Homebrew PCBs

Stefan,

It's much easier to adapt a video camera than to build an optical 
scope from scratch. You only need about ten power magnification for 
drilling. Video resolution, even the cheap cameras, are good enough. 
At ten power your 60 mil pad is .6 inches and easily centered in the 
screen or video monitor. 

Most of these scope drill went to the dump years ago but there are 
still some around. Keep searching and you will find one for the right 
price. I know there are some Excellon UniDrills in England if that 
will help you. I think Micromat in England also made some sort of 
optical drill. It used an air motor spindle. 

Tom


--- In Homebrew_PCBs@yahoogroups.com, Stefan Trethan 
<stefan_trethan@g...> wrote:
> thank you for the description of the viewing mechanism.
> i was thinking about how it is made.
> 
> but i have one question:
> what advantage has video viewing? i cant find any.
> why should a video image - reduced in resolution etc. be superior 
to a full 
> optical system?
> is the light source to weak to produce a clear projection?
> 
> such a machine would be nice but i have absolutely no idea where to 
get it 
> here in austria.
> i didn't see at ebay any here. also it would be too expensive for 
my few 
> boards.
> 
> regards
> stefan