bench grinder help

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nwcatman

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Sep 30, 2007
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south texas
i have a STEEL CITY 8" VS grinder and the vibrations is unreal. i have tried diff. wheels, balancers etc etc and nothing helps. i have spent more trying to fix the problem than the dam thing cost. it will vibrate objects right off the bench and when sharpening tools they bounce off the wheels like crazy no matter the speed. does anyone have any suggestions for a quality affordable grinder? BTW i just finished a gruelling 14 hr. shift at work so if some of this is unclear let me know and i will try and clear it up later. THANKS
 
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How is it without wheels?
Is it bolted to a stout workbench?
Best place is on an end with a leg under it.

With the wheels off, wrap a piece of masking tape around the shaft. With a Sharpie marker on the grinding rest, turn on the grinder and touch the tape with the marker tip. Turn it off after doing both sides. You want a complete circle.

If you have a complete circle on both sides, ensure grinder is firmly mounted with solid support under it. Then dress the wheels... Don't remove the label from the wheel, it's there for safety. Don't over tighten the wheels...

Did you do a "ring" test of the wheels? (Support the wheel on a screwdriver, then lightly tap with a wrench, you should hear a clear ring... Any "clunk and wheel is bad...)

If you don't have a complete circle on the tape, the shaft is bent. Return the grinder, not safe to use...
 
Just a thought. My grinder(s) will vibrate quite a lot depending on what they are sitting on. Have you tried sitting in on something else, maybe a bit more solid? Just a thought. I know it can be frustrating...
 
I have a grinder at work that runs just fine until you shut it off. then it shakes the entire building as it slows down. Never have figured out what is going on with that one. My first guess with yours is that it is not mounted to a sturdy enough base unless it is the bent shaft thing.
 
Daniel said:
I have a grinder at work that runs just fine until you shut it off. then it shakes the entire building as it slows down. Never have figured out what is going on with that one. My first guess with yours is that it is not mounted to a sturdy enough base unless it is the bent shaft thing.
Click to expand...

One thought on what Daniel is referring to.

This might be another issue than described above, but:

I think that grinders, like lathes, reach a point where the speed of the rotation causes a harmonic problem where it will vibrate. I notice this at some speed between still and full use speed - kind of broad huh?

Its like putting an out of round blank on a variable speed lathe and as you turn up the speed you will reach a point where the machine vibrates. However, if you turn it up higher, the vibration goes away - well until you go too far...
 
I once bought a high quality wheel from one of our well known suppliers. It was clearly out of round/flat/balance/everything.
I called customer service and explained the problem. The person I talked to said there was a very high percentage of defective grinding wheels and they had to exchange many. They did exchange with not cost to me.
But, the experience was worthwhile. Look to the wheels first and call the supplier or manufacturer for a resolution. Steel City is quality stuff. I don't believe they want a problem item out there with the owner bad mouthing their company.
Tell us what happens after you contact them.
 
I own a 25 year old 3/4 hp grinder. No famous name, just something my Dad bought & left me when he passed on.
I had a terrible issue with vibration, and "shimmy".
Shimmy is when the grinder is bolted down, yet slides back & forth.
I took it to my wood turning club & about 5 guys had a think tank to figure out what was wrong with it.
Since it's a double shaft grinder, (meaning 2 wheels, 1 on each side of the motor) they decided to take it apart & test it step by step.
Here's what they did. They took both wheels off, and fired it up.
No vibration whatsoever. A little wobble, but that was because it wasn't bolted down.
So, they bolted it down, tried again, no wobble.
Then they tried the wheels. Both weighed within 25 grams of each other, no big deal there. Both rolled fine when installed.
Turns out, the start & run capacitors were both shot.
I replaced them both for about $25, and it's been running perfectly ever since.
 
am gonna try removing the wheels and running it that way and see what happens. the bench its bolted to is pretty sturdy. bench never moves or shakes, just causes the loud vibrating "noise" and tools fall off the bench. and like i said, when sharpening tools they bounce off the wheel no matter what speed. and am using a one way vari-grind set up w/a norton 3x wheel fitted w/ a oneway balancing system. but with any wheel it does the same thing and i have tried about 4 diff. ones. grinder doesn't "shimmy" but causes terriffic vibrations. and....the bench had shelves w/heavy tools on them that should further dampen the thing. anyway, gonna try it w/the wheels off probably sun or mon.
 
UPDATE:
heres whats going on now.
1. took wheels and no vib
2. tape test shows ok
3. w/the wheel that came w/the grinder i get very low, normal, vib on both shafts
4. w/the norton 3X from CSUSA the vib are horrible no matter which shaft i use
5. the norton even has a balancer on it fron CSUSA
6. the ring test shows a much better ring from the "included" wheel from steel city

wondering if CSUSA is going to make this good as i didn't save the reciept. anyone know who i should talk to there? THANKS
 
If it's a new stone then you should 'dress' it. Buy a single point diamond tipped dresser and take very light passes. Dressing tools are very cheap and you should clean your stones periodically ( with a dresser ) to keep them working properly anyway.
 
skiprat said:
If it's a new stone then you should 'dress' it. Buy a single point diamond tipped dresser and take very light passes. Dressing tools are very cheap and you should clean your stones periodically ( with a dresser ) to keep them working properly anyway.
Click to expand...

been there done that.
 
Craft supply is great for customer service. Give them a call and they will take care of the problem. They have your info from when you ordered the wheels. Explain as you have here... Wheels are not perfect. If they won't balance, they need to be replaced. You've proved it's not the grinder. I bet they offer to send new wheels...
 
jwoodwright said:
Craft supply is great for customer service. Give them a call and they will take care of the problem. They have your info from when you ordered the wheels. Explain as you have here... Wheels are not perfect. If they won't balance, they need to be replaced. You've proved it's not the grinder. I bet they offer to send new wheels...
Click to expand...

yea thats gonna be my next step.
 
You've probably tried this and, if so, I apologize for repeating....

Try keeping the grinder wheel flanges fixed and rotate the grinder wheel ~ 15-20 degrees and re-test. I had this same problem when I replaced the stock wheels on a Woodcraft grinder with Norton wheels. After 2-3 incremental wheel rotations, most of the vibration disappeared. Installation of Oneway wheel balancer machined flanges took out all of the vibration but not a cheap fix @ ~$65.
 
got ahold of CSUSA and they will take back the defective wheel and send me a new one. i found a barely used norton 32A white wheel i had also bought from them some time ago and put it on. same bad vibrations. took it off, put back on the the no-name 60 grit gray wheel that came w/the grinder and it runs at least 95% smoother. no comparison. am i the only one getting bad norton wheels? and thats what it HAS to be if the non norton wheel is the only one that runs true. course, like everything else these days the norton wheels do say " made in mexico" on em. then again, so does the corona brand beer i'm swilling right now!
 
Lots of advise here, but lets ask the common sense question. Does your shaft size fit your grinding wheel hole size without slop. Sounds to me like you have the wheel mounted on a smaller shaft. Try that.
Steve
 
Sberger said:
Lots of advise here, but lets ask the common sense question. Does your shaft size fit your grinding wheel hole size without slop. Sounds to me like you have the wheel mounted on a smaller shaft. Try that.
Steve
Click to expand...

thought of that too but the wheels are actually hard to get off and on. and this is after i have cleaned and degreased the shafts. what you are suggesting is actually the most logical thing to look at but don't think thats the problem. after CSUSA sends me the new wheel and theres still a problem i guess i will have to find someone close by w/a grinder and try it on their machine. or start sharpening on a sander!
 
Should not have to force a grinding wheel on or off the spindle. One of the Norton wheels bought from Hartville tools had bad reducing bushing. Swapped out bad bushings so could get wheel on without forcing. Still had to dress the wheel an awful lot to run true.
 
i went to the shop and measured the shafts w/the same i use for reloading. now, i can add 2+2 and know that there 6 beers in a 6 pack but after that i'm lost mathmatically. anyway, measured between 0.624 and 0.628 on the two shafts. that sound right?
 
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