Homebrew PCBs

Hi Tony!

Yes, surprise, surprise!  To do the outlines from a Gerber file, I build
a table of nodes (typically the pads), and add connection data to each
entry.  the connection data is the number of the pad to connect to, and
the trace width to use.  Other data in the node is the location of the
node, size/type of pad, an the parent pad. 

I then "transverse" the "nets" of the list, and output (for now) PLC
code (point, line, circle for Vector) for each arc or line segment
needed to draw a net.  Each net must go completely around all pads and
traces that are connected together in a net.  

Well, it's working, at least for SIMPLE layouts.  No funny "stacks" of
multiple traces on top on one another.  Just the simple stuff.

PLC's for now, which quickly allows me to "see" the completed nets,
later it's an easy step to generate gcode instead.  It's just as if you
"traced" all around a net.  It's been a challenging program to write!

I started off thinking I could generate the outlines of the pads and
traces in Vector CAD/CAM, but anything more then a couple of pads and
traces was either too much for it, or required too much manual selection
to make it work.  I have wanted to do this kind of program since I got
my first IBM PC.

Sounds like you're doing a "flood fill" approach.  That would remove ALL
the unwanted copper.  It could work, however the work I've seen has been
outlines.  Eagle can do the outlines, but as I said, I've always wanted
to do this program!

Dolphin sounds interesting, but I'd hate to spend the time (and money)
to learn it, since I'm already using Vector.  The free 4-th axis does
sound interesting!

Alan  KM6VV

Tony Jeffree wrote:
> 
> Hi Alan -
> 
> We meet again ;-)
> 
> I will be interested to hear how you get on - strikes me that generating an
> outline from Gerber is potentially non-trivial. Would love to make use of
> any results you generate though!
> 
> Am also looking at the possibility of using DXF track layout output &
> importing that into Dolphin, then treating the tracks as a series of
> "islands" for an area clear. Might just work, depending on how smart
> Dolphin proves to be, but doing it that way may prove rather (mill) time
> consuming compared with the outline approach.  Waiting for the CD to
> arrive... <sound of drumming fingers...>
> 
> Regards,
> Tony