think Matt R. is suggesting that you manually pull up on the tracking arm while the grinder is running and see if the belt wobble goes away, if it does you need a new air spring.
Click to expand...

Thanks Mike-E, now I understand what Matt R meant and the air spring I believe is in good shape. Also the platen is behind the plane of the wheels. I do need to check the crown of the tracking wheel which I hadn't before. I had a similar instance on a band saw that would cause the blade to oscillate.

Well there is a few things I didn't check so thanks folks and if anyone else has any other ideas please share.

Scott
 
In addition to what has already been suggested, try the following.

1. Remove the platen and run the abrasive belt over one of the 2" platen idlers (instead of both 2" idlers). See what happens. Then try the other 2" idler.
2. While the grinder is running, grab the tension arm and apply steady muscle to the left. See what happens. Try it again, this time muscling to the right. It is normal for the tracking to walk to one side or another during this test - what you're looking for is an increase or decrease in the wobble.
3. With the abrasive belt installed and tensioned, try tightening the tension arm hinge bolt so there is no play. Start the grinder and see if the symptoms change.
4. As a last resort, buy or borrow some new wheels. Swap them out and see what happens.
 
My buddy had the same issue with his grinder, we finally found that when he milled his idler wheel it was not truly round, had a little wobble. I am with Stacey, check the idler wheel.
 
What weight is the gas shock? If it's 40 try ordering a 50lb from McMaster Carr about $5-10. Fixed my problem when I built my own
 
P.Brewster said:
In addition to what has already been suggested, try the following.

1. Remove the platen and run the abrasive belt over one of the 2" platen idlers (instead of both 2" idlers). See what happens. Then try the other 2" idler.
2. While the grinder is running, grab the tension arm and apply steady muscle to the left. See what happens. Try it again, this time muscling to the right. It is normal for the tracking to walk to one side or another during this test - what you're looking for is an increase or decrease in the wobble.
3. With the abrasive belt installed and tensioned, try tightening the tension arm hinge bolt so there is no play. Start the grinder and see if the symptoms change.
4. As a last resort, buy or borrow some new wheels. Swap them out and see what happens.
Click to expand...

P Brewster, just saw that you are located in Berks County. I'm in Alsace twp small world.
 
Dopic1 said:
P Brewster, just saw that you are located in Berks County. I'm in Alsace twp small world.
Click to expand...

Ha ha 'Pennsyltucky' indeed! I'm right down the road from you in Colebrookdale township. I have some spare KMG wheels if you want to borrow a few for troubleshooting purposes.
 
P.Brewster said:
Ha ha 'Pennsyltucky' indeed! I'm right down the road from you in Colebrookdale township. I have some spare KMG wheels if you want to borrow a few for troubleshooting purposes.
Click to expand...

That would be great! I have some work around the yard this weekend I'll shoot you a PM when I get a chance. Thanks for the offer!

Scott
 
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