I ended up boring the hole on the mill since that was the easiest set up. I clamped the wheel down through the hole first and swept the OD with a dial to get it centered. I indicated the OD as close to the abrasive as I could get. There were a few irregularities on the OD like it wasn't perfectly round, maybe it was the paint..... don't know. But I got it centered to within .0005. Clamped it down with the hold downs "gently" and bored the hole to 1.375. Then I made the PVC bushing. I allowed .002 push fit and opened up the bushing ID an extra .002 to allow for the "squeeze factor" and then tried it on the spindle. I ended up with a perfect fit and indicated it to about .002 run out. That's a hole lot better than what it originally was and it repeats when removed from the spindle and replaced, that's another important thing.
Ideally it would be nice to have every wheel mounted on a hub but for most of us it's just not reality. Those hubs aren't cheap and on my KO grinder it's a PIA to hold the spindle from behind and loosen the thing up and pop it off, and you also risk damaging the taper in doing so.
JL...............

Leave a comment: