Was that called a Uni Drill and then they had a Quad....thats going back a
bit.


"Leon Heller" wrote in message
...
"Tim Killian" wrote in message
...


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.

Dust? Drilling PCBs makes lots of abrasive dust that will get into your
bottom motor spindle bearings. If the board is already etched, you don't
need a microscope or cross hairs to align the drill bit in the center of
the pads. The lack of copper in the middle of the pad will center the bit
automatically if the operator can get it reasonably close. And if you
need better accuracy than that, then CNC is the way to go (it doesn't
need the microscope or cross hairs either).

The old Excellon PCB drilling machines used a similar arrangement. They
had a projection microscope that displayed the pads on a ground glass
screen, with cross hairs. I'd be inclined to use a web cam for viewing the
pad.

Leon
--
Leon Heller, G1HSM
http://www.geocities.com/leon_heller