CNC Machining: What is 3+2 Axis CNC Machining?

3, 4, and 5 axis are often heard in precision CNC machining, but 3+2 axis machining is also a good CNC machining method. This article mainly talks about 3+2 axis CNC machining? The advantages and disadvantages of 3+2 axis CNC machining and the difference between it and 5-axis CNC machining.

What is 3+2 axis CNC machining?

Strictly speaking, the principle of 3+2 positioning machining is essentially the realization of the three-axis function at a specific angle (ie "positioning"). The two rotating axes of a 5-axis machine tool are used to fix the tool in an inclined position. The axis and the fifth axis are used to determine the direction of the tool. They are different from continuous or synchronous 5-axis machining. Simply put, when the machine tool rotates the angle, the machining is performed in a normal three-axis manner.

How does 3+2 axis CNC machining work?

The two rotating axes fix the cutting tool in an inclined position first, and then perform processing by the feed axes X, Y, and Z. This kind of machine tool is also called a positioning five-axis machine tool, which can define a rotating work plane in space through 3+2 axis machine tool processing (such as a rotary head or a rotary table). In this work plane, 2D or 3D machining operations can be programmed.

Advantages and disadvantages of 3+2 axis CNC machining

Advantage: 　

1. The CNC machining distance is shorter, which reduces the time for inputting CNC program codes.

2. The spindle head can be extended to a lower position close to the workpiece to form a certain angle.

3. You can use a short and sturdy tool to undercut the cavity and steep walls.

Shortcoming:

In complex CNC machining parts, many oblique views may be required to cover the entire workpiece, but this will cause tool paths to overlap, which increases machining time.

The difference between 3+2 axis CNC machining and 5-axis CNC machining

Compared with 5-axis CNC machining, the rigidity of the spindle is stronger for 3+2 axis CNC machining. The cost of special fixtures and tools is higher than that of 5-axis CNC machining. For tighter tolerances and more complex shapes, 5-axis CNC machining is better, and 3+2 axis CNC machining allows the tool to tilt toward the part, which is suitable for positioning parts to obtain faster feeds and speeds.

Summarize    

3+2 axis CNC machining is five-axis positioning machining. It is processed by defining multiple coordinates. After positioning, the 4th and 5th axis will not move. What we usually call the five-axis CNC machining with 5-axis linkage. All 5 axes are moving during linkage. In a broad sense, it is 5-axis machining, but the real 5-axis is only considered as linkage.