Bill wrote:

I noticed that at the link you provided, they have multiple shaft sizes.
I believe the Delta grinder has 5/8" shaft. But as you point out, if the
wheels that come with the grinder have inserts because they are realy
cut larger, then I'll have to decide what to do.

Slightly larger. They're not like the wheels you might buy new. I
think most new wheels have something like a 1" center hole, and then
typically come with a variety of plastic/rubber inserts to accomodate
the different shaft sizes.

I'd be more tempted to buy the 5/8" Oneway balance system and use the
wheels as they are (unless this is dangerous) or buy new wheels.

You buy the Oneway kit based upon the shaft size of the grinder--not
the diameter of the grinding wheels. As I recall 5/8" sounds right
for the shaft size of the Delta.

Once the Oneway system is in use, the grinding wheels need to fit
a larger diameter shaft (i.e., that of the hub). If you want to
use the grinding wheels that come with the Delta and the Oneway
hubs--you MUST bore out the centers of the wheels.