"Mike Henry" wrote in message
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"Harold and Susan Vordos" wrote in message
. ..

"Ignoramus27305" wrote in message
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On 2009-08-09, Rich Grise wrote:
I'd think it depends on your definition of "freehand". I've ground
cutters, but there was always that platform where I could rest the
tool; from that point, it was "freehand", as long as that platform
was on the correct angle.

By freehand, I mean no platform whatsoever.

Not a great idea with carbide and diamond. The relief angles for carbide
are shallower than those for HSS, and are easily rounded if you don't
have a very steady hand. I do recommend a table for carbide, and I also
recommend you NEVER grind dry. Drip isn't very good, either, for you
risk fracturing the carbide by thermal shock. And----do not grind steel
with your diamond wheel. I can't stress that enough.

Glendo runs their diamond wheel slow, 300 rpm I think, and I've used it on
HSS for a touchup with no ill effects. Do you think that the slow speed
is OK?

snip

Everything I've read indicates that as long as you keep the grind under less
than red heat, you should be able to use diamond with no ill effects. It is
a good idea to do so wet, however, to keep the wheel free from loading.
Once you achieve excessive heat, the diamond is rapidly absorbed by the
steel involved. Once done, a wheel is restored to decent performance ONLY
by dressing away a percentage of the surface. It's clearly a stupid idea to
grind steel unless surface speed is very slow, as in your Glendo.

Harold