What Is 4 Axis CNC Router?Probably you know that 3 axis refers to axes of X, Y, and Z in the CNC field; Correspondingly, the 4-axis refers to axes of X, Y, Z, and A commonly, but sometimes A would be replaced by B-axis. Therefore, CNC Router with Axes of (X, Y, Z, A) or (X, Y, Z, B) is 4 axis cnc ro