Re: gEDA-user: Finished drawing two sided board in PCB. Any comment?

[sdb@xxxxxxxxxx (Stuart Brorson)]

Hi DJ --

Of course, I am not intending to criticize the outstanding work you've
been doing on PCB!

> 
> > The problem is that PCB has autogenerated your board outline in the
> > fab drawing assuming that it is the rectanglular drawing area.  PCB
> > developers: this is a misfeature, IMHO.
> 
> If the user doesn't create an outline layer, we really don't have
> anything else to go by.

In the fab drawing (foo_fab.gbr) the board outline and dimensions are
called out.  Please refer to Vax 9000's posted Gerbers to see what I
mean.  Of course, my head might be wedged abou this issue . . . . . .

The problem then is that if the user supplies a separate outline layer
(foo_outline.gbr), there are two contradictory pieces of information
in the design package.  As a consequence of Murphy's law, if there are
two contradictory pieces of info in any design package, one correct
and one incorrect, the fine folks in manufacturing will *always* chose
to fabricate based upon the incorrect instruction.

> 
> > In commerical tools, you would have a separate layer calling out the
> > board outline.  For PCB, you probably need to put a manual instruction
> > somewhere for the fab house to route the boad along the silkscreen
> > outline.
> 
> No, we have an outline layer also.  Maybe we need to *default* to
> having one of the layers named "outline"?  But then people will think
> we support less than 8 copper layers in rectangular boards.  Sigh.
> Time for the >8 layer patch.

Yeah, maybe naming one of the unused layers "outline" would be a good
idea.  It would help birdbrains like me remember to draw the board
outline unambiguously.

Stuart