Quantity   Component name
1 × Raspberry Pi The primary controller and interface
1 × Arduino Uno
1 × Arduino CNC Shield http://blog.protoneer.co.nz/arduino-cnc-shield/
4 × DRV8825 Pololu driver modules https://www.pololu.com/product/2133
1 × Defunct LPKF Protomat C40 As long as the motors work and the gantry moves correctly, you're in business!