"Ed Huntress" wrote in message news:...

"Harold and Susan Vordos" wrote in message
. net...

"Ivan Vegvary" wrote in message
news:MmRcj.2734$si6.1329@trndny08...
Hi Harold,

I followed your thread regarding diamond vs. silicon wheels. One point
of confusion. Steel should not be ground on diamond. How come the
Drill Doctor and my el-cheepo knife sharpener use diamond impregnated
wheels? Is it simply a matter of short life time and I buy a replacement
wheel? Or there alternative cutters for consumer quality products?

Thanks,

Your Jazz listening buddy from Oregon
Ivan Vegvary


I think you'll notice that the surface speed of these devices is well
below a critical threshold.
Where the problems begin is at red heat. If diamond is run on steel
at low surface speed, such that it doesn't get hot----no problem. Once
up to the heat of ignition, however, carbon begins transferring to iron,
which has an affinity for carbon. This process rapidly dulls diamond. If
you touch the base metal of brazed carbide tools to the diamond wheel (it
happens occasionally), there is an almost instant change in grinding
characteristics. It can be attributed to some loading of the wheel, but
the diamond is also dulled in the process. The wheel often requires
dressing to restore its qualities.

How do you dress diamond wheels? I wasn't aware they could be dressed, but
I've never had much to do with them, except for some old castoffs I
salvaged.

Oh, wait a minute. Are you talking about using a single-point diamond to
dress diamond wheels on a surface grinder? That I've seen. I was thinking
about the wheels on a bench grinder. Can you dress them the same way?

--
Ed Huntress