Handwheels again?!? was Re: true closed loop vs. hobby closed loop

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "C.S. Mo" <cs@v...> wrote:

>Every CNC shop I've been in has had at least one manual machine that
>they use for squaring stock, doing quick one-offs - anything they
>don't want to take the time to setup on the CNC machines.
> --C.S.

Hello,

And that's the machine (and area of the business/hobby) that's least
profitable, no doubt.

Please understand that I'm not against the "feeling" of turning
handwheels. I have manual machines, and enjoy using them. But I don't
do so under false illusions of it somehow being faster or more
accurate.

What is faster about putting a hunk a material on the table, cnc vs.
manual? Nothing. They both require the SAME steps. (whether using a
vise or fastening an irregular or large part with strap clamps.)

But with many cnc's I can just stick it on the table any old way, and
with two "edges" found, and one command; rotate the ENTIRE coord
plane to match what I've actually got! Do that manually... So I'll be
setup for even a quick and dirty cutoff or one-off more quickly...

Now that the material is fastened... You're telling me it's faster or
more productive to have a guy stand there and turn the wheels?
Because if it's a single pass cut, a single MDI line will handle it
and the guy doesN'T need to stand there! But if we want him to stand
there, he can just press the jog button and adjust the feedrate dial.
release when done. At the end of the day guess who's more productive,
hobby or otherwise...

You see, it's these simplest things that most easily respond to cnc
usage... Though if it were my shop, I'd set up a few macro's for the
uncommon "common things". Like squaring up, or quick one-offs.

The point that seems to be missed is that it takes the SAME amount of
time to affix the material, either way. And once fastened, there's NO
WAY a man or lady with mechanical handwheels can keep up with the
exact stop--at finest machine resolution, accurate travels, higher
feedrates, and ability to use macros, canned cycles, and arcs that a
cnc machine provides... (We're just not using the "program" part.)

This IS THE WAY TO USE A CNC MACHINE "MANUALLY". That's why there's a
thing called MDI in the first place! I'd still like to see a step by
step comparison of ANY item which clearly shows the superiority of
manual machining over a cnc machine used "manually"...

I'm betting that if we really keep our emotions out of it, and just
go on the reality, we all will benefit when it's clearly shown that
turning a mechanical handwheel just doesn't make sense, compared to
the DRO'd, power-fed, geometrically adjustable
(angles/offsets/rotations) and capable(arcs, macros, canned cycles)
reality of a cnc machine.

I'll even go so far as to say that if someone is using a cnc manually
(with mechanical handwheels), they are just not wanting to use the
mnachine they have to its fullest abilities... Which is fine. But
don't try to tell me it's faster, or more profitable. Or more
accurate. Cuz it just aint so... (Knowledge and attitude might have
to change for this inherent reality to be received however!)

Ballendo