Truing Up a Grinding Wheel

[Jack Hogoboom]

My new grinding wheel is unbalanced and shakes pretty good when it gets up to speed. Any tips for how to true it up would be greatly appreciated.

Thanks,

Jack

[Mike Linne]

Make sure wheel doesn't have any cracks (ring test). Make sure your arbors are true. If using a bushing, make sure it's a snug fit to the shaft so that your wheel is centered relative to the grinder shaft. Once you make sure there isn't excess slop in the fit to the shaft, mark the wheel top dead center on the blotter - this should be installed top again if you change the wheel. Reason - the wheel is always a little off center relative to the shaft (usually hangs down) and when you true the wheel you will be then be able to repeat it's position relative to the shaft if you change wheels. Tighten wheel on shaft (don't overtighten - just enough to keep wheel from slipping). Best truing tool is a diamond point truing stick. Hold stick at a 15 degree down angle and run lightly across the face of the wheel (not the side of the wheel) angle and distance relative to wheel. This should do the trick. If you don't have a truing stick just sharpen something making sure you use the full face of the stone - this should eventually produce a balanced wheel. Good luck.

[Dale Thompson]

Jack,
If your wheel is really out of balance, take it back for an exchange or a refund. I've seen the results of a grinding wheel "exploding" and it's not a pleasant sight. I NEVER turn on my grinder without a face shield and safety glasses as a backup. I walk away and let the grinder come up to full speed for 10-30 seconds before I use it.

If your "unbalance" is "side-to-side", forget balancing. NEVER approach a wheel from the side with any kind of tool or facing device. The adhesives used to hold those things together are meant to resist centrifugal (centripetal, if you are a physicist) forces perpendicular to their axis of rotation. They are NOT intended to resist axial forces forces parallel to the axis of rotation.

If your wheel is reasonably "unbalanced" in terms of vertical concentricity, you have several choices. I use a diamond dresser for my lathe sharpening wheels and the old "sparker" type for the courser grits. In any event, dressing a grinding wheel is my LEAST favorite maintenance item in the shop. Wear a dust mask. The dust is uncontrollable, ultra-fine and really a pain the the neck.

Whatever, Jack, don't mess with those wheels if they are REALLY out of balance. Otherwise, be prepared to duck - REAL FAST!!

Dale T.

[Jim Becker]

Jack, truing the wheels using a diamond tool will certainly help, but may not get them fully in balance. This is due to the way the wheels are made...by compressing material under high heat, etc. There will always be differences in density through the wheels, even with the most expensive ones you can buy. Honestly, I've been suffering with this for a number of years and am about to invest in the OneWay wheel balancing system and replace my wheels at the same time. The OneWay balancing system really does allow you to deal with the density issues and completely smooth out performance. Supposedly, it's a one-time adjustment for the life of the wheels, too. The bad news is that is requires spending more money. Sheesh!

But balancing obviously doesn't remove the need to groom the wheel with a diamond tool. I use a cheap tee-shaped one for quick touchups and have the Wolverine wheel dresser for when I want to actually get them back in round. But unless they are balanced, they will go out again reasonably quickly and require heavy re-dressing. Never-ending problem, unfortunately!