>
>It would certainly be possible, probably easiest to use a dot. Find
>a cheap surplus low power HeNe laser tube. Gas lasers have far
>better beam quality than diode lasers, and get a nice glass
>collimating lens and use that to adjust the focus to a tiny spot.
>
>Friend of a friend made a PCB drill with a laser pointing down from
>the top, then a foot pedal makes the drill bit poke up from the
>bottom. I just eyeball it with the little drill press I made but it
>is difficult tell where the bit is in more than one dimension before
>you plunge. It's so small and close up that depth perception is tricky.
>
Very nice solution, and an obvious (now that it's pointed out) way to
go. A bottom drill with a camera sight, a modified microscope stage
to hold the board and you're done! Of course, it would be just as
logical to put the camera on the bottom and the drill on top. Just
have to maybe use a little vacuum to stop the drill debris from
covering the lens. Might be a little more cumbersome than a bottom
drill because you would be completely dependent on the monitor, but
still should work well and be easy to implement.
Mark