Make your own PCB Mechanical Routing/Erosion/Milling Machine at a low cost.
PCB Mill - Jonathan Ward - MIT
"Design a low cost circuit board milling machine optimized to be mass-produced."
Low Cost PCB Mill lan Moyer
The overall device has a working area of 4" x 6" with a footprint roughly the size of a letter-sized sheet of paper. Capstan drives were chosen for their simplicity and low cost, and also serve as torque limiters to prevent excessive loads on the small-diameter drive cables.