# 6"x48" belt, 9" disc, belt driven, cast iron, Craftsman Sander help needed



## Mad (Dec 9, 2017)

*6"x48" belt, 9" disc, belt driven, cast iron, Craftsman Sander help needed*

I have a 6"x48" belt, 9" disc, cast iron Crafstman sander driven by a totally enclosed fan cooled 110v electric motor via V belt and pulleys.

The drive shaft may have worn a gullet so deep and wide as to make it unusable. 

Ive seen similar sanders offered for sale for parts, as well as eBay sellers who make a career out of dismantling used machines to sell the parts for more than the non working whole would go for, and one thing both types of sellers have in common is that they do not have the driven shaft for sale individually or in serviceable condition when selling the machine in total.

So I suspect that this is how I got burned, buying this machine. And I suspect this is a common problem with these machines. But if it is a common problem, then there might also be a common solution.

And that is where you come in. Has anyone reading this heard about or have this kind of sander, with this kind of problem?

There are no markings or model numbers whatsoever on my sander, but a google image search suggests that it might be any one of the following Sears models:

113.22521
113.225030
113.22831
113.279600c

The list above is not exhaustive, and may or may not include my specific sander model, but all of the above are very similar in configuration... From the casting details to the open leg stand to the underslung motor to the dust port design. 

Has anyone replaced the driven shaft of their similar belt driven sander?


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## woodnthings (Jan 24, 2009)

*What does this mean?*

The drive shaft may have worn a gullet so deep and wide as to make it unusable.

Which is the drive shaft, the one which has the pulley driven by the motor on the sander.... or do you mean the motor's shaft which drives the belt?

Where is this "gullet" .... on the sander casting that houses the bearings? How would this happen? Was the pulley rubbing on the casting? 


How about a photo? I have this very model sander, driven by a TEC 1 HP motor. I used it for about 30 or 40 years..... no issues, except replaced the bearings a few times. I grind metal on my belt sander.... blasphemy. :surprise2:


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## Mad (Dec 9, 2017)

The gullet is on the driven shaft. The shaft that is driven via a pulley and a V belt that is turned by the motor. The shaft which directly turns the disc wheel and directly rotates the drive end roller for the sanding belt. The shaft that rides on three NTN 6202Z enclosed bearing cartridges. The shaft upon which the drive belt pulley is directly attached. The driven shaft. That is the shaft that has the gullet on it.

A photo would be nicer than all the descriptive words, but I have no way to post a photo from this device, and have no other access online from my current location this week. I hope I was more clear this time around, and I apologize for any earlier confusion.

This driven shaft has a 1/2" wide, 1/8" deep gullet turned evenly all the way around it's circumference. This wide annular groove is positioned in the middle of the where the first bearing, nearest to the drive pulley, is positioned. This third pulley is actually mounted in the removable "hinge" casting that is retained to the major platen/roller casting via two bolts that facilitate and guide the platen's 90 degree arc of positioning adjustment.

The second bearing was trashed. The cage and two balls were pulverized, the inboard cover was floating free past the snap ring between the roller and the second bearing, but the inner race remained secure to the shaft, and had to be pressed off.

On the other hand, the inner race to the first bearing (in the minor hinge casting) does NOT have an interference fit to the shaft, despite the bearing part numbers being the same for all three bearings.

The shaft itself has at least four diameters along it's axis. The largest diameter is where the keyway is for the sanding roller. The smallest diameter is the gullet, which I do not as yet know whether or not was turned into the shaft by inadvertent wear, or by design. If by design, then is there supposed to be a pair of hemispherical bronze bushings that fit into the gullet to normalize the shaft diameter to match the bearings inner race diameter?

The remaing two shaft diameters are the slight turn downs for the second and third bearings, as well as the drive pulley and sanding disc wheel. The final diameter is the majority of the shaft. There are several grooves cut in for snap rings to hold the bearings in place.

I do not know what this shaft is supposed to look like. Especially in the area where the first two bearings that are next to each other are on the driven side. Is there a sacrificial bushing that is supposed to be inside that gullet? Or is that gullet even supposed to be there at all?


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## Mad (Dec 9, 2017)

Not "this third pulley". Replace text with "this first bearing". (phone very difficult to type with)


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## woodnthings (Jan 24, 2009)

*try E replacement parts*

https://www.ereplacementparts.com/c...disc-sander-parts-c-158286_162684_162840.html

Ebay has some bearings:
https://www.ebay.com/itm/Sears-Craf...089362&hash=item33aea6ec19:g:pNkAAOSwNyFWdlHY

I couldn't find a diagram of the driven shaft or the actual part itself. 

I did find a manual:
https://www.ebay.com/itm/CRAFTSMAN-...544064?hash=item489de2fcc0:g:xTwAAMXQstJTmIMU

The answer to your gullet/gouge is simply to take it to a machine shop, have it welded and ground down or turned down. It's from the loose set screw that slipped and got spun on the shaft. There needs to be a flat for the set screw, and the machine shop can make one for you if you are not handy with a mill file.

FYI, I used the model number off my sander to do this research.


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## Mad (Dec 9, 2017)

Thank you for your research. Like i mentioned in my post above, I don't have Internet access where the sander and I are currently located, and am working with an 8 year old iPhone 4 with a 3 inch screen that Apple has purposely depricated the functionality of (ie no more email) to get me to upgrade. And with no markings on my sander, I had no model number to be certain of. So I really was hoping to find someone here with some hands on experience with a machine like this. Looks like you are the man!

No, the gullet is NOT from an overdriven set screw. There is no set screw element where the gullet is. In fact, the gullet is underneath a bearing, and bearings are not retained by set screws. 

I might drive a couple hours back home just to post a photo of what im talking about. If this gullet is wear, it is remarkable how even, wide, deep, and symmetrical the "wear" is. Yet if it were not wear, it wouldn't make any engineering sense, as the gullet would weaken the shaft right where it would need to have the greatest strength.


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## woodnthings (Jan 24, 2009)

*It's been quite a few years since ....*

I've had mine apart to replace the bearings, but I do NOT remember any groove or gullet in the driven shaft. I do remember the step downs for the various components, the wide belt drive hub, the inner and outer bearings, some circ clip grooves for retainers and possibly a step down for the drive pulley ..... Short of taking mine apart, I can't tell "exactly" what it's like but that sounds about right.

You choice(s) are still limited. Find a new shaft with the correct bearings, maybe those I posted,OR fix this one. I have had machine shop work done at a rate of $40.00 per hour for simple drilling and tapping. This may be more expensive, but there doesn't seem to be another choice.

SAs a last resort, stop by and I'll weld it and turn it down for you.... :surprise2:


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## Gary Beasley (Jan 21, 2009)

The worn gullets are symptomatic of bad bearings sliding on the shaft. It happens because the bearings are installed without any set screws so when they start to bind up the shaft is rolling inside the bearing and removing metal. Ive had to deal with this in some fairly expensive bindery equipment just turning the shafts to powder. The shaft needs replaced or taken to a machine shop and built back uo with a plasma welder and remachined. Not cheap. It might be easier to have a local machine shop make a new shaft.


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## woodnthings (Jan 24, 2009)

*Plasma welder?*

I don't know about bindery equipment, but I do know that small shaft would be just fine with a MIG weld spotted around on each side opposing the last tack to prevent distortion. Then lathe turned to the same diameter on either side. Both operations would take me about 5 minutes each, maybe 10 minutes at most. There is not a whole lot of strain on this shaft, which even with the groove, worked up until the bearing failed completely.

Someone posted else where, the Craftsman Tools Thread I believe, that the Sears/Craftsman bearings were Metric internal and Imperial external, but I can't verify that. Check them with a caliper and check the shaft diameter as well. These sanders run great IF you do minor maintenance, like bearing replacement, since there is virtually nothing else to go wrong. I also think making a new shaft wouldn't be necessary and would be cost prohibitive, since there are several steps downs in diameter at precise locations as well as those circ clip grooves.

So I Googled Craftsman 6 X 48 sander issues and found this:

https://www.searspartsdirect.com/pa...25941&categoryName=Sander&brandName=CRAFTSMAN

The shaft is in stock and a bit pricey, but this could be cheaper in the long run than running about finding a machine shop...? It also has some woodruff keyways, another machining operation which would add expense.


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## Gary Beasley (Jan 21, 2009)

Plasma welder is what they called it at the shop we took it to. You could hardly tell where the repair was. I was told they sprayed metal powder in and fused it in place. There may be a more appropriate name for it now. Its a great way to restore worn and out of production parts like we had.


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## woodnthings (Jan 24, 2009)

*Spraying metal, I love it!*



Gary Beasley said:


> Plasma welder is what they called it at the shop we took it to. You could hardly tell where the repair was. I was told they sprayed metal powder in and fused it in place. There may be a more appropriate name for it now. Its a great way to restore worn and out of production parts like we had.


Welding meets science, great! I heard about it years back, but it never occurred to me as quick and dirty fix for repairs like these.... being a unceritfied welder I just make do with my MIG. I do have a TIG on my wish list however. :|


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## Mad (Dec 9, 2017)

So I made the journey home overnight, and made the photo below so that there is no doubt as to what we are dealing with as far as this shaft is concerned.

It sounds like Gary Beasley has got a good handle on this, having seen it before. Another friend of mine who worked with processing equipment involving thousands of conveyer belts said the same thing... the groove is shaft wear.


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## woodnthings (Jan 24, 2009)

*Here is the replacement part*

I can't imagine what the recess is for. It's not like that on the sander I own. Yours may be different OR you may be solving a non-existant problem. I would question why they would make the shaft in that manner.....


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## Mad (Dec 9, 2017)

woodnthings said:


> Yours may be different OR you may be solving a non-existant problem.


OR, mine may _not_ be different and I may be solving a very _evident_ problem.




woodnthings said:


> I would question why they would make the shaft in that manner.....


I did. And so far, no one I have asked was able to come up with any reason why the shaft would be _made_ in that manner. The only plausible explanation that seems to explain the deep gulley is that the shaft may have been _worn_ in that manner. 

But without first checking with other owners of identical equipment who may have occasionally lubricated or replaced their bearings, I had no way of knowing what the shaft should look like. Hence the posting of this thread.


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## Gary Beasley (Jan 21, 2009)

I can tell from looking your picture shows the bottom end of woodnthings illustration. If you can get the part go for it, along with all new bearings.


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## Larry42 (Jan 10, 2014)

Mad & woodnthings have two different sanders judging from the key ways. Woodnthings photo shows woodruff key ways while Mad's shows a milled keyway. 
Before you go too far check to make sure the castings are OK, not wobbled out bearing seats. A little lose is no big deal for the castings, you can use Loctite bearing fit stuff to fill minor gaps. 
If you can't find the shaft find a small machine shop and ask how much to make one. Take the new bearings with you so they can check fit. You should also get new snap rings. Someone was an idiot for running the bearing that long after it failed. I've got two of those sanders out of the 70's. The idler end failed on both but I've never had the driven end apart. Had to replace the motors and die cast sheaves & belts though.
Sears had a variety of manufacturers making their tools, so not all may use the same parts/bearings. Check the housing and shaft to make sure you can get the appropriate bearings from an industrial supply company. It they are odd (metric & imperial) get bearings to fit the housing and have the shaft made to fit the bearings & other parts. 

You may have to ask yourself if it is worth it, first.


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## woodnthings (Jan 24, 2009)

*We need a good model number.*

How would we locate the correct part, unless someone just happened to have their sander apart and found a shaft with a machined in recess OR a bearing failed that created the same condition? My view that's not likely to happen.:|

So now what? A machinist could probably tell if the recess was indeed "machined" OR a result of a failed bearing. Practically speaking, it absolutely makes no sense to have a recess in that place, where a bearing would sit...none. :frown2: 

The machinist may come to that conclusion, who knows? I'm just doing a diagnosis from space travel on the web...... and applying common sense, having had my own sander apart, albeit a few years ago. I am not a machinist, nor a certified weld either, but I've welded a whole lot of stuff and turned a whole bunch of stuff out of necessity. I've even made a few drive shafts for custom trucks in my time. 

So, I'll just wish you good luck and hope you can figure it out.


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## Tool Agnostic (Aug 13, 2017)

I agree with @Gary Beasley, backed up by the photo you posted. I think the bearing froze and stopped moving. The shaft continued to rotate, and the resulting metal-to-metal friction wore the groove in the shaft. 

Only yesterday I was looking at the same exact wear pattern, for the same exact reason, but on a much larger scale. It is a very busy, very heavy, motorized iron gate. A bearing on the main shaft had frozen, but the shaft kept rotating as the heavy gate opened and closed. Over time the shaft wore to the point where the wobble affected the position sensor switches. That's when we noticed. In our case, the shaft will have to be replaced, along with several other affected parts that were abnormally worn.

For the sander, I wonder whether you might hear a high pitched metallic squeal if a bearing is frozen?


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## Mad (Dec 9, 2017)

Tool Agnostic said:


> For the sander, I wonder whether you might hear a high pitched metallic squeal if a bearing is frozen?



Who knows? If it were my tool from the beginning, this would have never happened.


I bought the sander as part of a constellation of tools that included a panel saw, a job box, a vise, a couple of shop vacs, a table saw without a fence, etc. In other words, there was a lot of stuff to evaluate all at once within the hour or so of time that I had to review and reject or retain what was available and make a package deal offer. So I merely turned the sander on and off to verify that it ran. 


Had I known then what I have since learned after dismantling the machine for component inspection before use, (something I had already planned to do, but couldn't practically do at the site of sale), I would have known immediately what to look for, as this shaft / bearing / hinge / belt arrangement is clearly the weak point in this particular style of disc belt sander. Searching out this problem has uncovered two similar failures in machines that are currently being eBayed for their parts content. Only the critical part that actually gets ruined (the shaft) is missing from the parted out machines, in both cases.


I boxed up all the sander parts and hauled it away to storage, to get it out from underfoot. If I haven't solved the shaft issue by this time next year, there will be yet another one of these cast iron sanders on the market for the parts content, without the critical shaft needed for the otherwise perfectly functional assemblage to work.


All the suggestions you guys have provided (plasma weld build up at a machine shop, turning down to size, or buying a shaft from Sears for a similar machine and changing out the woodruff keys to the D style instead of the radius end style, as long as the other relevant diameters match, or finding some cold rolled stock and having an entire new shaft machined) are certainly viable. Perhaps an even cheaper solution is to simply find another used machine. Or a direct drive import. Time will reveal the most opportune and expedient solution. The mission of this thread was to confirm whether or not I have a problem. I do.


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