Why, What makes a belt crawl ?

Dennis Towns

Dennis Towns

Joined
Jun 8, 2006
Messages
254
Best I can tell wheel is square, but when I hit it with a blade it crawls from right to left. Be fore I start replacing the wheel or more I thought I would ask. Already tried different belts and such. Maybe too much or too little belt tension? Thanks for input.
 
Dennis Towns said:
Best I can tell wheel is square, but when I hit it with a blade it crawls from right to left. Be fore I start replacing the wheel or more I thought I would ask. Already tried different belts and such. Maybe too much or too little belt tension? Thanks for input.
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What size?
1x30"?
2x72"?

have you tried other belt manufactures?
Do you have a crowned tracking pulley?
 
Yes tried different type belts, it has a tracking wheel top center of the Bader type 2 x 72 grinder.
 
Yep, when putting pressure with blade in grinding and the belt starts moving to the side it's usually a slack belt. Those belts need to be pretty tight, especially when "hogging" with high pressure 'n speed.

We're "assume"ing the belt runs true with no wobble before you put pressure?
 
I’ve got the same problem on a new grinder I bought here in France. It uses a gas spring tension which I don’t love. I prefer the ratchet or cam mechanism.
I figured I’d have to upgrade the spring to a heavier rating
 
HSC /// said:
I’ve got the same problem on a new grinder I bought here in France. It uses a gas spring tension which I don’t love. I prefer the ratchet or cam mechanism.
I figured I’d have to upgrade the spring to a heavier rating
Click to expand...
And send the receipt to the belt grinder producer. :)
 
An alternative setup is to install a pneumatic cylinder and a small air regulator. raise or lower the tension by turning the air pressure up or down.
Some are smaller than others, and have different methods of pushing the tracking wheel. Here is one of a Dozier grinder:
1668266179927.png
 
I've seen those air cylinder setups on grinders in the past while looking on-line. While I do think it would work just fine, it does seem to be an overly complex solution to a simple spring or ratchet tension system. Perhaps for a grinder that's mounted in a fixed location along a wall where the air line can come in from the back it would work good. Just flip a valve to release tension or add tension with a regulator to adjust the amount of tension.
 
Dennis Towns said:
Yes tried different type belts, it has a tracking wheel top center of the Bader type 2 x 72 grinder.
Click to expand...
Which model of Bader Grinder do you have? Is the tooling arm made from square stock, but with the last few inches turned to a round in order to fit in a hole?
 
Dennis Towns said:
I think it was the belt not tight enough. I really thought it was but I added more tension and seems to be fixed. Thank you for the input.
Click to expand...

Yes, here's why:

Friction between the workpiece and belt increases belt tension, which increases deflection of the structure.

The wheels are cantilevered from the structure, so the deflection changes the wheels' angles and thus tracking.

With a low initial belt tension, the additional tension is proportionately greater and changes tracking more.

With higher initial belt tension, the additional deflection is relatively smaller, presumably to where the crowned tracking wheel can keep it under control.
 
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