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Lew Hartswick
07-04-2007, 08:24 AM
I think this has been addressed before but I can't find how to search
the archives. Soninlaw just got a bench grinder with 8 by 1 inch
aluminium oxide wheels and one or both are out of balance. (also a
little out of round) So am going to dress first but if still shakes would
like to balance the wheels. So where and how should the material be
removed? I've looked at the washers and they seen to be good, at
least no sign of dings etc. I could make a pair (2 sets :-) ) of
machined ones but not till I get home in a month. Also without a pair
of parallel, level knife edges to set a shaft on how good a balance
could I expect to get just depending on the wheel rolling on a shaft?
Or any other suggestions would be apprecaited.
Thanks.
...lew...

agrip
07-04-2007, 08:43 AM
Lew
A back woods get it done - -
You can fill in the thought behind the rough idea.
Don't have time, at moment, to cover all details.

IF the shaft is turning true enough - - -
Put the grinder base on some soft sponge.
Then torsionally wiggle the grinder frame by hand.

The wheels (and shaft) will seek the heavy side down.

If you whittle some sheet metal squares with hole in center. Place those under the wheel flanges and whack off the corners to lighten the heavy side.
Watch your index marks.

Hth Ag

Evan
07-04-2007, 08:44 AM
So where and how should the material be
removed?
Start by loosening the nut that holds the wheel on the arbor. Remove wheel and carefully smash with big hammer. Then buy some good wheels.

ammcoman2
07-04-2007, 08:45 AM
I recently received a gift coupon for Lee Valley Tools and decided to get the Oneway balancing system for grinding wheels http://www.leevalley.com/wood/page.aspx?c=2&p=49226&cat=1,43072

Sure one could make a set but I am glad I bought it. It can accomodate wheels with up to a 1 1/4" arbor (mine is a 1/2"). It does two wheels and they stay with the wheel so swapping out is a breeze.

The flanges are substantial, it is easy to set up and the sytems is well finished.

I am a happy camper.

Geoff

Evan
07-04-2007, 08:47 AM
Quality grinding wheels will be both balanced and round.

J Tiers
07-04-2007, 08:53 AM
Somebody should tell the good folks at Norton about that new idea that grinding wheels should be balanced and round. Apparently they have forgotten it.

Evan
07-04-2007, 09:09 AM
The wheels my wife sells are both balanced and round. If not they are defective and replaced.

[added] They are also made in USA, unlike Norton.

speedy
07-04-2007, 09:30 AM
The wheels my wife sells are both balanced and round. If not they are defective and replaced.[added] They are also made in USA, unlike Norton.

Are they available down this way Evan??

A.K. Boomer
07-04-2007, 09:40 AM
True them up first, if that doesnt bring them around it means there is deviation in the wheel material itself, if thats the case then pitch em.

platypus2020
07-04-2007, 09:58 AM
About 5 years ago, switched to Walter Abrasives, for all of my grinding wheels and flap disks, so far everything I bought was made in Canada, never had a problem. Good pricing and excellent quality, two features today that seem some what unrelated.

jack

GadgetBuilder
07-04-2007, 10:17 AM
There is a wheel balancing method described here that might be helpful:

http://www.homemetalshopclub.org/news/sep04/sep04.html

John

lazlo
07-04-2007, 11:50 AM
They are also made in USA, unlike Norton.

Norton's cheap consumer-grade ("Gemini") wheels are made in China, but the good toolroom wheels are still made in the USA.

I just bought a Norton TG (Seeded Gel) wheel and it's Made in the USA.
I just checked a "conventional" (aluminum oxide) Norton 32AA I bought on the same order (from J&L), and that's Made in the USA also.

Evan
07-04-2007, 11:50 AM
I'm not trying to advertise for my wife but trying to make a point. The fact that wheel balancers exist is a commentary on the state of the industry. There are only three manufacturers of grinding wheels left in North America. Very recently she had a customer complaint about out of round wheels. I check these sorts of things for her and in this case couldn't chuck them up in the lathe. I made a special arbor for my mill and checked them that way. Two of the wheels had a run out of around .025" and another was .080". They were replaced. The manufacturer apologized and explained that they had a bad batch but though they had caught them all before shipping.

An out of balance condition with no runout (after dressing) indicates a density problem. This is a possibly hazardous situation as it indicates improper packing of the grit.

Philip in China
07-04-2007, 12:06 PM
I agree with Evan. Get rid of those wheels and buy some new ones. I could introduce you to a woman who is a widow because her late husband saved a few pounds on grinding wheels and ended up with a chunk of carborundum through his skull.

Mcgyver
07-04-2007, 01:08 PM
whether it's balanced or not is a matter of degree isn't it? what might be fine for a bench grinder is out of balance for a surface or t&c grinder etc. also has to do with the weight of the machine. large heavy stuff will absorb a level of out of balance that my light t&c wont' for example. imo workmanship can be improved by balancing but its overkill on a bench grinder...asuming a decent wheel to start with

here's some pics i put up on the process, basically following Jan's example

http://bbs.homeshopmachinist.net/showthread.php?t=12741&highlight=balancing

lazlo
07-04-2007, 01:40 PM
That's a great thread, and great job on the balancing setup McGyvver!

You're right, of course, about the degree of balance -- on the high-end grinding machines they have extremely sensitive active dynamic balancers.