"RicodJour" wrote in message
...
On Dec 15, 10:15 am, "Ed Huntress" wrote:
"Smitty Two" wrote in message
In article ,
"Existential Angst" wrote:

Next, when you grok the difference between a "conventional cut" and a
"climb
cut", post back -- maybe then we can have an intelligent conversation.

Something you clearly don't, EA. Those terms apply to end mills when
using the side of the cutter. Applied to a circular saw blade, they're
just meaningless technobabble used to weakly obfuscate your ignorance.

Uh, I am *not* going to get into this argument, but climb cutting and
conventional cutting apply to many types of cutting tools, including saw
blades. In fact, in production woodworking, there are ripping saws that
operate in the climb mode for the express purpose of avoiding tear-out.
They
require fancy hold-downs and feed mechanisms for the workpieces, so they
don't go flying out of the saw. I've seen them, and I've written about
them,
and I've had discussions with the blade makers about the differences in
the
two types of blades.

Interesting. I've never heard of such a thing with a saw blade, and
DAGS to see if there was such a beast as a circular saw climb cut -
the search didn't turn up a single example in the first two pages of
results. Can you post a link to a climb cutting machine or something
you wrote about it?

I knew you'd ask that. g It was between 20 and 25 years ago; the story was
about using wirecut EDM to shape sinterred diamond compacts on the cutters
used in both metalworking (a minor use) and woodworking (the major use),
particularly on commercial spindle-shapers and routers. The discussion about
saw blades was peripheral to the subject, because EDM isn't used to shape
the edges of those.

All I can recall is this: In production rip-sawing, the issue is how the
cutter *exits* the cut, rather than how it enters. Apparently -- and this is
from memory -- saw blades used in commercial ripping just barely extend
through the top of the cut, so the re-entry isn't an issue. On the top side
of the work, it's almost the same whether you consider it climb- or
conventional-cutting. But it makes a big difference when the blade finally
leaves the bottom of the cut. If it's cutting when it comes out of the
workpiece, it's going to tear the edges of the cut, as any hobbyist
woodworker knows from conventional work with a table saw. In the discussion,
running the blade in the reverse direction of what most of us condider the
"conventional" one, in which the blade exits the work "not cutting," was
what they were calling "climb cutting," and apparently that's the preferred
mode for production. It requires friction drive and hold-down rollers; the
work is fed under power.

BTW, some commercial saws operate upside-down, with the blade(s) above the
work, so you might have to reverse "up" and "down" from this discussion.
That may just be for multi-blade ripping of lumber; I've never actually seen
one of those saws.

I never got involved in studying production woodworking except for that
single application, and it was because I covered tooling for a couple of
metalworking magazines and I had a client who made special wire EDMs for
that work, when I wasn't a staff editor.

Sorry I can't refer you to my article. That old stuff isn't archived online
and I wrote over 350 articles about metalworking and tooling, so I don't
remember where it ran.

In the machines you're talking about, the workpiece/sawblade is moving
in the opposite direction to the normal direction of movement. With
the Dual Saw type of saws, one of the counter rotating blades is
always moving opposite the 'normal' direction of movement - and in
fact that that is the primary reason the tool can get away without
hold downs and feed mechanisms (equal and opposite canceling and all
of that), and the reason that the tool shouldn't grab and kick, it
seems to me that the tool isn't climb cutting, so much as just
cutting. The adjectives canceled out. So is there really a climb cut
in such a tool?

A good question; I don't know about those saws. I hesitated to jump in here
at all, except to point out that there is something that is, or was, called
"climb cutting" in production sawing, and that it's similar to what we mean
by the term in metalworking, with milling cutters.

I will now go back to my nap. g

--
Ed Huntress