The Advantages of 5-Axis CNC Machining

CNC (computer numerical control) Machining is a means to remove material using high-speed, precision machines that use a wide variety of cutting tools to create the final design. A 5 axis machine has two more axes than the historically more common 3-axis machine. “5 axis” means that the cutting tool can access the part in 5 directions instead of 3, allowing for more movement and rotation. 5 axis platforms are achieved by adding tilt and rotation to either the work holding platform or the tool spindle itself. With a 5th axis, machinists can machine up to 5 faces in just one operation, making the process both highly precise and efficient.

Traditional CNC machines move in three linear axes (X, Y, and Z). Five-axis machines move in all three linear axes plus two additional rotary axes. The ability to precisely move the work piece without removing it has distinct advantages over conventional three-axis machining. Here are advantages of five-axis CNC machining: 1. Complex Shapes The major (and most well-known) advantage of five-axis machining is ability to machine complex shapes. The additional movement creates machining angles and arcs that were only previously possible with a multitude of special fixtures or additional setups. 2. Fewer Setups Five-axis machines can machine nearly every visible surface, excluding the bottom or clamping area. This breadth of ability significantly reduces the need for multiple setups or special fixtures. Of course, another big benefit of fewer (or ideally one) setup is… 3. Relational Accuracy Imprecision finds a way to seep in with every setup change. Once a part comes out of the machine, precise alignment is lost. By using the same “zero” or “home” location, feature-to-feature accuracy is improved. 4. 3+2 Axis Machining There are parts that can only be machined with simultaneous 5-axis movement. Then there are parts that are more efficiently machined with 3+2 movement. In 3+2 machining, the fourth and fifth axes are used to locate the work piece (or cutting tool, depending on the type of machine) in a fixed position. In these scenarios, there is no need for all five-axes to move simultaneously.

Continuous 5-axis CNC milling systems have a similar machine architecture to indexed 5-axis CNC milling machines. They allow, however, for the movement of all five axes at the same time during all machining operations. This way, it is possible to produce parts with complex, ‘organic’ geometries that cannot be manufactured at the achieved level of accuracy with any other technology. These advanced capabilities come of course at a high cost, as both expensive machinery and highly-trained machinists are needed.