Belt sander upper drum bearings

[tucsonguy]

The existing oillite bushings in the upper drum create friction, heat and vibration; the drum doesn't turn nearly so easily as the lower power drum, which has actual bearings.
I measured today, and the upper shaft is 5/8 OD and the outer diameter of the drum casting around the axle end is 25.7mm
You can buy needle and roller bearings that are 5/8 x 13/16 od (or 20.637mm), which seems to me like they would be thin enough to work, if the drum was machined to fit them.
Wondering if anyone else has ever gone down this rabbit hole?

BTW, here is a youtube video of the complete disassembly/reassembly of the belt sander, including the upper drum, which can easily be disassembled using regular tools plus one 10-32 machine screw + nut + washer.

https://youtu.be/vyAqXFSBm7o

[garys]

I've found that most bearings have their idendifying number stamped on them. Have you looked at the old bearings for numbers? If you find numbers on the bearings, it becomes a simple job to take them to any local bearing shop and get new ones from them.

[jsburger]

I've found that most bearings have their idendifying number stamped on them. Have you looked at the old bearings for numbers? If you find numbers on the bearings, it becomes a simple job to take them to any local bearing shop and get new ones from them.

The OP is talking about replacing the oillite bushings in the "upper drum" with bearings, not replacing the bearings in the "lower drum".

[tucsonguy]

I successfully removed the existing oillite bearings (bushings) in the upper idler drum and replaced them with two 5/8x13/16x12 roller bearings. The result is a remarkable improvement in performance - far less vibration.
I'm going to add a zerk grease fitting in the middle hole so I can maintain the grease level in the bearings without having to disassemble.
I believe this is a worthwhile modification which improves performance of the belt sander remarkably!
I'm doing this because I have turned the belt sander into a Tormek-grade tool sharpener, adding a 12mm Tormek style bar on an Axminster guide, which lets me mount any Tormek jig on the belt sander to precisely sharpen pretty much any tool. It's worked incredibly well. I also use 2x48 Trizact belts (which track well) for final edge at a 1200 grit level.
I've also added a shoplight and a quench tray, but that was just for fun.
Bottom line, the Shopsmith belt sander is a robust, well built machine that can be rebuilt to higher-than-factory specs to give tremendous results, not merely as a belt sander but as a tool sharpening station.