How To Achieve High-Precision Cnc Machining?

Select high-precision CNC equipment

The accuracy of the equipment is the basis for achieving high-precision machining. Aircraft engine manufacturing requires machining accuracy to reach micrometers or even nanometers, so CNC machine tools with high rigidity and high resolution must be selected. For example, some high-end machine tools use high-precision ball screws and linear guides, with positioning accuracy of up to ±0.001mm and repeat positioning accuracy of ±0.0005mm. At the same time, the spindle accuracy of the machine tool is also very important. The radial runout and axial movement of the high-precision spindle should be controlled within a very small range, such as below 0.001mm, to ensure the stability of the tool at high-speed rotation and provide guarantee for precise cutting.

Optimize CNC programming

Accurate programming is the key link to achieve high-precision machining. In the machining of aircraft engine parts, there are many complex surfaces and contours, which require programming with the help of advanced CAD/CAM software. Through accurate modeling by software, the generated tool path should fully consider the machining process, such as the reasonable combination of cutting speed, feed rate and cutting depth. The constant linear speed cutting control technology can keep the linear speed constant during the tool cutting process to ensure uniform surface quality of the parts. At the same time, the tool radius compensation function can accurately control the actual cutting contour of the tool and improve the processing accuracy. In addition, the tool entry and exit paths should be set reasonably during programming to avoid collision between the tool and the workpiece or unnecessary cutting marks.

Use high-quality tools and cutting parameters

The selection of tools and the optimization of cutting parameters have a significant impact on processing accuracy. For difficult-to-process materials such as high-temperature alloys and titanium alloys commonly used in aircraft engines, high-performance tools such as carbide coated tools or ceramic tools are required. These tools have high hardness, high wear resistance and good thermal stability. They can remain sharp under high-speed cutting and reduce the impact of tool wear on processing accuracy. In terms of cutting parameters, precise adjustments should be made according to material properties and processing requirements. Lower cutting speeds and feed rates help improve processing accuracy, but they reduce processing efficiency, so a balance needs to be found between the two. For example, when processing high-temperature alloys, the cutting speed can be controlled at 50-150m/min, the feed rate at 0.05-0.2mm/r, and the cutting depth at 0.5-2mm. The best parameter combination is determined through multiple tests.

Implementing precision measurement and error compensation

During the processing, real-time precision measurement and error compensation are important means to ensure high precision. High-precision measuring instruments, such as three-coordinate measuring machines, are used to perform real-time detection of workpieces during processing to promptly detect dimensional deviations and form and position errors. The error compensation function of the machine tool is used to adjust the tool path or machine tool motion parameters according to the measurement results. For example, by real-time monitoring of the thermal deformation error of the machine tool and using the thermal error compensation system to correct the tool position, the processing error caused by the thermal deformation of the machine tool can be effectively reduced, ensuring that the processing accuracy is always within the required range.