CNC machining program creation methods are divided into manual (human) programming and automatic programming. In manual programming, the entire program is written manually according to the instruction format specified by the CNC system. Automatic programming, or computer programming, can be divided into automatic programming methods based on languages and drawings. However, regardless of the automatic programming method used, corresponding supporting hardware and software are required.
To improve the level of production automation, shorten programming time, and reduce CNC machining costs, a series of advanced CNC machining technologies have been developed and used in the aerospace industry. For example, Computer Numerical Control (CNC) uses a small or microcomputer to replace the controller in the CNC system, and uses software stored in the computer to perform calculation and control functions. This soft-connected CNC system is gradually replacing the initial CNC system. Direct CNC uses one computer to directly control multiple CNC machine tools, which is very suitable for small-batch, short-cycle production of aircraft. The ideal control system is an adaptive control system that can continuously change machining parameters. Although the system itself is complex and expensive, it can improve machining efficiency and quality. Besides improvements in hardware such as CNC systems and machine tools, another important aspect of CNC development is the development of software. Computer-aided programming (also called automatic programming) involves programmers writing programs in a numerical control (NC) language, inputting them into a computer for translation, and finally, the computer automatically outputting punched tape or magnetic tape. A widely used NC language is APT (Automatic Programming Language). It is broadly divided into a main processing program and a post-processing program. The former translates the programmer's program and calculates the tool path; the latter compiles the tool path into a machining program for the NC machine tool. NC machining involves pre-writing programs on a computer before machining the workpiece, then inputting these programs into a computer-controlled machine tool for instruction-based machining, or directly writing instructions on the control panel of such a machine tool. The machining process includes tool feed, tool change, speed change, direction change, and stopping, all of which are completed automatically. NC machining is an advanced method in modern mold manufacturing. Of course, NC machining is not limited to mold parts processing; its applications are very wide-ranging.
