"Mark" wrote in message
...


Harold & Susan Vordos wrote:



The grinding wheel had a divot removed, but after dressing to get down
to a
full wheel the wheel was used again. Stopping them fast doesn't do any
damage. Apparently when they're well made, neither does wedging
them!
g


Geez, what can I write?

Agreed! I'm not sure who had the courage (or stupidity) to start the wheel
once the part was removed. As I stated, the crash occurred on the opposite
shift. However, when you come in to find the machine has been running for
hours, seems to me the wheel has been through the trial period that says
it's likely to stay together. It did.


If you want to trust your life and limb to a stressed wheel go right
ahead. God watches out for fools and drunks.

I'd like to think I was neither of them. I know I wasn't a drunk. On the
other hand, I'm not sure there's a God. We agnostics are like that.


Makes me wish I saved the manual with graphics of grenaded wheels. Had
one picture of a wedge dropped between a rest and wheel to illustrate
the need for a guard. Thousand words omitted.

You're talking with someone that has used grinding wheels long enough to
more than understand your point. A point I had concluded way back in the
early 60's, in fact.

Ever had any wheels blow on you? I've had two. One was on an internal
grinder with a spindle speed of 18,000 RPM. We had used the wheel way too
long (production job) and had dressed it down until it was just a thin
shell. When it blew I was standing right over it and the effect was much
like a fly landing on you. Seems all the energy was spent coming apart,
with particles so small they didn't do any damage. Call me lucky!

Second one was on a tool post grinder when I started it up without changing
the pulleys (it had been used previously for some internal work). Talk
about having your head in a dark place. A portion of the small diameter
wheel (roughly 4" diameter) was buried about 2" deep in the edge of a piece
of 3/4" plywood, a bench top. All I could visualize was my head in
place of the plywood.

I'm more careful now! :-)

Harold