Hello,

The shop that I work at has special order carbide inserts, and due to
heavy feed to speed ratios on our machines, we have found it necessary
to hone the inserts. To keep them in tolerance (.002 hone) we have put
them in a tumbler with some stones and silicon carbide sludge... this
method because its worked for us on lighter hones. This time though,
the inserts are all chipping to hell! I tried putting even one piece
at a time to fix it in case they were bumping each other, no help.

Now I am getting the blame from my boss, and whether it is somehow my
fault or not, getting the blame is just unacceptable.

Any advice from those experienced in honing carbide??

Thanks,
Erik

On 11 May 2005 14:19:34 -0700, "Erik G" wrote:

Hello,

The shop that I work at has special order carbide inserts, and due to
heavy feed to speed ratios on our machines, we have found it necessary
to hone the inserts. To keep them in tolerance (.002 hone) we have put
them in a tumbler with some stones and silicon carbide sludge... this
method because its worked for us on lighter hones. This time though,
the inserts are all chipping to hell! I tried putting even one piece
at a time to fix it in case they were bumping each other, no help.

Now I am getting the blame from my boss, and whether it is somehow my
fault or not, getting the blame is just unacceptable.

Any advice from those experienced in honing carbide??

Thanks,
Erik

So to make the fragile, easily broken pieces of carbide sharper, you
put them in a bouncing box of rocks?

This is a troll, right?

Gunner

"Veterans, and anyone sensible, take cover when there's incoming.
A cloud of testosterone makes a **** poor flack shield."
Offbreed

Actually, the stones make the carbide edges duller...the purpose is to
take the sharp edges off very evenly, making the carbide more durable
in heavy cutting operations...but i'm still inclined to agree with you
that it's a far from brilliant process. In most instances it actually
works, though.


Gunner wrote:
On 11 May 2005 14:19:34 -0700, "Erik G" wrote:

Hello,

The shop that I work at has special order carbide inserts, and due
to
heavy feed to speed ratios on our machines, we have found it
necessary
to hone the inserts. To keep them in tolerance (.002 hone) we have
put
them in a tumbler with some stones and silicon carbide sludge...
this
method because its worked for us on lighter hones. This time
though,
the inserts are all chipping to hell! I tried putting even one
piece
at a time to fix it in case they were bumping each other, no help.

Now I am getting the blame from my boss, and whether it is somehow
my
fault or not, getting the blame is just unacceptable.

Any advice from those experienced in honing carbide??

Thanks,
Erik

So to make the fragile, easily broken pieces of carbide sharper, you
put them in a bouncing box of rocks?

This is a troll, right?

Gunner

"Veterans, and anyone sensible, take cover when there's incoming.
A cloud of testosterone makes a **** poor flack shield."
Offbreed

I'm no rocket scientist, but I would think that if you changed the
tumbling medium to either a finer grit or a softer material, it might
help. You're really only polishing the edges away, right?
Ron

Erik G wrote:
Hello,

The shop that I work at has special order carbide inserts, and due to
heavy feed to speed ratios on our machines, we have found it necessary
to hone the inserts. To keep them in tolerance (.002 hone) we have put
them in a tumbler with some stones and silicon carbide sludge... this
method because its worked for us on lighter hones. This time though,
the inserts are all chipping to hell! I tried putting even one piece
at a time to fix it in case they were bumping each other, no help.

Now I am getting the blame from my boss, and whether it is somehow my
fault or not, getting the blame is just unacceptable.

Any advice from those experienced in honing carbide??

Thanks,
Erik



You can't get them honed by the manufacturer? Sure, probably add to
cost, but isn't what you are doing now adding the the cost as well?


michael

Seems to me you are just breaking down the edge, I bet it can be done
easily by chemically attacking the binder with acid.

http://www.accu-finish.com/

"Erik G" wrote in message
oups.com...
Hello,

The shop that I work at has special order carbide inserts, and due to
heavy feed to speed ratios on our machines, we have found it necessary
to hone the inserts. To keep them in tolerance (.002 hone) we have put
them in a tumbler with some stones and silicon carbide sludge... this
method because its worked for us on lighter hones. This time though,
the inserts are all chipping to hell! I tried putting even one piece
at a time to fix it in case they were bumping each other, no help.

Now I am getting the blame from my boss, and whether it is somehow my
fault or not, getting the blame is just unacceptable.

Any advice from those experienced in honing carbide??

Thanks,
Erik


I gather you have far too many to do them by hand? Breaking the edge of
carbide roughing inserts used to be the norm when I broke into the trade.
The recommendation was to hone a .005" 45 degree angle on the cutting edge,
which prolonged insert life considerably. For those that may not
understand, negative rake inserts do not touch at the tip when in use, but
cut back on the insert top, location depending on depth of cut and feed
rate. It's commonly referenced as the "false cutting edge".

I'd suggest a quick stroke with a diamond hone on each face and tip------I
think you could get them quite close with just a little effort.

Harold

On Sun, 15 May 2005 02:36:38 -0700, "Harold and Susan Vordos"
wrote:


"Erik G" wrote in message
roups.com...
Hello,

The shop that I work at has special order carbide inserts, and due to
heavy feed to speed ratios on our machines, we have found it necessary
to hone the inserts. To keep them in tolerance (.002 hone) we have put
them in a tumbler with some stones and silicon carbide sludge... this
method because its worked for us on lighter hones. This time though,
the inserts are all chipping to hell! I tried putting even one piece
at a time to fix it in case they were bumping each other, no help.

Now I am getting the blame from my boss, and whether it is somehow my
fault or not, getting the blame is just unacceptable.

Any advice from those experienced in honing carbide??

Thanks,
Erik


I gather you have far too many to do them by hand? Breaking the edge of
carbide roughing inserts used to be the norm when I broke into the trade.
The recommendation was to hone a .005" 45 degree angle on the cutting edge,
which prolonged insert life considerably. For those that may not
understand, negative rake inserts do not touch at the tip when in use, but
cut back on the insert top, location depending on depth of cut and feed
rate. It's commonly referenced as the "false cutting edge".

I'd suggest a quick stroke with a diamond hone on each face and tip------I
think you could get them quite close with just a little effort.

Harold


Or pick up one of the small bench top "lapping" machines that are
collecting dust in many machine shops, holdovers from days when
inserts were quite expensive.

They use a diamond wheel in the shape of a donut, held in place by
magnets, so you may swap between grits quickly. They will spin at slow
rpms either fixe or in a reciprocating motion, with a quickly setable
table with angle gauges.

I love mine, as inserts are expensive for me. Mine is a Leonard
Grind-Lap, but the name has been changed a number of times over the
years, nearly all being made in Santa Ana, California.

They turn slow enough to also work marvelously well on HSS also.

Gunner

"War is an ugly thing, but not the ugliest of things. The decayed and degraded state of moral and patriotic feeling
which thinks that nothing is worth war is much worse. The person who has nothing for which he is willing to fight,
nothing which is more important than his own personal safety, is a miserable creature and has no chance of being
free unless made and kept so by the exertions of better men than himself."
- John Stewart Mill

Something you might try.

I examined on of the new cnc drill pointers that "honed" the
drill after sharpening. Turned out they used an abrasive brush.
Brush had blue plastic bristles. Located what appeard to be the
same bruch in a local hardware store. Tried using it on regroud
drills and HSS lathe tools. Does a wonderful job of honing, much
better than I can do by hand in just a few seconds. I don't
think the hardware store abrasive brush would work with carbide
[I will try later today] but there should be plastic brush with
SiC [diamond? borazon?] in place of AlOx abrasives. Something
better than visegrips may be required to hold the inserts. Whats
your volume?

GmcD

On 11 May 2005 14:19:34 -0700, "Erik G"
wrote:
Hello,
The shop that I work at has special order carbide inserts, and due to
heavy feed to speed ratios on our machines, we have found it necessary
to hone the inserts.
snip

Silicon carbide in the brush is pretty common.

Thanks for all the feedback everyone.... The inserts are in large
volume, a few hundred at a time. They have rake underneath them...so
the hone needs to be somewhat exact... its expensive to let our vendor
hone them, and they do a poor job... I think Im going to talk them
into buying a silicon carbide deburring wheel bonded with nylon (3M
makes one i think). Then i will see if i can dress the form of the
insert on it and throw it on a surface grinder with the insert tipped
about 45 degrees... its worth a shot. i may try some form of brush
hone with silicon carbide also...

On 18 May 2005 13:58:43 -0700, "Erik G" wrote:

Thanks for all the feedback everyone.... The inserts are in large
volume, a few hundred at a time. They have rake underneath them...so
the hone needs to be somewhat exact... its expensive to let our vendor
hone them, and they do a poor job... I think Im going to talk them
into buying a silicon carbide deburring wheel bonded with nylon (3M
makes one i think). Then i will see if i can dress the form of the
insert on it and throw it on a surface grinder with the insert tipped
about 45 degrees... its worth a shot. i may try some form of brush
hone with silicon carbide also...


I did 10 inserts this weekend with my old lapper in about as long as
it took to type this post.

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