I thought I’d post this in the turning forum rather than power tools as it seems to me nobody needs a well behaved grinder more than a turner.
What a PITA to get the vibration down on my 8 inch grinder. The grinder sounded like an aircraft, so I knew things were really bad in the balance department. I had a coarse OEM stone on the left side and the Norton white on the right. I wanted to move the white to the left side and mount my Norton blue on the right. I removed both stones and began playing with the white stone on the left side. I finally got lucky and obtained a reasonably low vibration. I do mean lucky, there was nothing deterministic in what I did that could be repeated to obtain the same result again. In fact, the Norton blue is not mounted because I couldn't get lucky twice.
There is a tendency for severe and highly variable sideways wobble. I think most of the problem pertains to two issues. Firstly, the bushing plastic pieces that allows one to mount to a 1, 3/4 or 5/8 inches shaft have way to much slop. This arrangement must have at least 10 thou movement if not more. The second weak spot looks like the side washers (flanges?). I think they could be flattened and probably larger diameter too. In fact, at one point I mounted my 5 inch saw blade stiffeners (LV 16T01.02) and things looked much better, but they were rubbing against the shield a bit and I was worried about squeezing directly on the stones as opposed to the cardboard the OEM washers bear down upon.
For those whom are unfamiliar with the LV saw blade stiffeners, see below.
When I get a metal lathe working again, I am going to machine a proper bushing for the centre hole, including reaming the 5/8 diameter, and maybe even making some big washers if I don’t in the mean time buy a 3 ½ inch set of stiffeners at LV for the purpose. Or maybe the bushings exist as a commercial product. As the 1 inch bore on the stones probably is not very accurate, I’d probably even custom fit a bushing to each stone and epoxy it permanently in place.
It seems to me that grinding stones are another product that is unusable as it comes new from the store. Sure, I can see retailers not wanting to stock 3 different stones with 3 different bores, but why can't we buy proper bushings and flanges? Maybe the market is all welders who don't care about balance.
I am curious what people think of my observations.