Re: Re: Hobbyists strike again

Jon,
Interesting about the RS-274D standards, I had not idea.. So I wonder if
I convert the Gerber to g-code if it can mill as fine as I can etch (5
mil) without tearing the copper.

Some people do not like chemicals, and I understand that, but it's only
Ferric Chloride that's needed to etch the boards. For exposing the pre
sensitized PCB I use a Grow light reflector bulb at 6 inches for 75
seconds and develop using a mixture of Red Devil Lye which costs all of
$1.0 . mix about 10-15 grams into quart of water.. The Lye can be reused
many times... Ferric chloride can be purchased at your favorite radio
shack for about $4.- , My ferric chloride is about 4 years old and has
been "topped up" a couple of times, I'm still getting 8-10 minutes etch
time.

There's one more problem with milling PCB's and that is the requirement
to hold the board flat....vacuum is one solution, but requires all sort
of paraphernalia. !

I'll post my Excellon to g-code converter and rotation program at my web
site, as soon as I'm happy with the optimization.

regards
Hans Wedemeyer

Jon Elson wrote:

> hansw wrote:
>
> > As far as drilling, PIA exports Excellon drill files, they look a
> lot
> > like g-code except the measurements are not in decimal inches.
> > Here's a sample of Excellon
> > M48
> > INCH,LZ
> > T01F00S00C0.037
> > %
> > G90
> > T01
> > X+05188Y+02901
> > X+04588Y+02901
> > May be there's a way to use these directly with a regular g-code
> driven
> > mill,
>
> Well, there are many variants of G-code. Excellon IS, in fact, a
> permissible variant of RS-274D. It is no decimal point, TRAILING
> zero suppressed, and with a drilling canned cycle active.
>
> And, just to keep things interesting, the Gerber plot files are
> ALSO RS-274D, but no decimal point, LEADING zero suppressed,
> and using D01, D02, D03 for move, flash and draw functions.
>
> Both of these are archaic, obsolete forms of G code. But, once you've
> built a general purpose interpreter for these forms, it is pretty easy
> to write format converters and similar things.
>
> Jon
>
>
> ------------------------------------------------------------------------
> Welcome to CAD_CAM_EDM_DRO@...,an unmoderated list for the
> discussion of shop built systems in the above catagories.
> To Unsubscribe, read archives, change to or from digest.
> Go to: http://www.onelist.com/isregistered.cgi
> Log on, and you will go to Member Center, and you can make changes
> there.
> For the FAQ, go to http://www.ktmarketing.com/faq.html
> bill,
> List Manager
>
> ----------------------------------------------------------------
> [Image]
> Click Here
>