Bench Grinder
 

I've just bought a diamond wheel-dresser which is a steel rod with a
block of steel at the end with a 1.5" x 1/2" face with coarse diamonds
stuck to it.
Anyone know how the diamonds are attached? And how rugged are these
things to having the diamonds knocked off?
Can you just push it against a wheel at any angle? I mean with the
leading or trailing edge of the dresser hitting the wheel first? Or
must you be careful to get the centre of the dresser to hit the wheel
first? Should the dresser be held against the tool rest, or can you
just hold it freehand? Are light "cuts" advisable? I've been a naughty
boy and used the wheel for aluminium. I have stood to one side, just
in case, however.

Also. I've just bought a new slower speed grinder (1425 rpm - 4-pole
on 50Hz) with a gray GP wheel and a white alumina wheel. Which would
be the best for touching up carbide-tipped lathe tools?
Way back, I just used the grey wheel that was in the grinder without a
thought. jack

Bench Grinder
 

wrote in message
...
I've just bought a diamond wheel-dresser which is a steel rod with a
block of steel at the end with a 1.5" x 1/2" face with coarse diamonds
stuck to it.
Anyone know how the diamonds are attached?

They are usually set in a copper alloy of sorts.

And how rugged are these
things to having the diamonds knocked off?

Unless yours is one of the plated variety (it would likely be nickel colored
if so), you don't have to worry about knocking the diamond off, it's not
just glued on the surface. It is held captive by being poured in the
matrix.

Can you just push it against a wheel at any angle? I mean with the
leading or trailing edge of the dresser hitting the wheel first? Or
must you be careful to get the centre of the dresser to hit the wheel
first?

It's your dressing tool (they're called a cluster diamond), so use it as you
wish, but if you want it to last, make sure only the diamond comes in
contact with the wheel. If you introduce it at a wonky angle, you may hit
the matrix instead of the diamonds, and that has the potential to screw up
the mounting such that you could lose diamonds on the periphery of the tool.

Should the dresser be held against the tool rest, or can you
just hold it freehand?

While you may be able to use it freehand, a rest helps control the cutting
action. It's also a little safer, If you slip freehand, you can end up
tangled with the wheel. You can believe me when I tell you that hitting a
running wheel with your hands can ruin a good day.

Are light "cuts" advisable? I've been a naughty
boy and used the wheel for aluminium. I have stood to one side, just
in case, however.

Don't horse it----but insure that it makes contact well enough to actually
do something to the wheel. Introduce it to the wheel, then work it
sideways, slowly feeding inwards until you have the surface of the wheel as
you like it. Keep it moving side to side to avoid creating grooves in the
wheel, which can actually ruin the dressing tool.


Also. I've just bought a new slower speed grinder (1425 rpm - 4-pole
on 50Hz) with a gray GP wheel and a white alumina wheel. Which would
be the best for touching up carbide-tipped lathe tools?

Neither one.

While I don't recommend them, aside from diamond or CBN, only a silicon
carbide wheel will perform with any degree of satisfaction on carbide.
Aluminum oxide (both of your wheels are aluminum oxide) is far too soft to
be effective.

If you want really good results, buy a diamond wheel, and run it wet.
Otherwise, a green silicon carbide wheel will work. The dust is
hazardous------causes silicosis-----and the finish such a wheel leaves
leaves a great deal to be desired. Silicon carbide (green wheel) isn't all
that much harder than carbide, so it tends to club it off instead of cut it
cleanly the way a diamond wheel does.

Way back, I just used the grey wheel that was in the grinder without a
thought. jack

And it did a poor job of almost everything, didn't it?

Harold

Bench Grinder
 

"Harold and Susan Vordos" wrote:

Also. I've just bought a new slower speed grinder (1425 rpm - 4-pole
on 50Hz) with a gray GP wheel and a white alumina wheel. Which would
be the best for touching up carbide-tipped lathe tools?

Neither one.

While I don't recommend them, aside from diamond or CBN, only a silicon
carbide wheel will perform with any degree of satisfaction on carbide.
Aluminum oxide (both of your wheels are aluminum oxide) is far too soft to
be effective.

If you want really good results, buy a diamond wheel, and run it wet.
Otherwise, a green silicon carbide wheel will work.


I tried a green wheel once and took Harolds advice and bought a diamond
wheel. Like night and day. The carbide isn't chipped with the diamond
unlike it was with green wheel.

Wes

Bench Grinder
 

Wes wrote:

I tried a green wheel once and took Harolds advice and bought a diamond
wheel. Like night and day. The carbide isn't chipped with the diamond
unlike it was with green wheel.

replace unlike with like

Bench Grinder
 

On Tue, 25 Dec 2007 21:50:42 -0500, Wes wrote:

Wes wrote:

I tried a green wheel once and took Harolds advice and bought a diamond
wheel. Like night and day. The carbide isn't chipped with the diamond
unlike it was with green wheel.

replace unlike with like

Green for roughing and forming, diamond for finishing

Gunner



"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

Bench Grinder
 

On Wed, 26 Dec 2007 02:05:42 GMT, "Harold and Susan Vordos"
wrote:

wrote in message
.. .
I've just bought a diamond wheel-dresser which is a steel rod with a
block of steel at the end with a 1.5" x 1/2" face with coarse diamonds
stuck to it.
Anyone know how the diamonds are attached?

They are usually set in a copper alloy of sorts.

And how rugged are these
things to having the diamonds knocked off?

Unless yours is one of the plated variety (it would likely be nickel colored
if so), you don't have to worry about knocking the diamond off, it's not
just glued on the surface. It is held captive by being poured in the
matrix.

Thanks, Harold, this thing is silver all over (looks plated).
Does this mean it is fragile? If so, how should I care for it over and
above what you recommend in general?

Can you just push it against a wheel at any angle? I mean with the
leading or trailing edge of the dresser hitting the wheel first? Or
must you be careful to get the centre of the dresser to hit the wheel
first?

It's your dressing tool (they're called a cluster diamond), so use it as you
wish, but if you want it to last, make sure only the diamond comes in
contact with the wheel. If you introduce it at a wonky angle, you may hit
the matrix instead of the diamonds, and that has the potential to screw up
the mounting such that you could lose diamonds on the periphery of the tool.

This has many 50 grit diamonds, maybe thousands. I doubt you could hit
matrix without being wasted by diamonds beforehand.

Should the dresser be held against the tool rest, or can you
just hold it freehand?

While you may be able to use it freehand, a rest helps control the cutting
action. It's also a little safer, If you slip freehand, you can end up
tangled with the wheel. You can believe me when I tell you that hitting a
running wheel with your hands can ruin a good day.

This I know, but don't ask me how :)

Are light "cuts" advisable? I've been a naughty
boy and used the wheel for aluminium. I have stood to one side, just
in case, however.

Don't horse it----but insure that it makes contact well enough to actually
do something to the wheel. Introduce it to the wheel, then work it
sideways, slowly feeding inwards until you have the surface of the wheel as
you like it. Keep it moving side to side to avoid creating grooves in the
wheel, which can actually ruin the dressing tool.

By horse it, I guess you mean push it in so hard it slows the wheel?

Also. I've just bought a new slower speed grinder (1425 rpm - 4-pole
on 50Hz) with a gray GP wheel and a white alumina wheel. Which would
be the best for touching up carbide-tipped lathe tools?

Neither one.

While I don't recommend them, aside from diamond or CBN, only a silicon
carbide wheel will perform with any degree of satisfaction on carbide.
Aluminum oxide (both of your wheels are aluminum oxide) is far too soft to
be effective.

Why is one white and one grey? The Al2O3 white one is meant for HSS
and apparently does a better job on that, so what is the grey one
meant to do? The white wheel has WA 12 L stencilled on it, and the
grey has A 60 M, I think (not too sure about the A as only half of it
got stencilled) Then there is the maker's brand, and 40 m/s.

If you want really good results, buy a diamond wheel, and run it wet.

Can you do this on a 1425rpm dry grinder? What would an 8" diamond
wheel likely cost? Would you just let water drip slowly from a bottle
on a shelf via a plastic tube?

Otherwise, a green silicon carbide wheel will work. The dust is
hazardous------causes silicosis-----and the finish such a wheel leaves
leaves a great deal to be desired. Silicon carbide (green wheel) isn't all
that much harder than carbide, so it tends to club it off instead of cut it
cleanly the way a diamond wheel does.

Way back, I just used the grey wheel that was in the grinder without a
thought. jack

And it did a poor job of almost everything, didn't it?

Seemed OK to me, but then, I'm just an inexperienced amateur.
Maybe it had a SiC wheel in it, coz it seemed to put a nice edge on
out carbide tools. This was just a small lathe in a university
laboratory workshop.No critical work was ever done on it.

Thanks for your help, Harold, jack

Bench Grinder
 

On Tue, 25 Dec 2007 19:30:43 -0800, Gunner Asch
wrote:

On Tue, 25 Dec 2007 21:50:42 -0500, Wes wrote:

Wes wrote:

I tried a green wheel once and took Harolds advice and bought a diamond
wheel. Like night and day. The carbide isn't chipped with the diamond
unlike it was with green wheel.

replace unlike with like

Green for roughing and forming, diamond for finishing

Does this mean that the diamond wheel wears out?
Or is the diamond wheel just so much more expensive that you avoid
risking damage as much as possible?

All I want to do is touch up the odd carbide tipped metal lathe tool,
and various HSS woodworking tools. Perhaps some diamond strops, or
files might be better? I suspect I will not be reshaping any carbide
tools, just putting an edge on them occasionally. jack

Bench Grinder
 

Gunner Asch wrote:

Green for roughing and forming, diamond for finishing

Seeing how well the 150g diamond cut vs the green wheel, I'm going to
disagree this time.

Wes

Bench Grinder
 

"Gunner Asch" wrote in message
...
On Tue, 25 Dec 2007 21:50:42 -0500, Wes wrote:

Wes wrote:

I tried a green wheel once and took Harolds advice and bought a diamond
wheel. Like night and day. The carbide isn't chipped with the diamond
unlike it was with green wheel.

replace unlike with like

Green for roughing and forming, diamond for finishing

Gunner


Yeah, if you believe the rumors. Green wheels offer no
advantages---diamond will rough faster and better.

Harold

Bench Grinder
 

On Dec 26, 1:10*am, "Harold and Susan Vordos" wrote:
"Gunner Asch" wrote in message

...

On Tue, 25 Dec 2007 21:50:42 -0500, Wes wrote:

Wes wrote:

I tried a green wheel once and took Harolds advice and bought a diamond
wheel. *Like night and day. *The carbide isn't chipped with the diamond
unlike it was with green wheel.

replace unlike with like

Green for roughing and forming, diamond for finishing

Gunner

Yeah, if you believe the rumors. * *Green wheels offer no
advantages---diamond will rough faster and better.

Harold

There is one.

When roughing and reshaping, the green wheel will cut the steel
backing of a brazed carbide tool as well as the carbide itself. You
don't want to do that with a diamond wheel.

John Martin

Bench Grinder
 

wrote in message
...
On Tue, 25 Dec 2007 19:30:43 -0800, Gunner Asch
wrote:

On Tue, 25 Dec 2007 21:50:42 -0500, Wes wrote:

Wes wrote:

I tried a green wheel once and took Harolds advice and bought a diamond
wheel. Like night and day. The carbide isn't chipped with the diamond
unlike it was with green wheel.

replace unlike with like

Green for roughing and forming, diamond for finishing

Does this mean that the diamond wheel wears out?
Or is the diamond wheel just so much more expensive that you avoid
risking damage as much as possible?

Certainly, diamond wheels have a finite life----but keep steel off of them
and run them wet, and you can expect one to last your lifetime. I ran my
first diamond wheel for 16 years in a commercial environment. It wasn't
shot, but had worn unevenly because the setup wasn't perfect. It would have
lasted at least another 5 years otherwise.

The use of green wheels for shaping carbide isn't in your best interest. It
is far more expensive to use green wheels than diamond, but you can buy a
single green wheel for a lot less money than a diamond. Problem is, they
wear out much faster, so in the long haul they cost more to use. The most
undesirable feature is tools sharpened with silicon wheels tend to perform
very poorly as compared to tools ground with diamond.

Be advised, your health is at serious risk if you use silicon wheels
routinely. Avoid the dust from any such wheel, be it green or black.


All I want to do is touch up the odd carbide tipped metal lathe tool,
and various HSS woodworking tools. Perhaps some diamond strops, or
files might be better? I suspect I will not be reshaping any carbide
tools, just putting an edge on them occasionally. jack

Makes a good story, but in practice it never works out that way. What do
you do if you chip a tool? (And you will!)

Buy/build a high speed wet diamond setup, select a relatively fine wheel (my
choice is a 220), and let it serve you for the rest of your life.

I'm keen on grinding HSS without a rest, but carbide doesn't respond well to
that. One of the reasons is that carbide is typically ground with much
shallower relief, and it's easy to round the cutting edge, or to grind
excessive relief. Tools so ground tend to be very poor performers, either
cutting poorly, or enjoying a very short cutting life. All of that can be
avoided by grinding with a rest, and a firm understanding of good and proper
tool angles. You should have an adjustable table for grinding carbide.
Offhand grinding isn't in your best interest.

Harold

Bench Grinder
 

"Wes" wrote in message
...
Gunner Asch wrote:

Green for roughing and forming, diamond for finishing

Seeing how well the 150g diamond cut vs the green wheel, I'm going to
disagree this time.

Wes

That's true, even with a finer diamond. My 220 kicks ass compared to a
silicon wheel.

I've been around this stuff for more than 50 years now----and have yet to
see one good reason to use silicon over diamond------for anything.

The myth has been hard dying. There was a time when diamond wheels were
cost prohibitive----so they were not commonly found in the shop. That's not
the case any longer. A diamond wheel that used to cost $600 is now
readily available for under $200------so the cost is down more than 300%,
but the dollar has declined in buying power tremendously as well. It's
clear, the cost of diamond wheels today is but a tiny fraction of the cost
when they would recommend the use of green wheels. They make NO sense
today, NONE!

Gunner lacks the proper exposure to understand what I know all too well.

Harold

Bench Grinder
 

wrote in message
...
On Wed, 26 Dec 2007 02:05:42 GMT, "Harold and Susan Vordos"
wrote:

wrote in message
. ..
I've just bought a diamond wheel-dresser which is a steel rod with a
block of steel at the end with a 1.5" x 1/2" face with coarse diamonds
stuck to it.
Anyone know how the diamonds are attached?

They are usually set in a copper alloy of sorts.

And how rugged are these
things to having the diamonds knocked off?

Unless yours is one of the plated variety (it would likely be nickel
colored
if so), you don't have to worry about knocking the diamond off, it's not
just glued on the surface. It is held captive by being poured in the
matrix.

Thanks, Harold, this thing is silver all over (looks plated).
Does this mean it is fragile? If so, how should I care for it over and
above what you recommend in general?

That be the case, yeah, the diamond isn't all the securely set. I highly
recommend you do not use it to knock off the aluminum you mentioned. Use a
dressing stick or a star dresser to remove the aluminum, then use the
diamond to smooth the wheel.

You may not like the surface the diamond cluster leaves. Diamond, being
very sharp and hard, will prepare the surface so smoothly that it won't
grind as well as a wheel that is dressed with a star dresser. The
advantage of the cluster diamond is that it's a lot easier to get the wheel
true. You may find that you can use a (sintered) dressing stick to
slightly rough the wheel once it's true, which will actually improve its
cutting characteristics. I use dressing sticks almost exclusively for my
pedestal grinder, although on rare occasion I'll use a mounted diamond to
move a lot of wheel when it's required. For grinding HSS off hand, a
diamond dressed wheel is not good at all.


Should the dresser be held against the tool rest, or can you
just hold it freehand?

While you may be able to use it freehand, a rest helps control the cutting
action. It's also a little safer, If you slip freehand, you can end up
tangled with the wheel. You can believe me when I tell you that hitting
a
running wheel with your hands can ruin a good day.

This I know, but don't ask me how :)

I happen to know a bit about that as well! I'm getting the distinct idea
that it's for the same reason.
:-(



Are light "cuts" advisable? I've been a naughty
boy and used the wheel for aluminium. I have stood to one side, just
in case, however.

Don't horse it----but insure that it makes contact well enough to actually
do something to the wheel. Introduce it to the wheel, then work it
sideways, slowly feeding inwards until you have the surface of the wheel
as
you like it. Keep it moving side to side to avoid creating grooves in the
wheel, which can actually ruin the dressing tool.

By horse it, I guess you mean push it in so hard it slows the wheel?

I'm not convinced you could put enough pressure on the wheel to do that.
In your case, if you push too hard, you could dislodge diamonds. The
aluminum that's present will do its best to do so anyway. I was struggling
with the notion that you had a matrix set cluster, not a plated one. Be
real careful with the plated one-----the only thing that holds the diamond
on is the plating that is applied to the entire thing. Diamonds, being
conductive, allow for full encapsulation with nickel, so once you uncover
half the diamond, it's free to fall out, and often does. I suggest a light
touch, allowing the diamond to do it's work without grooving the wheel.
Keep the cluster in constant sideward motion, so it can't establish grooves
in the wheel. They'll undercut the sides of the diamond, then they'll
release.


Also. I've just bought a new slower speed grinder (1425 rpm - 4-pole
on 50Hz) with a gray GP wheel and a white alumina wheel. Which would
be the best for touching up carbide-tipped lathe tools?

Neither one.

While I don't recommend them, aside from diamond or CBN, only a silicon
carbide wheel will perform with any degree of satisfaction on carbide.
Aluminum oxide (both of your wheels are aluminum oxide) is far too soft to
be effective.

Why is one white and one grey? The Al2O3 white one is meant for HSS
and apparently does a better job on that, so what is the grey one
meant to do? The white wheel has WA 12 L stencilled on it, and the
grey has A 60 M, I think (not too sure about the A as only half of it
got stencilled) Then there is the maker's brand, and 40 m/s.

How the aluminum oxide is made makes a difference in how it performs.
That's why Norton offers various types of aluminum oxide wheels. Some are
far better suited to grinding particular types of alloys---such as the 38A,
which cuts fast and cool when grinding HSS. They all work, just some work
better than others. The rank novice may not notice the differences at
first.

Regards the markings, they defy common markings, so it's hard to say what
they mean. I'd venture a guess that the L is the hardness, as is the M.
The 12 is a mystery, unless it stands for 120, which would be a fine wheel.
W I have no idea, but the A likely designates aluminum (oxide). The
other marking makes more sense, with the A obviously aluminum (oxide), and
the 60 the hardness. There's a lot more to wheel markings than yours
display. My guess is they're not American made.


If you want really good results, buy a diamond wheel, and run it wet.

Can you do this on a 1425rpm dry grinder? What would an 8" diamond
wheel likely cost? Would you just let water drip slowly from a bottle
on a shelf via a plastic tube?

For carbide lathe tools, the type 1 wheel isn't a good choice. Carbide is
best ground without hollow grinding, so a type 6 wheel is the wheel of
choice. One that would serve your purpose very well would be only 6"
diameter, and would have a 3/4" face (on the side of the wheel, which is the
working surface). It yields flat grinds, so you don't undercut the tool,
weakening the edge. That's important if you put tools to work. No big deal
for scratch cuts, however, but then you are likely not taking advantage of
the use of carbide if that's how you're using it. HSS would likely serve
better unless you're machining hard materials.


Otherwise, a green silicon carbide wheel will work. The dust is
hazardous------causes silicosis-----and the finish such a wheel leaves
leaves a great deal to be desired. Silicon carbide (green wheel) isn't
all
that much harder than carbide, so it tends to club it off instead of cut
it
cleanly the way a diamond wheel does.

Way back, I just used the grey wheel that was in the grinder without a
thought. jack

And it did a poor job of almost everything, didn't it?

Seemed OK to me, but then, I'm just an inexperienced amateur.
Maybe it had a SiC wheel in it, coz it seemed to put a nice edge on
out carbide tools. This was just a small lathe in a university
laboratory workshop.No critical work was ever done on it.

If it put an edge on the tool and actually moved the carbide, it most surely
was silicon carbide. Aluminum oxide is substantially softer than silicon
carbide. So much so that when you apply tungsten carbide to an aluminum
oxide wheel, it tends to glaze each of them without doing much more. You'd
have a dreadful time trying to put an edge on tungsten carbide tools with
aluminum oxide, and they'd likely cut very poorly because the cutting edge
wouldn't be keenly sharp, which is key to performance with light cuts using
carbide tools. Roughing cuts are far more forgiving, assuming you go to
negative rake. That's a whole different world, not to be confused with
machining with positive rake.

Harold

Thanks for your help, Harold, jack

Bench Grinder
 

"John Martin" wrote in message
...
On Dec 26, 1:10 am, "Harold and Susan Vordos" wrote:
"Gunner Asch" wrote in message

...

On Tue, 25 Dec 2007 21:50:42 -0500, Wes wrote:

Wes wrote:

I tried a green wheel once and took Harolds advice and bought a diamond
wheel. Like night and day. The carbide isn't chipped with the diamond
unlike it was with green wheel.

replace unlike with like

Green for roughing and forming, diamond for finishing

Gunner

Yeah, if you believe the rumors. Green wheels offer no
advantages---diamond will rough faster and better.

Harold

There is one.

When roughing and reshaping, the green wheel will cut the steel
backing of a brazed carbide tool as well as the carbide itself. You
don't want to do that with a diamond wheel.

John Martin

---------------------------------------------------------------------------------

To which I replied:

I'll be damned if I know why this thing hasn't got the proper tick marks to
represent a reply, but even rebooting didn't change how my reply came up.

While it's true that a green wheel will grind steel with some degree of
success, it isn't a good choice, no more than using diamond. Steel has an
affinity for carbon, thus it dissolves the green wheels much the same way it
dissolves diamond. When you grind steel with a green wheel, you experience
premature dulling and shedding of the abrasive bits, shortening,
substantially, the useful life of the wheel, plus rendering it somewhat less
aggressive towards the carbide. Relieving the steel with an aluminum oxide
wheel is always the best idea. The only advantage of using silicon
carbide on tungsten carbide evaporated long ago, when diamond wheels became
affordable.

Harold

Bench Grinder
 

wrote in message
...
On Wed, 26 Dec 2007 02:05:42 GMT, "Harold and Susan Vordos"
snip---

Why is one white and one grey? The Al2O3 white one is meant for HSS
and apparently does a better job on that, so what is the grey one
meant to do?

Sorry----I failed to address your question about the gray wheel.

I think you'll find it is bonded harder than the white one, so it is
intended for grinding soft materials, such as mild steel, or even high
carbon steels in the annealed condition. The rule of thumb is hard wheels
for soft materials, and soft wheels for hard materials. It's all about how
long it takes for the wheel to shed dull bits to re-sharpen itself.

Hardness, in grinding wheels, is not related to the media, it's related to
how the wheel is bonded. A J wheel is softer than an M wheel.

Harold

Bench Grinder
 

"Harold and Susan Vordos" wrote:

That's true, even with a finer diamond. My 220 kicks ass compared to a
silicon wheel.

I've been around this stuff for more than 50 years now----and have yet to
see one good reason to use silicon over diamond------for anything.

I'd have gone with the 220 as you recommended back in October but enco had a
150G 1/16" resin bonded 6A2C wheel for sale at slightly under 57 bucks. I
figure I'll learn on this one and when it wears out hopefully Norton will be
in my budget.

Wes

Bench Grinder
 

Harold,
I set up my baldor carbide grinder with a diamond on one plate and a small
relief (5 degree?). The other plate at maybe 10 degree and an old green
stone.

I ruff on the green stone and finish on the diamond. As I often use insert
tooling, I only sharpen a few carbide bits a year. Would you change
anything?

Karl

Bench Grinder
 

On Wed, 26 Dec 2007 06:30:09 GMT, with neither quill nor qualm,
"Harold and Susan Vordos" quickly quoth:


"Wes" wrote in message
...
Gunner Asch wrote:

Green for roughing and forming, diamond for finishing

Seeing how well the 150g diamond cut vs the green wheel, I'm going to
disagree this time.

Wes

That's true, even with a finer diamond. My 220 kicks ass compared to a
silicon wheel.

I've been around this stuff for more than 50 years now----and have yet to
see one good reason to use silicon over diamond------for anything.

The myth has been hard dying. There was a time when diamond wheels were
cost prohibitive----so they were not commonly found in the shop. That's not
the case any longer. A diamond wheel that used to cost $600 is now
readily available for under $200------so the cost is down more than 300%,

I think you mean 66.67%, don't you? 300% would make them give you
$1,200 for every wheel you take from them. I'd like to attend that
sale, so let me know when that happens, won't you, 'Arry? g

We got our first dusting of snow yesterday afternoon, and there's
about half an inch on the tree branches now. It melted off the ground
so far. How's your White Christmas coming? And how are your neighbors
in flooded Chehalis doing?

--
Once we believe in ourselves, we can risk curiosity, wonder, spontaneous
delight, or any experience that reveals the human spirit.
--e e cummings

Bench Grinder
 

"Larry Jaques" wrote in message
...
On Wed, 26 Dec 2007 06:30:09 GMT, with neither quill nor qualm,
"Harold and Susan Vordos" quickly quoth:
snip---

The myth has been hard dying. There was a time when diamond wheels were
cost prohibitive----so they were not commonly found in the shop. That's
not
the case any longer. A diamond wheel that used to cost $600 is now
readily available for under $200------so the cost is down more than 300%,

I think you mean 66.67%, don't you? 300% would make them give you
$1,200 for every wheel you take from them. I'd like to attend that
sale, so let me know when that happens, won't you, 'Arry? g

Sigh!

I seem to have been comparing against the wrong number. Perhaps that
explains why I never received that $1,200 of which you spoke.


We got our first dusting of snow yesterday afternoon, and there's
about half an inch on the tree branches now. It melted off the ground
so far. How's your White Christmas coming? And how are your neighbors
in flooded Chehalis doing?

You're lucky! It started snowing here mid afternoon, and never really
stopped. We have about 8" of snow on the ground as we speak, although it
has quit snowing for the moment. They're threatening us with more tomorrow.
I hate snow. Rotten damned stuff knocked out our power about 4:00 AM..
Luckily, we placed a call to get it restored, which happened about 8:30.
Took a walk when it got light enough to see and found a branch had dropped
across two phases of our 3 phase service, knocking out one leg. We, alone,
were out of power, so it's a good thing we called. Otherwise, they'd have
never known.

As luck would have it, records show that our area has had a white Christmas
only five times in the past 100 years. Make it six in 101!

We drove to Chehalis Monday morning. Things are looking a lot better, but
far, very far, from being back to normal. Some of the stores had more than
6' of water inside, while others received just several inches. The
state liquor store is out of business for the time being-----and a few other
businesses are still not open. Large stores are back in business, although
some are restricting hours (Home Depot, for one) and don't have a full
compliment of wares. The flood is recognized as the worst one to hit,
according to records.

Thanks for asking.

Harold

Bench Grinder
 

"Karl Townsend" wrote in message
anews.com...
Harold,
I set up my baldor carbide grinder with a diamond on one plate and a small
relief (5 degree?). The other plate at maybe 10 degree and an old green
stone.

I ruff on the green stone and finish on the diamond. As I often use insert
tooling, I only sharpen a few carbide bits a year. Would you change
anything?

Karl



If you're happy with the results you're getting, no, I wouldn't recommend
you change anything, although you might consider reducing your roughing
angle, closer to the finish angle. Relieve the steel before using the green
wheel, and stop a bit short of having the tool where you want it. Let the
diamond bring it in-----which will happen quickly-----and will limit the
amount of carbide you remove. The real benefit will be ending up with
minimal relief, for strength.

When your old green wheel is gone, you might consider not replacing it. Use
the diamond wheel alone. There's really no benefit in using the green
wheel, but if you have it, you'll leave a few more miles on your diamond
wheel by using it.

Consider that unless you're a youngster (I think those days are gone for
both of us, eh?), you're highly unlikely to wear out your wheel if it's a
resinoid bonded one. If, on the other hand, you use a plated wheel, I'd
stick with the green wheel for roughing. Resinoid bonded wheels last for
years unless you abuse them. Pound for pound, you can grind carbide much
cheaper with diamond, and do a much better job. Most guys go with a green
wheel because the initial investment is much smaller----but so is the
performance. Silicon carbide, alone, is a false economy.

Harold

Bench Grinder
 

On Wed, 26 Dec 2007 17:22:07 GMT, with neither quill nor qualm,
"Harold and Susan Vordos" quickly quoth:


"Larry Jaques" wrote in message
.. .
On Wed, 26 Dec 2007 06:30:09 GMT, with neither quill nor qualm,
"Harold and Susan Vordos" quickly quoth:
snip---

The myth has been hard dying. There was a time when diamond wheels were
cost prohibitive----so they were not commonly found in the shop. That's
not
the case any longer. A diamond wheel that used to cost $600 is now
readily available for under $200------so the cost is down more than 300%,

I think you mean 66.67%, don't you? 300% would make them give you
$1,200 for every wheel you take from them. I'd like to attend that
sale, so let me know when that happens, won't you, 'Arry? g

Sigh!

I seem to have been comparing against the wrong number. Perhaps that
explains why I never received that $1,200 of which you spoke.

Oh, darn. I could use a good diamond wheel and an extra grand or two.
My shipment of heavy metal came in last week. I picked up my brand new
Toyota Tundra (gold instead of white, long story) and am having fun
with it already. I may go out in the snow later to see how it drives
with Michelins in the white crap.


We got our first dusting of snow yesterday afternoon, and there's
about half an inch on the tree branches now. It melted off the ground
so far. How's your White Christmas coming? And how are your neighbors
in flooded Chehalis doing?

You're lucky! It started snowing here mid afternoon, and never really

It has started and stopped 3 times since I wrote that. It's about 33F
out there so most of it melts pretty quickly. I sent my family over
the Siskiyou Summit this morning at 9. They usually keep I-5 pretty
clear.


stopped. We have about 8" of snow on the ground as we speak, although it
has quit snowing for the moment. They're threatening us with more tomorrow.
I hate snow. Rotten damned stuff knocked out our power about 4:00 AM..
Luckily, we placed a call to get it restored, which happened about 8:30.
Took a walk when it got light enough to see and found a branch had dropped
across two phases of our 3 phase service, knocking out one leg. We, alone,
were out of power, so it's a good thing we called. Otherwise, they'd have
never known.

Pretty wild! We still have the noisy power we always do. Within the
first year of moving up here I ended up putting a UPS on my computer
to keep it from rebooting 3-5 times a day, and last year I added one
to my entertainment setup. sigh


As luck would have it, records show that our area has had a white Christmas
only five times in the past 100 years. Make it six in 101!

I think we've had 2 since I've been here (6 years in Feb.)


We drove to Chehalis Monday morning. Things are looking a lot better, but
far, very far, from being back to normal. Some of the stores had more than
6' of water inside, while others received just several inches. The
state liquor store is out of business for the time being-----and a few other
businesses are still not open. Large stores are back in business, although
some are restricting hours (Home Depot, for one) and don't have a full
compliment of wares. The flood is recognized as the worst one to hit,
according to records.

Ugh!


Thanks for asking.

Best of luck to you all.

--
Once we believe in ourselves, we can risk curiosity, wonder, spontaneous
delight, or any experience that reveals the human spirit.
--e e cummings

Bench Grinder
 

On Wed, 26 Dec 2007 06:10:37 GMT, "Harold and Susan Vordos"
wrote:


"Gunner Asch" wrote in message
.. .
On Tue, 25 Dec 2007 21:50:42 -0500, Wes wrote:

Wes wrote:

I tried a green wheel once and took Harolds advice and bought a diamond
wheel. Like night and day. The carbide isn't chipped with the diamond
unlike it was with green wheel.

replace unlike with like

Green for roughing and forming, diamond for finishing

Gunner


Yeah, if you believe the rumors. Green wheels offer no
advantages---diamond will rough faster and better.

Harold


If you have a good selection of (expensive) diamond wheels. Green
wheels are cheap.

Gunner




"Pax Americana is a philosophy. Hardly an empire.
Making sure other people play nice and dont kill each other (and us)
off in job lots is hardly empire building, particularly when you give
them self determination under "play nice" rules.

Think of it as having your older brother knock the **** out of you
for torturing the cat." Gunner

Bench Grinder
 

"Gunner Asch" wrote in message
...
On Wed, 26 Dec 2007 06:10:37 GMT, "Harold and Susan Vordos"
wrote:


"Gunner Asch" wrote in message
. ..
On Tue, 25 Dec 2007 21:50:42 -0500, Wes wrote:

Wes wrote:

I tried a green wheel once and took Harolds advice and bought a diamond
wheel. Like night and day. The carbide isn't chipped with the diamond
unlike it was with green wheel.

replace unlike with like

Green for roughing and forming, diamond for finishing

Gunner


Yeah, if you believe the rumors. Green wheels offer no
advantages---diamond will rough faster and better.

Harold


If you have a good selection of (expensive) diamond wheels. Green
wheels are cheap.

Gunner

I'ts all in your perspective. You need but one diamond wheel to address
almost all your sharpening needs for lathe tools----the only limitation
being grinding chip breakers, and even then you're only limited, not
prevented.

The cost of three green wheels will buy you a diamond wheel, which, in turn,
will do the work of 20 green wheels. I don't see green wheels as being
cheap, and their performance sucks big time. Then you have to consider the
hazard of breathing the silicon.

I've been forced to use a silicon wheel when it really mattered----but the
shop in question was run by a bunch of dolts that had no clue and wouldn't
even entertain the idea of a diamond wheel. They wasted more money in
carbide annually than the value of a decent diamond wheel. As I said,
silicon carbide wheels are a false economy. The only thing to recommend them
is that they will shape carbide, at least after a fashion. I hesitate to
use the term "sharpen", for obvious reasons.

Harold

Bench Grinder
 

On Wed, 26 Dec 2007 08:25:11 GMT, "Harold and Susan Vordos"
wrote:


wrote in message
.. .
On Wed, 26 Dec 2007 02:05:42 GMT, "Harold and Susan Vordos"
snip---

Why is one white and one grey? The Al2O3 white one is meant for HSS
and apparently does a better job on that, so what is the grey one
meant to do?

Sorry----I failed to address your question about the gray wheel.

I think you'll find it is bonded harder than the white one, so it is
intended for grinding soft materials, such as mild steel, or even high
carbon steels in the annealed condition. The rule of thumb is hard wheels
for soft materials, and soft wheels for hard materials. It's all about how
long it takes for the wheel to shed dull bits to re-sharpen itself.

Hardness, in grinding wheels, is not related to the media, it's related to
how the wheel is bonded. A J wheel is softer than an M wheel.

Thanks for all your help, Harold.

I'm going to take my 4 wheels in to Australian Abrasives to ask
exactly what they are and to see if they have a diamond wheel that
would suit my application and my purse.

I'm assuming that diamond wheels are basically flat steel plates with
diamonds bonded to the side face of the wheel opposite the motor.
I will try to rig up a table and jig to hold tools at the correct
angle to this flat surface.

What would be an ideal speed for a diamond wheel, and how much water
is required if indeed it is? Would a drip a second, or similar be
adequate, or is it best to flood the area?

I've got a couple of extremely cheap 4" diamond cut-off wheels for a
4" angle grinder. One is labelled for wet cutting, and the other with
radial cutouts, for dry cutting of glass and ceramics and so on.
I wonder if these might be used for some rough tool shaping if the
angle grinder were clamped securely to a bench. The diamonds appear to
be rather coarse, and far apart, and the wheels are designed for max
rpm of 14500.

I wonder if any Australians here know where is a good place to get a
diamond wheel.

jack

Bench Grinder
 

wrote in message
...
snip-----

I'm assuming that diamond wheels are basically flat steel plates with
diamonds bonded to the side face of the wheel opposite the motor.
I will try to rig up a table and jig to hold tools at the correct
angle to this flat surface.

They are typically made of aluminum, not steel. The wheel I use, which is
commonly found on diamond grinders, is 6" in diameter, and 3/4" thick, It
has a counterbore 5/16" deep, 4-1/2" diameter. There is a 1-1/4" bore, and
a bolt circle, countersunk, for mounting the wheel. The working face is
3/4" wide, and can be obtained in either 1/16" or 1/8" thickness of diamond.

It's best to build a table that extends part the face of the wheel on the
outside, so the tool is supported when grinding the sides. Both sides of
the wheel (left and right) will be used, depending on the handing of the
tool in question, so it's important that the motor be able to be reversed.
The table should be adjustable between 0 degrees and up to 10 degrees of
angle. It need not have calibrations, just be adjustable easily. You'll
find you often change the angle on the table as you grind different features
of a given tool. Table centerline should be slightly below the centerline
of the wheel, so the wheel contacts the tool at the centerline. I'd
suggest 3/8", unless you use large tools. if you intend to grind on up to
3/4" tools, then I'd shoot for 1/2" below center with the table. That way
you won't be too low when grinding on small tools.


What would be an ideal speed for a diamond wheel, and how much water
is required if indeed it is? Would a drip a second, or similar be
adequate, or is it best to flood the area?

Ideal speed would be maximum allowable speed of the wheel, but you'll find
that a 3,450 or 3,600 RPM motor will provide excellent service. A slower
motor will function, but expect slower results. I suggest sticking with
the 3,000+ speed.

Regards coolant, the grinder is best built with a pan, which would have a
drain that returns the coolant for reuse. A chemical additive will keep
it from rusting. I use a small circulating pump, and feed the wheel at
its center, using some 3/16" copper tubing. I have a valve in the circuit
to control flow. I keep a steady stream, although it's a small one.
Drops tend to allow heating and cooling instead of a constant cooling. I'd
personally advise against a drip system, although I'd be first to agree they
work. They're just not quite adequate if you're roughing a tool, which is
often required because of edge chipping. You're also subject to thermal
shock if the interval between drips gets spread out to far.


I've got a couple of extremely cheap 4" diamond cut-off wheels for a
4" angle grinder. One is labelled for wet cutting, and the other with
radial cutouts, for dry cutting of glass and ceramics and so on.
I wonder if these might be used for some rough tool shaping if the
angle grinder were clamped securely to a bench. The diamonds appear to
be rather coarse, and far apart, and the wheels are designed for max
rpm of 14500.

If they're the HF variety of wheel, I'm familiar with them, having purchased
a set for use in the house building project that seems to consume all my
time. The problem you'll face with them, unless you have the one that
has no serrations, is the bumpy grind. Carbide doesn't take kindly to
interrupted cuts, so you could expect some chipping if you use them for that
purpose. They're not great for use on edge because there's a steel band
in the center of the wheel that won't cut. In abrasive materials (concrete,
for instance), the band is ground back in the course of use. Carbide would
likely act as a bearing, so the blade wouldn't cut well once that center
section was in contact with the tool. In general, I'd say they're not well
suited, but you might explore their use for grinding a chip breaker.

As an aside, I can send you a couple pics of my home made grinder. They'd
be small, under 100 kb in size. I'm on a dialup. Let me know if you'd
like to have them.

Hope some of this helps!

Harold