"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

"Ed Huntress" wrote:

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,

http://www.ind.nortonabrasives.com/M...20Sticks.pd f

Wes

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

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,

http://www.ind.nortonabrasives.com/M...20Sticks.pd f

Wes

Thanks, Wes. Verrry interesting. Have you done this? How fast does an
aluminum oxide stick wear when you're dressing diamond? I assume it just
shatters the diamonds, right? Or does it pull a layer completely out of the
matrix, exposing a new layer?

--
Ed Huntress

"Ed Huntress" wrote:

Thanks, Wes. Verrry interesting. Have you done this? How fast does an
aluminum oxide stick wear when you're dressing diamond? I assume it just
shatters the diamonds, right? Or does it pull a layer completely out of the
matrix, exposing a new layer?

I've never used the things for their intended use. We have them at work. I
believe to dress the diamond wheel dressing wheels that dress our cbn
grinding wheels.

I have used them to clean up a locating ring on a special chuck after the
operators spin a part on it. Remove the clamping arms, defeat the
interlocks, spin it up to 2500 rpm and hold the dressing stick against the
locating ring. Gitter done. Stick breaks down really quick on steel and
conforms to the ring while removing the boogers. Recenter the chuck on a
1st operation part and put the thing back into production.

Wes

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

Thanks, Wes. Verrry interesting. Have you done this? How fast does an
aluminum oxide stick wear when you're dressing diamond? I assume it just
shatters the diamonds, right? Or does it pull a layer completely out of
the
matrix, exposing a new layer?

I've never used the things for their intended use. We have them at work.
I
believe to dress the diamond wheel dressing wheels that dress our cbn
grinding wheels.

I have used them to clean up a locating ring on a special chuck after the
operators spin a part on it. Remove the clamping arms, defeat the
interlocks, spin it up to 2500 rpm and hold the dressing stick against the
locating ring. Gitter done. Stick breaks down really quick on steel and
conforms to the ring while removing the boogers. Recenter the chuck on a
1st operation part and put the thing back into production.

Wes

Hmm. OK. I'm still curious about an aluminum oxide dressing stick on
diamond, though. That one threw me.

--
Ed Huntress

"Ed Huntress" wrote:

Hmm. OK. I'm still curious about an aluminum oxide dressing stick on
diamond, though.

I think we are going to have to wait for Harold on that part.

Wes

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

Hmm. OK. I'm still curious about an aluminum oxide dressing stick on
diamond, though.

I think we are going to have to wait for Harold on that part.

Wes

Funny, suddenly I'm not seeing Ed's posts. MY damned ISP has been nothing
short of a PITA of late.

While I've used a dressing stick on my diamond wheel on rare occasion, I
avoid its use as much as is possible, for obvious reasons.

My casual observation indicates it tends to abrade the matrix, not so much
the diamond, which feely cuts aluminum oxide or silicon carbide. By
removing a small amount of the matrix, old diamond is released and new
diamond exposed. It's a combination of cleaning the wheel and changing the
exposed abrasive. Often the problem with a diamond wheel is
loading---while the diamond remains quite sharp. That's one of the best
reasons to run a diamond wheel wet---to keep it from loading. It makes a
huge difference in performance. Keeping soft materials off helps, too
(steel, for example).

Harold

Ed Huntress wrote:


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?
Yes, of course, but your results will be as accurate as your
hands are. With a light touch so the low spots in the wheel
don't "draw in" the dresser, you can do pretty well. Mostly,
I've used this to dress toolpost grinder wheels on the lathe or
diamond wheels on the mill, but I have done it freehand a few
times in special cases.

Jon

"Jon Elson" wrote in message
...
Ed Huntress wrote:


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?
Yes, of course, but your results will be as accurate as your hands are.
With a light touch so the low spots in the wheel don't "draw in" the
dresser, you can do pretty well. Mostly, I've used this to dress toolpost
grinder wheels on the lathe or
diamond wheels on the mill, but I have done it freehand a few times in
special cases.

What's the mechanism of action? Does it just sheer the diamond grit out of
the matrix, or does it fracture the particles of grit?

--
Ed Huntress

"Ed Huntress" wrote in message
...

"Jon Elson" wrote in message
...
Ed Huntress wrote:


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?
Yes, of course, but your results will be as accurate as your hands are.
With a light touch so the low spots in the wheel don't "draw in" the
dresser, you can do pretty well. Mostly, I've used this to dress
toolpost grinder wheels on the lathe or
diamond wheels on the mill, but I have done it freehand a few times in
special cases.

What's the mechanism of action? Does it just sheer the diamond grit out of
the matrix, or does it fracture the particles of grit?

--
Ed Huntress


I'd suggest it works on the matrix, but it will be equally as hard on the
diamond used for dressing. You end up with diamond against diamond in any
case.

While the notion of dressing a diamond wheel with a diamond likely works,
I'd avoid it like the plague. The layer of diamond in wheels is
finite----to dress away any of it, especially by hand, is not, in my
opinion, the smart thing to do. Diamond wheels are made true----so if they
run out, look elsewhere for the problems and address the error(s) in
question. Don't dress a good wheel to a bad mounting, in other words.
By dressing, you could easily ruin a wheel, or, at best, shorten its useful
life tremendously.

Dressing sticks do very little damage to diamond wheels, mostly just
clearing them of loading. Stick with dressing sticks, and use them only
when necessary.

Harold

Jon Elson writes:

Ed Huntress wrote:
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?
Yes, of course, but your results will be as accurate as your hands
are.

I've seen two mechanisms to give better results.

* You have a tool rest in front of the grinder, and you make a jig to
go around the diamond point dresser (essentially something with a
hole for the dresser). The top of the jig is held against the bottom
of the tool rest. You might be able to use some sort of clamp, or
Vice-grip.

* Woodturners use a grinding jig called Wolverine, and it has a
diamond point dresser option. However - it's pricy. It essentially
does the same thing.

--
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