Re: hpgl code and plotters

Chris,

Because hpgl works as expected, you just use it and forget it. You
don't HAVE to "go in" and massage it to account for variations the
way you do with gcode... (I'm not saying there aren't variations;
there are.) But on the whole, HPGL is much closer to a true standard
than Gcode.

(more below)

--- In CAD_CAM_EDM_DRO@y..., CL <datac@l...> wrote:
>It does what it does excellently. But, for
>machining anything past diamond drag engraving or vinyl cutting...
>It leaves much to be desired.

Your original question was why the engraving and vinyl cutters ahs
stuck with HPGL! You've answered your own question above...

<snip>Chances are even more slim that one would ever get Corel to use
>real Cad tools like trim, extend, and offset commands. So, first
>drawing a technical part is the first challenge and then
>toolpath "order" is the next.

Different customers; different tools. And toolpath order is generally
taken care of by the engraver or vinyl cutter internal s/w.

>So, why is it that companies seem to not "see" what the products
>capabilities are or where a market is that could use enhancements ?

Human nature, IMO. Most of us are busy enough doing what we "know"
that we don't spend too much time "looking" for things or areas that
we do not know... Also, it is much harder to see what you do not
already know, than it is to re-interpret what you know in different
ways. (the reason I use analogies so frequently)

An EXCELLENT book on this subject is "Flatland" by Edwin A. Abbott.
It is the tale of A. Square, being(trying to be) taught what "sphere"
means, by a sphere. And also visiting "line-land" and "point-land".
Limited by his own "two-dimensional" existence, the path is rough,
but enlightening for us to look upon. Written in the 1880's, parts
will be considered sexist today. But it is g-rated. And mind opening.

>Why couldn't a company like Corel include a G-Code Filter ? If hpgl
>can be exported, surely "G" could as well. You know the Sign
>Software companies accomplish it, why not Corel ? Same goes for
>AutoCad or AutoSketch. if they both can plot hpgl, why not G ?

We've come again to my favorite subject. The g code standard isn't.
And most programmers don't write "output drivers" anymore. They just
pick from what's already available, adding them to their product
(often without even understanding the code). If there was a universal
G-code driver that these companies could easily "add", I believe they
could be induced to do so...

But windows changed the way the game is played (compared to
dos). "You don't hafta write low-level stuff anymore; we did that for
ya" . I've used designcad since dos. When they changed to windows,
the hpgl "windows" driver no longer did arcs in a sensible "one
stroke" way. Instead what used to be a coupla hunerd (at most)
segments sequentially defining the circle, it worked quad by quad,
like a pecking chicken (if watching a pen plotter- or a cnc<G>)
Turbocad also had this problem. Designcad used to be pretty prominent
in the sign and engraving industry; largely due to their BasiCAD
programming allowing 3rd party companies to do as you suggest. Their
change to win hurt 'em, IMO.

In short, if the desired functionality is CLEAR (which g-code is
not), and available to programmers (that THEY are the TRUE customers
of the computer industry is Bill G's smartest realisation, IMO) in a
way that allows them to easily implement the feature; then it will be
done.

Isn't this borne out by the growth of EMC?

>Why not add that ? Welcome to basic CAM. "Basic", is all it needs
> be on that level.

I bet if you ask any of the control writers on this list if they knew
the variations they were going to be asked to support; to a person,
they'd say no. May start basic; doesn't stay there.
And most companies feed upon their strengths, and don't go looking
for a slippery slope to fall down...

>For SignCutters, Corel corp would have no problem raising their
>prices IF they incorporated the things the add-on or Sign software
>market has. What really stops them ??

One of those analogies: A man driving in the southwest sees another
man sitting in the sun, lazily enjoying the afternoon. He says, why
aren't you working? and continues, "If you work, you can save money.
With money, you can invest. With investemnts, you can retire.
Retired, you won't have to work!" To which the resting man
replies, "I'm not working now..."

Corel owned their slice of the market for years. By using agressive
pricing, and UNDERSTANDING THEIR CORE MARKET. If it aint broke...

> I would much rather dive into 20 or 30 thousand lines of G-Code
than Hpgl to "see" where I am and what is going on. At least you have
XYZ+ locations listed. I spent 5 years behind commercial engraving.
99% via hpgl. Constantly optimizing hpgl paths to make those routine
jobs run as efficient as possible ? I'm not looking back just yet.
> Chris L

Gcode machinists spend thousands of hours each year doing the same
thing. Your point is?

Hope this helps.

Ballendo