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