Craftsman bench grinder info
- Thread starter PatY
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Marvin Berry
Well-known member
I always took that to mean that the bearings were really good.
FrankLee
Well-known member
Bearings are dry. New sealed Electric Motor Quality EMQ bearings would be a good improvement.
These are what I installed on a 115.7575 earlier this year:
Always measure before ordering.
These are what I installed on a 115.7575 earlier this year:
Always measure before ordering.
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Nutria
Well-known member
Agreed re the dry bearings. Not difficult to replace.
kbuhagiar
Well-known member
Help me to understand how dry (under-lubricated) bearings would allow the grinder to spin for a longer period of time, as opposed to bearings that are properly lubricated. Dry bearings should produce MORE friction, thus a shorter spin-down time, not longer.
Longer spin-down time = better bearings.
What am I missing?
kbuhagiar
Well-known member
Me, too. I guess I've been wrong all of my life.
the grinder spinning for a long time indicates precision bearings & probably well balanced machine. it's a plus, and I fail to see how replacing perfectly good spinning bearings is an improvement
Nutria
Well-known member
Dry bearings have little lube, or old dry lube. That means little resistance and a long spin-down time. Sure, if you have a new imported grinder and compare it with a new Baldor, the Baldor would probably have a longer spin-down time. But after 20 years of good use, the spin-down time for both machines will almost certainly increase significantly. I say this based on dozens of machine restorations, which I'm sure that many others have under their belts as well.
As to "replacing perfectly good spinning bearings," what I find more often than not, when I remove the bearings from a shaft, is a lot of grit, crunchiness, and perhaps brinneling that wasn't apparent when the machine was assembled, even when turned by hand.
So, test it and find out. Time your spin-down on an old, well-used machine, replace the bearings, and see what you think after you do that.
When I get a new-to-me machine, I usually tear it down and examine the bearings by hand. If the bearings are high quality and seem silky smooth, shields or seals get removed, the bearings get re-lubed, and the old bearings get to stay. If they have any crunchiness at all, I replace them. Why not get it done while in there? That's my take anyway.
As to "replacing perfectly good spinning bearings," what I find more often than not, when I remove the bearings from a shaft, is a lot of grit, crunchiness, and perhaps brinneling that wasn't apparent when the machine was assembled, even when turned by hand.
So, test it and find out. Time your spin-down on an old, well-used machine, replace the bearings, and see what you think after you do that.
When I get a new-to-me machine, I usually tear it down and examine the bearings by hand. If the bearings are high quality and seem silky smooth, shields or seals get removed, the bearings get re-lubed, and the old bearings get to stay. If they have any crunchiness at all, I replace them. Why not get it done while in there? That's my take anyway.
FrankLee
Well-known member
Well said.
Here are the bearings from a Craftsman 115.6962 motor that I dismantled yesterday. This motor is dated July 1953. That's 70 years old! The grease has turned to wax and is useless. This motor had a long run-down time.
Just as Nutria said, these bearings are gritty and do not turn smoothly despite the run-down time.
Because these bearings are open on one side, I normally clean them in a sonic cleaner, assess them for wear, repack and reinstall.
Very nice grinder! I believe that 3/4 hp grinder model 397.19670 first became available in 1969. So, it could be as old as 54 years old.
I've seen enough old machines to recognize that the original paint should clean-up beautifully. The eye shield frames may need painting, but preserving the original paint is worth it.
Craftsman 150 drill press questions
Hello - I just picked up a craftsman 150 drill press this past weekend and would like to restore it. This will be my first time restoring a tool so apologies in advance for the noob questions. I did search the forums and read a ton already as well as watched a series of YouTube videos from a...
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Thanks guys. Ill look into the bearings. She runs as smooth as can be and is really quiet compared to some cheap bench grinders I've used. Seeing I didn't pay anything for it a few bucks in new bearings would be well worth it. It belonged to my brothers FIL who passed probably 15 years ago. It's been in my moms garage attic since my brother cleaned out his shop. There are bins of stuff up there I have to go through so hope to find some other gems. For the record, I am with the other guys here that thought the long run down time meant the bearings were really good. 
Learn something new here every day.
If anyone knows the part number for the bearings I would need, feel free to share.
Learn something new here every day.If anyone knows the part number for the bearings I would need, feel free to share.
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WillyBoy
Well-known member
Agree with the other posters, a dry bearing will spill more easily. Pinch the inner race of a dry bearing between thumb and finger and give the outer race a spin. Now do the same thing with a new, fresh, right-out-of-the-box bearing. Note the difference.
Some dry bearings will eventually overheat and then lock up. If it's a motor, the next most easily spun part will then start spinning. Sometimes it's the motor shaft inside the inner race. That's a good way to chew up a shaft.
Some dry bearings will eventually overheat and then lock up. If it's a motor, the next most easily spun part will then start spinning. Sometimes it's the motor shaft inside the inner race. That's a good way to chew up a shaft.
emeraldcoupe
Well-known member
check out this thread
www.garagejournal.com
let's see your craftsman block grinders
didn't see a thread like this. lets see you blocks! here's mine, 8" 1HP, paid $50 for it
www.garagejournal.com
Free is always nice, I picked up a 397.1949 recently for twenty bucks. There is a 397 on eBay for $400+. Haven't gotten around to going through mine yet, but is should clean up nice. Thinking of putting maybe a wire wheel on one side and a buffer wheel on the other. Did you know the bottom should have the date? See my last picture.
Also if you are missing any of the rubber feet Hillman 8846 grommets from Lowes should work perfectly. Credit to the gentleman from this post on VM http://www.vintagemachinery.org/photoindex/detail.aspx?id=39402
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Nutria
Well-known member
If you are good with getting new bearings, you can always see if you can gently pry away the shields to regrease. If it doesn't work out, nothing lost. Accurate Bearing is a good resource for bearings, if you don't have a local supply house that you like. I think that you'll enjoy that grinder.
$20.00 bucks is basically free these days!
That bottom tin piece with the date is either missing or it didn't have one. Looks like an electrical diagram label on top of the base. Can just barely make it out. Oil and dirt soaked.So I'm attempting the cheap route and I used my finger and slowly pressed grease into the bearing along the top of the shield. It was def allowing the grease in as you could feel the difference. Got it back together and it still free spins when shut down but it slows much faster than before. Nice and quiet and smooth. Its not going to see any heavy lifting at this point. Probably put a wire wheel on one side which will be my main use for it. Worse comes to worse I'll replace the bearings. The whole thing comes apart pretty easy.
Thanks for everyone's help!!!