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+-- Thread: Balancing grinding wheel (/showthread.php?tid=7293788)
Balancing grinding wheel - wood2woodknot - 06-02-2016
I just bought a new 120x white wheel for my bench grinder. I have a 36x wheel on the opposite side. When I first turn the grinder on the new wheel has a slight side-to-side wobble, but not the other wheel. As it builds speed, the wobble disappears. I'm using the plastic arbor adapters that came with it. The wheel is on tight with no slop. I gave it a cursory touch-up with a diamond wheel dresser. Everything seems to run smoothly except when the wheel is just starting and nearing stopping speeds. I tried grinding a few pieces without any problems.
Do I really need to do more? or is this fairly normal? Is there a way to fine tune the balance to reach perfection?
Re: Balancing grinding wheel - Timberwolf - 06-02-2016
A little "wobble" is pretty common..You might try loosing the nut and rotate the wheel on the shaft a few degrees, then tighten it and check for run-out.If it runs true, leave it but if there's still wobble, rotate it on the shaft again and try it.. Do this until you get improvement..if there's no improvement I wouldn't worry about it..Metal bushings might help providing they fit the shaft AND the wheel with little to no play..
Re: Balancing grinding wheel - wood2woodknot - 06-03-2016
Thanks, Jack.
PS- Was hoping to get in touch when we were down recently, but just too many things to take care off. Off and gone again before we knew it. One of these days I'll get to meet you.
Re: Balancing grinding wheel - daddo - 06-03-2016
If it is the wheel that is off, return it for one that is true. A wobbly wheel is just plain bad workmanship and can be dangerous as well as damaging to the motor bearings.
Otherwise, get a good metal sleeve.
Re: Balancing grinding wheel - mike4244 - 06-05-2016
Lateral movement is common and won't make a difference in your grinding. Sometimes the movement is from the motor shaft.Then both wheels would have similar movement .The balance will not cause lateral movement,will cause the grinder to vibrate badly.
The only thing you may want to try is add a cardboard washer to the wheel and then the flange nut.Might help.
mike
Re: Balancing grinding wheel - daddo - 06-05-2016
You should also test that wheel to make sure it isn't cracked, causing it to be untrue.
You cannot always see the crack or separation or softened area.
Remove the wheel and lightly hold it from the center hole and tap it with a piece of hard wood, butt of a screwdriver or lightly with a piece of metal- it should "ring". If it doesn't ring or it thuds, get rid of it!!
You do not want it coming apart at 3,600 rpm.!
Re: Balancing grinding wheel - wood2woodknot - 06-05-2016
More thanks to Daddo and Mike .....
Tried Jack's idea of re-positioning the wheel on the arbor. Thought I had it almost perfect, then one more tiny shift ... and I lost it. Couldn't find the sweet spot again. Improved it somewhat by adding two large washers behind the inner flange. Looking for a thin rubber washer between them to eliminate a slight rattle they make at slower speed.
Will look for a steel arbor adapter when ProTool opens on Monday. I think the plastic adapters that come with the wheel (and with all the other wheels I see in the stores) are slightly misfit.
Also, will have to ring test the wheel. I forgot to do that first thing.
In the meantime, I bolted down the the grinder to a workbench, adding a piece of rubber mat in between to minimize any vibration.
Get all that solved and it's on to making a jig for grinding plane irons and chisel blades, the reason I bought the white wheel.
Re: Balancing grinding wheel - rwe2156 - 06-07-2016
My experience is the problem often lies in the bushings, especially the plastic ones that are usually too loose.
If you have a lathe you can make your own bushings easily.
Also, check the inner washer for 90 to the shaft. I've had that be off, too.
I have fixed the issue with a paper shim here and there.
You can get wheel balancing kits, but I really think the problem is mostly in the grinder, not the wheel.