"Ignoramus12789" wrote in message
.. .
http://igor.chudov.com/tmp/baldor-grinder.jpg

It is a military surplus grinder. I bought a 7" and 6" wheels for
it. It works, it is very quiet and vibrates very little. The wheels
have plastic insert to match the hub and seem to be a bit off
center. How can I center them?

i


What Grant said, but make certain that your new spacers are not a press fit
in the wheel, or on the mandrel. There's good reason for this suggestion.
Should the bore of the wheel not be dead perpendicular to the side, when you
tighten the nut and the flanges restrain the wheel, it could crack it.
Make sure the bushing is an easy fit, but not sloppy. Also, insure that
it's shorter than the thickness of the wheel, so it isn't the high
spot-restricting the flanges from making full contact with the wheel. Be
sure to run wheels that have the blotters on them----the papers on each side
that have the nomenclature. They're not there for advertising alone, they
prevent wheel fracturing from uneven clamping of the flanges. Make sure to
ring the wheel before mounting it. If it doesn't have a clear ring, break
it and discard it. Do that even if the wheel is new. You have no idea how
wheels have been handles once they've left the manufacturer. To ring the
wheel, place it on a screw driver or other object, then tap it lightly with
a screwdriver handle. A dull thud or thunk sound comes from a cracked
wheel, a sharp ring from one that is intact.

When you get your wheel mounted, it's highly unlikely it will run true, and
even more unlikely that it will remain so, even if it is. Dressing a
grinding wheel is very much a part of using it. As much as I dislike the
star dressers Grant mentioned, they are the best possible dressing tool, but
present their own problems. For one, it's almost mandatory that one have a
tool rest to use them successfully----and I never use one for grinding tool
bits. The other problem is they're hard to use if you want to true up a
wheel with minimal waste. They work very well at removing wheel surface,
leaving what is the best possible surface for off hand grinding, but you can
go nuts getting the wheel absolutely true, a requirement when you use wheels
the way I do. YMMV.

If you find you're unhappy with a star dresser, use a diamond to bring the
wheel true, then rough it up slightly with a dressing stick. Make sure it's
not one of the boron carbide type, which are typically 1/4" thick, 1/2" wide
and 3" long. The proper one will be made of sintered silicon carbide ,
typically 1" square and 6" long. One, which shouldn't cost you more than a
couple dollars, will last your lifetime unless you get real serious about
dressing wheels. So you'll know, a wheel dressed with a diamond will be
more difficult to use, and will cut very hot, especially as compared to a
wheel dressed with a star dresser.

Good luck!

Harold