Belt sander idler drum question

[trainguytom]

Wow, it's been a long time since I've been here. It sure is easy to get sidetracked for a year or two.
Anyway, as I dive back into woodworking & my Shopsmith stuff, I decided to refurbish a belt sander that's been laying around for a while. (an old Greenie) Pretty straightforward take down & cleanup. The drive drum bearings were a bit lumpy, so I replaced them, but the idler drum is another matter.

The drum rotates, but feels somewhat "tight" as I do this. I can't feel any roughness. It feels smooth but there is resistance when I rotate it. I do have 2 more belt sanders, one a Goldie and the other another greenie, and they all feel pretty much the same, so I have nothing newer to compare this one to.
My question is whether this is normal and also, whether this might loosen up a bit with use. (as apposed to burning up with use)
I guess I'm also wondering if anyone has disassembled it to try & service it.

[Gene Howe]

Sounds like a Bill Mayo question. I recently bought one from him and the drum rotates freely.

[JPG]

I assume you did not 'replace the grease inside the drum. Good idea to stay out of there, but old grease tends to get 'stiff' for lack of a better word.

As long as the tension function works, I would not be concerned.

From one who has been inside that drum, and does not wish to return.




At least that is my long term recollection.(as I remember it)


P.S. IIRC, the bearings are sleeve bushings rather than ball bearings like the drive drum .

[trainguytom]

JPG, I did not get into the drum and, from the looks of it, I don't think I want to, but since you have, do you recall if the bearings are they close enough to the ends so that I might drop some light oil into the ends in hopes of getting some in to soften the old grease.

I assume you did not 'replace the grease inside the drum. Good idea to stay out of there, but old grease tends to get 'stiff' for lack of a better word.

As long as the tension function works, I would not be concerned.

From one who has been inside that drum, and does not wish to return.




At least that is my long term recollection.(as I remember it)


P.S. IIRC, the bearings are sleeve bushings rather than ball bearings like the drive drum .

[JPG]

JPG, I did not get into the drum and, from the looks of it, I don't think I want to, but since you have, do you recall if the bearings are they close enough to the ends so that I might drop some light oil into the ends in hopes of getting some in to soften the old grease.

I think this is accessible from the end. The oil would have to migrate to the bushing though.
[ATTACH]26500[/ATTACH]

I just looked at the exploded view in the manual. The large washer I believe is supposed to be between the drum and the guide bushing. In this pix they are reversed!!! Gotta check that out!!!:o

[billmayo]

I find almost all of the Idler Drum problems are from grease inside the drum getting hard. It will get to where you are unable to wind the spring the needed number of turns and/or the spring is restricted from applying the necessary pressure to keep the sanding belt tight. I find that if I remove the sanding belt, release the spring pressure and then can turn the tension knob 4 complete turns while hold the Idler Drum, then you are in great shape.

Years ago, I would drill a grease fitting hole through the hole in the middle of the Idler Drum and installed a grease fitting. I also drilled a hole in the center of the idler shaft (45) so grease could get to the spring (46). This way, I could use my grease gun to lubricate the Idler Drum when needed. I discussed this modification with Shopsmith QA in 2008 but they felt it was over kill due to the few reported problems in this area.

There is a Sawdust Session video for rebuilding the belt sander. You need to keep track of the location of all the parts removed when disassembling the Idler Drum assembly. I use what I believe is a #10 threaded screw to pull the spring end out to where I can remove the roll pin and to install the roll pin when done lubricating.

I try to include the attached part of the belt sander manual with any belt sander repair or rebuild and for questions about the belt sander. It contains excellent directions.