Computer Numerical Control (CNC) machines are used to shape metal parts by milling, boring, cutting, drilling, and grinding. A CNC machine generally consists of a computer-controlled servo-amplifier, servo-motors, spindle motor, and various tooling. The machine can be programmed to shape a part by use of a front control panel. More sophisticated models allow a CAD drawing to be uploaded to the machine. The electronic components within a CNC machine are particularly sensitive to the grounding techniques used in the electrical supply to the machine. Malfunction,