Balancing Grinding Wheels

[G-Auto]

Referencing the previous thread on the okamoto 1224 DX surface grinder....Okamoto 1214-DX

How are the wheels on this grinder balanced? Is the balancing done on the grinder or off on a balancing rig?

Does the Okamoto use hub adapters for the wheel?

 

[WILLEO6709]

There is a balancing arbor shipped with the grinders... generally, it may be optional. a Stuhr or other static balancing stand is generally used to achieve balance. On the okamotos there is set screw clamped wieght you adjust on the wheel flange.

 

[tdmidget]

The hub should have 3 weights. As an apprentice I was taught that to do it properly you must move 2 of them.

 

[Konrad]

check this out..

http://www.grindwell.com/GrindingTech/pdfs/BalancingOfGrindingWheels.pdf

 

[ben80]

double balance

What we did ,before they speeded up the process is to mount the wheel and balance it. Then true the wheel in on the grinder and then rebalance it. Takes more time but , does a good job. I am not sure why we balanced it the first time, no one ever said. It could have been to keep the vibration out of the grinder for the wheel clean up. I generaly marked the grinding face with spray blueing to see when it cleans up.

We would take off about .0008 in. per pass and on a 3 foot wheel it could take 30 to 130 pass's to clean it up the first time. Thats with a cluster diamond and you can get a little more agressive with a cluster, like .0012 if you want to hurry. More if you want to risk the diamond.

 

[Greg B]

Yes, only balance with two weights, at first that is. Makes it much easier than chasing your tail around the hub. When you have it really, really close, then you might need to tweak the third weight, usually just a tiny amount. I like to check at approx. 45 deg. intervals around the wheel. I start with 0, then 90, 180, & 270. Once I am close, I start checking in between each as well.
Plus, I mentioned in the other thread about double balancing as well. First dress dry, then balance again. You want to get the wheel balanced, then round and then back in perfect balance.
Note if you are rebalancing a wheel, one that has already been subjected to use with flood coolant, lay the wheel down flat overnight. Let any coolant that may be still in the wheel to settle towards one of the faces of the wheel rather than the periphery.

 

[MarcS]

I'm not familiar with your size Okamoto but on our 20" Okamotos here is how we mount and balance our wheels:

1. ring test, new blotters, torque to 35 ft. lbs.(don't trust our torque spec, might be wrong for others), nice clean hub

2. dress to true, if you are fussy dress the sides too, you can hear when it's dressed true

3. set up in balancer (we use the Okamoto supplied balancer), make sure balancer is level
-put a drop of oil on each end of the arbor so you don't score it all to hell

4. find heaviest spot and place at bottom, set 1st weight on heavy spot -important

5. place 2nd and 3rd weights at about a 35 degree included angle from 1st weight.

6. rotate wheel 90 degrees, check balance

7. adjust 2nd and 3rd weights equally from center to bring in balance
-for this return heavy weight to bottom so you can adjust the other two equally
-if you find that either the 2nd or 3rd weight has to be skewed more than the other then
you weren't careful enough finding the heavy side and centering the 1st weight in it.

Clear as mud?

If nothing else makes sense remember to adjust the 2nd and 3rd weights at the same time. If you adjust them one at a time you'll go in circles. If it gets too tricky the first few times pull the weights off and start over.

Good luck

 

[Konrad]

Marc,...you're 100% correct!

Konrad

 

[Lost in LA]

I am with Marc up to step #3.

I think I have a easier way by using only 2 balance weights.

4. Place the wheel and arbor on the balance stand with out the balance weights. The heavy side will end up at the botton. Mark the light side (top) with a marker pencil.

5. Remove the wheel and arbor and place two balance weights half way between the light and heavy side at 90 degrees apart.

6. Replace the wheel and arbor back on the balance stand and the wheel should come back to its previous location. If it does not repeat the balance weights are probably a little bit off location. Move them slightly until you get the original light side to the top.

7. Now move both balance weights in pairs toward the light side.

Lost

 

[MarcS]

That's interesting. This has only happened a couple times but I have had wheels where for whatever reason the wheel was out of balance more than usual and they balanced with only two weights. The way the weights normally end up they are all spaced fairly equally, which tells me our wheels and hubs are of pretty good quality and close fit. If, in the normal case I tried to balance one of our wheels with only two weights I suspect they would be too heavy for the lighter (un-weighted) heavy spot and would end up very close to 180 degrees apart. Other grinders/hubs/wheels such as Mattisons for example might balance all together different. Our balancer for example won't find the heavy spot by itself, you pull a pin and the whole aparatus swings on two knife edge pivot points. Mighty sensitive too. A couple Post It Notes on one side of the balancer and you can see it indicated.

I know where you are coming from though. Pretty hard to describe such a thing without an engineering degree...

 

[huntinguy]

What we did ,before they speeded up the process is to mount the wheel and balance it. Then true the wheel in on the grinder and then rebalance it. Takes more time but , does a good job. I am not sure why we balanced it the first time, no one ever said. It could have been to keep the vibration out of the grinder for the wheel clean up. I generaly marked the grinding face with spray blueing to see when it cleans up.
QUOTE]

You balance the first time because you don't want to have an out of balance wheel on a grinder. This first dress is to make the wheel round. The second dress is to make the wheel balanced when it is round. Think of it as rough and finish dress. (in a nut shell)