Multi-axis CNC Machines
In addition to classifying the machines according to the type of function or working method, CNC machines are also classified according to the number of working axes. Once the type of CNC machine is determined, the specific equipment can be further segmented based on the number of axes. Multi-axis machining is a type of CNC machining that utilises multiple axes of movement in order to achieve complex geometries and tight tolerances.For instance, a CNC milling machine can come in a 3-axis, 4-axis, and 5-axis variant, and the price and capability of each will vary drastically. Below are some of the most popular types of CNC machines.
2 axis CNC machines are the most basic CNC systems out there. They contain two axes of movement – the X-axis (vertical axis) and the Y-axis (horizontal axis).These machines typically create simple straight-line cuts or drill holes on boards or machining of only a single surface of a workpiece without repositioning it. These machines work on a stationary workpiece.
3 axis CNC machines are the most common type of CNC machines. They have 3 axes of movement – the X, Y, and Z-axis (depth axis) and can machine the basic parts in 2.5 dimensions. They can work on all six surfaces of a typically square or rectangular block of material, but the block requires repositioning. These machines also work on a stationary workpiece.
4-axis CNC machines are similar to 3-axis machines. Besides the three axes – X, Y, and Z, a 4-axis machine also contains an axis of rotation. This axis allows the rotating cutting tool to move along the X-axis, known as the A-axis. The workpiece might also be moved along the same axis instead. These machines are ideal for making cutouts and cutting along an arc.
5-axis machining adds a pivoting motion of the cutting tool (or the work table) along the Y-axis. The axis of rotating and pivoting is called the C-axis. These machines can create intricate and accurate parts due to the ability to work on five surfaces of a workpiece simultaneously without repositioning the work surface.
A 6-axis CNC machine adds a third rotary direction to the cutting tool (or the workpiece), known as the B-axis. These machines can create shapes of any possible surface finish by involving all possible movement directions of the cutting tool and workpiece. These machines are typical in the medical, aerospace, and military industries for precision applications.
7-axis CNC machines have three traditional axes involving the movement of the cutting tool, three axes for rotating the workpiece, and a seventh axis that rotates the arm holding the cutting tool. This axis is called the E-axis. These machines often manufacture aerospace, medical, and military equipment due to the complexity of the parts they can produce.
9-axis CNC machines are a combined CNC setup of a 5-axis milling machine and a 4-axis lathe machine. The milling machine works on the surface to create the required surface finish, while the lathe completes the internal features of the workpiece. This way, a 9-axis machine can make both internal and external features of the part. These machines can make dental implants, surgical tools, and complex aerospace equipment.
12-axis CNC machines are the most complex machinery in the industry and may be overkill for most applications. These CNC machines contain two cutting heads that move in all 6 possible axes – X, Y, Z, A, B, and C. These machines exponentially increase the accuracy and can double production speed or even more.