Re: Weight balancing calculation?

"Bryce" <bryceremove@xxxxxxxxxxxxx> wrote in message
news:pg1go2hsoih03pgiqfuckopq1rgrt0idlk@xxxxxxxxxx
On Tue, 19 Dec 2006 09:05:15 -0500, "Bart" <bborb@fusedotnet> wrote:

I can't help but think there's a reason it only has .025" of stroke. After
looking at:
http://www2.coromant.sandvik.com/coromant/pdf/Holemaking/C-1229-014/Part5.pdf
I'm having real trouble seeing this 1/16" offset letting the drill cut a
hole, even with a pilot hole unless the only engagement is with the
outermost insert, in which case I'd use a boring bar for better choices in
inserts.

Well, hard as it is to picture, I have drilled literally thousands of
holes 1/16" off center with the particular drill that I will be using,
as well as many others of the same brand and different brands. It
works extremely well in a turning center, and the geometry of the
machining is the same on a mill, just not the weight balance. The
drill body that I will be using is a .734" nominal size, and printed
right on the side is .884" max size. That means to me that I could
offset it up to .075" radially before exceeding their recommended
range, and I have. The inserts really are quite wide on their front
cutting edge, and they overlap in just the right places/amounts to
make it possible.

I would state that they do like lots of through coolant, and that in a
turning machine, they can make their first hole off center, and then
continue to take passes using the outside insert as a boring bar.
They do leave fairly close to a flat bottom, depending on the insert
geometry and the size of the drill. As expensive as they are, they
pay for themselves in perhaps one or two days of run time in the right
application.

--
Bryce

Thanks for the reply and setting me straight. That is a "cool tool" in that
it can drill 3/4" AND 7/8" holes. Saves from buying two separate drills. Is
there a link to this drill?
Thanks again,
Bart


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