Homebrew_PCBs

Hi Alan,
The Tit4Tat can run relays, stepping motors etc. It has
lots of outputs and several inputs. These type boards are used by
budding programers. Rather than just do a simple PCB layout I went
for making ARTWORK. In the old days the PCB traces were called
ARTWORK. When ICs came out the boards got ugly!
If you pull my DXF up in a Cad program using a .0125 Grid you
will see how I draw the traces and pads. I use a Mechanical Etching
bit from Think and Tinker. I put a picture of it in the KLEINBAUER
folder. I got the Piker 4x4 working but I am bogging down on the
rework. I am taking out extra cuts. Selling boards has become a real
mistake! There are so many people doing it. Like a fool I listened to
someone. Now I see there is a nice 3 axis controller board for only
$40 (Bare) L297/L289. My strength is in designing cheap CNC machines.
I was told to listen to my customers, bad idea.


John

--- In Homebrew_PCBs@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> Hi John,
>
> I sent a copy to Dave, and I've been to his site per a previous
> reference you made to him (His Mill Clone).
>
> I have ran the Gcode script with Eagle, "isolation" or "outlines" I
> think it's called. Yes, that provides a drop-in solution. My
intent
> was my own edification, and also to be able to take a Gerber file
from
> any PCB package (I had a friend with similar requirements say they
tried
> it, and ended up buying another product). The DXF output would
also be
> a place to start. I wasn't able to get Vector CAD/CAM to do
offsets to
> ALL my traces and pads automatically (from a DXF I imported to
Vector),
> so didn't go that way.
>
> I played with TCi last night, WOW! What fun! I laid down 6 pads
and a
> few traces, stored the Gerber file, and ran it through my code.
Instant
> success! So there is a possible "quick and dirty" way to generate
> simple board part programs. While this is too simple a board (not
> representative), it does demonstrate (prove) the concept.
>
> The "body" of the Gerber file generated was 6 blocks for my 6 pads
> (D03), and 24 blocks for my 12 traces (D02). I generated a 54 line
> Gcode program (using Vector CAD/CAM), which included 14 blocks for
the
> "rapids" needed. The program also included 8 blocks were arc's.
32 of
> the blocks were G01 cuts. Again, this is too simple a design to
> determine much, but it's not bad!
>
> TSP? Too simple to tell, but I think Vector CAD/CAM helped on
that. I
> do COMPLETE isolations of each net (pads and traces connected
together),
> and don't attempt to minimize cuts by "sharing" between adjacent
> traces. That's an interesting idea, however, and I have gathered
from
> your tit-for-tat board that adjacent traces an pads SHOULD share the
> same isolation (although I'll continue to cut them twice).
>
> Speaking of your posted board, what's on it? I see a DB25, a pair
of
> 14-pin packages (open collector buffers, I suspect), pads for
output,
> and pads which I'd assume are for pull-up resistors and bypass
caps. I
> didn't find the board on your web site, do you still offer it? I'd
be
> curious to see the corresponding schematic. I doubt if I'll be
building
> it, but it would be a nice small test. I'm thinking of "laying it
out"
> with TCi, and maybe Eagle also, to see how it plots out!
>
> Your isolation cuts for small pad's measure .1" I believe, and the
> larger ones are .15". What dia's are you calling out for them?
Also
> the trace cuts are .05", what is their width? What tool dia do you
use?
>
> How are you optimizing your rapids (TSP)? I suppose I could add
code to
> my controller software to report the total length of rapids and cuts
> (arc's?), and that would give me an idea. Also, I believe Vector
> CAD/CAM can report the "time" for a part file. That might result in
> some useful data.
>
> Are you doing a drill file, like Epsilon? What format? I'd like to
> take a look at it.
>
> Alan KM6VV
>
>
> crankorgan wrote:
> >
> > Alan,
> > Two things! Run this past Dave Kush at:
> >
> > http://www.calweb.com/users/d/dnjinca/
> >
> > Also, have you played with the SCRIPTS that are in
> > Eagle. There is one there to turn a PCB drawing into a DXF. In
> > the Cad_Cam conference there used to be a script that made
> > a PCB drawing into GCode. I only played with the DXF one. I
> > abandoned Eagle because of the Traveling Salseman Syndrome.
> > Someone showed me how to use ACE to fix my drawing. I think
> > you use Vector.
> >
> > John
> >
> > --- In Homebrew_PCBs@y..., Alan Marconett KM6VV <KM6VV@a...>
wrote:
> > > Hi to the Lists,
> > >
> > > I generated this demo RS-274X (Gerber) file header from Tci, a
> > French
> > > PCB program (pardon my french). I've had some of the parms
> > explained
> > > before, and I have the Gerber spec, so I have some Idea of their
> > use.
> > > What's not obvious to me is how they expect one to go about
parsing
> > it.
> > > I know it's in MM. The '*' are always end-of-block, which is
> > fine. I
> > > see '%' characters bracketing SOME of the blocks, but some at
start
> > and
> > > some at end (suggests several blocks are "together"?). And This
> > header
> > > seems to use G04 (delay) as a comment?
> > >
> > > I have a parser for Gcode, but this header stuff doesn't fit too
> > good
> > > (parser wise)!
> > >
> > > It looks like "ADD 10 C 0.318" (spaces added) sets aperture #10
to a
> > > circular pad, and "ADD 11 C 1.588 X 0.2" is for the traces. I
can
> > work
> > > through it from the CAD PCB layout to get the numbers right, But
> > this
> > > all seems rather haphazard, IMO.
> > >
> > > Any comments?
> > >
> > > G04 format : xxx.xxx unité : millimètre *
> > > %FSLAX33Y33*
> > > MOMM*
> > > OFA0B0*
> > > SFA1B1*
> > > IPPOS*%
> > > G04 définition des ouvertures pour les pistes *
> > > %ADD10C,0.318*%
> > > G04 définition des ouvertures pour les pastilles rondes *
> > > %ADD11C,1.588X0.2*%
> > > G04 tracé du CI *
> > >
> > > Alan KM6VV