GRBLshield CNC Milling Machine Conversion
Milling machine CNC conversion built around an GRBLshield from Synthetos.com. The GRBLshield is an Arduino shield that can drive three bipolar stepper motors up to 2.5 amps per phase, and contains an open source G-code interpreter called GRBL. Stream G-code over USB to the GRBLshield, and you’re in business. source