1、What is 3+2 positioning machining?

During the execution of a three-axis milling program, the cutting tool is fixed in an inclined position using the two rotating axes of a five axis machine tool, hence the name of the 3+2 machining technology, also known as the positioning five axis machine tool. The principle of 3+2 positioning machining is essentially the implementation of the three-axis function at a specific angle (i.e. "positioning"). Simply put, when the machine tool rotates the angle, it still processes in the ordinary three-axis manner.

2、What is 5-axis linkage machining?

According to ISO regulations, when describing the motion of CNC machine tools, the left-handed Cartesian coordinate system is used; The coordinate axis parallel to the main axis is defined as the Z axis, and the rotation coordinates around the X, Y, and Z axes are A, B, and C. Usually, five axis linkage refers to linear interpolation motion of any five coordinates in X, Y, Z, A, and B.

3、The difference between 3+2 positioning and 5-axis linkage

3+2 positioning machining and 5-axis linkage machining are suitable for different industry objects. 5-axis linkage machining is suitable for curved surface machining, while 3+2 positioning machining is suitable for flat surface machining.

Advantages of 3+2 positioning processing:

a. Shorter and more rigid cutting tools can be used.

b. The tool can form a certain angle with the surface, and the spindle head can extend lower and closer to the workpiece.

c. The tool movement distance is shorter and the program code is fewer.

Limitations of 3+2 positioning processing:

3+2 positioning machining is usually considered to set a constant angle to the spindle. Complex workpieces may require multiple oblique views to cover the entire workpiece, but this can result in overlapping tool paths and increase processing time.

Advantages of 5-axis linkage machining:

a. There is no need for special fixtures during processing, which reduces the cost of fixtures, avoids multiple clamping, and improves the accuracy of mold processing.

b. Reduce the number of fixtures used.

c. Many special tools are eliminated during processing, thereby reducing tool costs.

d. In machining, it can increase the effective cutting edge length of the tool, reduce cutting force, improve tool service life, and reduce costs.

Limitations of 5-axis linkage:

a. Compared to 3+2 positioning, its spindle stiffness is poor.

b. In some cases, it is not advisable to adopt a five axis plan, such as when the tool is too short or the handle is too large, which makes it impossible to avoid vibration under any inclined angle working conditions.

c. Compared to 3-axis machine tools, the machining accuracy error is large.