I acquired a box of used carbide endmills at a factory.

Some are outright broken, usually near the tips. For those, I wonder
if there is an easy and repatively healthy way of removing their
tips. On some, if I could grind off 1/8 -- 1/4 -- 3/8" off their ends,
I could at least use them for side cutting. So, is there some easy way
of doing this, maybe with a one time investment?

Second... Many other endmills in the pile, look used, but not really
worn out. Is there some quick way, with them, to evaluate sharpness of
their edges?

i

Ignoramus23245 wrote:
I acquired a box of used carbide endmills at a factory.

Some are outright broken, usually near the tips. For those, I wonder
if there is an easy and repatively healthy way of removing their
tips. On some, if I could grind off 1/8 -- 1/4 -- 3/8" off their ends,
I could at least use them for side cutting. So, is there some easy way
of doing this, maybe with a one time investment?

You can buy a diamond grinding wheel. It is possible to freehand grind
endmills, or
use one of the fixtures with a spindle that has the required tilts built
into it.
I have some ghastly scanned snapshot prints from when I did this stuff
20 years ago.
Endmills are so cheap today that I don't bother. I use 1/8" carbide,
which are quite cheap,
and for larger sizes I use HSS Cobalt (M42 and M57) endmills, which are
MUCH better than
plain HSS.
Second... Many other endmills in the pile, look used, but not really
worn out. Is there some quick way, with them, to evaluate sharpness of
their edges?

You can kind of feel the sharpness with your fingerprint ridges. It is
also possible to
cut yourself with brand-new endmills, the best ones are QUITE sharp.


Jon

Oh, crap, forgot the URL :
http://pico-systems.com/sharpen.html

Jon

"Ignoramus23245" wrote in message
...

Second... Many other endmills in the pile, look used, but not really
worn out. Is there some quick way, with them, to evaluate sharpness of
their edges?


I have a small pocket microscope I use to look at end mills edges. Its
really kind of amazing how rough a new one looks, but you can tell instantly
when one is in rough shape. In the day time I just step outside in the
sunlight to get enough light on the end mill.

That last bit may not work so well in greyer climates.

On Sat, 11 Dec 2010 21:00:39 -0600, Ignoramus23245
wrote:


I acquired a box of used carbide endmills at a factory.

Some are outright broken, usually near the tips. For those, I wonder
if there is an easy and repatively healthy way of removing their
tips. On some, if I could grind off 1/8 -- 1/4 -- 3/8" off their ends,
I could at least use them for side cutting. So, is there some easy way
of doing this, maybe with a one time investment?

Second... Many other endmills in the pile, look used, but not really
worn out. Is there some quick way, with them, to evaluate sharpness of
their edges?

i

Blink blink....you havent scored a KO Lee tool and cutter grinder yet???

A B300 will do a fine job for you with a tiny footprint


Gunner

Top 10 Democrat Party Slogans

10. Bitterly clinging to aborton and taxes
9. We didnt destroy your freedoms, you can
visit them at the Smithstonian
8. If you want us to listen to your opinion, move to Europ
7. Someday none of this will be yours
6. We can't tax terrorism, so who cares?
5. Please don't vote us out!! None of us can hold a real job!
4. Why the Founding Fathers limited Government:
Racism!
3. Reducing America's carbon footprint, one job at a time.
2. America: We just cant wait to see how it ends!!
1. Making everything in this country free, except you.

On Dec 11, 10:00*pm, Ignoramus23245 ignoramus23...@NOSPAM.
23245.invalid wrote:
I acquired a box of used carbide endmills at a factory.

Some are outright broken, usually near the tips. For those, I wonder
if there is an easy and repatively healthy way of removing their
tips. On some, if I could grind off 1/8 -- 1/4 -- 3/8" off their ends,
I could at least use them for side cutting. So, is there some easy way
of doing this, maybe with a one time investment?
...
i

I salvage chipped end mills by surface-grinding a small bevel on the
tips with one of these:
http://www.nolansupply.com/small_images/67677143.jpg
set on the angled surface.

Regardless of how dull they were they can now mill a flat surface,
cutting as deep as the bevel height (~0.040"), and so far the corner
angle hasn't interfered when I use one to cut setscrew or wrench flats
on a round shaft. They let me save my few new endmills for the finish
pass on sharp-cornered steps.

If I need to cut deeper I rough out most of the metal by plunging
downwards so the wear is on edges that I can resharpen.

That simple fixture is enough to form a new end after hand grinding a
badly chipped endmill shorter.

I have a fixture for grinding side flutes but don't use it much. It's
fussy to use and slightly undersized endmills look just like full-
diameter ones.

jsw

On Sat, 11 Dec 2010 21:15:54 -0600, Jon Elson
wrote:

Ignoramus23245 wrote:
I acquired a box of used carbide endmills at a factory.

Some are outright broken, usually near the tips. For those, I wonder
if there is an easy and repatively healthy way of removing their
----------
Whassat, Ig?


tips. On some, if I could grind off 1/8 -- 1/4 -- 3/8" off their ends,
I could at least use them for side cutting. So, is there some easy way
of doing this, maybe with a one time investment?

You can buy a diamond grinding wheel. It is possible to freehand grind
endmills, or
use one of the fixtures with a spindle that has the required tilts built
into it.
I have some ghastly scanned snapshot prints from when I did this stuff
20 years ago.
Endmills are so cheap today that I don't bother. I use 1/8" carbide,
which are quite cheap,
and for larger sizes I use HSS Cobalt (M42 and M57) endmills, which are
MUCH better than
plain HSS.

I know that cobalt is much tougher than HSS, but why is it better and
how does working with them differ from HSS. Better cutting speeds
because you can push them harder?


Second... Many other endmills in the pile, look used, but not really
worn out. Is there some quick way, with them, to evaluate sharpness of
their edges?

You can kind of feel the sharpness with your fingerprint ridges. It is
also possible to
cut yourself with brand-new endmills, the best ones are QUITE sharp.

We Wreckers use the ScarySharp(tm) method of sharpening our tools.
When a blade is very well honed, you can push an atom up to the edge
and if it splits it, it's ScarySharp(tm). "Sharp" is when you can put
the edge perpendicular against a fingernail and feel a catch when you
move it, peeling up a shaving with no pressure. Far too many people
have never experienced "sharp", thinking that shaving hairs off their
arm means that it's sufficiently sharp. That's nowhere close.

--
Know how to listen, and you will
profit even from those who talk badly.
-- Plutarch

Iggy Jon Elsen's reply is spot on. You can feel the edge with your finger. If it doesn't readily cut you, is isn't sharp enough. I
almost exclusively use M35, M42 or M57 end mills as they are much better for what I do. I almost never use carbide. Carbide will
never be as sharp as HSS even new.
Steve

"Ignoramus23245" wrote in message ...

I acquired a box of used carbide endmills at a factory.

Some are outright broken, usually near the tips. For those, I wonder
if there is an easy and repatively healthy way of removing their
tips. On some, if I could grind off 1/8 -- 1/4 -- 3/8" off their ends,
I could at least use them for side cutting. So, is there some easy way
of doing this, maybe with a one time investment?

Second... Many other endmills in the pile, look used, but not really
worn out. Is there some quick way, with them, to evaluate sharpness of
their edges?

i

On Dec 12, 10:49*am, "Steve Lusardi" wrote:
Iggy Jon Elsen's reply is spot on. You can feel the edge with your finger.. If it doesn't readily cut you, is isn't sharp enough...
Steve

I can't quite agree with that. Endmills that seemed dull to me from
touching the edge still cut well enough. There is an analysis of wear
life in a Lindsay reprint that says the width of the worn contact
strip behind the edge is more important, since it makes the edge skate
over the work instead of digging in.

I thought this was the book but can't find anything in the index and
this online version is far too big for my dialup access:
http://www.archive.org/details/treat...llin00cincrich

jsw

I'll add that a sharp edge reflects no light.. a glimpse of even the
slightest bit of reflected light shows that the edge is rounded/gone (or not
there yet, in the case of sharpening).

A sharp edge is difficult to measure, well beyond .0001", which should
emphasise the importance of quality cutting lubricants in metalworking (and
yet it escapes many).

Anyone who's handled Chinese tools/parts/goods has experienced what a sharp
edge is, as the parts are rarely deburred.. unless you're handling a cutting
tool.

When 1 or both sides of an edge are concave, that can produce a truly sharp
edge, but often very fragile.

The cutting edge geometry on some metalworking cutting tools is somewhat
amazing, and a bit confusing to determine an appropriate sharpening
setup/method.

--
WB
..........


"Larry Jaques" wrote in message
...

----------
Whassat, Ig?
I know that cobalt is much tougher than HSS, but why is it better and
how does working with them differ from HSS. Better cutting speeds
because you can push them harder?

We Wreckers use the ScarySharp(tm) method of sharpening our tools.
When a blade is very well honed, you can push an atom up to the edge
and if it splits it, it's ScarySharp(tm). "Sharp" is when you can put
the edge perpendicular against a fingernail and feel a catch when you
move it, peeling up a shaving with no pressure. Far too many people
have never experienced "sharp", thinking that shaving hairs off their
arm means that it's sufficiently sharp. That's nowhere close.

On Dec 12, 1:00*pm, "Wild_Bill" wrote:
...
The cutting edge geometry on some metalworking cutting tools is somewhat
amazing, and a bit confusing to determine an appropriate sharpening
setup/method.
WB

It certainly is, especially circular relief grinds and such.

The recommendations I've found all seem to overlap at about 5 degrees
of back relief so that's what I use.

jsw

On 2010-12-12, Gunner Asch wrote:
Blink blink....you havent scored a KO Lee tool and cutter grinder yet???

A B300 will do a fine job for you with a tiny footprint

Gunner, would you recommend a small size T&C grinder that can do end
mills? Kuhlmann? Or what model?

i

On Sun, 12 Dec 2010 19:17:19 -0600, Ignoramus18047
wrote:

On 2010-12-12, Gunner Asch wrote:
Blink blink....you havent scored a KO Lee tool and cutter grinder yet???

A B300 will do a fine job for you with a tiny footprint

Gunner, would you recommend a small size T&C grinder that can do end
mills? Kuhlmann? Or what model?

i
Ive got a KO Lee, B300 with all the accessories, and its no bigger than
about 30x30" and does a myrid amount of work.

Ive also got a Darex E90 endmill grinder kicking around somewhere in my
Stuff.

The Kuhlmans are great grinders..but they are one purpose devices.

The KO Lees (and others) can double as a surface grinder, OD/ID grinder
etc etc etc

Any T&C grinder with a traveling table will do the job for many
different applications, from sharpening lathe cutters to mill cutters,
to drill bits, to surface grinding, etc etc etc. The B300 has one of
the smallest "do it all" footprints out there. Look for one at one of
your auctions.

http://picasaweb.google.com/gunneras...61074120982738

Gunner

Top 10 Democrat Party Slogans

10. Bitterly clinging to aborton and taxes
9. We didnt destroy your freedoms, you can
visit them at the Smithstonian
8. If you want us to listen to your opinion, move to Europ
7. Someday none of this will be yours
6. We can't tax terrorism, so who cares?
5. Please don't vote us out!! None of us can hold a real job!
4. Why the Founding Fathers limited Government:
Racism!
3. Reducing America's carbon footprint, one job at a time.
2. America: We just cant wait to see how it ends!!
1. Making everything in this country free, except you.

Gunner, would you recommend a small size T&C grinder that can do end
mills? Kuhlmann? Or what model?

i
Ive got a KO Lee, B300 with all the accessories, and its no bigger than
about 30x30" and does a myrid amount of work.

Ive also got a Darex E90 endmill grinder kicking around somewhere in my
Stuff.

The Kuhlmans are great grinders..but they are one purpose devices.

The KO Lees (and others) can double as a surface grinder, OD/ID grinder
etc etc etc

Any T&C grinder with a traveling table will do the job for many
different applications, from sharpening lathe cutters to mill cutters,
to drill bits, to surface grinding, etc etc etc. The B300 has one of
the smallest "do it all" footprints out there. Look for one at one of
your auctions.

http://picasaweb.google.com/gunneras...61074120982738

Gunner

I've got a Cinncinatti Monoset. Great do it all grinder.

When you look at eBay pricing for top quality endmills, you would have
to put a very low value on your time re-sharp carbide endmills. Its
slow tedious work.

Now making custom tooling and resharping custom cutters is a great use
for a T&C grinder.

Just my 2 cents

Karl

On Dec 12, 8:17*pm, Ignoramus18047 ignoramus18...@NOSPAM.
18047.invalid wrote:
On 2010-12-12, Gunner Asch wrote:

Blink blink....you havent scored a KO Lee tool and cutter grinder yet???

A B300 will do a fine job for you with a tiny footprint

Gunner, would you recommend a small size T&C grinder that can do end
mills? Kuhlmann? Or what model?

i

A Toolmaker surface grinder like mine works pretty well for general
sharpening.
http://media.photobucket.com/image/t...se_2copy-1.jpg
A 5"x 10" mag chuck is probably the largest that will fit as the tee
slot is 12-1/2" long. The swivel table centers are high enough for a
10" saw blade.

It's more like a versatile Shopsmith than a precision Cincinnati but
it does a reasonably decent job for non-commercial use. I use mine for
cleanup and as a milling machine for hardened steel. You can see a
typical surface finish pattern on the cam disk he
http://picasaweb.google.com/KB1DAL/H...33137678036386

jsw

On 12/12/2010 08:40 AM, Larry Jaques wrote:


I know that cobalt is much tougher than HSS, but why is it better and
how does working with them differ from HSS. Better cutting speeds
because you can push them harder?


I don't really know what the difference is. But, I started my milling
experience with a box of stellite cutters, without actually knowing what
they were, and they almost lasted forever. When they were showing a lot
of wear, I bought some plain HSS cutters, and the results were horrible,
I could wear one out in an hour, easily. I went to M42 cobalt
tools, and the life on those is MUCH better, maybe 4 - 7 X better on
Aluminum. I'm sure you can push them harder, but I generally don't. I
just go easy on them, and get months or more of life out of them.

Jon

On 12/12/2010 09:49 AM, Steve Lusardi wrote:
Iggy Jon Elsen's reply is spot on. You can feel the edge with your
finger. If it doesn't readily cut you, is isn't sharp enough. I almost
exclusively use M35, M42 or M57 end mills as they are much better for
what I do. I almost never use carbide. Carbide will never be as sharp as
HSS even new.
On the other hand, carbide is massively stiffer than any HSS. I do a
lot of panels out of 1/8" aluminum, and use 1/8" diameter solid carbide
end mills for that type of work. They are great, although you can
pretty easily damage them accidentally. I once cracked one of the
cutting edges when touching off the Z zero, just bringing it down onto
an aluminum panel. (I usually slip a piece of paper under it and when
the paper gets stuck I set Z to .003", but went down too far that time.)

Anyway, these last a long time, and cost about $3-4 each when I need to
buy a dozen or so. I plow (full width cut) at 10 IPM and 2800 RPM,
you'd never get away with that on a 1/8" HSS cutter.

Larger carbide cutters get quite a bit more expensive, and I only have a
couple. But, these 1/8" units are so cheap that they are cost-effective.

Jon