Big old bench grinder - Need Info!

[NotStock]

I started the hunt for a bench grinder three weeks ago and I'm happy to say I finally found one. It runs smooth and weighs more than me (my main concerns when buying it).

I have absolutely no info on it, so I was hoping the GJ could offer up some help. Its an 8" with no maker's marks. The name plate has been removed at some point (two small machine screws are missing from the front).

There is a little bit of yellow writing on the motor, but it isn't legible.

The tool rests are cast (well one is, the other is a home built rig) and the base is definitely homebrew.

Here are the pics

 

[drivesitfar]

no idea. the badge looks like it was pretty small because only two screws or rivets. I've seen badges that small on companies that are no longer in business or that have moved on to making machines for big factories.

nothing cheap about those wheel guards and gotta love the craftsmanship on that little aluminum switch box and homemade base plate.

i'll be watching as the Old guys that probably used these when they were working because betting that is older than 60's and probably 40's or 50's.

nice find and post the restore pics if you are planning to spiff it up would be a great before and after.

good luck

 

[AndrewH]

We actually have one that looks just like that, although in better condition in service here at work. I'll check it out for you and see what I can find!

Andrew

 

[NotStock]

awesome! Thanks for the help.

It will be getting a lot of love. Teardown and inspection tomorrow. Plan is new cord, switch, stones, and a fresh coat of the obligatory rustoleum (tremclad) gloss grey.

Cant wait to find out who makes it.

The wheel guards are the first thing I noticed on it too! They are cast HEAVY. I kind of like the hand built base too. It makes me happy that someone saw fit to build a new base instead of toss the grinder in the garbage. And if you like that base, you should see the beast of a tool rest someone built for it... pics to come.

 

[drivesitfar]

not sure where you live, but that looks like snow on the edge of your grinder. is it? better get it off the dining table even though it is worthy because that water will not be good for the table or if you have a bride in the house.

looking forward to pictures of the tool rests because I was trying to see how they would be attached.

 

[zkling]

Big is a relative term. Not sure on maker, but it is an interesting setup, especially the guard and dust chutes. Looks like a quality built unit.

 

[NotStock]

Big is a relative term.

Hah, should have qualified it with "Bigger and older than the tiny 5 inch that it replaces". This thing is a monster compared to what I'm used to.

not sure where you live, but that looks like snow on the edge of your grinder. is it?

Good eye! Yeah, its a little snow. Don't worry, its all cleaned up now

 

[drivesitfar]

here's one I owned with the smaller badge that I think was a Cinncinatti (sp?) Tool company which later became a different name that builds huge tools for factories now. I probably should have kept it, but my friend that keeps my cars running saw it and was drooling all over it so now it resides in his garage and I asked him to will it to me if he goes before I do.

good effort picking up that hunk of steel in the snow.

 

[Unmarked Bill]

inb4 the "grinders are too dangerous to use unless you're an engineer" tin foil hat hysteria

 

[NotStock]

Any ideas on how to get the inside plates off?? I added a pic.

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[Outlawmws]

Is that rusted disk part of the guard, or a separate piece? it almost looks like its separate... Threaded on or press fit?

Better pics of the back side and this side from an angle?

 

[NotStock]

Appears to be a woodruff key or something inside that tiny square hole, although there isn't a groove in the shaft. On one side the little plate spins freely on the shaft. On the other, it is held solid. Both sides will slide in and out on the shaft about a 16 or so, but then they bind up.

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[Outlawmws]

OK, that disk is the back support plate for the wheel! Man, that was NOT obvious! CAREFULLY get it off the shaft; don't break it! You may want to apply a little heat on the outer edge (Bernz-O-Matic torch)

The you should be able to access the screws holding the guard on.

 

[drivesitfar]

Outlaw, if he doesn't want to or isn't able to put a little torch on that would a few squirts of Kroil maybe soaking for 24 hours and then another squirt or two before trying to pry it off maybe work?

 

[NotStock]

Alright, it is apart. Finally. I don't have a ton of tools, but it took almost all of them to get this grinder apart.

Backing plates are in fact a light press fit, but were coming up solid against a slight shoulder they'd worn in the shaft. Took me a long time to get the balls to pry on them hard enough to move. Three screws on each side to take the guards off.



So... now that I'm inside, I think this grinder is a lot newer than I originally gave it credit for. The sealed bearings are mint and the inside is fresh as a daisy. I'll replace the ugly wires and it will look like new.





Few issues: one of the guards was broken at some point and brazed (probably the same incident that claimed the original base and one of the tool rests). The home fab'd base is a lot worse than I thought. The rust was hiding a lot of sins. It isn't very square, and the scrap that was used to build it has a lot of extra random holes. A LOT of flap disc and welder time will be required to patch it up, but I'm up for it after seeing how good this thing is inside.

 

[drivesitfar]

I've never seen one of these old cast guards broken there so it must have gotten dropped? the arm looks straight and not bent though? you have made a ton of progress today and sounds like you have all the skills to make that old girl shine.

did you end up heating the wheel guard piece or just using that pry bar with a little more behind it like you mentioned and hoping it wouldn't break? in any case you got r dun.

i'll sit back and enjoy all the pictures of the progress and post as many as you wish of all the parts of your restore so we can all learn something if you wish to while you are working on it.

good luck

 

[WWIIjeep]

So... now that I'm inside, I think this grinder is a lot newer than I originally gave it credit for. The sealed bearings are mint and the inside is fresh as a daisy. I'll replace the ugly wires and it will look like new.

Those bearings are NOT mint. The brown stuff on the outside of the one in your photo means the grease has broken down from age and heat, and what's left inside is almost certainly waxy instead of oily.

If you want it to run like new along with looking like new, you should replace the bearings. Since you've already got it apart, that's a very easy job.

 

[Outlawmws]

I wouldn't be to concerned about the braze job. It should hold up fine from the looks.

the base while usable is rough at best. a base from a dead grinder could probably be used. Hmmm what is he outside diameter of the motor casing? I have one here from a dead Taiwan Grinder I think and if its the same diameter, you can have it for shipping.

 

[NotStock]

Those bearings are NOT mint. The brown stuff on the outside of the one in your photo means the grease has broken down from age and heat, and what's left inside is almost certainly waxy instead of oily.

Interesting. I assumed they were good based on how smoothly they ran. Should be easy to source replacements. I'll measure them up and see what I can find for a generic bearing. Thanks for the tip!

the base while usable is rough at best. a base from a dead grinder could probably be used. Hmmm what is he outside diameter of the motor casing? I have one here from a dead Taiwan Grinder I think and if its the same diameter, you can have it for shipping.

Thanks for the offer! I'll measure tomorrow when I check out the bearings. I'm in eastern Canada, might be spendy to ship, but I'll get the diameter at the very least and go from there.

I've never seen one of these old cast guards broken there so it must have gotten dropped? the arm looks straight and not bent though? you have made a ton of progress today and sounds like you have all the skills to make that old girl shine.

did you end up heating the wheel guard piece or just using that pry bar with a little more behind it like you mentioned and hoping it wouldn't break? in any case you got r dun.

I'm pretty sure it was dropped hard on that side. I don't have a dial indicator to check runout, but it doesn't look like the arm took any of the hit. As for the plates, no heat, just some careful pry bar work

Going forward, anyone know how tight the nuts holding the wheels on should be? I'm assuming just barely snugged, but some advice would be nice. Grinding wheels are one of those things I don't like to mess around with. I have a bit of grinder anxiety.

 

[NotStock]

I wouldn't be to concerned about the braze job. It should hold up fine from the looks.

On this topic... part of me wants to spend an hour and file and sand the brazing out smooth to hide the fix before painting.I'm a bit worried that I will end up losing a lot of strength if I do that. The crack wasn't ground out or beveled in any way prior to brazing.

Thoughts? Should I risk it?

 

[Outlawmws]

If I'm seeing it right, it's on the bottom. I'd leave it. It won't be seen much if at all once rests and guards are in place.

 

[WWIIjeep]

Interesting. I assumed they were good based on how smoothly they ran. Should be easy to source replacements. I'll measure them up and see what I can find for a generic bearing. Thanks for the tip!

They may well still have some life left, but any time there's dried grease on the outside of a sealed bearing, it means grease has leaked out of the bearing, and that the remaining grease inside is probably deteriorated.

Also, just spinning a bearing by hand doesn't compare to the forces it's subjected to when the motor is running with a pair of grinding wheels attached.

It's a lot easier to change them now, while you have the motor open, than later, when it's all assembled and you have to take it all apart again. New motor bearings like that are cheap compared to the labor involved in taking the motor apart again to change them later.

The bearings are probably 6204. That, or some other 6200-series number, should be etched or engraved on the side of the bearing. Any bearing house or power transmission parts supplier should have those in stock.

Going forward, anyone know how tight the nuts holding the wheels on should be? I'm assuming just barely snugged, but some advice would be nice. Grinding wheels are one of those things I don't like to mess around with. I have a bit of grinder anxiety.

Depends on your definition of "barely snugged." The nuts thread on opposite the direction of rotation so centrifugal force theoretically keeps them tight--LH thread on the left side, RH thread on the right side. But I'd call it "firm" rather than "barely snugged." And on a wire wheel, I'd say "tight."

 

[NotStock]

The bearings are probably 6204. That, or some other 6200-series number, should be etched or engraved on the side of the bearing.

I had no idea how cheap bearings were. Yeah, they are getting replaced. Now I just need to figure out how to pull them off the shaft.

If I'm seeing it right, it's on the bottom. I'd leave it. It won't be seen much if at all once rests and guards are in place.

Yup its on the bottom. Interesting thing here is that the guards are identical castings. The top and bottom have big lugs cast in to drill and tap for the tool rest holders. Its funny because they are drilled for a big 1/2" bolt for the tool rest on one lug, then the identical top lug is drilled for a tiny machine screw to hold eye shields. made me laugh a bit as it looks like mega overkill until you understand that they are identical left to right.

 

[Outlawmws]

SNIP

Depends on your definition of "barely snugged." The nuts thread on opposite the direction of rotation so centrifugal force theoretically keeps them tight--LH thread on the left side, RH thread on the right side. But I'd call it "firm" rather than "barely snugged." And on a wire wheel, I'd say "tight."

on this. you're not killing the nuts but you also done want them vibrating loose. make damn sure you put the armature/shaft back in the right way, the nut are RH/LH so they tend to tighten in use. however, I have had then come loose under vibration...

On stones, I'd keep the paper/cardboard label on them I like that it provides a cushion between the brittle stone and the steel spreaders.

And definitely tighter on the WW. their centers tend to flex/collapse and can slip or even come loose.

An aside on the Heavy wire wheels; if you are looking for heavy fast action, (Say on cast iron and the final finish isn't really a concern...) I've doubled up a pair of braided wheels (both need to be new/same condition...) and wow (assuming you have the HP to pull it off for the load...); wheels tend to last longer too.

 

[drivesitfar]

Awesome information WWII and Outlaw and thanks again for sharing. by the way Outlaw can you post a picture of a double wheel you just mentioned if you have one set up or did I read that wrong?

I second the motion of not messing with that brazing since it doesn't really show and if it cracks or breaks while you are smoothing it out what is your option for replacing or repairing it.

 

[johno]

I don't know what it is, but I have an 8" Baldor, and it doesn't look like that.

So I think you can rule that out.

 

[Outlawmws]

Awesome information WWII and Outlaw and thanks again for sharing. by the way Outlaw can you post a picture of a double wheel you just mentioned if you have one set up or did I read that wrong?

I second the motion of not messing with that brazing since it doesn't really show and if it cracks or breaks while you are smoothing it out what is your option for replacing or repairing it.

I don't have one setup. but you just buy two braided wheels, and put both on at once. If the centers are radically dished, (some are) you may want a spacer between them so they only compress a little before getting tight. It gives you more than 2X the practical working surface, and the only drawback is getting into nooks and crannies, but the cutting action is awesome if the HP is there.

I think the lasting longer part is due to less flex as you use it, and that probably helps the cutting action also.

 

[drivesitfar]

as in spacer are you thinking washers or would a couple needle bearings work better if needed. by the way cool idea. we can always use a little Dremel or Fein tool for the nooks and crannies.

 

[Outlawmws]

Most of these wind up needing one of those plastic spacers to center the wheel, one of the shorter ones (larger than needed for spacing could be used), or close fitting washers (don't get it out of balance)

 

[NotStock]

Bearings are Hoover 77204s. I'm going to try to source a replacement locally, but there is a real good chance I'll just buy them on eBay... from my couch... in my sweatpants... I love eBay.

EDIT

Looks like these are equal to 6204 bearings as suggested above.

47mm od, 20mm id, 14mm wide


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[NotStock]

This is quickly turning into a build thread.

Today's progress:

Decided to keep this base and make it work

Before

After


Cut it square with the portaband then used the grinder to clean up the edges. I welded up the holes that I didn't want to keep and hit them with the flap wheel. I also built up one edge that was a bit chewed up.

Started painting



I also ordered some SKF 2RS1 bearings. These are rubber seal type bearings that should work well in a dirty, nasty application.

 

[drivesitfar]

great pics and just an FYI the last one didn't come through so try again. are you having to work outside or is the edge of your bench under a leak? looks like the framing of your bench is in perfect shape and if I was closer i'd have a couple pieces of plywood to hand you.

I like that you are keeping that modified base that was on it when you bought it. are you also keeping the same switch box?

good luck

 

[NotStock]

Hah! Yeah, I forget how sad that bench is. It was in the house when I bought it. I'm working in the dimly lit, crappy part of my little shop in that pic. The other end is bright and has nicer work surfaces. I'm slowly getting my shop set up the way I want it. The nice end has my lathe, toolbox, and welding table, as well as some t8 fixtures I installed. This end has 3 incandescent bulbs and chip board benches. Unfortunately there is a much bigger project taking up the good end


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[drivesitfar]

I don't feel too bad for you since I don't own or have the skill yet to use a welder, but had to let you know I was paying attention to your restore. I have worked on similar workbenches in my younger days and maybe a piece of good thick cardboard might be a good option to set on that wasted pressboard until you get the time to fix or rebuild it and give you a nice smooth surface.

Handy guys can be handy along side a freeway with rain or snow and only one tool if that's all available. I saw a guy on Youtube take a Wilton vise apart on what looked like a crate with minimum tools and his tool box was an abandoned fridge. he did an awesome job restoring that vise.

you are doing a great job and that grinder should run for 50 more years after you get done with it and only needing the wheels change and a cleaning now and then. i'd buy a used Baldor over almost any new or use grinder because they seem to perform better than the others.

 

[Davefr]

This is quickly turning into a build thread.

Today's progress:

Decided to keep this base and make it work

Before

After


Cut it square with the portaband then used the grinder to clean up the edges. I welded up the holes that I didn't want to keep and hit them with the flap wheel. I also built up one edge that was a bit chewed up.

It's your choice, but I wouldn't use that base. Where do you plan to put the capacitor?

I had the same problem and found that the base from a cheap Asian grinder had the same exact O.D. as my motor. You might look into that option.

My original base:

Guess where this base came from?

 

[my58]

Great Thread, Keep the progress going and the pictures coming! I enjoy seeing an older abused tool receive some TLC.

I hear what others are saying about replacing the base, however I think the homemade base with your repairs and improvements adds character. As long as its not a safety issue I would stick with the existing base.

Keep up the great work!

 

[NotStock]

The capacitor fits in pretty nicely! I wish I had pictures from taking it apart. The cap's mounting strap goes on the motor mounting bolt. I have a really nice 20 amp weatherproof switch that fits right in the existing cover.


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[fordbroncodave]

looks like an older model wissota or possibly a souix

 

[G20-Budo]

Great thread! Subscribing to keep updated on your progress.

 

[larryq]

Great progress so far, thanks for sharing.

Would like to see pics / techniques on replacing the bearings, I have a couple of grinders that could use the same. How much were the SKF bearings, may I ask, and where did you get them?

My skills at getting bearings on and off is practically nil. If need be how much would it cost a (machine shop/whoever) to replace the existing ones, and can it be done with the shaft still in the motor, but obviously with the sides off?