How Does a 5 Axis CNC Machine Work?

5-axis CNC machining describes a numerically-controlled computerized manufacturing system that adds to the traditional machine tool’s 3-axis linear motions (X, Y, Z) two rotational axes to provide the machine tool access to five out of six-part sides in a single operation. By adding a tilting, rotating work holding fixture (or trunnion) to the work table, the mill becomes what is called a 3+2, or an indexed or positional, machine, enabling the milling cutter to approach five out of six sides of a prismatic workpiece at 90° without an operator having to reset the workpiece.

It is not quite a 5-axis mill, however, because the fourth and fifth axes do not move during machining operations. Adding servomotors to the additional axes, plus the computerized control for them – the CNC part –would make it one. Such a machine- which is capable of full simultaneous contouring- is sometimes called a “continuous” or “simultaneous” 5-axis CNC mill. The two additional axes can also be incorporated at the machining head, or split – one axis on the table and one on the head.