How do you retain balance after dressing?

[KEW]

I recently decided to refine my sharpening system to the next level and bought the Wolverine dressing and balancing set-ups.
So, I get my new toys and, since I've learned that the grinding wheels will always sit slightly different every time they are removed and reinstalled, I balance the wheels first.
I start the grinder and amazed by the lack of vibration - no more shudder as the grinder passes through a couple of resonant frequencies as it gets up to speed and the whirring noise at final speed is almost gone!
So far so good.

Next I true the wheels using the dresser and the "out-of-round" wobble is eliminated. However, truing has (of course) disturbed the nearly perfect balance.

So I rebalance and retrue the wheels for a second iteration, but while the balance is better, it still is not as good as before truing.

Obviously, this could go on all day and I'm not sure at what point I'm just pissing in the wind. The system is certainly better tuned now than ever before, but I'm wondering if I am missing something which will allow optimal balance and trueness at the same time. I'm kind of anal this way, but really like smooth running machines! (It wouldn't be so bad if I hadn't experience the optimally balanced wheels before truing, LOL)

Thanks for any comments/suggestions you can offer!

--------------------
Cheers,
Kurt

 

[GeorgeH]

Do you want to balance your grinding wheel statically or dynamically? The reason I ask is that, like you, I tend to be a bit anal about the balance of my grinding wheels. I've learned that something as simple of humidity can affect their balance; as moisture collects in the wheel(s) and migrates to the bottom of the wheel over time.
I've satisfied myself with static balancing, generally because dynamic balancing requires a lot of machinery I don't really want to pay for.
Here's a sight that discusses the issue (near the bottom of the page) that might help you.

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

 

[Bill Boehme]

If the bushings that you have do not give a reasonably snug fit between the wheel and the arbor, you may wind up chasing your tail forever. The sequence that I believe you ought to go is:

1. True the wheel with snug fitting bushings installed, but not the balancing kit.
2. Make an index mark on borh the wheel and the end of the arbor before removing the wheel.
3. Balance the wheel on the fixture.
4. Install on grinder with snug fitting bushings after the balancing set up from the fixture.
5. Align the index marks and tighten arbor nut.
6. Perform final truing.
7. Tweak the position of the balance weights slightly if vibration has increased. If vibration is worse, move weights in other direction.

If you try this, let me know if it works.

 

[KEW]

Nuturner,
Of course, I would love to dynamically balance my grinder wheels, but that is not really an option. Too bad I can't take it to the tire store and give them $7 to balance it!!

Boehme,
The balancing kit actually includes machined aluminum bushing/stabilizer flanges which are sized to the grinder shaft. Thus, these flanges replace the bushings. It has less slop than the original bushings, but is still not a press fit.
Thanks for the stepwise process. It is good food for thought and I think I can refine the system using your strategies. Here is what I'm planning to do. Let me know if you see any errors or opportunities for improvement.
1) Right now it is trued, but slightly out-of-balance.
2) Loosen the nut enough to allow the bushing to fall (take a set) and retighten.
3) Mark the 12 O'clock position on the shaft, nut, flange, and wheel (this will indicate where the assembly bottomed out from step 2).
4) True the wheel.
5) Balance the wheel
6) Reinstall wheel on grinder taking care to locate all components in the 12 O'clock orientation from step 3.
7) Turn on grinder and touch a pencil to the wheel to make a line around the periphery.
8) Make one pass (.001") with the truing jig and inspect for pencil mark. If removal of mark is uneven, mark the outside of the wheel indicating the center of the portion removed.
9) Complete truing.
10) Evaluate how much material removal was required in step 9 and if the grinder has more vibration than it had at step 7.
11) If needed shift weights slightly towards the mark made in step 8.
12) Tweak according to improvement or worsening of vibration.

I'll post the results when I do this.
Right now, I've been cutting bait long enough - I'm going fishing!! :cool2: :cool2: :cool2:

Thanks!!!

 

[Barbara Gill]

KEW, I used the Oneway Balancing system and the Oneway dressing system. I have not had any problems. I use the dressing system maybe every 7 times the wheel needs to be dressed. The other times I use the regular rectangle diamond dresser. My wheels run as smooth as velvet.

 

[JRutten]

Retain Balance after dressing?

My problem is I find it hard to retain balance while dressing. I always get one leg in my pants and lose my balance trying to get the other one in.

 

[Bill Boehme]

My problem is I find it hard to retain balance while dressing. I always get one leg in my pants and lose my balance trying to get the other one in.

It is one of the joys of getting old.

The trick is to look forward and not down so that you can maintain balance. Now, that opens the door to another problem ... getting both legs down the same pants leg.

 

[john lucas]

I prefer hopping while dressing. It burns calories and developes coordination.

 

[David Wilkins]

Put the wheels on the balancers, and the balance weights at opposite ends.
True up your wheel.
Then take the wheel and balance it.
Each time there after that you dress your wheel it should remain balanced.
There is a distinction between dressing and truing the wheel.

 

[john lucas]

There has been a fantastic wheel balancing article in Home Shop Machinist May/June and July/August 2009. shows you how to build a wheel balancing stand and discusses the intricacies of really balancing a wheel. Of course that also assumes you have a high quality grinder.

 

[Richard Baker]

Guess I'm just not very picky, and can tolerate a little vibration if the wheel is true and produces a good edge. BTW I put on both pants legs at the same time. No loss of balance that way.

 

[odie]

Guess I'm just not very picky, and can tolerate a little vibration if the wheel is true and produces a good edge.

Personally, I think Texian has given the most insightful answer here!

It's my job to run a Royal Master centerless grinder where I work. The wheel I use is a 2" x 10" with four movable weights for balancing. Balancing is done statically, very similar to the article George H. has posted. The exceptions would be the jig has four bearings that the balancing arbor sets on, rather than two parallel plates.....and, the balancing weights are permanently left on the work arbor.

No matter how well the wheel is balanced, it is never absolutely perfect. When the machine is turned on there is always a very small amount of vibration that can be felt by the touch of your fingers to the running machine. Despite a lack of absolute perfection in balance, I regularly produce medical tools/instruments to a tolerance of +/- .0003" (plus or minus three ten thousandths of an inch)

I have a feeling that some of you are seeking the unattainable.....or, absolute perfection.

In my home shop, I've been able to push/pull, or turn wheels on the arbor shaft to get a very good balance.......just how much vibration you will accept is up to you, but a little vibration is "normal", and will produce an edge that will cut wood cleanly.

I suppose an absolutely perfectly balanced wheel will give the best edge, but how much better a cut it will make is a matter for speculation.......since, as I said, perfection is a mighty difficult thing to achieve.....even with specialized equipment, and jigs.

One other thing to consider, is wood lathe tools are hand held, or at least not tight in the Wolverine (or similar) "V" jig. There will always be some amount of "give" to the tool in your hands.......no matter how perfect the wheel balance is.

ooc

 

[Alex Ku]

The best solution to retain balance after dressing is to buy a belt grinder.
In my opinion belt grinder is ten times better for tool sharpening or re-shaping than any wheel grinder. Sorry Tormek.

 

[Richard Baker]

Odie,
Thanks for your support.

 

[MichaelMouse]

Nuturner,

Thanks for the stepwise process. It is good food for thought and I think I can refine the system using your strategies. Here is what I'm planning to do. Let me know if you see any errors or opportunities for improvement.

1 Remove the stone on the opposite end.

14 Balance stone on opposite end of the same shaft.

Or forget the whole silliness and hold the tool firmly on the rest, letting the stone come to it.

Why has no one suggested weighting the grinder stand or using shot-filled handles?

 

[john lucas]

I don't sharpen my free hand tools on the tool rest so wheel bounce is a serious issue. Weighting the handle doesn't help much with this either. It would help when using the tool rest.
I do have a weighted stand and a heavy grinder but if you get wheel bounce from an out of balance wheel you still get vibration that makes it more difficult to freehand grind.

 

[Bill Boehme]

I am a stinkin' Tormek user.

OK, there ... I've said it. And, not only that, I enjoy going wet when sharpening.

I feel relieved now that I have come out in the open about this sensitive issue! Please be understanding and recognize that there is diversity amongst woodturners.

I invite others who have adopted an alternate sharpening style to come forth and make it known that you have eschewed the "same old grind".

 

[Richard Baker]

Bill,
That might be the answer. If all these cats would just run their grinders at 90 rpm they wouldn't vibrate so much.

 

[odie]

I don't have a Tormek, but I do have a slow speed wet grinder that is the same sort of thing......not sure Tormek was in existence when I bought this one.

I also have a Delta 1825 rpm grinder.

Back in the early 1980's, I tried using an old 4x36 belt sander for sharpening. Nothing wrong with that, but I wouldn't go back to it.......mainly because belts are expensive, and need to be dedicated to the specific purpose of sharpening.......not to mention that it's a pain to continually swap out belts and track them.

These days, for gouges, it's a three step process.....Delta pedestal grinder 80grit, then wet grind 200grit, then slip stone.

I'm not saying what works for me is best for everyone, but I am saying that what works for me, is also what is best for me......gives me the sharpest, and most consistent edge I've been able to achieve over other methods.

ooc

 

[Gretch Flo]

Odie's tool caddy

Odies-just curious if you've ever lacerated your hands or arms reaching for a tool. I have been lazy and not built one. Just lay frequently used ones on my wheeled table next to the lathe, less frequently used laid on another out of the way table. I realize the sharpness may suffer, but how much??? Gretch

 

[MichaelMouse]

I don't sharpen my free hand tools on the tool rest so wheel bounce is a serious issue. Weighting the handle doesn't help much with this either. It would help when using the tool rest.
I do have a weighted stand and a heavy grinder but if you get wheel bounce from an out of balance wheel you still get vibration that makes it more difficult to freehand grind.

John, I was tweaking the Weeble people and those who tout a heavyweight handle as an answer to vibration (on the lathe) types. Sorry to have mislead you.

So what do you do with your freehand sharpening, just lay the bevel up well above center and roll the tool? I am too squeamish to do that without benefit of a toolrest, just as I am squeamish about cutting on the lathe without one. Only exception is planing, where my thumb holds the tool to the piece as the other hand pushes.

As a freehand grinder of many years standing, including on huge sandstone wheels a' la Roy, I only work without a rest when the stone is rotating away from me, where I can follow its ups and downs, ins and outs easily.

 

[Mark Mandell]

Not a Real Problem

I just lay off the sauce until undressed.

BTW, sharpening only needs to produce an edge that cuts wood well. It's not a contest or metaphysical search for a wood scalpel with tooling tolerances to .00000" Takes me all of 20 seconds to refresh an edge and get back to cutting wood. I keep the stones' working surfaces trued relative to the rest, and a little vibration in the grinder is meaningless for my purposes.

Precision machinists will, of course, have a different view.

ps: Now my carving chisels are a very different story. They are taken down to scary sharp status. Had a gouge get knocked off a high bench while I was sitting on the floor under it. Hit me in the leg, went through my jeans, and opened a 3" incision that took 6 stitches to close. They do, however, leave a beautiful polish on the cut surface of wood.

 

[john lucas]

MM I lay the lower part of the bevel on the wheel well above center, then raise the handle until the bevel is flat on the wheel. Sharpen until you see sparks come over the top. If you use very gently pressure and don't have a bouncy wheel you get a grind very close to the Wolverine quality but a shape that would be very difficult to grind with a jig.

 

[odie]

Odies-just curious if you've ever lacerated your hands or arms reaching for a tool. I have been lazy and not built one. Just lay frequently used ones on my wheeled table next to the lathe, less frequently used laid on another out of the way table. I realize the sharpness may suffer, but how much??? Gretch

Howdy Gretch.......

So far, I've never cut myself on those upward facing tools held in PVC pipe.......but, it could happen if I'm not paying attention, I suppose.

For tools in constant use, I do something similar to what you are doing. For those, I use a rolling cart that was intended for use by auto mechanics. There is ample space on this cart for laying out an array of tools in more popular use, or expect to be used for a current application. As you have probably found, laying out current tools flat is a good way to keep things real handy.......!

I've never found that sharpness suffers by doing things this way......well, not unless I get careless, anyway. There is a rubber mat on the bottom of the rolling cart tray......and, of course, sharpness will likely not ever suffer with those tools kept in the PVC pipe.

ooc