"Marty Escarcega" wrote in message
...
Anyone use abrasive belt grinders to sharpen HSS tool bits? Supposed to be
easier and cooler on the steel?

Under normal circumstances I do not endorse the idea. The speed gained is
not worth the precision lost, but it's pretty good for roughing. If you
have the typical belt sander, you'll notice that the belt does not run tight
against the back stop. Even when they do, they still don't cut with the
desirable precision of a wheel. The problem is you get miniscule edge
rounding from the belt. If you grind with a single face, it is often
noticeable when you stone your tool. In a sense, you start out with a
somewhat worn tool. There's no substitute for a final grind on a wheel.

Harold

"Sam" wrote in message
...
I've been following this thread, but there's an issue that has not
been addressed which I'd like to ask about.

I'm new at this and have been learning from a shop class, and from a
mentor who has been machining for about 50 years.

My mentor first taught me to grind tools. He showed me to run the tool
back and forth across the wheel, to keep the wheel in good shape.

That is the proper way to grind when it's possible. It isn't always
possible, however. It requires a wheel that is kept flat and one that is
dressed often enough to keep the wheel "sharp". Abrasive grains dull and
quit cutting without excessive pressure. That's when they cut very hot, and
is also when a wheel is most dangerous because you have to bear down so hard
you're out of control when the tool slides off the edge of the wheel. It's
especially dangerous when the grinding support is gapped to far from the
wheel.

I started a machine tool class and the teacher there demonstrated
grinding a tool by shoving it right into the wheel. I couldn't find a
decent wheel on any of the grinders in that shop.

Your teacher likely knows less about sharpening than you do. I don't
intend any slurs towards those that have little experience, but it's a fact,
those that rely on insert tooling generally lack the necessary skills to
properly sharpen either HSS or brazed carbide tooling. Those of us that
came up in the shop before insert equipment was as widespread as it now is
had no alternative but to learn to grind tools. There was nothing else
available. Can it be your new instructor is young, or lacks experience?

You'd do everyone a service by dressing the wheels properly and resetting
the rests, but I'd certainly check with the instructor before doing so.
It's entirely possible he is so poorly trained that he doesn't understand
the benefit of a well dressed wheel. He obviously has no clue about proper
sharpening, and is passing along very poor procedures. They can be hard to
lose down the road, so I don't suggest you learn them.

It's not uncommon to see wheels like you've described when they are used for
all kinds of grinding, including for welding projects. One should have a
wheel that is used for tool sharpening exclusively, equipped with a proper
hardness and abrasive grain size wheel. Such a wheel does not serve
well for general purpose grinding because it would be too soft and fine.
You may not have that luxury in a shop class, though. Be sure to practice
acceptable procedures as best you can. Don't learn any bad habits.

Harold

Gary Coffman wrote:
: Quenching won't anneal anything. Quenching hardens heat treatable
: steel.
--Just so. What I meant was that if he grinds until there is
discoloration from heating he will distress the tool more than necessary.
He's going to burn his fingers, too.. :-)

--
"Steamboat Ed" Haas : Why does it take so long to
Hacking the Trailing Edge! : see the blindingly obvious?
http://www.nmpproducts.com/intro.htm
---Decks a-wash in a sea of words---

Geez and I do just the opposite. Firm pressure and maybe move the bit
across the wheel so as not to get grooves in the wheel. The tool bit
does get hot so dunk it in water to cool it off. Hey I am using HSS
tool bits, so why worry about getting it hot. If the chips don't come
off brown, your speed isn't as high as it might be. The tool gets hot
in use, that is why it is called High Speed Steel. Dunking the bit
in water may cause micro cracks, but if the tool isn't chipping during
use, why worry about it.

Now if I am grinding the end of a file smooth to use as a scraper,
then I don't want to get the steel very hot. So light pressure and
frequent cooling off in the water. Files are not made of hss.

This is not meant to blast you, just to say what I do is different and
seems to work okay for me.

Dan


Anthony wrote in message you

Patience!!....
#1 thing....Patience.
Use light pressure and 'stroke' the tool, don't just hold it to the
surface of the wheel. Use the tool rest, that's what it's for. Adjust the
angle of the rest to get your desired grind angle, then using light
pressure, move the tool back and forth across the face of the wheel,
stopping every few strokes to let it cool off.
A trick for cooling without hardening the edge is to dip the shank of the
tool in the water. Let the water draw the heat out through the shank.
The shank won't (shouldn't ever) be hot enough to alter the grain
structure of the tool. If you are careful, the actual grind face won't be
either. Oh...and did I mention Patience?

In article , Harold & Susan Vordos says...

If you haven't used a parting wheel on a cutter grinder before, it's an
awesome display. Because the wheels are very narrow, they cut like gang
busters. I still have the short end of a 1" tap we cut off in something
like 15 seconds using the procedure, spinning the tap while parting.
It's a lot faster than parting on a lathe. :-)

Funny you should mention that.

They delivered a multi-million dollar tool here a few months
ago, and were setting it up in a lab. The install guy screwed
up and cross-threaded one of the 3/4 inch levelling screws
in the base.

Big consternation because this was one that would be holding
much of the weight and it had to be solid.

I had the correct metric tap to clean it up, but the underside
was too badly buggered to get the tap to start right. The
topside of the threads were open, but the tap was just a *tad* too
long to get it in the area above the threads.

So I took the tap down to the shop and used the dry cutoff
wheel to buzz a quarter inch off the end. That was a bit
nerve wracking with the HSS tap buried in the wheel, holding
it up against the fence by hand. Came out all right and
I was a hero for getting the thing ready to roll.

The guy I was helping said he would get me a replacment tap
to make good on the one I modified. It was from a good
Greenfield set so I said, buy one of those, and gave him
the MSC part no.

It came in, and he called me. He said they shipped some
kind of bogus brand, it wasn't greenfield. I said bring
it down and I would check it. Sure enough it looked OK,
but said GTD on it. Hmm. Never heard of that. But I
went to put it away in the set, and *all* those taps
said "GTD" on them.

Doh. Greenfield Tap and Die.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

"jim rozen" wrote in message
...
In article , Harold & Susan Vordos says...

If you haven't used a parting wheel on a cutter grinder before, it's an
awesome display. Because the wheels are very narrow, they cut like gang
busters. I still have the short end of a 1" tap we cut off in something
like 15 seconds using the procedure, spinning the tap while parting.
It's a lot faster than parting on a lathe. :-)

Funny you should mention that.

They delivered a multi-million dollar tool here a few months
ago, and were setting it up in a lab. The install guy screwed
up and cross-threaded one of the 3/4 inch levelling screws
in the base.

Big consternation because this was one that would be holding
much of the weight and it had to be solid.

I had the correct metric tap to clean it up, but the underside
was too badly buggered to get the tap to start right. The
topside of the threads were open, but the tap was just a *tad* too
long to get it in the area above the threads.

So I took the tap down to the shop and used the dry cutoff
wheel to buzz a quarter inch off the end. That was a bit
nerve wracking with the HSS tap buried in the wheel, holding
it up against the fence by hand. Came out all right and
I was a hero for getting the thing ready to roll.

The guy I was helping said he would get me a replacment tap
to make good on the one I modified. It was from a good
Greenfield set so I said, buy one of those, and gave him
the MSC part no.

It came in, and he called me. He said they shipped some
kind of bogus brand, it wasn't greenfield. I said bring
it down and I would check it. Sure enough it looked OK,
but said GTD on it. Hmm. Never heard of that. But I
went to put it away in the set, and *all* those taps
said "GTD" on them.

Doh. Greenfield Tap and Die.

Jim

Amazing how well parting wheels work on hardened objects. Much better than
on soft steels.

The GTD is an old marking, as you've discovered. They've been making taps
for a long time. I have some that are machined instead of ground. That
means they were heat treated after being made. Tell me modern technology
isn't an improvement!

Harold

On Sat, 31 Jan 2004 22:24:38 -0800, "Harold & Susan Vordos"
wrote:


"Errol Groff" wrote in message
.. .
snip---

First, I ALWAYS use the toolrest. I have it set to the angle that I
have found works for the type of jobs that we do and God help the kid
who changes the angle setting.

I fully agree in your particular setting. When one is in a learning curve,
and the work at hand is relatively predictable, so leaving the rest at a
desired angle is certainly not unreasonable. Where that begins to get in
the way is when one is far more familiar with tool grinding and desires to
grind features not generally taught in class. The use of a tool rest,
perhaps when learning, keeps you out of trouble regards safety, and helps
establish proper relief angles, but is a definite liability when you have
gained enough experience to grind tools well. That was a hard lesson for
me to learn. It came only when I was hired in a job shop where time was
ultra critical.

I had been working as a machinist for over 8 years when I was exposed to the
no tool rest concept. Very uncomfortable at first, it was. In the end,
though, I can honestly say it is the best thing I ever learned about
sharpening tool bits, and I never struggled with them from day one. It just
made an easy job all the easier for me.

I don't see that it matters what face of the tool is done first or
last, having said that I usually do the side, top and end in that
order. Some years back I got sick and tired of grinding from solid
and made a simple jig to hold the tools for top and side grinding on a
surface grinder. The ends I always do by hand on the pedastal
grinder. Re-sharpenings are done on the pedastal grinder.

I'm with you. The only rule I have is that I generally sharpen the front
face last, but only because it guarantees the width of many of the tools I
grind. I'm comfortable with grinding parting and grooving tools within a
thou, and the last bit is best done by removing a tiny amount from the face.
It also allows you to achieve a right angle with the sides, leaving you a
bit more wander room as you rough out the tool. YMMV.

In place of a surface grinder, when I finally get my shop up and running
again, I plan to use parting wheels to rough out toolbits. That only because
I picked up an old cutter grinder, though. Grinding parting and grooving
tools is slow business, but they can be roughed out in less than a couple
minutes with a parting wheel by removing pieces instead of grinding
everything away. All that is left is to grind proper relief and rake on
the tool, saving at least 80% of the grinding time. That, for me, is and
always will be a hand process, which is far easier than making constant
changes on a cutter grinder for all the different grinds. You have the
added benefit of being able to tailor the cut to the occasion. A holding
fixture on a surface grinder may or may not offer that option. Hopefully
you've designed it into yours..

Grinding parting and grooving tools ??? What is that? Thin disks?
What size of HSS are you using? I should just get my SG going and not
worry about it. Good thread. BTW, how do you know diamond dressed
wheels are "dull" and have to be fixed? I've stood in front of huge
grinding wheels for many hours. I need to work on my very cheap
grinder present , but figured if I was going to get it from one it
would have been long ago. I use to think of such things when starting
them up in the morning and wondering if some idiot hit it with
anything. ) Put a steel plate over the top so it won't knock you
out (head injury) , you can always bleed slowly , maybe. The biggest I
worked with was "about" 3.5' Dia. X 3". I was trained in three weeks
from completely broke and asking gas station patrons if they wanted to
buy this redwood waterbed that I built out of 3.5" X 13" laminated
beams. The guy was curious and asked me my background and told him
that I understood linear and rotational geometry and he was like do
you want my job I'll train you ...? I just bought machines and
figured it out may years later about cutting instead of grinding.
I have no real guards or rests , should! I'd love to have someone
show me something I don't know or could "see".
I get lost in printed descriptions. I just tense up and do it with a
very and hopefully non debated form 3 dimensionally in my mind and
do it. Like grinding the top ? If you put in a chip breaker then you
really have to grind a lot for the next when it wears out. Don't ask
me. The others know more.


If anyone is interested I will draw up the grinding jig and post it to
the dropbox.

I'd love to see it, Errol. Please let us know when it's there.

If you are holding the tool close ehough to the business end to
control the grind you wil know when the heat is building and cool the
tool long before it gets hot enough to bother the steel.

Yep! And if you happen to get it a bit too hot, place it against another
flat piece of steel and allow some of the heat to dissipate before quenching
it. That keeps the tool from fracturing.

As others have said the main key is practice, practice, practice.

Just my .02 on the subject.

Worth much more, Errol!


Harold

"Sunworshiper" wrote in message
...
On Sat, 31 Jan 2004 22:24:38 -0800, "Harold & Susan Vordos"
wrote:
snip---

Grinding parting and grooving tools ??? What is that? Thin disks?
What size of HSS are you using?

Not thin disks. Narrow tools, just like a commercial parting tool, but
made from various sizes of HSS tool steel. I grind them from 3/8" and 1/2"
square mostly. 1/4" X 1/2" saves a lot of grinding time but limits your
ability to place the tool where you might like it in your tool block. I
prefer the square ones. When you grind the tools, they are usually right
handed, so they cut near the chuck. That's especially important for parting
tools. Grooving tools are generally ground to specification, for such
things as O ring grooves, or snap rings. Piece of cake with a good running
wheel and no work rest.

I should just get my SG going and not
worry about it.

You can get in trouble with very thin tools, including on a surface grinder.
Tool steel has incredible tensile strength, but breaks easily when shocked,
so you have to be careful, especially if you're grinding a long, narrow
tool. As long as you use the right wheel and keep it sharp, though, you
can expect pretty good results on a surface grinder. The only hard part is
getting precisely the angle you desire. That is usually determined by the
holding fixtures. One that is commonly found in shops is a 60 degree one
for sharpening threading tools. That's likely one of the most desirable
fixtures to have if you are fortunate to own a surface grinder.

Good thread. BTW, how do you know diamond dressed
wheels are "dull" and have to be fixed?

If you're making reference to them being dull from dressing with a diamond
instead of a dressing stick where hand grinding is concerned, I know it from
experience, having dressed wheels by every conceivable method aside from
crush rolling. The only way you'll understand the difference between a
wheel that is roughed up with a dressing stick as compared to one that is
diamond dressed is to A-B the wheel. Dress one with a diamond then grind
with it. Touch it up with a dressing stick and repeat. You tell me which
one cuts the best. All that goes out the window on a precision grinder,
though. Diamond dressing is the only way, but conditions are not the same.

If you meant a wheel that is dull from use, then my response is:

It's from experience, and something that may not be real apparent to the
novice. There are signs you can look for, though. One of them is a shiny
surface on the wheel. If a grinding wheel takes on a glaze from use, it's
not breaking down anywhere nearly fast enough. As the grains get dull, the
surface begins to shine and the wheel cuts poorly. It will make a hell of
a lot of heat, but will remove very little material. At that point you
have to decide if you're using the wrong abrasive, or if the wheel is too
hard. There are certain absolutes that are known, so you can make good
decisions about your particular problem. For one, if you're using a
silicon carbide wheel and you're grinding steel of any kind, it's the wrong
selection and the wheel will display the condition I mentioned, and quickly.
Frequent dressing doesn't help.

Another sign of a wheel needing dressing is if it is loaded. That's pretty
easy to see, especially if you're grinding with white aluminum oxide wheels.
The surface of the wheel takes on a black appearance and gets packed off
with swarf. Simple. Dress the wheel. It doesn't take very much, either.
A few thou will get the wheel back to good condition.

I've stood in front of huge
grinding wheels for many hours. I need to work on my very cheap
grinder present , but figured if I was going to get it from one it
would have been long ago. I use to think of such things when starting
them up in the morning and wondering if some idiot hit it with
anything. ) Put a steel plate over the top so it won't knock you
out (head injury) , you can always bleed slowly , maybe.

That theory might work on small wheels, but if you're running large wheels,
say on a crank grinder, if the wheel goes and you're in line with it, pretty
good odds there's going to be a funeral. I'm sure some have survived
exploding wheels, but I wouldn't bank on it. Wheels of that size would
likely move the steel and get you anyway. Lots of energy there.

The biggest I
worked with was "about" 3.5' Dia. X 3". I was trained in three weeks
from completely broke and asking gas station patrons if they wanted to
buy this redwood waterbed that I built out of 3.5" X 13" laminated
beams. The guy was curious and asked me my background and told him
that I understood linear and rotational geometry and he was like do
you want my job I'll train you ...? I just bought machines and
figured it out may years later about cutting instead of grinding.
I have no real guards or rests , should!

I'd love to have someone
show me something I don't know or could "see".
I get lost in printed descriptions. I just tense up and do it with a
very and hopefully non debated form 3 dimensionally in my mind and
do it. Like grinding the top ? If you put in a chip breaker then you
really have to grind a lot for the next when it wears out. Don't ask
me. The others know more.

Depending on the nature of the chip breaker, you can often just grind it
slightly deeper and push it farther back towards the opposite edge of the
tool. The net effect is to lower the cutting point of the tool, but you
can get considerable mileage from the tool that way.

The best part of chip breakers is that when you understand them and can
apply them properly, you can take cuts that you otherwise would not be able.
Boring is a great example. By winding the chips tight enough to break them,
you not only can take a better cut (thanks to the positive rake developed by
the chip breaker), it is also much safer because you don't generate long
strings that can pull you in when they get wound up in the chuck.

Harold

On Sun, 01 Feb 2004 15:57:12 GMT, Marty Escarcega
wrote:

Anyone use abrasive belt grinders to sharpen HSS tool bits? Supposed to be
easier and cooler on the steel?

Every day. both a 6x48 and a 1x42. Then finish on a ruby or white, then
hone on a diamond.

Works for me.

Gunner

Liberals - Cosmopolitan critics, men who are the friends
of every country save their own. Benjamin Disraeli

In article , Harold & Susan Vordos says...

Not thin disks. Narrow tools, just like a commercial parting tool, but
made from various sizes of HSS tool steel. I grind them from 3/8" and 1/2"
square mostly. 1/4" X 1/2" saves a lot of grinding time but limits your
ability to place the tool where you might like it in your tool block. I
prefer the square ones. When you grind the tools, they are usually right
handed, so they cut near the chuck.

An example is shown in the photo below, it's the one coming
right out at the viewer. Kinda looks tilted off to one side
but it really is straight out. The side relief makes it
look a bit twisted.

http://www.metalworking.com/DropBox/_2000_retired_files/Tp3.jpg

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

"Harold & Susan Vordos" wrote in message
...
"Pete Bergstrom" wrote in message
...
and don't use
the tool rest - hold it free at all times.

Pete,
I wonder if you understand how fortunate you are to have been instructed
as
you have. I've been grinding toolbits since 1953 or so and that's the
one
thing that set me free. Until you can sharpen a HSS toolbit free-hand
with no obstructions, you will always struggle with them. My method of
grinding toolbits involves a grinder with no tool rest. All they do is
impede you.

Thanks, I do recognize the quality of my instruction and was disappointed
that the school administration didn't offer the same course this semester
(he just barely managed to keep it going by having a couple of shop stewards
at local companies vouch for the importance). This semester the class is at
the Ford plant near my house and I couldn't get an invitation. Maybe next
fall I can get another night class.

There are two main reasons for holding the tool free that I learned: first
to do it right. Second, to avoid a possible pinching point. They made good
sense to me.

Keep the wheel (aluminum oxide only, J hardness, 60 grit) running very
true
and flat, no bounce, and slightly roughed up with a dressing stick if you
dress with a diamond. You can grind toolbits with a single grinding
pattern per face with almost no effort. It helps to have the grinder
mounted high, about the height of your elbow, so you can stand erect to
grind the tools. It's a bit uncomfortable at first, but, guaranteed,
once
you master the art, you'll NEVER go back to a typical grinder with a tool
rest, especially mounted low.

Thanks!
Pete

"Errol Groff" wrote in message
...

I just did a bit of calculation and estimate that I have sharpened
toolbits for some 2400 freshman students in the past 17 years. That
probable adds up to well over 5000 induvidual sharpenings and
re-sharpenings.
...
I don't see that it matters what face of the tool is done first or
last, having said that I usually do the side, top and end in that
order.

There's no particular importance to the order I learned, as far as I know.
However, picking a system and following it as I built my muscle memory is
invaluable, in my opinion.

If you are holding the tool close ehough to the business end to
control the grind you wil know when the heat is building and cool the
tool long before it gets hot enough to bother the steel.

As others have said the main key is practice, practice, practice.

I'm only at about a dozen sharpenings, but I also believe that practice will
be key to my improvement.

Thanks,
Pete

"Harold & Susan Vordos" wrote in message
...
I'm gaining more and more respect for your tutor. Using the rest for any
other purpose is really a waste. The only thing I don't like about the
idea
that you're using at all is if you happen to get your finger caught
between
the wheel and the rest, I don't think I need say any more. Make certain
that the gap between the wheel and rest is almost non-existent.

From the looks of the rests I saw last week I recall them being very very
close
to the wheel so that shouldn't be a problem... Can't really take them off I
think
he would get a bit upset plus high school kids use them during the day. They
need all the protection they can get.


It is almost mandatory that you be able to see a picture in your head when
grinding turning tools, and to be able to grind the tool without guides.
The very idea that you use the tool rest simply to steady your hand is
very
good, in my opinion. The method you're being taught would be restrictive
only in that you would have a difficult time using the corner of the wheel
for grinding a chip breaker, where you often have the tool running
parallel
to the wheel.


I wish I could picture them in my head at this point I've seen a cutting
tool all of about
5 times. So might take some time to really know what I'm supposed to be
picturing
But I know I'll get there! Chip breaker? Haven't got that far yet. 3rd night
is coming up
tomorrow so we will see.

If you feel you're capable of making a nice project, what I'd recommend is
you make an arbor that fits the shaft of the motor that will accept 7" X
1/2" X 1-1/4" grinding wheels. They are likely the most abundant wheel
on
the market because of their use on surface and cutter grinders. You can
buy them easily off ebay for a good price if you're patient. By placing
set
screws in two places at 120 degree intervals around the arbor, you can
make
one that is fully adjustable on the motor shaft so it can be adjusted to
run dead true. Your motor runs a perfect speed for 7" wheels, and they
are
much easier to use to grind toolbits than are smaller diameter wheels.

My grinder has a 1/2 inch arbor and is big enough to handle a 7 inch
wheel...
even though the name plate says 6". OH and it does have a pass thru arbor
so should I put a "diamond" wheel on the other side? And what grit should I
be using on the main side? Currently my ginder is mounted on my work bench
oppsite end of my vise at about waist level.

Once you have the arbor and wheel installed, you can then fabricate a
wheel
guard that exposes the front portion of the wheel, perhaps 90 degrees of
it,
where you'd do your grinding. The wheel should have a lens of sorts to
keep dirt out of your face and eyes, although I use mine without that
feature. You can fabricate the wheel guard from a piece of pipe, some
3/16" or 1/4" plate, plus some flat bar for brackets, and hang it off the
screws that hold the motor together if there are no other choices for
anchoring the brackets.


This sounds like fun. I noted that the ginder does have screw holes close
to where the arbor goes in. Perhaps it had a guard at one time or another.

That's exactly what I use, the only difference likely is my motor has a
shaft out of each end, so I use the other end for a wet diamond wheel, and
have a reversing switch so I can choose the direction of rotation I need
for
the diamond wheel. When I power the diamond wheel, I use a different
switch position, which also turns on the coolant pump. It runs only when
needed that way. You can build a very nice grinder if you're willing to
dedicate some time to it. If you go this route, be certain to mount it
high so you can stand erect when using it. Makes all the difference in
the
world in comfort. It can be hung off the wall with an L bracket easily,
which is how mine used to be mounted. It now has its own base, which is a
bit quieter.

A grinder stand might be a great idea. Is there ever a need to go to the
other
side of a grinder? Or should it be mounted with one side usable?

Thanks,
Paul

On with the reading wow thread.

This is interesting I'll give it a shot since I have to use the rest at
school
Dressing up the wheel is something else I don't know how to do yet either.
May have to start a new thread for that.
Paul


"Harold & Susan Vordos" wrote in message
...

"Backlash" wrote in message
...
Paul, one of the best little tricks I have ever learned in the tech
world
is
to use your unused fingers, hands, or arms, etc. during a job as a
reference
to the work. Your brain can rapidly compute where your working fingers
are
relative to this. Examples are....
Welding is steadier when you have your thigh pressed against the
welding
table.
Grinding is easier when you use your knuckles for reference to the
wheel
by touching the tool rest.
Operating hydraulic equipment is smoother when you just let an unused
finger on the same hand touch one of the other unused levers, such as on
a
forklift.
With these things in mind, give it a try.

RJ

Yep, I agree. I use the wheel itself for my reference when grinding.
It
takes a lot more to get used to, but it works.. It also explains why
the
wheel can't have any bounce. I'm no good at sharpening a tool on a
bouncy
wheel. Don't know how anyone could be.

Harold

Awesome will have to get a hold on a couple of old chucks!
Reno, Paul

"Gunner" wrote in message
news
On Sat, 31 Jan 2004 13:40:23 -0800, "Paul"
wrote:

The tool length that we are using is about 3 inches so they do tend to
heat
up. Either way...so If I'm dunking my cutting tool every time it gets too
hot to hold... I'm pressing too hard or is this proper technique?
Perhaps
this is just something the teacher is
having us to "before" getting to using HSS. He did however show us using
a
torch
what quenching a cold rolled steel does to the strength. Smacking it with
a
hammer
while it was held in a vice snapped it right in two. However before
mistreating it
with water and the torch it would bend waaaaaay before breaking.

Paul


Ill tell you a trick that really helps when freehand grinding HSS and
for grinding bolts off to length on a grinder or band saw.

Grab a drill chuck, clamp it down on your bit or bolt and use it as a
handle.

Ive dog robbed a number of old drill motor chucks and keep one at every
belt sander and grinding station in my humble shop just for this
purpose. This is a good use for those old chucks that are worn and run
out.

btw...cold rolled steel is NOT HSS. It doesnt have much carbon in it.
Hss starts out harder than the best hardening you can do to a chunk of
crs.

Gunner



"Gary Coffman" wrote in message
.. .
On Sat, 31 Jan 2004 17:43:14 GMT, steamer wrote:
--Do it the way the teacher says until you're comfortable with the
process. Nothing wrong with using the tool rest; safer, too, for a
newbie.
I still use it faithfully. The only time I *don't* use a tool rest is
when
I'm sharpening a drillbit. As for quenching: don't let the tool get
hot
enough to change color B4 you quench and you won't have the annealing
problem. Dunk the tool B4 you start grinding; when the last of the
liquid
boils off dunk it again, etc.

Quenching won't anneal anything. Quenching hardens heat treatable
steel.

HSS is used for tool bits because it doesn't lose its strength at a red
heat. It won't lose its strength at a red heat when grinding either.
But
the very edge in contact with the wheel gets to yellow heat (note the
color of the sparks), and dipping it in water will cause microcracks at
the edge which will weaken it.

You wouldn't quench an oil or air hardening steel in water, because
it would crack. Don't do it with HSS bits you're grinding either, for
the
same reason. The water pot on a bench grinder is the devil's invention,
don't use it. If the bit gets too hot to handle while grinding, set it
down for a minute, and don't press so hard next time.

Gary


Liberals - Cosmopolitan critics, men who are the friends
of every country save their own. Benjamin Disraeli

I pretty much was dunking it every time it got hot enough for me
to feel a some good heat coming from the blank. Tomorrow night
more grinding! 3rd day on its way and in the past 5 days I've gotten
100+ years of experience in grinding knowledge. Thus goes to show
the internet is way to nice of a tool. And cheap to!
Reno, Paul

"steamer" wrote in message
...
Gary Coffman wrote:
: Quenching won't anneal anything. Quenching hardens heat treatable
: steel.
--Just so. What I meant was that if he grinds until there is
discoloration from heating he will distress the tool more than necessary.
He's going to burn his fingers, too.. :-)

--
"Steamboat Ed" Haas : Why does it take so long to
Hacking the Trailing Edge! : see the blindingly obvious?
http://www.nmpproducts.com/intro.htm
---Decks a-wash in a sea of words---

In article ,
steamer wrote:
--Do it the way the teacher says until you're comfortable with the
process. Nothing wrong with using the tool rest; safer, too, for a newbie.
I still use it faithfully. The only time I *don't* use a tool rest is when
I'm sharpening a drillbit.

Note that Teenut (I sure miss that man), in his "Bionic Darex"
posting, *did* suggest using the tool rest on the grinder when
sharpening drill bits -- but using it to support your left *hand* to
give more control during the motions involved in performing a clean
sharpening job.

Enjoy,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"Pete Bergstrom" wrote in message
news:401e87af$0$41288
snip--------

Thanks!
Pete


You're most welcome! I hope some of it was worthwhile for you.

Harold

"jim rozen" wrote in message
...
In article , Harold & Susan Vordos says...

Not thin disks. Narrow tools, just like a commercial parting tool, but
made from various sizes of HSS tool steel. I grind them from 3/8" and
1/2"
square mostly. 1/4" X 1/2" saves a lot of grinding time but limits
your
ability to place the tool where you might like it in your tool block.
I
prefer the square ones. When you grind the tools, they are usually
right
handed, so they cut near the chuck.

An example is shown in the photo below, it's the one coming
right out at the viewer. Kinda looks tilted off to one side
but it really is straight out. The side relief makes it
look a bit twisted.

http://www.metalworking.com/DropBox/_2000_retired_files/Tp3.jpg

Jim


Very nice, Jim.
One comment: I always grind my tools RH so I'm not restricted when near
the chuck. Not usually important for grooving tools, but almost mandatory
for parting.

For those that aren't grinding their own tools, you can grind almost
anything that suits your fancy if you learn to grind proper toolbits.
Especially for guys like us, it makes absolutely no sense to load up on
insert form tooling when they can be made so easily. Unless you find
yourself using a large number of a particular configuration, making your own
is far better, both as a learning tool and for your wallet. It leaves the
money otherwise spent for those things that you can't make yourself. I
heartily endorse the use of HSS toolbits. They've served me very well for
all of my machining career.

Harold

On Mon, 2 Feb 2004 17:16:20 -0800, "Paul"
wrote:

Awesome will have to get a hold on a couple of old chucks!
Reno, Paul

Check the swap meets and perhaps the Sears service center, etc etc. Any
old drill motor that has a good chuck, but has been burned out, run over
etc is good as you simply remove the chuck and toss the rest.. Often
times you can get such for free or half a dollar. Second hand stores
are also good. Tell the manager you are looking for old drills that are
messed up. They typicly plug them in, and if they dont run, toss em.

Gunner


"Gunner" wrote in message
news
On Sat, 31 Jan 2004 13:40:23 -0800, "Paul"
wrote:

The tool length that we are using is about 3 inches so they do tend to
heat
up. Either way...so If I'm dunking my cutting tool every time it gets too
hot to hold... I'm pressing too hard or is this proper technique?
Perhaps
this is just something the teacher is
having us to "before" getting to using HSS. He did however show us using
a
torch
what quenching a cold rolled steel does to the strength. Smacking it with
a
hammer
while it was held in a vice snapped it right in two. However before
mistreating it
with water and the torch it would bend waaaaaay before breaking.

Paul


Ill tell you a trick that really helps when freehand grinding HSS and
for grinding bolts off to length on a grinder or band saw.

Grab a drill chuck, clamp it down on your bit or bolt and use it as a
handle.

Ive dog robbed a number of old drill motor chucks and keep one at every
belt sander and grinding station in my humble shop just for this
purpose. This is a good use for those old chucks that are worn and run
out.

btw...cold rolled steel is NOT HSS. It doesnt have much carbon in it.
Hss starts out harder than the best hardening you can do to a chunk of
crs.

Gunner



"Gary Coffman" wrote in message
.. .
On Sat, 31 Jan 2004 17:43:14 GMT, steamer wrote:
--Do it the way the teacher says until you're comfortable with the
process. Nothing wrong with using the tool rest; safer, too, for a
newbie.
I still use it faithfully. The only time I *don't* use a tool rest is
when
I'm sharpening a drillbit. As for quenching: don't let the tool get
hot
enough to change color B4 you quench and you won't have the annealing
problem. Dunk the tool B4 you start grinding; when the last of the
liquid
boils off dunk it again, etc.

Quenching won't anneal anything. Quenching hardens heat treatable
steel.

HSS is used for tool bits because it doesn't lose its strength at a red
heat. It won't lose its strength at a red heat when grinding either.
But
the very edge in contact with the wheel gets to yellow heat (note the
color of the sparks), and dipping it in water will cause microcracks at
the edge which will weaken it.

You wouldn't quench an oil or air hardening steel in water, because
it would crack. Don't do it with HSS bits you're grinding either, for
the
same reason. The water pot on a bench grinder is the devil's invention,
don't use it. If the bit gets too hot to handle while grinding, set it
down for a minute, and don't press so hard next time.

Gary


Liberals - Cosmopolitan critics, men who are the friends
of every country save their own. Benjamin Disraeli


Liberals - Cosmopolitan critics, men who are the friends
of every country save their own. Benjamin Disraeli

"Paul" wrote in message
...

"Harold & Susan Vordos" wrote in message
...
snip
I wish I could picture them (chip braeakers) in my head at this point I've
seen a cutting
tool all of about
5 times. So might take some time to really know what I'm supposed to be
picturing
But I know I'll get there! Chip breaker? Haven't got that far yet. 3rd
night
is coming up
tomorrow so we will see.

Don't get in a hurry with them, either. Get to know and understand how to
grind a tool, and why it cuts. Once you do, grinding chip breakers is sort
of a natural. You'll want to control how the chip comes off the machine,
and in many instances improve the ability of the machine to make the chip.
Chip breakers that are ground by hand are generally accomplished by creating
positive rake, so they tend to cut better than normal cutting tools with
similar geometry. One of the best kept secrets in machining tough
materials (stainless comes to mind) is how generous positive rake can be
useful. You have to modify how you cut and feed, but it has a place and
often increases production. The method I use tends to defy logic, and is
not the most conventional approach, but it works, and well. It's more
than you need to know at this point, best discussed when you are comfortable
with cutting geometry and can visualize tools in your mind.

If you feel you're capable of making a nice project, what I'd recommend
is
you make an arbor that fits the shaft of the motor that will accept 7" X
1/2" X 1-1/4" grinding wheels. They are likely the most abundant wheel
on
the market because of their use on surface and cutter grinders. You
can
buy them easily off ebay for a good price if you're patient. By placing
set
screws in two places at 120 degree intervals around the arbor, you can
make
one that is fully adjustable on the motor shaft so it can be adjusted to
run dead true. Your motor runs a perfect speed for 7" wheels, and they
are
much easier to use to grind toolbits than are smaller diameter wheels.

My grinder has a 1/2 inch arbor and is big enough to handle a 7 inch
wheel...

You'd still want to make an adapter arbor, it gets the wheel away from the
motor so you can manipulate your work better, and it opens the door to a
MUCH greater variety of grinding wheels. One of the smartest things you can
do for tool grinding is get away from small wheels, and away from wheels
that are typically offered for grinding. Cutter grinder wheels are very
accurately made and controlled and are available in a myriad of hardnesses
and abrasive types. In addition, they are inexpensive when you shop. We
can talk about that more if you're interested.

even though the name plate says 6". OH and it does have a pass thru arbor
so should I put a "diamond" wheel on the other side? And what grit should
I
be using on the main side?

See below.

Currently my ginder is mounted on my work bench
oppsite end of my vise at about waist level.

Tough on the back when grinding for long periods. Much more effective built
higher..

Your grinder may be a great candidate for an upgrade to a diamond wheel, but
they are not much use to you without a coolant system and a work rest
(table). That's the one place I insist they be used. The rest on a diamond
grinder, however, is very unlike one on a pedestal grinder. They have a
tilt table much like a table on a circular disk grinder, often found on belt
sanders. Mine is so built, a 6" X 48" Powermatic with a 12" disc on the
side. Diamond wheels have a rather high friction coefficient and don't
lend themselves well to offhand grinding. For the most part, the should be
run wet, too. In order to avoid having more than one wheel, a grit of
around 200 is a good choice. Resinoid bond is almost mandatory, don't get
any other type. It will rough carbide reasonably fast, and yield a very
nice finish on the tool. That's quite important when sharpening carbide
because chipped edges generally lead to almost immediate failure, especially
when machining tougher material, say chrome-moly.

If you're interested in a photo or two of my grinder setup, fully home
built, contact me on the side and I'll take a few shots and describe in some
way what I did and how I did it. I built mine when I started my small
commercial shop when I had almost no money, so I had no choice but to build
it. It has served me quite well. I rebuilt it some time later to increase
the size of the splash guards on the wet side, which I made from stainless
so they wouldn't rust. Otherwise I have just used the original design,
which I built in the fall of '67.

Once you have the arbor and wheel installed, you can then fabricate a
wheel
guard that exposes the front portion of the wheel, perhaps 90 degrees of
it,
where you'd do your grinding. The wheel should have a lens of sorts to
keep dirt out of your face and eyes, although I use mine without that
feature. You can fabricate the wheel guard from a piece of pipe,
some
3/16" or 1/4" plate, plus some flat bar for brackets, and hang it off
the
screws that hold the motor together if there are no other choices for
anchoring the brackets.


This sounds like fun. I noted that the ginder does have screw holes close
to where the arbor goes in. Perhaps it had a guard at one time or another.

That's exactly what I use, the only difference likely is my motor has a
shaft out of each end, so I use the other end for a wet diamond wheel,
and
have a reversing switch so I can choose the direction of rotation I need
for
the diamond wheel. When I power the diamond wheel, I use a different
switch position, which also turns on the coolant pump. It runs only
when
needed that way. You can build a very nice grinder if you're willing
to
dedicate some time to it. If you go this route, be certain to mount it
high so you can stand erect when using it. Makes all the difference in
the
world in comfort. It can be hung off the wall with an L bracket
easily,
which is how mine used to be mounted. It now has its own base, which is
a
bit quieter.

A grinder stand might be a great idea. Is there ever a need to go to the
other
side of a grinder? Or should it be mounted with one side usable?

If you end up with a wet diamond grinder, yes, it's important to be able to
access that side. You use the grinder by facing the end of the shaft. The
type of diamond wheel you use for grinding brazed carbide tools is known as
a type DH2 as I recall. They have a flanged face of varying thickness of
diamond on the outer edge of the face of the wheel (on the side, not the OD)
which is where you do your grinding, unlike a typical grinding wheel, where
you use the outer edge, or the OD..

Thanks,
Paul

Sure thing!

Harold

"Paul" wrote in message
...
snip--
Dressing up the wheel is something else I don't know how to do yet either.
May have to start a new thread for that.
Paul

Surely the subject has been discussed in your class? A dull , out of flat
or loaded wheel is a terrible device to use.

There's more than enough guys supporting dressing wheels by various means,
but there's one ultimate method that works, and is very easy. In most
cases the person involved hasn't tried any other method but they are not
about to be told anything either. Unless you've used wheels dressed by
various methods, there's no way to understand when a wheel isn't cutting as
it could.

The best condition is established by a star, or impact dresser. Problem is
they waste a lot of the wheel and it can be difficult to get a smooth
running wheel, especially if you dress and grind without a tool rest.
Diamond makes it easy to get a smooth running wheel, but they dress the
wheel so fine that they are harder to get to cut, more or less acting like a
bearing. They run very smooth, but cut hot as hell. A dressing stick
lets you meet in the middle. Smooth wheel, but rough enough to cut well.
Quite a bit has been posted just recently in that regard.

Harold

Harold & Susan Vordos scribed in
:

and don't use
the tool rest - hold it free at all times.

effort. It helps to have the grinder mounted high, about the
height of your elbow, so you can stand erect to grind the tools.

just to tweek your nose Harold (-:
my grinder sits on a 8 inch high carboard box, on the floor.
I sit at it on a small stool.....

weird, but at least the grit doesn't fly all over the lathe etc.

swarf, steam and wind

--
David Forsyth -:- the email address is real /"\
http://terrapin.ru.ac.za/~iwdf/welcome.html \ /
ASCII Ribbon campaign against HTML E-Mail - - - - - - - X
If you receive email saying "Send this to everyone you know," / \
PLEASE pretend you don't know me.

"DejaVU" wrote in message
...
Harold & Susan Vordos scribed in
:

and don't use
the tool rest - hold it free at all times.

effort. It helps to have the grinder mounted high, about the
height of your elbow, so you can stand erect to grind the tools.

just to tweek your nose Harold (-:
my grinder sits on a 8 inch high carboard box, on the floor.
I sit at it on a small stool.....

weird, but at least the grit doesn't fly all over the lathe etc.

swarf, steam and wind

--
David Forsyth -:- the email address is real /"\


Oooohhh! My aching back! ;-)

Harold

In article , Harold & Susan Vordos says...


The best condition is established by a star, or impact dresser. Problem is
they waste a lot of the wheel and it can be difficult to get a smooth
running wheel, especially if you dress and grind without a tool rest.

For a home shop, with minimal use of the grinder, a star
dresser is best IMO. They don't use up the wheel at a
terribly great rate, and the cost of replacing a wheel
once every couple of years is small.

The *real* problem with star dressers (or nearly any kind
for that matter) is that there's a huge amount of abrasive
debris flung off. A real shop can afford to have a
grinder room to keep this apart from the other machines,
a home shop seldom has that luxury. My bench grinder is
tucked as far away from my other machines as possible.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

In article , Harold & Susan Vordos says...

http://www.metalworking.com/DropBox/_2000_retired_files/Tp3.jpg

Very nice, Jim.
One comment: I always grind my tools RH so I'm not restricted when near
the chuck.

That cutoff tool *is* set for working close in to the
chuck.

Jim

==================================================
please reply to:
JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com
==================================================

Harold & Susan Vordos scribed in
:

good idea when you have the necessary clearance. I hand grind
parting tools from 1/2" square HSS. Think of the amount of stock
that gets removed! It's a sad moment when I break a new one when
parting, and it does happen. :-(

Harold, have you tried an angle grinder for the roughing when you're
taking so much off? I'd go with a 4.5" wheel, 1mm thick. that's the
fastest cutting wheel you'll ever use as it has to remove so little
metal to do it. The ones I have now are 1.6mm, is that 1/16"?
also nice, but the 1mm is faster.

in fact, within a day or two I'll be using mine to modify a 2 flute
endmill (homemade from O1 toolsteel) that needs to cut a little
deeper. I'll be keeping it cool so I don't need to reharden and
resharpen as it is the right size right now.

swarf, steam and wind

--
David Forsyth -:- the email address is real /"\
http://terrapin.ru.ac.za/~iwdf/welcome.html \ /
ASCII Ribbon campaign against HTML E-Mail - - - - - - - X
If you receive email saying "Send this to everyone you know," / \
PLEASE pretend you don't know me.

Harold & Susan Vordos scribed in
:

For those that aren't grinding their own tools, you can grind
almost anything that suits your fancy if you learn to grind proper
toolbits. Especially for guys like us, it makes absolutely no
sense to load up on insert form tooling when they can be made so
easily. Unless you find yourself using a large number of a
particular configuration, making your own is far better, both as a
learning tool and for your wallet. It leaves the money otherwise
spent for those things that you can't make yourself. I heartily
endorse the use of HSS toolbits. They've served me very well for
all of my machining career.

amen and amen Harold

give me a HSS blank (or bit of old file) and I'll make just about any
toolbit you can think up.
example of old file tooling
http://terrapin.ru.ac.za/~iwdf/lathe/ringt1.jpg
inside and outside threading for a camera filter adapter. 0.75mm
pitch threads

HSS grooving tool for same adapter. tip is about 35 thou wide
http://terrapin.ru.ac.za/~iwdf/lathe/ringt2.jpg
HSS if from a CNC leather cutting machine, thus the holes for the
original mounting. other end is the threading bit as above.

http://terrapin.ru.ac.za/~iwdf/lathe/th01.jpg
HSS threading bit, which I 'invented' myself and then discovered had
been in use for decades. oh well, at least i'm on the right
track (-:

boring bar?
http://terrapin.ru.ac.za/~iwdf/lathe/qc15.jpg
no sweat. 3/8" hot rolled bar drilled for a 3/16" X center drill
(since shortened). square bar got it's corners knocked off in the 4
jaw when a job happened that needed a little more cleanrance.
quick, effective and easy.
this bar can actually take another bit that is 'square' and made from
a piece of ball race casing and then hand ground to shape. the bit
is about 9x4x4mm.

flycutter?
bit of HSS leather cutter blade in a 32mm thick steel disk, held in
the chuck
http://terrapin.ru.ac.za/~iwdf/lathe...tter/fly02.jpg
this one is flat topped and has cut steel flawlessly. only has side
and end rake.

planning to make a shell mill from a ball race casing 'real soon now'
I'll use the angle grinder with a 1.6mm cutoff disk to make the
teeth.

swarf, steam and wind

--
David Forsyth -:- the email address is real /"\
http://terrapin.ru.ac.za/~iwdf/welcome.html \ /
ASCII Ribbon campaign against HTML E-Mail - - - - - - - X
If you receive email saying "Send this to everyone you know," / \
PLEASE pretend you don't know me.

jim rozen scribed in
:

The *real* problem with star dressers (or nearly any kind
for that matter) is that there's a huge amount of abrasive
debris flung off. A real shop can afford to have a
grinder room to keep this apart from the other machines,
a home shop seldom has that luxury. My bench grinder is
tucked as far away from my other machines as possible.

I plan to fit a vacuum hose the the rear of the wheel guard when I
finally decide where to mount my grinder, to solve this very issue of
dust everywhere. my shop is much too small to think that the dust
does not go near the lathe, but at least with the grinder just about
on the floor as it is at the moment, the dust has to WORK to get UP
onto the lathe.

swarf, steam and wind

--
David Forsyth -:- the email address is real /"\
http://terrapin.ru.ac.za/~iwdf/welcome.html \ /
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If you receive email saying "Send this to everyone you know," / \
PLEASE pretend you don't know me.

Harold & Susan Vordos scribed in
:

I sit at it on a small stool.....


Oooohhh! My aching back! ;-)

hehe
my aching back comes from standing since I sit all day anyway
(computer geek for money for tools)
I have 2 stools in the workshop, a tall one and a short one.
both made from scrap lumber on the spur of the moment.

swarf, steam and wind

--
David Forsyth -:- the email address is real /"\
http://terrapin.ru.ac.za/~iwdf/welcome.html \ /
ASCII Ribbon campaign against HTML E-Mail - - - - - - - X
If you receive email saying "Send this to everyone you know," / \
PLEASE pretend you don't know me.

Harold & Susan Vordos wrote:

bearing. They run very smooth, but cut hot as hell. A dressing stick
lets you meet in the middle. Smooth wheel, but rough enough to cut well.

I guess I missed it. You have mentioned dressing sticks before. Could
you post a picture of one to the dropbox or direct me to a catalog? I'd
like to see what I should be looking for.

Ted

On Tue, 03 Feb 2004 18:46:33 GMT, Ted Edwards
wrote:

Harold & Susan Vordos wrote:

bearing. They run very smooth, but cut hot as hell. A dressing stick
lets you meet in the middle. Smooth wheel, but rough enough to cut well.

I guess I missed it. You have mentioned dressing sticks before. Could
you post a picture of one to the dropbox or direct me to a catalog? I'd
like to see what I should be looking for.

Ted

Me too. I think I have one that I picked up at a used machinery
dealer thinking it was something else , don't remember what I thought
it was. Anyhow, its about 1"X1"X6" and black and kind of soft like a
pumis stone. We want to know how to use it also BTW.

"Ted Edwards" wrote in message
...
Harold & Susan Vordos wrote:

bearing. They run very smooth, but cut hot as hell. A dressing
stick
lets you meet in the middle. Smooth wheel, but rough enough to cut
well.

I guess I missed it. You have mentioned dressing sticks before. Could
you post a picture of one to the dropbox or direct me to a catalog? I'd
like to see what I should be looking for.

Ted

Hey Ted,

The dressing stick I have in my possession is likely all of 35 years old, so
it no longer resembles what they look like when new. That alone should
tell you what a bargain these things are. I've used it for years on end
and still have about half of it.

Because I have my shop out of commission, a result of moving from Utah to
Washington, I have not kept current with catalogs. I've done almost no
buying of anything, and likely won't until I have the house finished. I
last catalog I received from MSC is the 95/96 edition, so I'll have to
direct you to that one. On page 877 there is a picture of an imported stick
which they call an Abrasive Dresser Stick. These sticks are generally 1"
square and 6" long. They are made of what appears to be coarse silicon
carbide crystals, perhaps something around 24 grit, maybe even coarser.
For dressing aluminum oxide wheels for a pedestal grinder in the machine
shop there is no better system, and for reasons I've already outlined.
I do not have that opinion for a weld shop, where the star type dresser is
superior. You'll find other dressing sticks available, one of which is a
solid boron carbide stick, 1/4" X 1/2" X 3". I do not recommend them for
the home shop because they have the same effect as a diamond, only they dull
the wheel even more. They are generally used by precision grinders for
forming wheels and do not lend themselves well to actually sharpening them.
I've used them in any way possible and prefer to not use them at all except
for forming. They are not as aggressive as the other dressing stick type.

To find dressing sticks, at least in MSC's catalog, look in the index under
abrasives, then look for finishing sticks and stones. They will be included
there, but you'll have to look for them by going to the pages mentioned.

Harold

"jim rozen" wrote in message
...
In article , Harold & Susan Vordos says...


The best condition is established by a star, or impact dresser. Problem
is
they waste a lot of the wheel and it can be difficult to get a smooth
running wheel, especially if you dress and grind without a tool rest.

For a home shop, with minimal use of the grinder, a star
dresser is best IMO. They don't use up the wheel at a
terribly great rate, and the cost of replacing a wheel
once every couple of years is small.

The *real* problem with star dressers (or nearly any kind
for that matter) is that there's a huge amount of abrasive
debris flung off. A real shop can afford to have a
grinder room to keep this apart from the other machines,
a home shop seldom has that luxury. My bench grinder is
tucked as far away from my other machines as possible.

Jim

You're a tough sell, Jim, but have obviously not used a dressing stick or
you'd change your tune. Not only are they superior to the star dresser, but
they raise a lot less dust, too. Because they are not a spinning impact
type dresser, there is nothing to fling the abrasive about. You can run a
vacuum cleaner nozzle directly under the stick when dressing and capture
virtually 100% of the dust. Try that with a star dresser.

Not only is a dressing stick superior, they are also more economical to use.
A dressing stick that costs less than $2 has lasted me for almost my entire
time in the shop. It will see me to my grave, and would have done so even
if I had acquired it the first day I touched machines. That's a big
statement considering I spent years as a precision grinder, where it was
used daily.

You most likely recall Bucky Goldstein, later Pete Somebody. He was,
without out a doubt, one of the most intelligent people that posted here.
He was less than thrilled with me, but we had numerous exchanges on the side
in which I did my best to help him as he developed his machining skills.
One of the things we discussed time and again was this very issue. He
held to Teenut's concept with vigor (using a star dresser), but one day I
finally convinced him to try a dressing stick. Instant believer. You
will be, too. Crack open that moldy wallet and spend a couple dollars with
the idea that you're going to disprove my suggestion. Get back to me.
I'm willing to bet that my real life experience is more valuable than your
opinion.

Harold

"DejaVU" wrote in message
...
Harold & Susan Vordos scribed in
:

good idea when you have the necessary clearance. I hand grind
parting tools from 1/2" square HSS. Think of the amount of stock
that gets removed! It's a sad moment when I break a new one when
parting, and it does happen. :-(

Harold, have you tried an angle grinder for the roughing when you're
taking so much off? I'd go with a 4.5" wheel, 1mm thick. that's the
fastest cutting wheel you'll ever use as it has to remove so little
metal to do it. The ones I have now are 1.6mm, is that 1/16"?
also nice, but the 1mm is faster.

in fact, within a day or two I'll be using mine to modify a 2 flute
endmill (homemade from O1 toolsteel) that needs to cut a little
deeper. I'll be keeping it cool so I don't need to reharden and
resharpen as it is the right size right now.

swarf, steam and wind

--
David Forsyth -:- the email address is real /"\

I haven't done so, but understand the speed they move metal quite well. I'd
be a bit caution about roughing parting or grooving tools because of the
rough grinding, though.. It's not all that difficult to break the blade off
the shank due to the slender, long remaining piece, but the angle grinder
would surely be good to get rid of a lot of material. Your point,
however, is exactly mine in parting on a cutter grinder. That I have done,
time and again. Because the tool and wheel are both rigidly held, no
vibration, and fed at the proper angle, there is little risk of anything
breaking. You can honestly slit a 1/2" square toolbit 1" deep faster than
you can reset the bit to cut at 90 degrees to remove the portion you split.
Narrow wheels, when properly applied, cut at an astonishing rate.

Harold

"DejaVU" wrote in message
...
Harold & Susan Vordos scribed in
:

I sit at it on a small stool.....


Oooohhh! My aching back! ;-)

hehe
my aching back comes from standing since I sit all day anyway
(computer geek for money for tools)
I have 2 stools in the workshop, a tall one and a short one.
both made from scrap lumber on the spur of the moment.

swarf, steam and wind

--
David Forsyth -:- the email address is real /"\

I thought a bit about that after I posted and soon realized that if you are
sitting at the right height relative to the grinder, that could be a great
way to sharpen tools. You can get right down cozy with the wheel without
leaning over when it's done right. Whether standing or sitting, if you're
not comfortable, you're highly unlikely to grind very good tools. Seems
all you'd have on your mind is getting it done so you could find comfort.

Harold

"jim rozen" wrote in message
...
In article , Harold & Susan Vordos says...

http://www.metalworking.com/DropBox/_2000_retired_files/Tp3.jpg

Very nice, Jim.
One comment: I always grind my tools RH so I'm not restricted when near
the chuck.

That cutoff tool *is* set for working close in to the
chuck.

Jim

Oops! See my red face? I realize what I was looking at is the bottom of
your tool block, not the shank of the tool. A second look with some
concentration put it right in focus. I stand corrected.

Nice setup, Jim. Couldn't help but notice all HSS used.

Harold

"DejaVU" wrote in message
...
snip-----

planning to make a shell mill from a ball race casing 'real soon now'
I'll use the angle grinder with a 1.6mm cutoff disk to make the
teeth.

swarf, steam and wind

--
David Forsyth -:- the email address is real /"\

Chuckle!

Not much gets wasted in your shop, eh David?

Thanks for the tour of your work. Very nicely done. I think you and Ted
Edwards may just be the leading champs of creativity in the shop. Ted is
very big on making tools and does an outstanding job of making use of
materials most of us ignore. I'm convinced both of you are fearless!

Harold

On Sun, 1 Feb 2004 22:42:31 -0800, "Harold & Susan Vordos"
wrote:


"Sunworshiper" wrote in message
.. .
On Sat, 31 Jan 2004 22:24:38 -0800, "Harold & Susan Vordos"
wrote:
snip---

Grinding parting and grooving tools ??? What is that? Thin disks?
What size of HSS are you using?

Not thin disks. Narrow tools, just like a commercial parting tool, but
made from various sizes of HSS tool steel. I grind them from 3/8" and 1/2"
square mostly. 1/4" X 1/2" saves a lot of grinding time but limits your
ability to place the tool where you might like it in your tool block. I
prefer the square ones. When you grind the tools, they are usually right
handed, so they cut near the chuck. That's especially important for parting
tools. Grooving tools are generally ground to specification, for such
things as O ring grooves, or snap rings. Piece of cake with a good running
wheel and no work rest.

I should just get my SG going and not
worry about it.

You can get in trouble with very thin tools, including on a surface grinder.
Tool steel has incredible tensile strength, but breaks easily when shocked,
so you have to be careful, especially if you're grinding a long, narrow
tool. As long as you use the right wheel and keep it sharp, though, you
can expect pretty good results on a surface grinder. The only hard part is
getting precisely the angle you desire. That is usually determined by the
holding fixtures. One that is commonly found in shops is a 60 degree one
for sharpening threading tools. That's likely one of the most desirable
fixtures to have if you are fortunate to own a surface grinder.

Good thread. BTW, how do you know diamond dressed
wheels are "dull" and have to be fixed?

If you're making reference to them being dull from dressing with a diamond
instead of a dressing stick where hand grinding is concerned, I know it from
experience, having dressed wheels by every conceivable method aside from
crush rolling. The only way you'll understand the difference between a
wheel that is roughed up with a dressing stick as compared to one that is
diamond dressed is to A-B the wheel. Dress one with a diamond then grind
with it. Touch it up with a dressing stick and repeat. You tell me which
one cuts the best. All that goes out the window on a precision grinder,
though. Diamond dressing is the only way, but conditions are not the same.

If you meant a wheel that is dull from use, then my response is:

It's from experience, and something that may not be real apparent to the
novice. There are signs you can look for, though. One of them is a shiny
surface on the wheel. If a grinding wheel takes on a glaze from use, it's
not breaking down anywhere nearly fast enough. As the grains get dull, the
surface begins to shine and the wheel cuts poorly. It will make a hell of
a lot of heat, but will remove very little material. At that point you
have to decide if you're using the wrong abrasive, or if the wheel is too
hard. There are certain absolutes that are known, so you can make good
decisions about your particular problem. For one, if you're using a
silicon carbide wheel and you're grinding steel of any kind, it's the wrong
selection and the wheel will display the condition I mentioned, and quickly.
Frequent dressing doesn't help.

Another sign of a wheel needing dressing is if it is loaded. That's pretty
easy to see, especially if you're grinding with white aluminum oxide wheels.
The surface of the wheel takes on a black appearance and gets packed off
with swarf. Simple. Dress the wheel. It doesn't take very much, either.
A few thou will get the wheel back to good condition.

I've stood in front of huge
grinding wheels for many hours. I need to work on my very cheap
grinder present , but figured if I was going to get it from one it
would have been long ago. I use to think of such things when starting
them up in the morning and wondering if some idiot hit it with
anything. ) Put a steel plate over the top so it won't knock you
out (head injury) , you can always bleed slowly , maybe.

That theory might work on small wheels, but if you're running large wheels,
say on a crank grinder, if the wheel goes and you're in line with it, pretty
good odds there's going to be a funeral. I'm sure some have survived
exploding wheels, but I wouldn't bank on it. Wheels of that size would
likely move the steel and get you anyway. Lots of energy there.

The biggest I
worked with was "about" 3.5' Dia. X 3". I was trained in three weeks
from completely broke and asking gas station patrons if they wanted to
buy this redwood waterbed that I built out of 3.5" X 13" laminated
beams. The guy was curious and asked me my background and told him
that I understood linear and rotational geometry and he was like do
you want my job I'll train you ...? I just bought machines and
figured it out may years later about cutting instead of grinding.
I have no real guards or rests , should!

I'd love to have someone
show me something I don't know or could "see".
I get lost in printed descriptions. I just tense up and do it with a
very and hopefully non debated form 3 dimensionally in my mind and
do it. Like grinding the top ? If you put in a chip breaker then you
really have to grind a lot for the next when it wears out. Don't ask
me. The others know more.

Depending on the nature of the chip breaker, you can often just grind it
slightly deeper and push it farther back towards the opposite edge of the
tool. The net effect is to lower the cutting point of the tool, but you
can get considerable mileage from the tool that way.

The best part of chip breakers is that when you understand them and can
apply them properly, you can take cuts that you otherwise would not be able.
Boring is a great example. By winding the chips tight enough to break them,
you not only can take a better cut (thanks to the positive rake developed by
the chip breaker), it is also much safer because you don't generate long
strings that can pull you in when they get wound up in the chuck.

Harold

Experience answer is ok with me , but I was hoping you were going to
come back with something about the under magnification grains, how
they break, and the "glue" holding the wheels together. Maybe, I'm
just missing it or think too much. Tell more , I dressed wheels a
couple of times a day and just don't see how a diamond dressed wheel
can get any better, except the loading problem, and trying to
visualize it being too smooth. When and after I use to grind aircraft
and huge Cat cranks I was thinking how the coolant oil and the steel
doesn't load up the wheel fast... What are you suppose to think about
when machining. ) After the 60 other different things your not to
forget. I see now after D just posted pic.s from you how I got lost?
I don't have a cut off tool holder and never used one , but I've made
them from 1/2" HSS cause I was desperate. I don't enjoy the thought
of cutting work right off the lathe and catching it , ya'll say its
easy, but I need to see it done once to feel comfortable about doing
it myself. That or have a real need for going in 2". See, I was
thinking and still missed I guess that you were talking about cutting
the HSS lengthways kinda , but you talking about parting tools made
under 1/2 deep /downward wise when in use.

I wonder if the wheel was loaded on this one crank I was doing that
the machine that took a number of steps to the other end started
chattering. I'm sure you know what a headache chatter means when your
in the middle of something you can't reset. They didn't have a dresser
that would do it under the work you have on the machine and can't
move. I use to try to calculate in my head where best to stand and
cringe when pushing the start button. 11.25 degrees or 22.5 , 30 + was
out of the question , you have to be right there close and if it let
go I'm with ya on the funeral part. All for just above minimum wage.

No one told me how to sharpen or make metal cutting tools , I just
read and mathematical pictures of how the metal fractures and did it.
I still am stumped on how the bit will load/pile up where I can't see
the edge (even closely examined with it off the machine) and its
cutting just fine. Maybe that isn't suppose to happen , but on some
material I can't seem to stop it.

My mom made me go to school for architecture and I took as many math
and mechanical engineering classes as I could get away with. It was
way more interesting and I had planed to live in Florida and continue
flight lessons to be a corp. pilot. I blindly bought a lathe and had
no real idea how to use it 20 yrs. after school and grinding cranks. I
just got sick of paying machinist to make me stuff. I can't even
recall how I know what is happening , but just have a nak at it. I
really get lost on alot of posts cause I don't know the jargon of
shoulder here and what ever there in the printed work , but pictures
are clear as day. Oh, send me pictures of the grinder you built, even
though I'm not sure if the small upgrade will let me see pictures from
email. I'll just keep it if I can't open it. I finally got to see
the drawings of the holder to grind blanks that wouldn't open from the
drop box. BTW my planer would make those easy. What would be cool is
cast iron blanks to bolt it down on the surface grinder and cut
different angles with the planer to accept the blanks.

"Sunworshiper" wrote in message
...
On Tue, 03 Feb 2004 18:46:33 GMT, Ted Edwards
wrote:

Harold & Susan Vordos wrote:

bearing. They run very smooth, but cut hot as hell. A dressing
stick
lets you meet in the middle. Smooth wheel, but rough enough to cut
well.

I guess I missed it. You have mentioned dressing sticks before. Could
you post a picture of one to the dropbox or direct me to a catalog? I'd
like to see what I should be looking for.

Ted

Me too. I think I have one that I picked up at a used machinery
dealer thinking it was something else , don't remember what I thought
it was. Anyhow, its about 1"X1"X6" and black and kind of soft like a
pumis stone. We want to know how to use it also BTW.

What you have is a stone for dressing diamond wheels. They get loaded so
you use such a stone to clean them. The diamond wheel is far more aggressive
than the dressing stick in this instance, so it will eat the dressing stick
considerably, but the dressing stick will remove loading from the diamond
wheel in the process. Use it sparingly, you don't want to destroy the
diamond wheel, which is especially true if you run a resinoid wheel. That's
the proper choice of wheel matrix type for use on cutters.

The dressing stick for aluminum oxide wheels was described in some detail
for Ted. Please refer to that post.

Harold