Grinding wheel-ology

[Josh Bowman]

This is may have already been covered. I have a pair of White Norton General purpose grinding wheels. I have used Geigers methods to remove the wobble and one of the wheels seems balanced however the the other seems to have a heavy spot on one side. My question is, are all grinding wheels made the same, iaw are any of them likely to be unbalanced and untrue? Or would spending 50 bucks a piece on some Norton SG wheels make a difference? I'm resisting buying a balancing system, it seems the grinding stone folks should provide some kind of wheel that will run true. I feel getting a true wheel is important since I've witnessed the one wheel I have trued, really makes a much better edge after I tuned it.
Below is what I have:
http://www.sharpeningsupplies.com/images/norton_white.jpg (http://www.sharpeningsupplies.com/images/norton_white-z.jpg)

[Tim Rinehart]

Josh,
I would start by obtaining a set of steel bushings to replace the plastic ones. Retrue using the Geiger tool and see if improved.
Sure, any wheel could have some inconsistencies requiring balance...though I suspect the bushing issue may resolve alot. I have a hard time believing the structure of the material in a wheel is so far off to require balance at the speeds we run....but I suppose possible. More than likely...it seems that the balancing is more important if you run at high speeds (3000+) and have bushings that are not providing a good fitment.
This is the bushings I bought... McMaster-Carr 8491A562. (I bought them for when I have to replace my wheel which I dress with Geiger tool...but after 2 years and ALOT of sharpening...I still have alot of wheel left.

Maybe I'll try the CBN route when ready to replace my wheels. But heck, I gave about $85 for my slow speed grinder from Woodcraft at a wood show in March 2009, and expect to get another couple years from it. It may be cheaper to just buy a new grinder with the same wheels at that price. Kinda like how it's often cheaper to replace an entire printer, getting new ink cartridges with it, than to replace just the cartridge. Not the greenest thing to do, but geez...the economics are sure there sometimes.

[David Weaver]

I had to go with the balancing system on a baldor, because all of the wheels I tried had some inconsistency, except for one (and that one was part of a pair of the same model# wheels - one was well balanced and the other wasn't, so it was probably by chance that one wheel was better than the other.

Just my opinion, but if I have to spend $35 on wheels and $70 on a balancer or $100 wheels that may or may not be true, and I may want to change out, I'll buy the cheaper wheels and balancer.

I ended up with brown "premium" al-ox wheels from Mcmaster carr. They were about $18 per, but I don't sharpen turning tools as often as grinding plain tool steel.

(the white norton wheels I got at rockler long ago are also out of balance. one of the two mcmaster wheels was the only in-balance wheel I've found).

[Tim Thiebaut]

Hi Josh, I use the same ones you do and also have some issues like this as well. I know that there are a few folks here that use the new CBN wheels, they are very expensive, but from what I have heard work top notch and some swear by them, I know this is most likely more then you want to spend, but thought I would point them out to you as a possible option down the road, here they are...

http://www.d-waytools.com/tools-diamond-grinding-wheels.html

[Reed Gray]

Bill Nedow did an article in the latest American Woodturner AAW mag. about grinding wheels. There are 2 different styles out there. As a user of them for 5 plus years, they are well worth the money. They are balanced to start off with, and last seemingly forever. Cost is $180 or so to $300. In the time I have had mine, as a production turner, I would have spent way more money on conventional wheels, not to mention the time spend truing the wheels time after time as they wore.

robo hippy

[Josh Bowman]

Reed, I read the AAW article, did you buy he Boron type? If so where?

Bill Nedow did an article in the latest American Woodturner AAW mag. about grinding wheels. There are 2 different styles out there. As a user of them for 5 plus years, they are well worth the money. They are balanced to start off with, and last seemingly forever. Cost is $180 or so to $300. In the time I have had mine, as a production turner, I would have spent way more money on conventional wheels, not to mention the time spend truing the wheels time after time as they wore.

robo hippy

[Reed Gray]

Josh,
I got mine through NW Super abrasives here in Eugene, and I believe that they are a part of Burton Saw company. Phone number is 541-683-2171. D Way tools is also carrying them. If you look in the yellow box at the end of the article, some contact info is in there.

robo hippy

[Don Geiger]

Hi Josh:

As some of the other folks mentioned, I recommend the following:
1) Ditch the plastic bushings and replace them with headless drill bushings (www.mcmaster.com (http://www.mcmaster.com) 1" o.d. X 5/8" i.d. X 1" long, p.n.: 8491A562 $9.60 ea.)
2) Use a pencil and make tick marks on each side of each wheel to identify the apex of wobble on each wheel.
3) Remove the side cover plate and loosen the nut and WITHOUT rotating the wheel on the axle, install a stack of about 4 paper sticky dots (Available from Walmart and are used for price marking) between the side of the wheel and the inside edge of the cup washer on the radius line from the center of the tick mark to the axle of the grinder. Do the sides facing the motor first, then the ones facing outside.
4) Tighten the nuts to 5 to 7 ft. lbs of torque (or whatever the manufacturer recommends).
5) Replace the side cover plates.
6) Stand out of the line of fire and start the grinder.
7) Observe the results. If one or both wheels are still wobbling, make new tick marks and repeat the procedure.
8) Once you get the wobble corrected, use a WHEEL TRUING device (such as my Tru-N-Dress or One Way's) and make the wheels concentric to the axle.

By doing this, your grinder should have much less vibration and tools, when applied to the surfaces of the wheels, should not bounce. I truly believe that the distribution of aggregate in grinding wheels is very consistant. Thus, balancing alone will not usually correct the vibration of the grinder and the tools. Even if you decide to use a wheel balancing system you will still need a good wheel truing system first, because the wheels need to be trued BEFORE using weights to gravimetrically balance the wheels. I have never seen a case where, if you went through the procedures I recommend above, that wheel balancing was necessary. Economically speaking; purchase the bushings, paper dots and a good wheel truing system, try it and if it works (and I'm 100% sure it will) you will save money by not having to purchase a wheel balancing system.

I just returned from assisting Ellsworth at Arrowmont (for the 7th time!!!) and when I arrived on Sunday, I found that the wheels on one grinder had significant side to side wobble. I went through the procedure described above and corrected the problem in about 15 minutes. The grinder ran great when I finished. I've done this to about 50 or more grinders and have always had success. I've instructed many people to do the same and they all reported success.

Good luck and please let me know if I can be of further assistance.

Don Geiger

[Josh Bowman]

Don,
I've been a real follower of your method and have done it all to both wheels. One of my wheels really does well the other has no wobble after your procedure but still vibrates bad, the face has been trued. It just does not seem right that I have to buy a balancing system. My real question is if more expensive wheels are more balanced, because it seems the ones I bought for 25/wheel are not.

[Tim Thiebaut]

Hey Don, thanks for this info., I am going to give this a shot and see how it goes, thanks again! Tim




Hi Josh:

As some of the other folks mentioned, I recommend the following:
1) Ditch the plastic bushings and replace them with headless drill bushings (www.mcmaster.com (http://www.mcmaster.com) 1" o.d. X 5/8" i.d. X 1" long, p.n.: 8491A562 $9.60 ea.)
2) Use a pencil and make tick marks on each side of each wheel to identify the apex of wobble on each wheel.
3) Remove the side cover plate and loosen the nut and WITHOUT rotating the wheel on the axle, install a stack of about 4 paper sticky dots (Available from Walmart and are used for price marking) between the side of the wheel and the inside edge of the cup washer on the radius line from the center of the tick mark to the axle of the grinder. Do the sides facing the motor first, then the ones facing outside.
4) Tighten the nuts to 5 to 7 ft. lbs of torque (or whatever the manufacturer recommends).
5) Replace the side cover plates.
6) Stand out of the line of fire and start the grinder.
7) Observe the results. If one or both wheels are still wobbling, make new tick marks and repeat the procedure.
8) Once you get the wobble corrected, use a WHEEL TRUING device (such as my Tru-N-Dress or One Way's) and make the wheels concentric to the axle.

By doing this, your grinder should have much less vibration and tools, when applied to the surfaces of the wheels, should not bounce. I truly believe that the distribution of aggregate in grinding wheels is very consistant. Thus, balancing alone will not usually correct the vibration of the grinder and the tools. Even if you decide to use a wheel balancing system you will still need a good wheel truing system first, because the wheels need to be trued BEFORE using weights to gravimetrically balance the wheels. I have never seen a case where, if you went through the procedures I recommend above, that wheel balancing was necessary. Economically speaking; purchase the bushings, paper dots and a good wheel truing system, try it and if it works (and I'm 100% sure it will) you will save money by not having to purchase a wheel balancing system.

I just returned from assisting Ellsworth at Arrowmont (for the 7th time!!!) and when I arrived on Sunday, I found that the wheels on one grinder had significant side to side wobble. I went through the procedure described above and corrected the problem in about 15 minutes. The grinder ran great when I finished. I've done this to about 50 or more grinders and have always had success. I've instructed many people to do the same and they all reported success.

Good luck and please let me know if I can be of further assistance.

Don Geiger

[Don Geiger]

Hi Josh:

I have not seen any case where balancing was necessary. Have you replaced the plastic bushings with steel? What wheel truing system did you use?

Let's work together on this and see if we can figure out the problem.


Don



Don,
I've been a real follower of your method and have done it all to both wheels. One of my wheels really does well the other has no wobble after your procedure but still vibrates bad, the face has been trued. It just does not seem right that I have to buy a balancing system. My real question is if more expensive wheels are more balanced, because it seems the ones I bought for 25/wheel are not.