wrote:

A fair bit back, Jim Rozen described a drill press for Printed Circuit
Boards that sounded like a good design. A microscope with a cross hair
to align the board, and a drill that comes up from the other side to
drill the hole.


Here's what I do. http://pico-systems.com/wwspndl.html

Of course, I was incredibly lucky to get these Westwind air bearing
spindles.
The guy who sold them to me had no idea that bad units carried a $6000
core charge with the rebuilders! (Maybe a rebuild is $6000 with return
of the
core, I'm not sure anymore.)

I made a bracket to clamp it to the spindle of my Bridgeport. I have
successfuly
drilled boards with .018" drills. I can't drill a stack of two boards
at that size,
however. This blind drilling allows me to use backup material and entry
material,
so I get minimum ridges around the holes. I use blank (no copper) PCB
material
as the back-up, and .010" aluminum roof flashing as the entry material.
I align
pre-etched boards without the entry material first, then insert the
entry material
under the clamps on one side first, then the other, so that the board
can't move.

I also pre-drill the blank boards, then laminate the resist and expose
and etch.
That way I don't have to fool around with the aligning on the mill.
But, I can't
have pre-laminated board blanks at the ready, either.

I make master artwork for exposing the resist with my laser photoplotter
http://pico-systems.com/photoplot.html (Ugh, GOT to make new photos
of this project!)

Before all this automation, I had a hand-steered drill with a pedal to
stroke the
bit. It worked pretty well, too. Really no need for a microscope.

Jon