Homebrew PCBs

If I understand the problem correctly...

An easier solution might be to map out the distortion using something like
grid paper and use a clear stencil for "cross-hair" like grid lines.


On Thu, Jun 9, 2011 at 4:30 PM, Leon Heller <leon355@...> wrote:

>
>
> On 09/06/2011 20:51, Boman33 wrote:
> > A very long time ago commercial hand drilling was done with the drill
> > mounted under a table and a microscope with cross hairs was used on the
> top.
> > The drill was on an air cylinder so when things were lined up a
> footswitch
> > was pushed. No parallax. A similar rig was also used to create a NC paper
> > tape so additional boards could be drill automatically.
>
> They had one of those at a French university where a friend of mine
> works. I tried it out when I was working there, and it works very well.
> They got rid of it when they closed down their in-house PCB fabrication
> facility. It was made by Excellon, who invented the drill file format
> that we still use. Someone in the UK actually offered me one of those
> machines three or four years ago, but I wouldn't be able to get it up
> the stairs here.
>
> Leon
> --
> Leon Heller
> G1HSM
>
>  
>


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