Homebrew PCBs

Hi Alan,
        Please note most people in the group will be using Kcam-
TurboCad or Eagle. You seem to have a handle on the situation. The
TCI program I got in the files section here I beleive. The program is 
in French?  After you draw the circuit board. Save it! Then hit 
Gerber! A Gerber file of the same name will appear in the directory 
where you save the board file.

        You mentioned circles that don't meet in my DXF file. Sounds
like a Ground Pad. On boards I sell to the public I outline a ground
connection for parts or wire on three sides. My new boards look like
cartoons. After I get the board working I go back and combine traces
with only a common border. Since a board is stuffed from the component
side I am taking out unnecessary cuts. My first boards were done this 
way. I can get two large boards per bit. Milling time is also cut in 
half.

       Just remember I try to keep things cheap and simple. 

                                           John



--- In Homebrew_PCBs@y..., Alan Marconett KM6VV <KM6VV@a...> wrote:
> Hi again John,
> 
> Not to beat a point to death (or belittle a fine product), but 
FREEWARE
> KCam might not be the best example of generating Gcode from a Gerber
> file!  And as you say, it's generating EIGHT SIDES (like you do), 
not a
> SINGLE ARC, as I've said can be done.
> 
> My program (actually just a FUNCTION in my controller program) is 
still
> quite LIMITED in  what it can do with a Gerber file 
(not "automatic" by
> any means), but I'd LOVE a new sample of Gerber of "real work".  
I've
> been able to do most of "DEMO1R" file that they supply.
> 
> I was not able to get KCam to read my Gerber files, so I know 
little of
> KCam.
> 
> Yes, the "Traveling Salesman Problem" affects all such machining, 
board
> stuffing, etc.  You are lucky in that you can "hand optimize" the 
order
> of your cuts.  I'll just import into Vector CAD/CAM, and let Vector 
do
> it for me.  Or I can select the closed "trace cuts" in the order I 
want
> (the trace cuts themselves will already be ordered properly).
> 
> That is until I decide that TSP's an interesting problem to solve, 
and
> apply it to my own code!  No rush!
> 
> I'd love to examine the Eagle (TCI3?) and/or Gerber files for your 
test,
> if you wouldn't mind.  What is TCI3?  TurboCad??  Is your file 
RS274X or
> RS274D?  'X' has a "header" in the file with all the aperture data,
> while 'D' usually has an additional file (wheel file) with the
> apertures.  Can you supply?
> 
> Thanks for your contributions to this list!
> 
> Alan  KM6VV
> 
> 
> crankorgan wrote:
> > 
> > Hi Group,
> >          I made a test pcb in TCI3. I saved it as a Gerber file. I
> > then put it in KCam. The round pads became eight sided shapes.
> > Forty-two pads became over 1000 lines of code. The Gcode drew the 
pads
> > in the same order I drew them in TCI3. So I suspect if you don't 
want
> > your machine to spend more time traveling than cutting you better
> > have a plan.
> >          I will admit I have very little experence with Gerber. 
But I
> > get the feeling the "Traveling Salesman Sydrome" is hiding there
> > also. Plotting out a PCBoard with a good PLT file is much faster 
than
> > a GCode file run on a homemade PCBMill. A Sherline or Taig 
running at
> > 10,000 rpm can only cut circuit boards at 5" per minute. So do a 
test
> > board before it is too late!
> > 
> > John