Shopsmith Forums

On the belt sander, why is the direction of rotation of the belt important?

dusty wrote:On the belt sander, why is the direction of rotation of the belt important?

1) If using the table, motion upward will raise the workpiece off the table.

2) Not sure, but will reverse direction cause the tensioning to release?

3) DC will be rather ineffective.

My belt sander is currently inaccessable or I would try it out.

Assumption: 6x48 belt sander.

[quote="JPG40504"]1) If using the table, motion upward will raise the workpiece off the table.

2) Not sure, but will reverse direction cause the tensioning to release?

3) DC will be rather ineffective.

My belt sander is currently inaccessable or I would try it out.

Assumption: 6x48 belt sander.]

Sorry! My question is poorly worded.

My question was regarding the belt itself. The belts all have arrows on the inside indicating direction of rotation.

The arrow has to do with the manufacturing processes associated with the belt. If you sand against the arrow the belt may come apart during use. Also the type and grain of the backing also comes into play. The fastening of the belt seam is also a factor. Newer belts have no arrow and can be run in either direction.
Case in point. A few of our local woodworking club members were using the bench top sanders and the belts kept coming apart at the seams. They were inadvertently running the belts backwards.(against the arrow) Also sometimes the orientation of the cutting medium will pose some problems such as rapid clogging if they are used backwards.
Bill V

dusty wrote:On the belt sander, why is the direction of rotation of the belt important?

I believe that has to do with the glue line in the belt. So that the bump doesn't catch on anything.

wa2crk wrote:The arrow has to do with the manufacturing processes associated with the belt. If you sand against the arrow the belt may come apart during use. Also the type and grain of the backing also comes into play. The fastening of the belt seam is also a factor. Newer belts have no arrow and can be run in either direction.
Case in point. A few of our local woodworking club members were using the bench top sanders and the belts kept coming apart at the seams. They were inadvertently running the belts backwards.(against the arrow) Also sometimes the orientation of the cutting medium will pose some problems such as rapid clogging if they are used backwards.
Bill V

Thank you for that feedback. I did not know. I have never put the belt on backward but that is because I am a "blind follower".

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judaspre1982 wrote:What Bill said.

I read somewhere, belts that have a butt splice seam are run in one direction.
The ones that have a diagonal splice can be run in either direction.

Dave

I have one with no arrows and four that do have arrows. I would normally refer to the splice as a butt joint on the diagonal.

All of the sanding belts that I have are older versions. I bought them on an email special.

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I am of opinion that the arrow is to allow those with really deep pockets to install the belt backwards thus replacing them more often. A few years ago I had a fellow helping with a project in my shop. He changed a belt on one of my belt sanders and intentionally installed it backwards to prove I was nuts and it made no difference. When it flew apart at the seam after a very short interval, I said said okay mister deep pockets the deal was the loser buys the winner a dozen belts. Come to think of it those replacement belts outlasted the Craftsman sander. Jim