The CNC Mill (Heavy Duty) consists of a milling table, a headstock carrying the spindle motor, and a cast-iron vertical column with dovetail slide. Two ball screws, each driven by a stepper motor, are used to move the table along the X axis (left and right) and Y axis (backward and forward) to feed the stock through the periphery of the end mill. A third ball screw, also driven by a stepper motor, is used to move the headstock along the Z axis (up and down) for positioning the end mill. The speed of each stepper motor can be programmed separately for feed rates up to 508 mm/min (20 in/min).