This is done on our gantry mill.

http://www.electronicsam.com/images/KandT/cbottom.JPG
http://www.electronicsam.com/images/KandT/ctop.JPG
(The reason the holes don't line up towards the top of the of the circuit board (ctop.jpg) is we had not squared the gantry at that point)

Emc2 as the machine control. http://www.linuxcnc.org/
Using a "rotozip" as the spindle.
Eagle pcb software. http://www.cadsoft.de/
Pcb-Gcode http://groups.yahoo.com/group/pcb-gc...guid=148844392
engraving bits from here. http://thinktink.com/stack/volumes/v...e/mechmill.htm

The board was held down by a wood top vaccum box.

over all very powerfull.

sam