A 4- or 5-axis machining centre has one or two rotary axes in addition to the three linear axes X, Y, and Z. Depending on the machine and its kinematics, this can be the A-, B-, or C-axis. This axis configuration is defined in the standard DIN*66217. Every rotary axis is assigned to a linear axis. The A-axis turns around the X-axis, the B-axis turns around the Y-axis and the C-axis turns around the Z-axis.
In Figure 1 the axis configuration in accordance with DIN*66217 and the “right hand principle” are displayed. If you hold your right hand in front of your face like in the picture, then the Z-axis is seen from the front (middle finger). This is how the axis configuration can be best remembered.
Figure 1: Coordinate system in accordance with DIN 66217
In Figure 1 the axis configuration in accordance with DIN*66217 and the “right hand principle” are displayed. If you hold your right hand in front of your face like in the picture, then the Z-axis is seen from the front (middle finger). This is how the axis configuration can be best remembered.

Figure 1: Coordinate system in accordance with DIN 66217