Big old bench grinder - Need Info!

[NotStock]

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?

I think you're giving me more credit than I deserve. I've never done this before, but right now my plan is to chuck up a length of 3/4 schedule 40 pipe in the lathe and cut the end perfectly square, then use that to drive the bearings on with a deadblow. Not sure if this is right or wrong, but its my best plan at this time.

Removal is going to be even less sophisticated. I'm planning to cut the bearings almost all the way through with a zip cut, then split the inner race with a chisel (only once I have the new bearings in hand and have inspected them to make sure they are right).

The bearings cost $11 on eBay (as per my earlier plan lol) for the pair and shipping was another $10. The shipping would have been free in the states, but I'm a canadian, so I have to pay a lot in shipping. Oddly enough, shipping from china is almost always free... go figure.

Tonight's progress:

Painted parts waiting to dry fully before assembly. You can also see the little covers all cleaned up. I think I'm going to leave them shiny, but haven't really decided yet.

 

[Davefr]

I think you're giving me more credit than I deserve. I've never done this before, but right now my plan is to chuck up a length of 3/4 schedule 40 pipe in the lathe and cut the end perfectly square, then use that to drive the bearings on with a deadblow. Not sure if this is right or wrong, but its my best plan at this time.

An arbor press would be best but this should work. However I'd put the rotor in the freezer for a couple hours. Now I'd set each bearing unit on top of a light bulb for a few minutes to heat it up. That slight shrinkage of the shaft and expansion of the bearing can help.

Removal is going to be even less sophisticated. I'm planning to cut the bearings almost all the way through with a zip cut, then split the inner race with a chisel (only once I have the new bearings in hand and have inspected them to make sure they are right).

Do you have a gear puller with a long reach?

 

[drivesitfar]

I second the hot and cold getting the bearings out and the new ones back in. All the threads I have read seem to do that process without breaking the grinder's part that holds your bearings.

Looking good and nice welding bench.

good luck

 

[NotStock]

Changed out the capacitor leads

 

[NotStock]

More work. Slowly but surely.

Cleaned up panel. These are actually stainless. I didn't think they were at first because there was a little surface rust, but after taking the grinder to them to clean up the welds, I'm pretty damn sure they're stainless.



Here is the new sealed switch installed

 

[G20-Budo]

Wow, that's looking really good! Keep up the great work.

 

[Packard V8]

Very nice work and a good common-sense approach. You'll have a nice grinder when it's back together.

jack vines

 

[NotStock]

Bearings arrived!



My method for removing the old bearings was almost as crude as promised. I ended up clamping the flange of the old bearing in my bench vise, then struck the end of the armature with my deadblow. The bearings slid right off. It helps that I was able to check how tight the press fit is with the new bearings. They really aren't very tight on there.

Then I cut my bearing pressing tool on the lathe and pressed in the new bearings.



I didn't get pics, but after seeing how loose the press fit is, I grabbed the armature in the 3 jaw and pressed the bearings on with the tailstock of the lathe. Really didn't seem to generate much more force than drilling. Might be lathe abuse...



With the new bearings in, I could put the bearing supports on. This was VERY disheartening for a guy who has never reassembled a grinder. Do not get discouraged until everything is tight and square. The armature has a very small amount of clearance to the magnets(?) and will drag and bind until the supports are seated.



Then I cut the end off a cheap princess auto extension cord and wired it in as a new plug. I like the integral plugs on these better than the DIY screw together ones, so I do all my new plugs this way. Just looks more professional



I am very happy so far. When I power up the grinder, the centrifugal starting switch thing makes a little noise, but once it is spinning, the grinder runs silent. The new bearings make a huge difference. Thanks to whoever suggested that I swap the bearings. Good call.

 

[NotStock]

I installed the new 80 grit stone and wire wheel today and I'm not happy with it. With the wire wheel on the thing vibrates pretty bad. Is this normal for a wire wheel? With the stone and no wire wheel it spins smoothly through all RPMs.

Also, my weatherproof switch packed up. Not happy with that either. It just jammed in the on position making for some interesting dancing around.

Anyway, off to PA to buy a new switch. Not sure what to do about the wire wheel. Thoughts? I might just **** it up and get a convolute deburring wheel. They seem like an ideal solution to the nasty but useful wire wheel.

 

[DenisG]

Looks like this Queen City grinder (Cincinnati, OH):
http://vintagemachinery.org/photoindex/detail.aspx?ID=11801

 

[WWIIjeep]

The new bearings make a huge difference. Thanks to whoever suggested that I swap the bearings. Good call.

You're very welcome. It's satisfying when you get to see an obvious before and after difference in a repair, eh?

I installed the new 80 grit stone and wire wheel today and I'm not happy with it. With the wire wheel on the thing vibrates pretty bad. Is this normal for a wire wheel? With the stone and no wire wheel it spins smoothly through all RPMs.
<snip>
Not sure what to do about the wire wheel. Thoughts? I might just **** it up and get a convolute deburring wheel. They seem like an ideal solution to the nasty but useful wire wheel.

Wire wheels are often pretty badly out of balance. You can try rotating the wheel to a slightly different position on the arbor, or even flipping the wheel around to rotate in the opposite direction (assuming it's a brand new wheel without a set to wires), but it may not make much difference. They make paired balancing washers to solve minor out-of-balance problems with grinding wheels, but the crappy import wire wheels that are just about the only ones available anymore are usually too far out of balance for those to work well.

A convolute deburring wheel would be a HUGE improvement in balance, and they don't throw shrapnel at you the way wire wheels do. The only drawback to convolute wheels is that they're not suited to working concave surfaces with tight radii, or for cleaning threads or other fine details like knurling, engravings, etc.

FWIW, I use 3M convolute deburring wheels for about 90% of my cleanup and polishing needs and keep a small (6") fine wire wheel on the other side of my dedicated buffer/polisher for the other 10%. YMMV depending on the types of things you work on.

 

[Davefr]

I installed the new 80 grit stone and wire wheel today and I'm not happy with it. With the wire wheel on the thing vibrates pretty bad. Is this normal for a wire wheel? With the stone and no wire wheel it spins smoothly through all RPMs.

It shouldn't vibrate. Did you use a bushing or collar washer to mount the wheel to the shaft.

 

[NotStock]

It shouldn't vibrate. Did you use a bushing or collar washer to mount the wheel to the shaft.

I got the bushings in there, but ended up having to turn a spacer to fit the wheel backing plates to the spacers. The spacers were too short and were backing out of the wheel. It is running a lot smoother now. The wire wheel is still a little garbagey and unbalanced, but much better now.

A convolute deburring wheel would be a HUGE improvement in balance, and they don't throw shrapnel at you the way wire wheels do. The only drawback to convolute wheels is that they're not suited to working concave surfaces with tight radii, or for cleaning threads or other fine details like knurling, engravings, etc.

FWIW, I use 3M convolute deburring wheels for about 90% of my cleanup and polishing needs and keep a small (6") fine wire wheel on the other side of my dedicated buffer/polisher for the other 10%. YMMV depending on the types of things you work on.

I work on motorcycles (total hobby, not professionally). I like junk bikes that usually have a pretty good amount of rust and corrosion. I'm really hoping to find a nice way to clean engine cases up, remove nasty paint and rust, and prep for paint/polish. I think I'm going to realistically need a wire wheel and a convolute deburring.

Looks like this Queen City grinder (Cincinnati, OH):
http://vintagemachinery.org/photoindex/detail.aspx?ID=11801

I think you're right! I'm really excited to finally have a lead on the brand and model!! thanks!

 

[drivesitfar]

NotStock: Outlaw has had success with the rope style wire wheels and using 2 on the one side to give it a little more coverage. then he uses a dremel or the like kind tool to get the little areas you can't get with a wire wheel. also the little wires won't be flying out into your shirt and face as often.

if you really want to remove rust and paint we just finished or are still adding to a really nice thread on Electrolysis tanks which are a snap for a guy that just rebuilt a grinder.

http://www.garagejournal.com/forum/showthread.php?t=237752&highlight=electrolysis

good luck with your new grinder and thanks for sharing your rebuild with us. don't forget to ad some more pictures with the wheels on it before you move on to other projects.

 

[NotStock]

Done for now. Better pic quality for the final pics.



Found some more cool stuff during cleanup. Check out this awesome brazing on the tool rest. Damn right I'm leaving that exposed.



The guy who did the first rebuild was no hack. He did a nice job.

You can also see some of the flaws in the somewhat rushed paint job. I can only imagine I'll end up doing another full teardown and rebuild at some point in the distant, distant future.

 

[Fretters]

Check out this awesome brazing on the tool rest. Damn right I'm leaving that exposed.

Good choice. That's tidely done and gives it a nice bit of individuality.

You can also see some of the flaws in the somewhat rushed paint job. I can only imagine I'll end up doing another full teardown and rebuild at some point in the distant, distant future.

Wouldn't worry about it. It'll end up getting knocks, scratches and covered in dust etc., so a bit of iffy paint ain't going to kill it. It looks a lot better than was, and the paint is only there to protect the surfaces from rusting, at the end of the day.

 

[ALLFAST]

NotStock,
I was directed to your informative thread by Outlaw. It has already helped dating my grinder because clearly cast in your exposed wheel guard is a date and some warning....I have the warning visible but need to remove the arbor nut (another small speedbump) and stone to see the date...I'm very cloze.!
Thanks for posting this rehab...I appreciate it ! .Shawn

 

[ALLFAST]

Is the horsepower and wheel size of this tool known ?

Thanks,

Shawn