gEDA-user: Board fabrication

[phil at plastitar.com]

John Griessen wrote:
> What if we made a via shape for ease of non-automated drilling, (for 
> prototyping)?   I think a concentric circle of copper to aim the drill 
> bit in and keep it from walking away from the center of the larger via 
> or mounting hole would be helpful.

I've used small vias w/ blown-up pads to center drill holes.  you have 
to drill some copper, but using hs drills it doesn't seems to be a problem.

Luciani has an approach to this and a lot of his parts have a cross for 
drill alignment of bigger holes.  I have worked on some old electronics 
that were hand-built and it's clear that they center punched on crosses 
to get drills lined up.

Nice as it sounds, I don't think pcb will let you put a via inside a via 
and still generate output.

phil