# Noisy bench grinder ?



## WesPete66 (Dec 4, 2017)

So I have this bench grinder, and on occasion it squeals a bit.. It's nothing special, just a common 6" grinder (Mark 1, says industrial grade & ball bearing, no external means to oil it). It looks easy enough to split it open, but is there anything I can do to it to quiet it down if I did open it?  Or is it time to upgrade?
Thanks,
Wes


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## machPete99 (Dec 4, 2017)

Probably need to remove and replace worn out bearings. Use a name brand with seals. (Get numbers from old ones).


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## CluelessNewB (Dec 4, 2017)

Bearings, do them now, don't wait for catastrophic failure!


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## Silverbullet (Dec 4, 2017)

YUPP it will too, when they squeal there gonna go fast. They can lock up and tear up the surfaces on the shaft and the housing. And do upgrade your bearings , shielded types are best metal shields even much better . The cost really isn't much different . Not like high precision for a spindle.


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## Cactus Farmer (Dec 5, 2017)

back while I was in college, I worked at an automotive machine shop. The valve grinder started being noisy so we took it apart and found bearing with numbers that were the same as ones we had on the shelf. They were Chevy alternator bearings so we put in a pair. It was louder than before! After a couple phone calls we went to the bearing house and bought a pair of precision bearings with the exact numbers. They were 4 or 5 times as expensive as the ones we sold. LSS, they were as quite as can be imagined!  Precision is just that and well worth the cost! The numbers on the bearings were the same but the precision is not visible.  Buy the best for your tools!  Now when repairing my planter opener discs I use what I can find. Afterall, I'm dragging it through the dirt planting grass seeds.


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## Bob Korves (Dec 5, 2017)

I recommend double sealed instead of shielded bearings in any gritty application, and as a default for most any application that is not running at very high speeds.


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## Ulma Doctor (Dec 5, 2017)

Hi WesPete,
you'll want to get some ABEC3  2RS bearings
shielded bearings are nice, but they only shield dust.
2RS sealed bearings have 2 neoprene seals that keep all but the most intrusive things out.

for example....
ABEC3 6203-2RS is a 17mmX40mmX12mm single row, grade ABEC3, (EDIT Ball bearing with 2 Neoprene seals for maximum sealing
they are common in small motors and are easily found on Ebay and at local bearing houses.
for a grinder, i'd go with a German, Japanese or USA manufactured bearing.

these are my usual goto brands for electric motor bearing replacement as well as in my general work, in no specific order:
SKF
NSK
Nice
FAG
Peer
INA


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## Bob Korves (Dec 5, 2017)

Ulma Doctor said:


> Hi WesPete,
> you'll want to get some ABEC3  2RS bearings
> shielded bearings are nice, but they only shield dust.
> 2RS sealed bearings have 2 neoprene seals that keep all but the most intrusive things out.
> ...


All good, Mike, except 6203 bearings are BALL bearings, not ROLLER...  And I know that you know that...    But the OP might not...


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## Ulma Doctor (Dec 5, 2017)

nice catch Bob, i didn't even see my mistake until you pointed it out!


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## markba633csi (Dec 6, 2017)

Sometimes the centrifugal start switch squeals- a shot of silicone spray might help if you can find an opening
Mark


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## whitmore (Dec 6, 2017)

WesPete66 said:


> So I have this bench grinder, and on occasion it squeals a bit.. It's nothing special, just a common 6" grinder (Mark 1...


Yep, I've got the same one.   The bearings aren't sealed (shielded one side), but the
problem when mine started to glitch was just the contacts on the centrifugal switch.
Be careful with the end housings (gentle tap on the shaft after removing the bolts).  
The centrifugal switch is inside the righthand bell, the bearing is slip-fit to the shaft and should
stay in the bell when you pull.   I had no great difficulty pressing the bearings out,
and did clean and regrease 'em.   The bell housings, though, are pot metal
and you want to be gentle.

A swipe or two with fine sandpaper was all it took to get it working like new.


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## WesPete66 (Dec 6, 2017)

Yep, you'se guys hit it right on the money..  I took it apart last night, and the ball bearings were almost unable to turn. They are shielded on one side only, and the closed side was towards the motor leaving the open side towards the working end (aka. dirty environment). The grease that was in them had turned to gummy gunk that ran onto the shaft..  It's time for new bearings, and I'll look at the switch too.
Thanks!


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## Reddinr (Dec 20, 2017)

That's kind of how I acquired a belt/disk sander years ago from my place of work.  It screeched and vibrated.  I mentioned to the shop manager that it was probably just the bearings full of sawdust etc. but the manager said it was cheaper to just buy a new one.  "New math" I guess...  Anyway it was going to be tossed so I took it home.   I stopped at Napa (I think) and picked up a matching set of bearings for probably $10 or so, spent an hour repairing/ cleaning it up and many years later it is still going strong.  It was an easy job as I remember it.


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