Belt Sander Drive Drum

[DLB]

My Belt Sander, bought new in the early 80's, has never tracked really well. I'm pretty constantly needing to re-adjust. I now understand this is most likely due to crowning of the drive drum. I want to try removing the crown myself. My first question: Can I remove the sleeve in a way that allows it to be re-installed? If yes, how is that done? Is there any kind of adhesive holding it? I know a machine shop can do this easily, but I'm thinking the cost will be in the same ballpark as a replacement. Thought I might as well give it a try. If anyone has done this successfully I'd appreciate any pointers.

- David

[DLB]

My Belt Sander, bought new in the early 80's, has never tracked really well. I'm pretty constantly needing to re-adjust. I now understand this is most likely due to crowning of the drive drum. I want to try removing the crown myself. My first question: Can I remove the sleeve in a way that allows it to be re-installed? If yes, how is that done? Is there any kind of adhesive holding it? I know a machine shop can do this easily, but I'm thinking the cost will be in the same ballpark as a replacement. Thought I might as well give it a try. If anyone has done this successfully I'd appreciate any pointers.

Going to answer my own questions in case anyone wants to try this. I was able to rework my crowned Dust Sander drive drum and on initial test it does seem to improve tracking considerably. I have no explanation for this. Nick mentioned it in a Sawdust Session without explanation. In essence: At one time both the Idler and Drive Drums were crowned for improved tracking. It was later found that crowning only the Idler yielded better tracking, and that is how current Belt Sanders are made. I don't know the time frame for the change, and I don't think he mentioned it.

There was adhesive on roughly the outer 1-1/4" on both ends of the drum. On mine I was able to peel the rubber sleeve off without damage. I used a little WD-40 in an attempt to soften the adhesive with marginal results. But whatever adhesive is used, it sticks much better to the aluminum than to the rubber so I was able to remove the sleeve. I think I got a little lucky here, but it is worth trying if your sleeve is in good shape. A replacement sleeve is available from Shopsmith, around $12 IIRC. A complete un-crowned drum is also available, ~ $112 includes new bearings and the sleeve.

I adjusted the Belt Sander work table to use as a tool rest/guide, removed the backup plate and dust collection. I just sanded the crown out, stopping frequently to check progress. I ran it about 900 RPM, I don't think speed is critical. When checking, carefully ensure your straightedge is parallel to the axle. This is not the ideal tooling if you were doing ten of these, but for one it was okay. I initially tried a file but it loaded up quickly and so was slower than coarse sandpaper.

I used double-sided tape to reinstall the sleeve. I'm sure there are numerous alternatives. Tape goes on very evenly and will be easy to remove if necessary. My best guess at the original adhesive is the same product as bandsaw tire adhesive.

You do have to disassemble the Belt Sander almost completely to do this. Twice. Removing and installing the sleeve is done with the drive drum removed. I also replaced one of the bearings while I had it apart, I had replaced the other a couple of years ago. I didn't use them, but I would advise sealed bearings for this, it is a particularly nasty environment for bearings. The originals in mine, and those I used as replacements, were shielded bearings 6202-10-ZZ. If I had a do over I'd choose 6202-10-RS. I don't know if all Belt Sanders use the same bearing, but I'm reasonably sure all old ones use these.

- David

[edma194]

Good job on that! Using sealed bearings makes a lot of sense on this sander. I haven't had mine long, don't know how much it was used before and not sure what kind of life to expect from the bearings.

[chapmanruss]

David,

Thanks for the information. It will be helpful to others who may have that tracking problem. I am adding this thread linked in my SPT's What When and Where posts.

My 1977 Belt Sander tracks very well after I learned how to set it correctly. I just checked it and there is a slight crown to the sleeve on the Drive Drum. I am not sure if this is wear on the sleeve or if it actually is crowned. The crowning on the Drive Drum Sleeve is much less than and almost unnoticeable, than the crown on the Idler Drum.

I refurbished a 1989 Belt Sander I got with a collection of SPT's and a Mark V a few years ago. It needed to have the Idler Drum replaced which was bent. I assume from being dropped by a previous owner and after replacing the Idler Drum it tracked as it should so I am not sure if it had a crowned Drive Drum or not.

[DLB]

Just to expand on earlier comments: The Sawdust Session where this is discussed is SS112, topic 3, Belt Sander Tune-up. The flat Vs. crowned Drive Drum starts about 11:45 in. Nick also mentioned the Drive Drum bearings being sealed, but mine were shielded originally. And the reference I used to buy the bearings was 'ZZ' (shielded) somewhere here on the Forum. Whether Nick misspoke or the new ones are sealed I'm not sure, but I'm in agreement that sealed is the better choice. Everett's bearing guide also says they are SS PN 502962 and that they are sealed. So, it seems probable that SS also changed these to sealed bearings at some point in production.

- David