re: rE:Re:RE: programming by hand

Fred wrote:

>I do not however, agree that subroutines should be placed at the
>beginning of a program. The most elegant that I have seen is to
>place the individual routines in sub-programs. It is much more
>intuitive also to have them at the end "out of the way", and to call
>them from a main program that is much better to have at the
>beginning. That way it is easier to see the order of processing
>and what tools are required, etc.

DITTO!

>If you knew what you were doing with even Bobcad, you can run
>circles around anyone doing manual programming at the machine.
>snipped details of how and why>

Much of what you are saying can ALSO be done with/at the control!
(subprograms with comments and operator msg's)

>If you spent a little time with a good Cad-Cam system, you would
>realize that when you know what you are doing, you can exercise MUCH
>more control over the toolpath than you can manually.

This is a good point. But... "a little time" is relative, for many it
will be "a LOTTA time"! And I would say you cannot exercise any MORE
control over the toolpath, but you MAY exert some 'sorts' of control
more easily.

>Also most drawings being generated today are in electronic CAD
>format, so the issue of having to draw the part to machine it, is
>becoming obsolete.

MANY shops STILL get 'paper' drawings! They may have COME from CAD,
but the files are back at the customers' location... Especially for
simpler parts, it is often easier to just work from the paper
IMMEDIATELY, than to "hook up" to get the electronic file. I will say
that this should only happen with new customers, and hopefully, only
once...

>The benefit is that you won't make a typographical error when you
>try to type in a coordinate value like X10.0 instead of X1.0. The
>CAM programs won't make this kind of mistake, but operators/
>programmers DO!

No, CAM programs make OTHER kinds of mistakes... extra axis moves,etc.

>Last point, lest some think I am biased in favor of CAM systems, and
>this is a point that many who squeezed in to the CNC discussion last
>year at Names have already heard:

Of course you are! You sell them for a living. Now it's not a bad
thing to BELIEVE in what you sell... Even when you know it's not the
ONLY way, there is STILL a bias... And that's okay. But don't tell us
there isn't...

>Often times it is more efficient to produce the part with a manual
>machine rather than a CNC.

Sorry to break up the 'flow', but here I'd have to say 'sometimes',
rather than 'often'.

>
>This is not a particularly popular thesis, but I can guarantee you
>that for a single hole I can walk over to my Bridgeport and poke it
>into a part faster than you can warm up and boot the controller
>on most CNC machines. You want it tapped and a chamfer at the top?
>3 tools? I will have it done before you poke the macro program on
>your conversational machine OR program it on your Cad-Cam system.

Why would I poke a macro? I'd MDI it! And why wouldn't my machine
already be running?

BTW, This would be a fun "event" at a CNC get-together (like names,
or prime). Manual vs. CNC. Conversational/macro vs. CAM. Drawings
given on paper. Drawings given on CAD. Maybe on sherlines so the
tooling doesn't skew the results...

I think the results would surprise more than a few people...

It might even be more fun to give several different systems the same
part(s) and, letting them decide "best way", see who makes it
first/best/etc. Again using "matched" machines...

Call it CNCCAR Racing (C N C Competition About Reality; or Results)

>I am concerned that those getting advice don't always understand the
>background of the advisor & maybe it would help in some cases if
>people would describe a little about the kinds of parts that given
>kinds of approaches are suggested for.
>
>As an example sometimes Rhino is suggested as a great Cad system.
>It is , provided that you want to make swoopy, nurbs surfaces. It
>is however not that great if you want to make simple 2 axis CAD
>drawings of parts with edges. The free Intellicad may do a
>better job in this case.
>
>For another instance, if I make parts that consist solely of shapes
>cut from solid rectangular bar stock, with drilled and tapped holes,
>my techniques will be very different than if I make 3D sculpted
>artwork, with no straight lines anywhere. I often times see people
>arguing over the best technique to do these two things, but they
>don't say that the techniques are for making different kinds parts.

Good points, these! I DO try to say "for this" and "for that". It
often balloons the post size, and many can 'figure it out' by
context, based on responses I've gotten. And when they can't, I
sometimes get a personal Email asking... seems to work ok.

Hope this helps.

Ballendo