Grinder runout

[cmyoung2]

How much runout or wobble is acceptable on a new 6" grinder? The 1/2" shaft is out of round .001" on one side. The other side seems to be fine. That .001 translates to about 1/16" side to side wobble at the outer edge of the wheel. The grinding edge seems round, just moves side to side a little. I haven't used a stationary grinder much, just the portable/right angle type.

 

[dstig1]

0.001" on a shaft in a non-precision tool? :laughing: Go check your drill press for comparison. If it is under 0.010, you will be lucky. Not trying to be mean, but if you truly have 0.001" runout, you are fine, IMHO. Likely the wheel just needs to be trued up as it is new. There is always system runout to be accounted for, and the way to do that is true it in place. To do that you need a grinding wheel dressing tool. Like these:

Grinding dresser - Wikipedia, the free encyclopedia

But if you are saying the arbor is bent slightly, then take it back and get it replaced. No sense fighting a defective tool. I'm just saying that runout is a fact of life, even on high end tools. It just decreases with cost.

 

[Scooby074]

What dave said. Its just a grinder.

 

[cmyoung2]

Dave, I'm not a machinist so the terms might not be correct. The runout I see would be what I would call a bent shaft. What worries me is that at the outside edge of the 6" wheel there is about 1/16" wobble. I just know I would have problems with that if it were a table saw blade, just don't know on a grinder. I do have a diamond wheel dresser, so getting the wheel round is not a problem, maybe.

 

[whistlepig]

I'm not sure how .001" run out on a shaft could cause 1/16" run out on a 6" wheel. I can see where a .001" run out on a shaft causing .006" run out on a 6" wheel (.001"x 6") but sure not 1/16 of an inch (.062"). It would take .010" run out on a shaft to produce 1/16" run out on a 6" wheel.

 

[dstig1]

I'm guessing what you are describing is not what you are really seeing and that the shaft is actually bent.

Play dumb. Bring it back, start it up and show the guy and say "Does that look right to you?" If he says yes, ask to try another one for comparison. If he says no, try another one for comparison. Find one that works right. If the wheel is really wobbling, then something is probably wrong. But do keep in mind, it could be the wheel...so try another wheel before you take it back.

 

[Scooby074]

How are you measuring this runout? What kind of grinder is it? If its a chicom special, your probably well within its tolerances.

if the stone is wobbling, it could be the crappy stone it came with, or a bent /crooked flange...

 

[whistlepig]

1/16" run out is a lot and unsafe. It will overwork the grinding wheel to the point that it will fatigue. A good recipe to eat a grinding wheel.

 

[Craig Clayton]

As I understand it you are talking about a 6" bench top mounter electric grinder with 1" wide silicone carbide wheels.
Measure the run out of the shafts without the wheels on.
Remember these grinder wheels have PRECISION PLASTIC insert bushings to fit the different shaft sizes.

Craig Clayton

 

[cmyoung2]

I took it back, checked another one in the store, it seemed fine. Think I will be much happier.:thumbsup: I just didn't like a wobble I could see with my old eyes

 

[Haywire]

I've got a 25% harbor fright coupon for new years, I may pick one up today. I've been wanting a bench grinder for a while now.

Ian