Wheel balancing required?

[Yannick P]

Hello guys, I would just like to share with you an idea that I had in order to help me balance a wheel without an arbor and/or wheel balancer. I took 2 bowls of water, one mounted on a cantilever plate on the wheel guard and the other on the machine. I managed to substantially improve the vibration marks on the part. It's just an idea to help out. If I have more time I will come back to explain more détails on the procedure. I repair machine-tools for living so I ran quite a few grinders over the years. I wish a nice day to all my friend machinists.

 

[Tyrone Shoelaces]

How does that work then ? Is it as good as slaughtering a chicken over the spindle ?

Regards Tyrone.

 

[michiganbuck]

Name brand wheels are pretty close to balance out of the box. and most can run that way. (I mostly don't balance a wheel)
Still, It doesn't hurt to balance wheels if you wish, You may get a better finish and it may be better for your spindle(?). A balancing arbor can be bought for a low price, and a couple of rectangles set on your level chuck or surface plate make a good wheel balance set-up. A carbide drill can crush a dent in the (vitrified) wheel for balancing or a wheel weight mount can be used.

A manufacturer might void a spindle warranty by asking "Did you balance every wheel"
A wheel balance arbor is an easy thing to make on a lathe.

The hole fit to the mount is important and a wheel with a worn-out hole tends to run out of balance.
all wheels should have a mount-up line added to accommodate the hole clearance so the next time put on it will run smoothly to the last dressing, and run smoother to the last balancing.
Important to run wheels after the coolant is turned off to sling coolant out of the wheel.
Good to store wheels on a peg board so less likely to get dropped, * and the wheel board should be covered so shop dust does not fall on the wheels.
Wheels should be tight, hearing guys say that just shutting down the machine can loosen a wheel is just stupid IMHO. I would not have such a dangerous guy in my shop.

Balancing should be done after dressing the wheel. (or balance it twice.)
For super finishing, I also dress the front and rear face, and I dress the OD taper of cup wheels. (Mostly don't do that unless some special finish spec.)

Fresh diamond facet/edge. lightly rub a wood stick after dressing. ring test wheels, inspect mount flange, always a blotter, don't exceed listed RPM. block-in should bump high on a part in the Go Direction. push a risky part with two fingers and if it tips over readjust your set-up..
*I like to hand turn and then jog start a grinder spindle that has set for a time. A slug of dry oil or grease can make a ball drag at the start and harm a bearing. I jog start all my grinders every time / it only takes a few seconds. (even for bench grinders.

It so not uncommon for overhead dressers to not be turned and they get flat-nosed.

 

[michiganbuck]

Hello guys, I would just like to share with you an idea that I had in order to help me balance a wheel without an arbor and/or wheel balancer. I took 2 bowls of water, one mounted on a cantilever plate on the wheel guard and the other on the machine. I managed to substantially improve the vibration marks on the part. It's just an idea to help out. If I have more time I will come back to explain more détails on the procedure. I repair machine-tools for living so I ran quite a few grinders over the years. I wish a nice day to all my friend machinists.View attachment 367771

Yannic P,
That is a nice-looking grinder, what makei s it?
That is an interesting idea, I have thought about it but have never tried it.
*From here it looks like your wheel has a couple of edge chips outs, which happens from a wreck or bumping a wheel at handling and even dropping a wheel, and good for newbies to know that a wheel with a few chip outs is still an Ok wheel if it still ring tests with a ring sound. tap it with something and it makes a ring sound.

Oh, welcome to PM.
Buck

 

[eKretz]

I would be interested in hearing more. I'm not sure how one would quantify the vibration with a bowl of water... Perhaps counting rings that form in the water due to vibration?

I didn't generally go to the trouble of balancing wheels on the big grinders like a Mattison - they are so stiff that a wheel would have to be massively out of balance for that to show up in the finish, but it can be helpful on smaller ones. I've never found it necessary, per se, as long as the wheels are well dressed and not running out anywhere, but it can certainly improve the finish a bit.

 

[Tyrone Shoelaces]

It doesn’t sound very scientific to me. There are three balance weights on that wheel arbour. What’s the method of adjusting them to reduce the vibration ? I presume that’s the plan ? Surely even a rudimentary balancing iron set up would work better.

Regards Tyrone.

 

[Bill in PA]

I use 10" wheels on both the surface grinder and cylindrical grinder. I do have to balance each time I mount a new wheel. There is noticable vibration without doing so. The balancing fixture I made is simply two vertical plates with 1/4" drill rod screwed to the top for the arbor to roll on. I set the fixture on a mill table that is level.

My procedure is to mount the wheel and dress, then balance. I take out the three weights and put one back on at the heavy spot. The other two go back on 180* from the single one. Easy to adjust from there.

I only have one hub for each machine. I cannot seem to find the time to make more.

Bill

 

[cyanidekid]

Yannick, what is that chain for? (and that wheel is a bit of a mess, that's a big chunk missing, not sure id run it, despite what buck said, which I generally agree with...)

 

[michiganbuck]

I did not notice the chain, perhaps they lifted the table to remove balls if it is a ball machine.
Perfectly Ok to fear that wheel and toss it. Definitely at least pull it and ring it if wishing to use it.

It took a sizable wreck to knock out wheel chips like that. Likely the chuck took a beating also

Used to be that some wheel mounts had balance holes or dints in them. Might be good to balance check a wheel mount, and balance it if it is way out.

 

[metalmagpie]

http://www.nwnative.us/Grant/shop%20articles/sharpTable/balancing

 

[Milling man]

I would be interested in hearing more. I'm not sure how one would quantify the vibration with a bowl of water

It's just a very, very inaccurate way to see the amplitude of vibrations. Of course, this way you will not be able to see the position of the maximum point of imbalance. This method helped me a couple of times, but on a milling machine. When we got an accelerometer in our lab, I didn't do that anymore.
On grinding machines, we always balance the complete grinding wheels with their mounting mandrels. The standard procedure after installing a new wheel is to remove all balancing weights from the mandrel - dressing - balancing. Then, in the process of work, sometimes you have to repeat the balancing, if the wheel is of a very "highest" quality
I use the classic way of static balancing with strictly horizontal knives and a cylindrical mandrel, and of course 3 weights on a fixing mandrel with a circle.
On a large machine (like grinding crankshafts with a 35" wheel) I would be too scared to run a wheel without balancing But I'm talking about aluminum oxide or silicon carbide wheels - not CBN or diamond wheels.

 

[michiganbuck]

It seems that watching the water bowl vibration and moving weights about would be more time-consuming than setting a balance wheel assembly with an arbor on a pair of straight edges.

 

[Milling man]

It seems that watching the water bowl vibration and moving weights about would be more time-consuming than setting a balance wheel assembly with an arbor on a pair of straight edges.

It is not always possible with good accuracy to remove and put a rotating "something" from the machine to the balancing device - and then back.
But in general, of course, you are right. It probably took me a day or so. I managed with the accelerometer in half an hour.

 

[stressrelieve]

Yannick, what is that chain for? (and that wheel is a bit of a mess, that's a big chunk missing, not sure id run it, despite what buck said, which I generally agree with...)

Probably the chain is used to lift the longitudinal (reciprocating) table off the (transverse) saddle. One manufacturer I knew of was in the habit of shipping its machines with the table removed, fitting it only when the machine was in its final operating location. Perhaps more manufacturers do the same…I don’t know.

 

[michiganbuck]

​

Welcome to Pm Yannick
Tell us a little about your surface grinder.
It seems odd that the wheel head dial goes that way for up?
Buck

 

[michiganbuck]

Qt Milling Man; (It is not always possible with good accuracy to remove and put a rotating "something" from the machine to the balancing device - and then back.

I agree with that. I have a line-up mark at my spindle end and put my mounts at the same radial spot for each mounting, and a line-up line on the wheel that also is my mount-up line.. I used to line up my spindle mount line and then skim my mount face if it was not zero, but you can't do that if haveing two grinders that use the same mounts.

 

[Milling man]

but you can't do that if haveing two grinders that use the same mounts.

I can only dream of having two different machines with the same wheel mount..... The labyrinth seals on the spindle will definitely be different