"Joseph Gwinn" wrote in message
...
snip-----

.. I understand the split-point geometry well enough,
but first I need some practice hand-grinding, so I'll do plain points at
first.

Certainly not a bad idea. Hand sharpening is a bit of an art and requires
considerable practice. No sense rushing things.

Following another poster's suggestion, I hand flattened the mating
surfaces by wet sanding on a granite surface plate, and broke the sharp
corners with a hand file. Stones still wobbled, but one possible cause
eliminated. The irregularities should also be much reduced, if the two
surfaces of the flanges are parallel.

The term "stone" is not generally applied to grinding *wheels* in the
industry.

Do you have any machining capabilities? I'd suggest to you that making new
flanges would be in order. Having read below that your flanges are
pressed steel, I can't help but think that they are in large part your
problem. The very idea that you moved the wheel about and got it to run
better indicates to me that the
wheel(s) are also not great. That doesn't mean they aren't serviceable,
assuming you can get flanges that run true. You can always dress the sides
of a wheel to improve how it runs. Fact is, that's fairly common.

The problem of wheels not being parallel is not uncommon, which I may have
mentioned. Norton has a terrific reputation in the abrasive world, and
still manages to turn out the occasional wheel that isn't parallel.


The stones are 1" wide and 8" (not 6") in diameter, on a 5/8" arbor, are
gray, and claims to be made by Ryobi.


The only problem I see is that the abrasive is likely not well suited to
grinding HSS. You will be somewhat limited as to the wheels that are
available to you, however. The greatest selection tends to come from
wheels that have a 1-1/4" arbor. Such wheels are used on cutter grinders and
small surface grinders.


Don't over tighten. It's not necessary.

Define "over-tighten", please. The spindle nuts are now looser than
they were in the as-received machine, but still I'd like to know the
limit to be avoided.

Sort of hard to describe. If you hold the wheel by hand, and tighten the
nut with a wrench, when the wrench overcomes your ability to hold the wheel
from turning, you have it tight enough to serve without problems. I
tighten wheels on my grinder by that method and don't have any problems with
the wheels coming loose, even when running in reverse. If you do heavy
grinding, such as might be done in welding, that may not be tight enough.


Using a dial indicator, I measured the wobble on one flange: 0.008" at
1.25" radius. This would translate to (4/1.25)(0.008)= 0.0256" at the
outer edge of the stone. This is approximately what I see by eye.


That clearly sucks. Flanges should run true, or be free to float, so they
*can't* hold a wheel at an angle. The shoulder on the arbor should be
true. In turn, it should hold the flange true. Anything less isn't a good
thing.

(Don't want to grind the dial indicator probe tip, so didn't indicate
against the stone.)

Good decision. No need to-----the flanges tell you everything you need to
know. Until they run true, nothing else matters.


Another poster suggested ditching the OEM stones, which are made by
Ryobi. Is this likely to solve the problem, or at least help?

Assuming you end up with wheels that have a similar discrepancy, and you
have the good fortune to align them such that the errors cancel one another,
yes, it could help, but the best fix is to get the flanges running true.
Once you do that, you can readily correct the wheels by dressing, should
they need correcting.

If all else fails, and you're "stuck" with the flanges that don't run true,
you might try tapping them gently with a soft hammer until you get them to
run true. If they are a snug fit on the arbor, as you suggest, that
could improve performance. Beyond that, the way I see it, new flanges are
in order.

Let us know how it goes.

Harold