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I’ve got a belt sander that is beginning to bog out during use. As I sand something with it, the belt will slow, then regain speed when I remove the work from the belt.

Can this be fixed, or is this Fairly Important Tool dying?

What kind of sander and what kind of motor?

Worn brushes maybe? Can you see any arcing coming from inside?
If variable speed, sometimes the switch when on the way out might cause it.
Course, it could just be worn out:)
Check brushes first, usually an easy cheap fix, if that is the problem.

It is an old craftsman 6x48 belt/disc sander that I’ve turned sideways to use as an edge sander.

Sure hope it’s fixable as I spent 700$ a few years ago having it rebuilt...

I've no idea if this is relevant to your sander, but when my belt sander bogs down it's because the key in the drive shaft has slipped out so that there's not a solid connection between the drive shaft and the belt. There's still enough friction that the belt turns, but it immediately slows down when pressure is applied.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

Ouch!
Unless it is really old it is doubtful it has brushes. Does the motor get usually warm or hot during operation? It could be worn bearings (which can be replaced for not too much money) or it could be the lacquer melting off the windings (reducing their strength) which is less fixable (in extreme cases they can be re-varnished).
When the motor died on my belt sander a few years back I couldn't replace it cheaply because it has a shaft shaped to take the "drum". I removed the fan housing, fan and centrifugal switch and connected another motor's shaft to that shaft. I rewired the switch to the working motor. A bit of a bodge job, but so far so good.

Yowzah! I’ll check for heat...

Much to my delight, the solution was very simple. It turns out the set screws on the roller had come loose, so it wasn’t actually an electronics problem. I’m glad, as that machine is buried deep in the bench...



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Nice!

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

That’s a nice setup idea too! Especially that big dust scoop.


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Good save, usually bad motors will give that telltale “ bad motor smell”.
A word to the wise when dealing with electrical/electronic items, don’t let the smoke out, you can’t get it back in.

B

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My memory is so good, sometimes I remember things that never happened.

Glad it wasn't an expensive fix.

I had the V belt self destruct on my shop compressor yesterday. They make quite a racket when they go. The belt was old and dry rotted.I had just fitted a 2 hp motor to the compressor because the old motor had died a couple of months back. It was a "C" face motor so I had to bodge together a bracket to attach it. I used an old aluminium serving tray that I screwed on to the capacitor housing and then bolted the tray to the tank.

I WOULD TIGHTEN THE BELT.
It might be slipping.
Mike

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Mike Collins

There is no belt, other than the sanding belt...

I have an old Craftsman belt/spindle/disc sander. It uses a centrifugal clutch to vary the speed and mine was slipping. The clutch is supposed to slide in and out on the shaft to vary the tension on the belt. (think John Deere Gator) Mine was stuck so I took it apart and cleaned and lubricated the shaft.

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Good judgement comes from experience. Experience comes from poor judgement.

I should have read all of the replies before posting. Glad it was a simple fix.

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Good judgement comes from experience. Experience comes from poor judgement.

Maybe a half drop of thread locker before reassembly and or a small spring washer

Steve

Yeah I’m going to pick up some loc-tite...