Re-balanced wheel, new wobble....?

[Jamie Straw]

My grinder wheels have had the Oneway balancing system in place since day one. When I came back to turning this summer, the fine wheel was not running well, and yesterday I finally took the time to take both wheels off and re-balance them. The fine one runs great now, but the coarser one has a new wobble. It sharpens OK, but isn't as smooth as it was and I can see a side-to-side wobble. Mystified as to why this is, but wondering if it could have something to do with tightening the Oneway pieces down. Could I have over-tightened? Mis-tightened? I used to be really strong, but not nearly so now and hard to imagine I could over-tighten. What are your thoughts? [they were tightened per instructions, clamping flats in a vise and turning wheel by hand. No way to judge torque, of course, though they give a range of 25-30 foot lbs.]

 

[Bill Boehme]

There could be several causes. The wheel might be out of round, the hole might not be true, the plastic bushings may not center the wheels properly, or a less likely possibility might be that the beveled washers (AKA Bellville warshers) aren't true. The best way to check for side-to-side wobble is with the grinder off and marking a piece of paper on the platform with the maximum deflection each way. It is very likely that you won't see much. When the grinder is running, it is difficult to determine the main cause of the vibration because lateral and radial vibration interact -- each one exciting the other.

While you are at it, check for the wheel being out of round. If it is, the Oneway diamond dresser can get the wheel round again. Any kind of handheld dresser is only going to make the problem worse if the wheel is badly out-of-round because the grinder is shaking and you aren't.

Another thing to do while tuning up the grinder is get rid of the plastic bushings and replace them with metal bushings if you haven't done that yet.

As far as the Oneway balancing kit is concerned, I don't like it because it is the wrong solution for the most common problems. It might help for a while with an out-of-round wheel, but when the wheel wears down a bit, the process will need to be done again. There are better solutions that also cost less. I suggest reading this link to Geiger Solutions. I met Don Geiger several years ago at SWAT when he was helping Brent English in the Robust lathe booth.

 

[hockenbery]

My grinder wheels have had the Oneway balancing system in place since day one. When I came back to turning this summer, the fine wheel was not running well, and yesterday I finally took the time to take both wheels off and re-balance them. The fine one runs great now, but the coarser one has a new wobble. It sharpens OK, but isn't as smooth as it was and I can see a side-to-side wobble. Mystified as to why this is, but wondering if it could have something to do with tightening the Oneway pieces down. Could I have over-tightened? Mis-tightened? I used to be really strong, but not nearly so now and hard to imagine I could over-tighten. What are your thoughts? [they were tightened per instructions, clamping flats in a vise and turning wheel by hand. No way to judge torque, of course, though they give a range of 25-30 foot lbs.]

I haven't used the ONEWAY balancer.

I have used Two ways to deal with the wobble when mounting a new wheel.
1. Make a mark on the end of the shaft and a mark on the wheel. Loosen the nut. Rotate the wheel 30 degrees tighten the nut.
Turn on the grinder. If it still wobbles too much rotate another 30 degrees. Somewhere on the rotations it will stop wobbling.

2. You have to have the wide washers for this to work. Get some round circles with adhesive on the back any color will do.
Mark the wheel and the shaft so you can keep the wheel in the same position on the shaft.
Run the grinder and turn it off. While it is coasting to a stop put a pencil lightly against the outside flat of the wheel
The idea is to put a short arc on the high spot. Draw a line from the center of the arc through the center of the wheel.
To line up the wheel the arc side needs to move toward the motor the Sid opposition needs to move away from the motor.
Take loosen the nut a lot. Stick a dot on the outside of wheel on the arc side of the line under the edge of the washer.
Put one on the inside of the wheel on the opposite side under the edge of the inside washer.
These two paper shims will move the wheel more in alignment. Be sure to tighten the nut with the wheel in the same alignment with the shaft.
Don Geiger taught me this trick. The advantage is if you do it a few times you begin to start with a stack of 3 dots and you get to alignment without needing luck.

Al

 

[Mark Wollschlager]

If you dress the coarse wheel, is it still uneven?
Could be grit between the grinder shaft washer and the wheel.

 

[Jamie Straw]

There could be several causes. The wheel might be out of round, the hole might not be true, the plastic bushings may not center the wheels properly, or a less likely possibility might be that the beveled washers (AKA Bellville warshers) aren't true. [snip, snip, snip]

This is a brand-new wobble. Same wheel, same side of grinder, new wobble. Will look at the diamond dresser and Geiger solution, but doubt I can afford to change things up. There really isn't noticeable shaking (which there was before, but from the other wheel).

 

[Jamie Straw]

safety issue

I'm going out now and taking that wheel off, checking for grit, dressing and testing again. If the wobble is still there, I think I'll loosen the Oneway set and retighten (may have to rebalance if anything moves around). If by some weird chance this is a result of a bad tightening job, I'm concerned it will stress the wheel.😱 For those who've not seen the Oneway, there are 2 steel plates, one on either side of the wheel that screw together through the hole, clamping the wheel between them.

 

[robo hippy]

Well, save up and get some CBN wheels when the ones you have are gone, and sell the Oneway balancing system too, well, if you can find some one who wants one. That takes care of any wobbles, unless they are on the grinder itself. Some times rotating the wheel 1/4 or more of a turn on the grinder shaft will do the same thing. You can take wobble and run out with a hand held cleaning tool, but it takes a light hand.

robo hippy

 

[Bill Boehme]

I would do what Al and I suggested and forget about the Oneway balancing tool -- what Al described is very similar to the meethod that Don Geiger describes in the link that I gave. Also, if it turns out that the wheel isn't round, I think that the Geiger truing tool is better than the Oneway tool and it costs less. But, even without doing that part, just following the procedure described where you put sticky dots or pieces of tape if you are Scottish will help a lot. The Oneway wheel balancing kit is not only unnecessary, it isn't as good as what you can do for no cost. As Don Geiger says, the Oneway balancing tool only treats the symptom. The method that he describes treats the cause.

 

[Steve Worcester]

The balancer assumes there is no runout on the shafts of the grinder. If you have a low end grinder, Woodcraft, Rikon, then there is almost for sure runout. The balancer also only works real well with the dressing attachment. As long as the wheel face is true, the vibration within reason, doesn't matter. It is just an anoyance. If the wheel face is true, you don't have hops in the wheel, then it will sharpen just fine.

With runout in the shaft, CBN wheels don't solve all of the problems, but they help.

 

[Jamie Straw]

MUCH better....

I dismounted the wheel, made sure shaft and washer were clean, made a very minor adjustment of one balance weight, and everything is copacetic. Trued up both wheels just for good measure.

Sorry, Bill, I'm going to pass on the Geiger stuff for now, since everything seems fine. (FYI, I use a cheap truing tool, not a Oneway. Aim to get a single-point "one of these days.") Reed: can't afford CBN wheels but would like to someday. Though it's sounds like I should prepare to buy a new grinder at the same time. This is a Woodcraft, if memory serves, and I bought and returned two Delta slow-speed grinders before I got this one. It actually is very quiet and smooth now. If I have to rebalance wheels every 2 or 3 months, no big deal.

 

[Odie]

The balancer assumes there is no runout on the shafts of the grinder. If you have a low end grinder, Woodcraft, Rikon, then there is almost for sure runout. The balancer also only works real well with the dressing attachment. As long as the wheel face is true, the vibration within reason, doesn't matter. It is just an anoyance. If the wheel face is true, you don't have hops in the wheel, then it will sharpen just fine.

With runout in the shaft, CBN wheels don't solve all of the problems, but they help.

Just quoting Steve's post for emphasis. Everything here is good information.

Seldom does any matrix wheel run perfectly true on the sides, but as long as the face is true, it will grind well enough for any turner's purposes. The side to side wobble can be trued up somewhat by using paper shims between shaft washers and the wheel itself. This isn't perfection, but is an improvement over what it was prior to installing the shims. I use a hand held diamond tool for truing up the outside surface (the surface used for the actual grinding of your tools).....do this with very light pressure until the entire surface is dressed evenly.

The photo below is my grinder after truing and shimming a Norton SG wheel. Note the two balanced nickels perched on top of the grinder while a gouge is being sharpened.

I'm not willing to say what the value of the Oneway balancer is, but I'm stressing that wheels can be put into balance with other more primitive methods. I can say that the Oneway method is similar to a more sophisticated balancing system I use for a much bigger grinding wheel I use at work......basically the same principle, but the cradle and movable weights are more precise than the Oneway.

ko

 

[Jamie Straw]

[Snip] Seldom does any matrix wheel run perfectly true on the sides, but as long as the face is true, it will grind well enough for any turner's purposes. [Snip]

The photo below is my grinder after truing and shimming a Norton SG wheel. Note the two balanced nickels perched on top of the grinder while a gouge is being sharpened.

[Snip]. I can say that the Oneway method is similar to a more sophisticated balancing system I use for a much bigger grinding wheel I use at work......basically the same principle, but the cradle and movable weights are more precise than the Oneway.

ko

• It was a pretty big wobble (yesterday), where there was none before, only reason I became concerned🙁
• Ah! I'll try the nickel trick, see if it works!😎
• Hubby tells me the Oneway is similar, in a miniature way, to how they used to balance car tires.😉
• Have no idea what fixed it, but happy it's fixed

What model grinder is yours? What's that little white mail-box flag on the right?

 

[Odie]

question, Jamie:

When your grinder was in storage, were the wheels mounted during that time?

Is it possible they were exposed to water, or a humid atmosphere?

These wheels are porous, and could have absorbed moisture during storage. If so, gravity will eventually pull absorbed moisture to the bottom. The reason I ask is the larger wheel I use at work, is used with an oil based coolant, and if it sets for a period of time, the coolant will flow to the bottom of the wheel. The out of balance condition is short lived after using the grinder, because the coolant becomes evenly distributed once again.

That was just a guess........

But, I have no good theory on why your one wheel seems to have developed a warp. From what you can tell, do you think a warp is a reasonable assumption as to the cause of your wheel running with a distinct wobble.....?

ko

 

[Jamie Straw]

Toooo funny!

question, Jamie:

When your grinder was in storage, were the wheels mounted during that time?

Is it possible they were exposed to water, or a humid atmosphere?

Hah hah hah!! I live outside of Seattle!!! RH in shop during winter is 70%+ -- lots of rust after 5 years off, LOL.

That was just a guess........

But, I have no good theory on why your one wheel seems to have developed a warp. From what you can tell, do you think a warp is a reasonable assumption as to the cause of your wheel running with a distinct wobble.....?

ko

The wobble is gone, but just to clarify -- that wheel was fine Tuesday morning, wobbled Tuesday night. Evidently, there was some little somethin' that got disrupted when I remounted it to the grinder after re-balancing it. This afternoon, I fixed it. Tomorrow, it will still be fixed I hope. Oh, to answer your first question...the grinder sat there in the unheated shop for upwards of 5 years, not being used (as did all my tools). But that's irrelevant to the now-solved wobble. It may be relevant to why the fine (120 grit) wheel got so out-of-whack during that time, who knows? I'm just happy to have everything spinning smoothly now. Re-sharpened a spindle gouge today, and it was S-W-E-E-T!!

 

[Odie]

Hah hah hah!! I live outside of Seattle!!! RH in shop during winter is 70%+ -- lots of rust after 5 years off, LOL.



The wobble is gone, but just to clarify -- that wheel was fine Tuesday morning, wobbled Tuesday night. Evidently, there was some little somethin' that got disrupted when I remounted it to the grinder after re-balancing it. This afternoon, I fixed it. Tomorrow, it will still be fixed I hope. Oh, to answer your first question...the grinder sat there in the unheated shop for upwards of 5 years, not being used (as did all my tools). But that's irrelevant to the now-solved wobble. It may be relevant to why the fine (120 grit) wheel got so out-of-whack during that time, who knows? I'm just happy to have everything spinning smoothly now. Re-sharpened a spindle gouge today, and it was S-W-E-E-T!!

OK......guess everything's ok now, and you are back in business!

Good luck in your efforts, now that the desire has been reinstated.

ko

 

[Steve Worcester]

Hah hah hah!! I live outside of Seattle!!! RH in shop during winter is 70%+ -- lots of rust after 5 years off, LOL.



The wobble is gone, but just to clarify -- that wheel was fine Tuesday morning, wobbled Tuesday night. Evidently, there was some little somethin' that got disrupted when I remounted it to the grinder after re-balancing it. This afternoon, I fixed it. Tomorrow, it will still be fixed I hope. Oh, to answer your first question...the grinder sat there in the unheated shop for upwards of 5 years, not being used (as did all my tools). But that's irrelevant to the now-solved wobble. It may be relevant to why the fine (120 grit) wheel got so out-of-whack during that time, who knows? I'm just happy to have everything spinning smoothly now. Re-sharpened a spindle gouge today, and it was S-W-E-E-T!!

Another thing that can happen. The wheel is balanced, if the wheel nut is loose, when it spins up, the wheel rotates and is now out of balance.

 

[Jamie Straw]

Another thing that can happen. The wheel is balanced, if the wheel nut is loose, when it spins up, the wheel rotates and is now out of balance.

This I don't understand. The wheel is balanced before it is mounted onto the shaft, then mounted and it runs smooth. Why would moving the wheel on the shaft (on purpose in this example, not by accident due to loose nut) -- why would that unbalance the wheel? [This part of conversation is hypothetical, since the practical problem no longer exists.]

I can understand that if the nut wasn't tight when I mounted the wheel Tuesday afternoon, firing up the grinder could have tightened it in a weird way that produced wobble. I just can't comprehend how a pre-balanced wheel can become unbalanced simply by moving it on the shaft.

Not that grinder nuts are ever tight -- not like putting on lug nuts. The first time I set a grinder up, I couldn't figure out why the darned shaft kept moving when I tightened the nut. Nuts.

 

[Bill Boehme]

It has been a while since I checked, but I seem to recall that the left side has a LH thread so that both sides tend to tighten due to start up torque. Not saying that there can't be slipping, but with the cup washers and locknuts, the likelihood seems low. BTW, from what I have read, most wobble comes from the cup washers and not the wheels. That makes sense to me since the washers are stamped steel. That also explains why Don Geiger's solution works. Although my grinder doesn't have a vibration problem, I have been interested in getting the machined cup washers and bushings from Craft Supplies for my grinder.

 

[robo hippy]

One reason you can not tighten the nuts all the way down is to keep you from tightening too much and cracking your wheel. The wheels are brittle, and even a big tool catch on one can crack the wheel. If it ever gets chipped, you are supposed to trash the wheel. You do not want that coming apart on you...

robo hippy

 

[hockenbery]

Any time you have a wheel off the grinder it is a good idea to give it a couple of light taps with something like a screwdriver handle.
You should get a ringing sound all the way around a sound wheel.

Al

 

[Jamie Straw]

It has been a while since I checked, but I seem to recall that the left side has a LH thread so that both sides tend to tighten due to start up torque. Not saying that there can't be slipping, but with the cup washers and locknuts, the likelihood seems low. BTW, from what I have read, most wobble comes from the cup washers and not the wheels. That makes sense to me since the washers are stamped steel. That also explains why Don Geiger's solution works. Although my grinder doesn't have a vibration problem, I have been interested in getting the machined cup washers and bushings from Craft Supplies for my grinder.

Yep, RH / LH, I was just reflecting on the confusion years ago, the first time I set up a grinder....had no idea at the time. The Oneway balancing kit comes with machined washers that they instruct the user to install on the grinder (though they're not "cup" washers).

 

[Jamie Straw]

Any time you have a wheel off the grinder it is a good idea to give it a couple of light taps with something like a screwdriver handle.
You should get a ringing sound all the way around a sound wheel.

Al

Thanks, Al, I will do that.

 

[Jamie Straw]

...super-careful

One reason you can not tighten the nuts all the way down is to keep you from tightening too much and cracking your wheel. The wheels are brittle, and even a big tool catch on one can crack the wheel. If it ever gets chipped, you are supposed to trash the wheel. You do not want that coming apart on you...

robo hippy

Yep, I figured that out ("keep you from tightening too much..."). I'm extra careful to keep the tool well above center so I don't get a catch. The mere thought gives me shivers. I've always been a fairly careful sort of gal, despite my love of galloping over fences cross-country, but the two trips to Level I Trauma Center last year have made me extra, extra, extra paranoid. I now know what it's like to really get hurt.😱🙁 On a first-name basis with the local paramedics, not a good thing.