Re: Gerber to G-code

--- In CAD_CAM_EDM_DRO@y..., Jon Elson <elson@p...> wrote:

> marble_h wrote:
>
> > I think A while back there was some mention of Gerber
> > to G-code is there a program that will do the change
> > yet if so can some one post the web address .
>
> Gerber IS "G-code", officially RS-274D. It is a very
> wierd dialect, for sure, but it IS, in fact, G-code.
>
> Jon

All:

Two comments:

1)

Jon is correct. The Gerber file format used to
describe printed circuit boards is the RS-274X
dialect of RS-274D. The specification can be
found at:

http://www.barco.com/ets/data/rs274xc.pdf

(I believe that Barco purchased Gerber.)

Basically, Gerber started by selling a device called a
photoplotter. This is basically a plotter that uses
light and optics to paint images directly onto film.
I don't think anybody actually uses photoplotters anymore,
but the file format persists. If you understand how a
photoplotter works, you can figure out what is going
on with Gerber files.

There is something called an aperture wheel that contains
various squares, circles and what not. Using the appropriate
code, you select an aperture. (This very similar to selecting
a tool.) Next, you can turn on a light bulb that shines
through the aperture. If you want a square pad, you can
select a square aperture and flash the light to "print"
the sqaure onto the film. If you want to draw a line,
you can select a round aperture, turn the light on, and
"draw" a line. And so on.

The RS-274X variant, provides additional syntax for
specifying what shapes are on the aperture wheel.
Read the specification if you want dig in some more.

2)

There is some software out there that takes RS-274X
as input and generates standard G-codes for doing
printed circuit board mechanical etching. Basically
this code figures out what the outline of each circuit
trace is and generates standard G-codes to cut the
outline of each trace.

Companies like LPKF:

http://www.lpkf.de/

sell both the hardware and software to mechanically
etch printed circuit boards. If you want to see
some truly impressive mechanical etching, please take
a look at:

http://lpkf.herrlich-ramuschkat.de/artikel/view/examples.html

-Wayne