The benefits of 5-Axis CNC Machining and design tips

The benefits of 5-Axis CNC Machining and design tips 

The 5-axis CNC machining processing is the machine here means that there are at least five coordinate axes ( 3 linear coordinates and 2 rotating coordinates) on a machine tool, and it can be processed simultaneously under the control of a computer numerical control system. Such 5-axis linkage CNC machining is compared with general three-axis linkage CNC machining.

The following is the advantages of 5-Axis CNC machining:

1) It can process the parts with continuous and smooth free-form surfaces that cannot be processed by 3-axis CNC machine tools or are difficult to complete processing in one clamping. 

For example, blades of aerospace-engines and steam turbines, screw propellers for ships, and many shells and molds with special curved surfaces, complex cavities and holes, etc., such as processing by 3-axis CNC machine tools, due to the tool work-piece The pose angle cannot be changed during the processing. When processing some freedom, interference or under-processing may occur (that is, it cannot be processed). When machining with a 5-axis linkage machine tool, since the position and angle of the tool and work-piece can be adjusted at any time during the machining process, the interference of the tool and work-piece can be avoided and all machining can be completed at one time. 

2) It can improve the machining accuracy, quality and efficiency of free-form surfaces 

For example, when a three-axis machine tool is used to process complex curved surfaces, ball-end milling cutters are often used. Ball-end milling cutters are formed by point contact, which results in low cutting efficiency. In addition, the tool and workplace angle cannot be adjusted during the machining process. The best cutting point on the ball end milling cutter (that is, the point with the highest linear speed on the ball end) for cutting, and it may happen that the cutting point falls on the center-line of rotation where the upper line of the ball ice dragon knife is equal to zero. At this time, the unfair cutting efficiency is extremely low, the quality of the processed surface is seriously deteriorated, and manual repair is often required, so accuracy may be lost.The five-axis machine tool is used for machining. Since the position and posture of the tool work-piece can be adjusted at any time, injustice can happen, and it can also make full use of the best cutting point of the tool for cutting, or use line contact forming spiral end milling The tool replaces the ball-end milling cutter of point contact forming, and even milling can be performed by further optimizing the pose angle of the tool and the work-piece, so as to obtain a higher cutting speed and cutting line width, that is, to obtain higher cutting efficiency and more A good machining surface quality is shown in the figure as an example of the effect of milling the same free-form surface with a constant pose angle and an optimized pose angle. The surface roughness of blade milling with constant pose angle (Sturz method) is one level lower than that of blade milling with optimized pose angle (P milling method-star company patent), and the time it takes is lower than that of the former. The latter is 30-130% more.

The average Ra value of the surface quality grade is N81.6-3.2um, N70.8-1.6um, N60.4-0.4um.

3) The structural characteristics of the five-axis processing machine

The biggest difference between a five-axis processing machine tool and a general machine tool is that it has at least two rotary coordinate axes in addition to the three linear coordinate axes of a normal machine tool, and it can be processed with five-axis linkage.

The difference between the five-axis processing machine tools, in addition to the vertical and horizontal points, is mainly in the structure of their five-axis movement and the distribution (configuration) of the five movements. Generally speaking, a five-axis machine tool has three structure types and three motion configuration methods. The combination of these two can get 9 possible five-axis structure types.

So parts with complex construction can’t done in one horizon and split and welding is not acceptable then should using 5-Axis CNC milling.