Sears Craftsman Bench Grinder - any worth?

[freebo86]

Figured I could use a bench grinder in the garage.. sourced this on marketplace. When I got there I realized this things bigger than I expected. My garage space is limited.. ‍♂

Figured since I went there I picked it up anyways, $20.

1/2HP, Sears Craftsman, I pulled one of the wheels off its 7”, arbor size 5/8s. The wheel I pulled off seems to be for aluminum, the other wheel I think says steel on it. The light even works. when I run it and turn it off it spins forever until it stops. Looking online these things are listed as 6” grinders so I’m a bit confused now why there is a 7” wheel and it looks to be original.

Should it actually be running 6” wheels? I was thinking of cleaning, and repainting the larger parts (mini-resto). Need to replace the cord on it as it’s frayed. But would like to know if it’s worth it before I dive in.

Thanks!

 

[gilbo]

You can be the judge if these are worth anything

 

[RoninB4]

The wheel I pulled off seems to be for aluminum,

-If this is the wheel you interpreted as "for aluminum" I can assure you that it is NOT for grinding aluminum. Aluminum oxide wheels are very common but used for steel and ferrous materials only. If you want to know why just ask, I'll tell you and you'll be sorry you asked.

Attempting to grind aluminum with this wheel will quickly clog the wheel with material and render it almost useless. If enough material clogs the wheel there's even a chance the wheel will explode when the aluminum expands with heat, very dangerous when that happens. There are other abrasive wheels (silicon carbide) for non-ferrous materials but I wouldn't suggest the average consumer use these as they're very soft and aimed at industrial applications. How to tell some novice has attempted to grind aluminum? The wheel begins to look like this.


The only solution for this condition is to dress the wheel until ALL the aluminum comes off. Before anybody replies that they've ground aluminum in a bench grinder with an Al2O3 wheel please spare yourself the embarrassment of revealing that you're an idiot that should not be allowed around a bench grinder without adult supervision. If you must somehow abrade a non-ferrous material (aluminum, brass, some SS, etc.) use a flap wheel, sanding belt, or some other type of abrasive. A clogged bench grinder wheel immediately confirms that there's an idiot in the shop/garage.

 

[Lassen Forge]

Um, it's not FOR grinding aluminum, the abrasive is Aluminum Oxide.

Silicon Carbide is used for non ferrous, but are a whole different animal, and can get expensive even WHEN used correctly.... I have a set of SiC wheels for my grinder, but don't mount them unless I'm working with bronze or aluminum or some other NF metal.

 

[fatfillup]

$20 for an 1/2 hp Cman block grinder.
That's approaching suckage status, many would say you do ****

I sell those from $50 to $80 depending on condition and buy every one I can.

Bought an absolutely filthy one last week at an auction for $5. Needs wheels but runs fine

Enjoy

 

[seber]

If the wheel fits and the speed does not exceed the RPM listed on the wheel, you are fine. As Ronin stated, NEVER grind aluminum on a bench grinder. And it does not matter what type of abrasive the wheel is made from. Just don't do it.

 

[freebo86]

Thanks for the info and link! So seems these are somewhat sought after.. lol.

I was tired and late, I only realized after that the aluminum was what the wheel was made of lol and not what it’s FOR! Appreciate the feedback, won’t be grinding aluminum. I may swap one of the wheels for a wire brush one, and still want to see what the other wheel actually is as I do see the wording steel on it..

I looked through the thread linked, seems that this unit is mostly complete besides the rubber feet missing.

I think I’ll strip it down, clean up the hardware, repaint in a proper “grey” tool color, lol and keep it. I think it may need to have the wheels dressed as it does somewhat move around a lot when it runs.

 

[fatfillup]

Dress the wheels outside, makes a lot of dust

 

[1982fxr]

-If this is the wheel you interpreted as "for aluminum" I can assure you that it is NOT for grinding aluminum. Aluminum oxide wheels are very common but used for steel and ferrous materials only. If you want to know why just ask, I'll tell you and you'll be sorry you asked.

Attempting to grind aluminum with this wheel will quickly clog the wheel with material and render it almost useless. If enough material clogs the wheel there's even a chance the wheel will explode when the aluminum expands with heat, very dangerous when that happens. There are other abrasive wheels (silicon carbide) for non-ferrous materials but I wouldn't suggest the average consumer use these as they're very soft and aimed at industrial applications. How to tell some novice has attempted to grind aluminum? The wheel begins to look like this.


The only solution for this condition is to dress the wheel until ALL the aluminum comes off. Before anybody replies that they've ground aluminum in a bench grinder with an Al2O3 wheel please spare yourself the embarrassment of revealing that you're an idiot that should not be allowed around a bench grinder without adult supervision. If you must somehow abrade a non-ferrous material (aluminum, brass, some SS, etc.) use a flap wheel, sanding belt, or some other type of abrasive. A clogged bench grinder wheel immediately confirms that there's an idiot in the shop/garage.

I've bought and sold a LOT of used bench grinders. My hypothesis based on years of field research is that all Grinding wheels must have come from the factory with aluminum in them.

 

[RoninB4]

-Just for additional info, the silicon carbide wheels are often a green color. They can also be used for rough grinding carbide (cemented carbide lathe bits, insert touch up. carbide end mill relief, etc.) but they don't leave a very good finish for a cutting edge. The edge will be rough and serrated under magnification. Just thought someone would want to know.

 

[RoninB4]

My hypothesis based on years of field research is that all Grinding wheels must have come from the factory with aluminum in them.

-I can see where your field data might have led to your conclusion. You'd also have to include the sheer number of idiots out there in with access to those wheels. I've run into them in machine shops where they ought to know better (but didn't seem to).

 

[freebo86]

Pulled the other wheel, same type of wheel. I managed to preserve the tag on this one, grit #36.

I’ve dismantled the unit fully. The bearings seems solid, no odd noises or movements from them.

 

[Nutria]

when I run it and turn it off it spins forever until it stops.

That is not necessarily a good thing. People assume that this means that the bearings are in good shape, and they might be. More likely: the bearings are bone dry-- the original grease either gone or turned to stone-- so there's no resistance. I'd have a look at the bearings and verify. It's sometimes possible to regrease if the originals are high-quality. Otherwise, order in some good replacements from Accurate or elsewhere.

Nice grinder; good luck.

 

[sk farmer]

somebody picks up a nearly 100% complete 1/2 hp block grinder that has original wheels meaning almost no use for 20 bucks and doesn't get a you ****?

 

[1982fxr]

That is not necessarily a good thing. People assume that this means that the bearings are in good shape, and they might be. More likely: the bearings are bone dry-- the original grease either gone or turned to stone-- so there's no resistance. I'd have a look at the bearings and verify. It's sometimes possible to regrease if the originals are high-quality. Otherwise, order in some good replacements from Accurate or elsewhere.

Nice grinder; good luck.

This is essentially advising everyone with a good running grinder that has a long spin down time (whatever that might even mean) thar they need to do a teardown to inspect bearings.

Totally ridiculous. He didn't even say how long forever is. That could mean anything to anyone. Again, totally ridiculous.

 

[freebo86]

So I looked closer at the bearings, while in hand there is zero resistance and the bearing when armature rod spins. The bearings are 6203Z Nachi NB Japan.

Being a smart a&& I removed one of the bearings. I’ve had luck in the past greasing metal shield bearings by drilling a small pilot hole in the shield and then injecting grease using my needle adapter. Well did that and now there is a ‘notch’ felt when I spin it..

Would these Timken be good replacements?

2PCS TIMKEN 6203-ZZ Double Metal Seal Bearings 17x40x12mm Ball Bearings : Amazon.ca: Industrial & Scientific

2PCS TIMKEN 6203-ZZ Double Metal Seal Bearings 17x40x12mm Ball Bearings : Amazon.ca: Industrial & Scientific

www.amazon.ca

 

[Nutria]

So I looked closer at the bearings, while in hand there is zero resistance and the bearing when armature rod spins. The bearings are 6203Z Nachi NB Japan.

Well, you'll certainly have lots of options for 6203 replacements-- super common. I like to replace bearings in machines that will see abrasive dust with sealed bearings (2RS), even though there is slightly more drag with the sealed bearings. Others prefer the ZZ shielded bearings. Probably not a big deal either way.

Nachi and Timken are both fine names. I think that the COO has changed for both, but I think that quality control remains good. I personally would prefer not to buy bearings from Amazon, though you might have good luck there. Consider contacting the competent and pleasant folks at Accurate Bearing-- family business, and they may well have a competitive price for you. I've probably purchased over a hundred bearings from them. They pay attention to their product, so you can trust what they sell you.

Enjoy your project and using that cool grinder.

Bearing Supplier Leader In USA & International | Same-Day Shipping

Top US & international bearing supplier of electric motor bearings and power transmission parts with no minimum orders and same-day shipping. Accurate Bearing Company is the industry's value leader.

www.accuratebearing.com

 

[fatfillup]

somebody picks up a nearly 100% complete 1/2 hp block grinder that has original wheels meaning almost no use for 20 bucks and doesn't get a you ****?

See post 5, I more or less did

 

[1982fxr]

Well, you'll certainly have lots of options for 6203 replacements-- super common. I like to replace bearings in machines that will see abrasive dust with sealed bearings (2RS), even though there is slightly more drag with the sealed bearings. Others prefer the ZZ shielded bearings. Probably not a big deal either way.

Nachi and Timken are both fine names. I think that the COO has changed for both, but I think that quality control remains good. I personally would prefer not to buy bearings from Amazon, though you might have good luck there. Consider contacting the competent and pleasant folks at Accurate Bearing-- family business, and they may well have a competitive price for you. I've probably purchased over a hundred bearings from them. They pay attention to their product, so you can trust what they sell you.

Enjoy your project and using that cool grinder.

Bearing Supplier Leader In USA & International | Same-Day Shipping

Top US & international bearing supplier of electric motor bearings and power transmission parts with no minimum orders and same-day shipping. Accurate Bearing Company is the industry's value leader.

www.accuratebearing.com

Congratulations on getting a guy to tear down a perfectly running machine with total ********.

I hope others don't follow.

 

[mreisner]

Congratulations on getting a guy to tear down a perfectly running machine with total ********.

I hope others don't follow.

My dad brought one of those grinders new in 1974 and I remember as a kid marveling how long it would take for it to spin down once it was shut off. It's been bolted to the same spot since that day in 1974 in an unheated shop and saw a lot of rough use for half a century and still takes forever to spin down. I buy every one of those grinders I see at estate sales garage sales Etc. I've got probably a dozen of them and I don't think I have paid more than $25 for any one. I don't need more than two or three of them, but I like to know I'll never run out of them, and anything new with the Craftsman name on it in a grinder is ****.

 

[freebo86]

Well I pulled the shield off the bearing I drilled the pilot hole. The shield had pushed in a bit where the hole was drilled so maybe it was catching on the ball bearings a bit. I used a small grinding stone and got rid of the burr on the inside of the shield also flattened the shield with a socket.

Put the bearing in some diesel overnight to see if I can get it to break down whatever is inside of it and then I’ll add some new grease and see if I can preserve it. Hate getting rid of Japanese bearings.

 

[freebo86]

I ordered the Timken on Amazon, will see what arrives. The Nachi bearing is still in diesel I’ll try to grease it tomorrow and see if it’s smooth again.

The power cord on this unit was cut and spliced, bare wire was exposed, lol. Grabbed new cabtire 16/3c cord today, wanted 18/3 but they didn’t have any so went up a gauge. The plug end will be non original of course..

Got the covers wire wheeled and washed in dawn soap. Applied a coat of primer this evening. The housing will be Krylon Metalic Dark Metal, the center piece that has the sticker - not sure yet.

 

[larry4406]

@mattblast can help you with the sticker/label if you are so inclined to want a reproduction.

 

[NUTTSGT]

For $20, you did fine, especially since you didn't already have one.

However, I would have merely cleaned it up and put it to use.

 

[freebo86]

@mattblast can help you with the sticker/label if you are so inclined to want a reproduction.

The sticker is actually in quite good condition! I covered it with tape there, not to paint it. It’s not a hard type, just a sticker.

For $20, you did fine, especially since you didn't already have one.

However, I would have merely cleaned it up and put it to use.

Hehe, I enjoy doing this! Needed a small project. Did a similar thing to a walker turner drill press a few years ago. That one I gotta fix the run out on tho.

 

[freebo86]

Little bit more progress. Evaporust always amazes me.

Hardware has been cleaned, I’ll get it blued and into some oil to prevent from rusting.

The casing has been painted. Still waiting on the bearings..

 

[freebo86]

So I’ve put the unit together and it runs smooth without the wheels on. However when I mount the wheels it does vibrate and shake - I guess I need to dress the wheels or is there more to getting this thing to run a bit more stable?

Photos incoming.

 

[Nutria]

Congrats-- nice work.

There are lots of balancing options, and you can decide how much effort you want to put into it. Dressing for a start, for sure, for getting it better radially. Larger, machined flanges will help with lateral wobble, ditto machined spacer bushings vs plastic ones (if needed). You will probably still have some side to side wobble, and that can be improved via trial and error by using sticking dots under the flanges (you'll find a bunch of info on this if you google "grinding wheel balancing, sticky dots"). And there are fancy balancing kits out there; one is made by Oneway, I think. Spendy though.

For me, it's dressing the wheels, sometimes better flanges and bushings, and then the dots. I haven't tried the balancing kits, but people seem to like them. You can nibble away at it, and see where you are happy with things.

 

[torqueman2002]

Just my 2-cents; I would not use stones that came with a used grinder. New ones are not expensive and available from AZ, Grainger, Zoro, ...

The reason is the unknowable history of the stones. They can have cracks that may not show up with a ring test, and if they have not been stored/use in a dry environment, the vitreous binder maybe compromised. The worst that may happen is the stone may fly apart violently.

Additionally, I stand to the side of the grinder when powering it on.

For more information, Google 'can grinding wheels be harmed by moisture'.

 

[RoninB4]

-The wheels have to fit the arbor/shaft properly. Excessive play allows the wheel to run off center and can account for the vibration. The wheels should have a plastic bushing in the center that just barely slips onto the arbor/shaft. If it's a loose fit it's not right. Do you have a paper blotter on either side of the wheel? This helps prevent fracturing the wheel when it's tightened, fractures can lead to the wheel exploding like @torqueman2002 posted above.

 

[1982fxr]

So I’ve put the unit together and it runs smooth without the wheels on. However when I mount the wheels it does vibrate and shake - I guess I need to dress the wheels or is there more to getting this thing to run a bit more stable?

Photos incoming.

The same wheels as before? Did it do that before with the wheels on?

 

[freebo86]

Thanks for the info! The stones don’t use any bushings or spacers, they are exact fit to fit over the arbour, 7/8s. There are two large washers on each side of the stones that the nut pushes against but this seems to be original and on other machines I’ve seen tear down photos of.

What wheels would you recommend? The ones on it currently are 7”, I was contemplating changing one out to a wire wheel and one to a grinding
stone.

Here is some finished photos, new cord and end was added as the other was cut and spliced. Still need to polish out the eye protectors (any recommendations?) and reinstall the rear arm/light it had some surface rust so I gotta clean that up.

 

[seber]

I like to dress my wheels with a single point diamond. It is faster than multipoint and leaves the grit open so no subsequent operation is required. Besides, single points are cheap and last just about forever. Most of my grinding is done on a belt grinder so the only wheel that gets regular use any more is a white (soft) bond 60 grit for sharpening tool steel. Fine and coarse wire wheels get used constantly. One caveat. When you buy wire wheels, do not go cheap. Good wheels don't throw wires. Cheap ones will have you looking like a porcupine.

 

[1982fxr]

Thanks for the info! The stones don’t use any bushings or spacers, they are exact fit to fit over the arbour, 7/8s. There are two large washers on each side of the stones that the nut pushes against but this seems to be original and on other machines I’ve seen tear down photos of.

What wheels would you recommend? The ones on it currently are 7”, I was contemplating changing one out to a wire wheel and one to a grinding
stone.

Here is some finished photos, new cord and end was added as the other was cut and spliced. Still need to polish out the eye protectors (any recommendations?) and reinstall the rear arm/light it had some surface rust so I gotta clean that up.

Do you have all 4 decent rubber feet on it?

 

[patrickw10]

Check the model number. Some older Craftsman grinders came with 7" wheels even though they were marketed as 6". The spin time is a good sign. Smooth bearings. The frame looks solid. For $20, it's worth a new cord and a cleanup. Even if you don't use it often, it's a tool that'll last forever. Don't overthink it.

 

[1982fxr]

I like to dress my wheels with a single point diamond. It is faster than multipoint and leaves the grit open so no subsequent operation is required. Besides, single points are cheap and last just about forever. Most of my grinding is done on a belt grinder so the only wheel that gets regular use any more is a white (soft) bond 60 grit for sharpening tool steel. Fine and coarse wire wheels get used constantly. One caveat. When you buy wire wheels, do not go cheap. Good wheels don't throw wires. Cheap ones will have you looking like a porcupine.

Who makes good wire wheels nowadays?

I was disappointed with Weiler a few years ago.

 

[RoninB4]

Thanks for the info! The stones don’t use any bushings or spacers, they are exact fit to fit over the arbour, 7/8s.

-Better quality grinding wheels (for surface grinders anyway) have the plastic bushings. These help avoid metal-to-wheel contact that can lead to stress fractures in the wheel. Even a paper/carboard bushing is more desirable that those without.

There are two large washers on each side of the stones that the nut pushes against but this seems to be original and on other machines I’ve seen tear down photos of.

-Yes those should be there. To avoid the metal-to-wheel contact a circular piece of thicker paper (called a "blotter") is used on either side of the wheel. It's no absolutely critical but it is something you want to have. If blotters aren't available they can be easily made from construction paper.

What wheels would you recommend?

-I've always used Norton or Radiac in the machine shop but there are other brands. I'd avoid getting the really cheap ones from the third world. A lot depends upon what you're going to grind, how much material to remove, how fast that abrasive rate should be, and (perhaps most importantly) the grit index. I prefer an aluminum oxide wheel is 36 grit for general grinding. A higher grit number (60) has a tendency to overheat and burn the material. You should also verify the spindle speed of the grinder and check the RPM (or SFPM) for any wheels you're considering. There's an upper speed limit for every abrasive or wire wheel that you should NOT exceed or you'll risk the wheel exploding from centrifugal force. I would also advise NOT to use any wheel that's you don't know the history of and how it was handled. Abrasive wheels are surprisingly fragile and it doesn't take much to cause a fracture. Do you know how to test a wheel for fracture? Look it up, it's a fast and easy test. I would also strongly recommend setting up a water cup at the grinder, you'll need it.

The ones on it currently are 7”, I was contemplating changing one out to a wire wheel and one to a grinding
stone.

-A wire wheel and grinding wheel is a good garage setup. Do you have anything to dress the wheel? I also like using a single point diamond but there's a good chance of losing the diamond (overheating) if you aren't familiar with using one. I'd suggest a dressing stick for starters. They're inexpensive, impart a fair finish, and won't break like diamond dressers. When you're sharpening woodworking tools that need a keen edge you want something else but this should do for general garage grinding.

Here is some finished photos, new cord and end was added as the other was cut and spliced. Still need to polish out the eye protectors (any recommendations?) and reinstall the rear arm/light it had some surface rust so I gotta clean that up.

-It looks good, you did a nice job. Get a small spotlight and a water can for it.

 

[seber]

Who makes good wire wheels nowadays?

I was disappointed with Weiler a few years ago.

The last ones I bought were Walter. They are doing fine.

 

[freebo86]

Do you have all 4 decent rubber feet on it?

Not a single rubber foot is on it..

 

[mreisner]

Here is some finished photos, new cord and end was added as the other was cut and spliced. Still need to polish out the eye protectors (any recommendations?) and reinstall the rear arm/light it had some surface rust so I gotta clean that up.

Flitz to polish.