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  librecad Gene Heskett <gheskett@shentel.net> - 2018-12-06 23:40 +0100
    Re: librecad "hdv@gmail" <hdv.jadev@gmail.com> - 2018-12-06 23:50 +0100
      Re: librecad Yves <ydubeau@pm.me> - 2018-12-07 01:30 +0100
        Re: librecad Doug <dmcgarrett@optonline.net> - 2018-12-07 02:10 +0100
          Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-07 03:10 +0100
        Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-07 02:50 +0100
      Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-07 01:50 +0100
        Re: librecad John Hasler <jhasler@newsguy.com> - 2018-12-07 02:50 +0100
          Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-07 03:20 +0100
            Re: librecad John Hasler <jhasler@newsguy.com> - 2018-12-07 03:30 +0100
              Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-07 04:40 +0100
              Re: librecad Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2018-12-07 19:50 +0100
                Re: librecad John Hasler <jhasler@newsguy.com> - 2018-12-07 20:20 +0100
                  Re: librecad Greg Wooledge <wooledg@eeg.ccf.org> - 2018-12-07 20:30 +0100
                  Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-08 00:50 +0100
                    Re: librecad John Hasler <jhasler@newsguy.com> - 2018-12-08 02:00 +0100
                      Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-08 03:50 +0100
                        Re: librecad Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2018-12-08 05:20 +0100
                          Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-08 06:50 +0100
                            Re: librecad John Hasler <jhasler@newsguy.com> - 2018-12-08 14:40 +0100
                              Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-08 20:00 +0100
                                Re: librecad John Hasler <jhasler@newsguy.com> - 2018-12-08 20:50 +0100
                                  Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-08 21:10 +0100
                                    Re: librecad John Hasler <jhasler@newsguy.com> - 2018-12-08 21:30 +0100
                                      Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-08 22:00 +0100
                                    Unpacking a large zipfile, was Re: librecad David Wright <deblis@lionunicorn.co.uk> - 2018-12-09 00:20 +0100
                                Re: librecad "Jeremy Nicoll" <jn.ml.dbn.25@letterboxes.org> - 2018-12-09 00:10 +0100
                                  Re: librecad John Hasler <jhasler@newsguy.com> - 2018-12-09 01:50 +0100
                                  Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-09 02:50 +0100
                                    Re: librecad John Hasler <jhasler@newsguy.com> - 2018-12-09 03:20 +0100
                                      Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-09 03:30 +0100
                                    Re: librecad "Jeremy Nicoll" <jn.ml.dbn.25@letterboxes.org> - 2018-12-09 03:30 +0100
                Re: librecad (was) Gene Heskett <gheskett@shentel.net> - 2018-12-08 00:40 +0100
          Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-07 04:20 +0100
          Re: librecad Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2018-12-07 04:50 +0100
        Re: librecad "hdv@gmail" <hdv.jadev@gmail.com> - 2018-12-07 10:30 +0100
          Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-07 14:50 +0100
            Re: librecad "hdv@gmail" <hdv.jadev@gmail.com> - 2018-12-07 15:10 +0100
        Re: librecad Joe <joe@jretrading.com> - 2018-12-07 11:00 +0100
          Re: librecad "hdv@gmail" <hdv.jadev@gmail.com> - 2018-12-07 11:30 +0100
    Re: librecad "Jeremy Nicoll" <jn.ml.dbn.25@letterboxes.org> - 2018-12-07 07:50 +0100
      Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-07 14:50 +0100
        Re: librecad John Hasler <jhasler@newsguy.com> - 2018-12-07 16:20 +0100
          Re: librecad Erik Christiansen <dvalin@internode.on.net> - 2018-12-08 03:00 +0100
            Re: librecad Gene Heskett <gheskett@shentel.net> - 2018-12-08 04:30 +0100
          Re: librecad John Hasler <jhasler@newsguy.com> - 2018-12-08 04:50 +0100
      Re: librecad John Hasler <jhasler@newsguy.com> - 2018-12-07 15:10 +0100

Page 3 of 3 — ← Prev page 1 2 [3]

#203106

On Thu, 6 Dec 2018, at 22:32, Gene Heskett wrote:

> Or is there an even better 2d app for such?

There was a discussion here starting in Nov 2017, entitled

   "software to do drawings of houses, gardens, etc."

where several people bemoaned the difficulty they had in getting
any GUI-based CAD program to do what they needed, without a
huge learning curve.

Someone described how they'd instead used hand-coded PostScript
(which is in essence a set of drawing commands, normally sent to a
laser printer) to draw plans for house changes. 

Something like that might be easier to get to grips with.   A /big/
advantage of using scripts is that one gets to place comments in 
the script explaining what's going on, why one did something in a
particular way etc.

Also scripts easily allow parameterisation of values - eg (for the 
house plans) what the thickness of a piece of timber is, or what 
the spacing between regular items should be. 

-- 
Jeremy Nicoll - my opinions are my own.

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#203119

On Friday 07 December 2018 01:39:35 Jeremy Nicoll wrote:

> On Thu, 6 Dec 2018, at 22:32, Gene Heskett wrote:
> > Or is there an even better 2d app for such?
>
> There was a discussion here starting in Nov 2017, entitled
>
>    "software to do drawings of houses, gardens, etc."
>
> where several people bemoaned the difficulty they had in getting
> any GUI-based CAD program to do what they needed, without a
> huge learning curve.

Thats a huge part of the problem, but theres another fence to jump. most 
of these so-called cad programs cannot generate even the most basic 
gcode.  And if you have to hand translate its printouts into gcode, you 
may as well write the gcode to do the job in the first place. First, 
your gcode is 10-5000 times more compact, I have it doing 10 holes in 
the needed pattern in under 90 LOC right now, probably under 150 LOC 
when its ready to be actually carved into the alu back panel of this 
box.

> Someone described how they'd instead used hand-coded PostScript
> (which is in essence a set of drawing commands, normally sent to a
> laser printer) to draw plans for house changes.
>
Never tried that. but my customer is a cnc controlled milling machine. 
Not a printer. This process is subtractive, not additive.

I couldn't get to sleep, so I've been up writing gcode since bout 4am 
local, and have about 75% of it done and working, with the rest being a 
matter of getting some measurements from my as built box so far, and 
setting up 2 more of LCNC's 10 available co-ordinate maps to place an 
already written dsub connector pattern in the correct 2 locations.  Then 
I screw the panel to a piece of sacrificial wood and hit r on the 
keyboard and go take a nap. gcode may look like magic, but its quite 
straight forward once its understood. Then one more hole, for a packing 
gland to restrain the line cord, and I'm done. But not till it gets here 
next week so I can measure what size hole it needs. Might as well do it 
all in one pass.

> Something like that might be easier to get to grips with.   A /big/
> advantage of using scripts is that one gets to place comments in
> the script explaining what's going on, why one did something in a
> particular way etc.
>
gcode allows that.

> Also scripts easily allow parameterisation of values - eg (for the
> house plans) what the thickness of a piece of timber is, or what
> the spacing between regular items should be.

gcode can do that. Also has if/else/endif/while/endwhile/repeat etc 
language constructs. And subroutines. Cuts threads at any tpi or tpmm. 
Imperial or metric, no gears limiting what you can do as the coupling 
between the spindle and the workpiece is electronically geared together 
to submicron accuracy. Whats not to like other than cleaning up the mess 
as its made?

-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>

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#203124

Gene writes:
> Thats a huge part of the problem, but theres another fence to
> jump. most of these so-called cad programs cannot generate even the
> most basic gcode.

I can see not wanting to learn even a small part of a CAD program if all
you want to do is draw a simple floor plan and then never use it again,
but doing CNC without CAD is baffling.

Freecad can produce gcode which you can inspect and modify.  The
post-processor can be customized for your particular machine.
Solvespace can also output gcode.  I have no idea how good the gcode
produced by either of these programs is because I have no way to use it.

The major feature of these CAD programs is the constraint solver, which
understands geometry and does a huge amount of work for you.  You can
draw a part with dozens of equally spaced holes, change the length of
the part, and the holes will move appropriately.  Draw an angle bracket
with a brace, change the angle, and either the bracket length or
position will adjust appropriately depending on how you constrained it.
Draw a gear specifying pitch and tooth count and the diameter will be
computed. Change the pitch or tooth count and the diameter will
change. The diameter will only change by a commensurate amount: no need
for you to calculate allowable dimensions (unless you want
fractional-tooth gears).

You can also do assemblies and specify constraints between assemblies so
that a change in one part will cause appropriate changes to others.
Interferences that would result in two objects occupying the same space
won't happen.  You can animate assemblies and watch the machine run.  No
more making cardboard models of linkages and then having to stick to the
tested ratios.

There are also lots of contributed macros and add-on toolbenches for
Freecad.

-- 
John Hasler 
jhasler@newsguy.com
Elmwood, WI USA

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#203149

On 07.12.18 09:17, John Hasler wrote:
> Gene writes:
> > Thats a huge part of the problem, but theres another fence to
> > jump. most of these so-called cad programs cannot generate even the
> > most basic gcode.
> 
> I can see not wanting to learn even a small part of a CAD program if all
> you want to do is draw a simple floor plan and then never use it again,
> but doing CNC without CAD is baffling.
> 
> Freecad can produce gcode which you can inspect and modify.  The
> post-processor can be customized for your particular machine.
> Solvespace can also output gcode.  I have no idea how good the gcode
> produced by either of these programs is because I have no way to use it.

Gene would have no trouble tweaking that if it was in the ballpark,
after his years of writing the stuff from scratch. (Although
auto-generated gcode will be a bit primitive, with a lot of data points,
rather than a few optimised functions.)

While I'm the one who did the 8 house plan drawings in Postscript, I
wouldn't advocate that path for CAD for CNC. OK, Postscript can "print"
text to stdout in addition to its drawing operations, so it could spit
out gcode equivalent to what is drawn for inspection, _but_ you'd have
to hand knit the gcode to be generated by each of your hand knitted
drawing functions. After a couple of months of development you'd have a
nifty library available for re-use, but it's quite a hike to get there.

> The major feature of these CAD programs is the constraint solver, which
> understands geometry and does a huge amount of work for you.  You can
> draw a part with dozens of equally spaced holes, change the length of
> the part, and the holes will move appropriately.  Draw an angle bracket
> with a brace, change the angle, and either the bracket length or
> position will adjust appropriately depending on how you constrained it.
> Draw a gear specifying pitch and tooth count and the diameter will be
> computed. Change the pitch or tooth count and the diameter will
> change. The diameter will only change by a commensurate amount: no need
> for you to calculate allowable dimensions (unless you want
> fractional-tooth gears).

If moved to try that in Postscript, you'd have to program the
computations, and therefore decide in advance what would be
auto-adjusted, e.g. input gear pitch and tooth count, then diameter will
result. (While tolerances may appear on a drawing, gcode specifies a
precise toolpath, and it's up to the machine to do its best to follow
that. LinuxCNC will issue a "following error" and stop if it can't meet
run-time tolerance specs.)

> You can also do assemblies and specify constraints between assemblies so
> that a change in one part will cause appropriate changes to others.
> Interferences that would result in two objects occupying the same space
> won't happen.  You can animate assemblies and watch the machine run.  No
> more making cardboard models of linkages and then having to stick to the
> tested ratios.

Hmmm ... D for design, not just drawing. Powerfully tempting, if I ever
have to do more than shuffle bits of house plans around on a sheet.
(There the human utility, convenience, and comfort considerations, and
even building regulations aren't amenable to automation, so drawing
suffices, I found.)

Sounds like Gene's bitten the bullet and done the job with what he has,
by the sound of it. That's never a wrong move when it works.

Erik
(Who's gone owner-builder (swore I wouldn't do that again), and is
currently too flat out to look at Freecad.)

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#203152

On Friday 07 December 2018 20:54:44 Erik Christiansen wrote:

> On 07.12.18 09:17, John Hasler wrote:
> > Gene writes:
> > > Thats a huge part of the problem, but theres another fence to
> > > jump. most of these so-called cad programs cannot generate even
> > > the most basic gcode.
> >
> > I can see not wanting to learn even a small part of a CAD program if
> > all you want to do is draw a simple floor plan and then never use it
> > again, but doing CNC without CAD is baffling.
> >
> > Freecad can produce gcode which you can inspect and modify.  The
> > post-processor can be customized for your particular machine.
> > Solvespace can also output gcode.  I have no idea how good the gcode
> > produced by either of these programs is because I have no way to use
> > it.
>
> Gene would have no trouble tweaking that if it was in the ballpark,
> after his years of writing the stuff from scratch. (Although
> auto-generated gcode will be a bit primitive, with a lot of data
> points, rather than a few optimised functions.)
>
> While I'm the one who did the 8 house plan drawings in Postscript, I
> wouldn't advocate that path for CAD for CNC. OK, Postscript can
> "print" text to stdout in addition to its drawing operations, so it
> could spit out gcode equivalent to what is drawn for inspection, _but_
> you'd have to hand knit the gcode to be generated by each of your hand
> knitted drawing functions. After a couple of months of development
> you'd have a nifty library available for re-use, but it's quite a hike
> to get there.
>
> > The major feature of these CAD programs is the constraint solver,
> > which understands geometry and does a huge amount of work for you. 
> > You can draw a part with dozens of equally spaced holes, change the
> > length of the part, and the holes will move appropriately.  Draw an
> > angle bracket with a brace, change the angle, and either the bracket
> > length or position will adjust appropriately depending on how you
> > constrained it. Draw a gear specifying pitch and tooth count and the
> > diameter will be computed. Change the pitch or tooth count and the
> > diameter will change. The diameter will only change by a
> > commensurate amount: no need for you to calculate allowable
> > dimensions (unless you want
> > fractional-tooth gears).
>
> If moved to try that in Postscript, you'd have to program the
> computations, and therefore decide in advance what would be
> auto-adjusted, e.g. input gear pitch and tooth count, then diameter
> will result. (While tolerances may appear on a drawing, gcode
> specifies a precise toolpath, and it's up to the machine to do its
> best to follow that. LinuxCNC will issue a "following error" and stop
> if it can't meet run-time tolerance specs.)
>
> > You can also do assemblies and specify constraints between
> > assemblies so that a change in one part will cause appropriate
> > changes to others. Interferences that would result in two objects
> > occupying the same space won't happen.  You can animate assemblies
> > and watch the machine run.  No more making cardboard models of
> > linkages and then having to stick to the tested ratios.
>
> Hmmm ... D for design, not just drawing. Powerfully tempting, if I
> ever have to do more than shuffle bits of house plans around on a
> sheet. (There the human utility, convenience, and comfort
> considerations, and even building regulations aren't amenable to
> automation, so drawing suffices, I found.)
>
> Sounds like Gene's bitten the bullet and done the job with what he
> has, by the sound of it. That's never a wrong move when it works.
>
> Erik

Thanks for the flowers Erik. What would probably amaze all the"papered" 
folks on some of these lists is that I am a C.E.T., and carry a long 
expired 1st Phone (because the commission thru us all under the bus 20 
years ago by downgrading the license and makeing the new one lifetime) I 
have a GED too, but I quit school in the high school freshman year to go 
to work fixing the then new fangled things called tv's, then switched to 
broadcasting in late 62, and have accumulated 23+ years as the Chief 
Engineer of a tv station, all on an 8th grade education. I was a "nerd" 
before the word was invented I think. I had the great good fortune to 
have a mother who was somewhat technical, the only girl in the 1929 
class on aviation technology at the Des Moines IA technical high school. 
If a little boy asked a question she did not know the answer to, she did 
know where the library was, so along with the McGuffy's readers, I was 
also reading high school physics textbooks by the age of 7.

But now I'm an old fart of 84, playing nursemaid/housekeeper to my 3rd 
wife of 29 years last week, she is late stage COPD. And harassing these 
email lists. Keeps me connected to the world, and outta the bars 
don'tcha know. :)

> (Who's gone owner-builder (swore I wouldn't do that again), and is
> currently too flat out to look at Freecad.)

Take care Erik, you are at times one of my teachers. :)

-- 
Cheers, Gene Heskett
--
"There are four boxes to be used in defense of liberty:
 soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
Genes Web page <http://geneslinuxbox.net:6309/gene>

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#203154

A caveat about Freecad: weird units.  Always select "Imperial", not "US
Customary" if you want to use inches.  They are European and added "US
Customary" at my behest, but screwed it up (deliberately, I suspect) by
having it jump to feet and inches when you go over 12 inches and to
yards, feet, and inches when over 3 feet.  The only way to get
everything in inches and decimal fractions thereof is to select
"Imperial".

Freecad has better documentation than Solvespace IMHO.
-- 
John Hasler 
jhasler@newsguy.com
Elmwood, WI USA

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#203121

> Something like that might be easier to get to grips with.   A /big/
> advantage of using scripts is that one gets to place comments in 
> the script explaining what's going on, why one did something in a
> particular way etc.

Both Solvespace and Freecad allow comments.  Both support 2D
drawing. Freecad has extensive support for scripting in Python.

> Also scripts easily allow parameterisation of values - eg (for the 
> house plans) what the thickness of a piece of timber is, or what 
> the spacing between regular items should be.

These are key features of any CAD program.
-- 
John Hasler 
jhasler@newsguy.com
Elmwood, WI USA

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