Unusual belt sander

[Glug]

This belt sander recently came up at an online auction where I wasn't close enough to inspect. I puzzled over it a bit and thought I would share.

I haven't seen one like it and think it is shop made. The motor is a 1/3 hp baldor. It was described as 1", but the pulleys look sized for 2". Maybe the wide pulleys are for belt stability/retention and it is a 1" design.

The configuration suggests it was solely intended for slack belt grinding. Though there is something hidden behind the auction tag, maybe a platen.

Starting at the top.. The wheels have quite a bit of crown. The flex of the arm, which I estimate is 3/4" wide, appears to provide the belt tension. Like a bow of sorts. It seems to provide a large area of belt for slackbelting. I wonder if the long unsupported belt is unstable? Maybe part of the intent is to limit the force the operator can apply? It also seems to provide a lot of work area for large pieces. My 1x42" belt sanders really don't have a lot of room, even if the platen is removed.

It seems very tall, even to the point that 1x42 belts would not fit. I tried measuring using the cinder blocks for scale, but they don't seem to be standard size and the perspective makes it difficult. It seems the distance from the motor shaft to the top of the shadow on the brick is about 21". So maybe it does take a 1x42. Though that doesn't account for the distance from the motor to the front wheel.

The triangular plates near the bottom of the main arm are curious. I see four holes but only two appear to have fasteners. I wonder if they are some provision to adjust the arm and belt tracking? I see no other provision for tracking adjustment, other than the crown.

On the bottom, it appears the front wheel support slides fore-aft along the horizontal column.

Hidden behind the auction tag, there appears to be an extending tool arm, possibly with a rest or even platen.

I'm not sure of the purpose of the red knob under the motor. Maybe it is a quick release that allows the motor to be moved fore-aft on the base.

Someone else bought it for approx $143 total. I might have been more interested if it was variable speed, I was closer, or if I wasn't bidding on a burr king the next day.

[oxford]

To the left is what looks like a standard abrasive cutoff saw. It goes up 4.5 blocks, saw is another 3 higher. You can use that for scale. I would say, no way a 42” belt is fitting in that machine.

[johnc]

If it had handles I would say it looks like a handheld crankshaft polisher.

[Paul Alciatore]

1. If this was in the US, cinder blocks are about as standard as you can get. I have never seen one that was anything but 8" x 16" except for decorative purposes and even then usually that size. And the abrasive blade on the saw is probably a worn 16" one and it appears to be a bit less than two blocks high. So that sander is around 6 X 8" high or 48". Going to need around 100" or more of belt.

2. I notice the paint is worn off on the upper 8-10 inches of the vertical arm. That suggests that the upper pulley may be adjustable.

3. Also the front pulley seems to be adjustable on that square, horizontal arm. That also could be for belt length/tension adjustment.

4. The triangular plate on the vertical arm is probably for mounting it to a wall or a floor stand.

5. No way I would pay over $100 for that, shipping included. Since someone already did, this discussion is moot.

[reggie_obe]

Pipe/tube belt sander or polisher

[Doc Nickel]

Pipe/tube belt sander or polisher

-This. That and crankshafts, as noted. Behind the triangular plate is a chainsaw type handle.

Doc.

[boslab]

Very useful bit of kit , shafts tubes we had one in work with a selection of belts, even the worn belts were handy for polishing, crank journals flame build ups, blending stuff in, general making it pretty.
it’s a very home shop build possibility imho, the one shown is best used with spinning work, the ones for pipework kind of wrap the belt round the tube, like a deep throated thing .
I did wish there was a smaller one myself the bow was forever catching the back shield tin of the lathe
mark

[BCRider]

I think it's a workable concept. Although I'm also thinking that the spring arm to the top pulley should be wider to avoid springing over to the side and messing up the belt tracking. It looks like it would want to twist too easily.

But hey, the proof is in the pudding as the odd old saying goes. What happens when you belt it up and use it?

[MichaelP]

If your buddy who lives on the second floor doesn't have a grinder, this one can be shared.

[wierdscience]

It's a Goodson crank polisher- https://goodson.com/products/72-port...haft-polishers

I got one I bought at an auction maybe 20 years ago in a lot full of misc stuff. I didn't buy the lot for it, there was a bunch of Bronze barstock in the mix and I got the lot cheap. After I got the stuff home and was going through it, the polisher was all there, but the special Baldor 10k rpm drive motor was shot. A new motor back then was $350. I stuck it on a back shelf and forgot about it until recently. I ended up modifying it to use a 4-1/2 angle grinder as the motor and also to use 2x42 belts. It works pretty good, but it's a bit crude.

[Glug]

It's a Goodson crank polisher- https://goodson.com/products/72-port...haft-polishers

Excellent! Mystery solved. Thanks.

I watched the video of the unit on the site (most of the video is prep and not use). Maybe the auction unit was an early version or even a copy. In the video they said they did not design it. Doc was spot on that the triangles were to mount a handle. It's possible they've been using it in more of a bench config.

Pretty neat tool for that application. I've seen lots of lathes in auctions that have been dedicated to belt grinding and/or polishing. Some of them are sweet setups and I'll bet they produce great low effort finishes on tube, etc. I recently saw one that was a rare baby 16x30 Powerturn. The machine looked fairly pristine. Tough to say but it might have been a great rescue for someone.

Having a bow belt polisher on your lathe would be nice if not for the risks.

[Illinoyance]

Looking at the picture, there appers to be a square socket in the front. It could be a crank polisher with a part missing.

[gellfex]

It's a Goodson crank polisher- https://goodson.com/products/72-port...haft-polishers

I got one I bought at an auction maybe 20 years ago in a lot full of misc stuff. I didn't buy the lot for it, there was a bunch of Bronze barstock in the mix and I got the lot cheap. After I got the stuff home and was going through it, the polisher was all there, but the special Baldor 10k rpm drive motor was shot. A new motor back then was $350. I stuck it on a back shelf and forgot about it until recently. I ended up modifying it to use a 4-1/2 angle grinder as the motor and also to use 2x42 belts. It works pretty good, but it's a bit crude.

10K rpm? That sounds terrifying. I've been smacked by a 42x1 snapping and it wasn't fun. I have a classic Rockwell 42x1 and one of the sweet things about it is how many configurations you can make with the pulleys. If you put the top one high and remove the backplate you can do some nice floating tube polishing etc.

[Georgineer]

...

But hey, the proof is in the pudding as the odd old saying goes...

No, that's the new saying, and it makes no sense. I was shouting at the telly only last evening when the stupid man kept saying it. Grrrr!

"The proof of the pudding is in the eating." Sorry, I didn't mean to derail the thread.

George

[wierdscience]

10K rpm? That sounds terrifying. I've been smacked by a 42x1 snapping and it wasn't fun. I have a classic Rockwell 42x1 and one of the sweet things about it is how many configurations you can make with the pulleys. If you put the top one high and remove the backplate you can do some nice floating tube polishing etc.

Not really, the belt drive pulley is small, maybe 2" in diameter, so the belt isn't moving very fast and given the lack of a belt tension mechanism, it slips pretty easy too. I had a 1x42 Rockwell, those are great sanders.