Overview

What do you picture when you see the words standard 5-axis machine? Many industry buzzwords are used when describing 5-axis machines. Some of them include: staggered guide-ways, constant dynamic control, digital AC servo motors with pre-tensioned ball-screws, permanent positioning monitoring system, maximum utilization layout, long-term accuracy, and so on. To simplify things, we will say that there are three major building blocks to these types of machines.

1. The physical properties of the machine

   The physical properties of the machine describe the way the axes are stacked, the rigidity and flexibility of the iron, the horsepower, torque, and maximum RPM of the spindle motor, the quality and workmanship of the guides/slides, and the rotary bearings.

2. The CNC drive system

   The drive system is the muscles or the components that make the machine slides and spindles move. The system includes the servo motors, drive system, ball screws, the way positioning is controlled and monitored, and the rapid-traverse and feed capabilities.

3. CNC controller capabilities

   The controller is the brain of the machine. Data handling, available on-board memory size, and dynamic rotary synchronization controls, are some of the things controlled here.

The perfect combination of the above characteristics will build a fast, accurate, easy-to-program and operate, 5-axis CNC milling machine. Many manufacturers have spent many years trying to come up with the perfect combination, and as a result there are many variations and solutions.

The illustrations in Figure 2-1 show some of the variety that exists in the machines that...