In article , DoN. Nichols says...

In article ,
jim rozen wrote:

[ ... ]

If this grind is done with back angle, then the
cutting tool has both side, and back rake as
well. Many folks feel that back rake is essential
to good cutting, I've never found that to be true.

There is one exception -- which is already taken care of in the
quick-change tool holders for Aloris style toolposts. That is the
parting tool, which is mounted in its holder with a built-in rake angle.
....

And yet, even there it's hardly essential.

I have one of those Enco toolposts with a quick change
position. I think somebody even sent me one of the
holders at one time.... but no matter. Anyway,
I wanted to put a cutoff tool into play one day, and
did not have the proper QC holder for it. So I did
a horrible cheat, I put the cutoff blade into a
turning boring holder, the one with the V-notch at the
bottom - the notch typically used to accept a round
shank boring bar.

The square bottom of the cutoff tool lined up with
the notch, but the top - what to do about the top?
One could imagine a small piece to adapt the setcrews
to the top of the blade, a narrow strip with a slot
on its underside.

But I was in a hurry, and I knew that the cutoff blade
is a bit wider on top than on the bottom. So I just
brought each of the four setscrews to bear on the
top of the blade, and carefully tightened them
in turn to keep the blade vertical.

Consider - there's hardly and side force on a cutoff
blade. And it worked so well, I did my other one that
same way. I like to have a square-tip cutoff, and also
and angle-tipped one. Never hand one pop out under cut,
never had any trouble with the crazy setup. So I
keep using it.

And, because the tool holder has a flat bottom, the
blade has exactly zero rake. And they seem to work as
well as the genuine aloris cutoffs I have here at work.

Jim

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