Selection of Machining Tools for CNC Machine Operation

With the rapid development of the manufacturing industry and the continuous advancement of machining technology, more and more machining methods are utilizing CNC machines. The machining method of CNC machines differs from that of conventional machines. The choice of machining tools directly impacts the machining precision, surface quality, and machining efficiency. This requires programmers to master the basic principles of tool selection and cutting parameters determination, considering the characteristics of CNC machining when programming, to correctly choose the cutting tools and cutting parameters. Programming is a leading element in the entire machining process. Only by ensuring the correctness of this leading element can the subsequent series of machining processes be effectively carried out.

Generally speaking, the principles of tool selection in CNC machining are: easy installation and adjustment, good rigidity, high durability, and precision. Under the premise of meeting machining requirements, it is advisable to select a shorter tool shank to enhance the rigidity of the tool during machining.

Basic Methods for Selecting Machining Tools in CNC Machine Operation

When selecting tools, the dimensions of the selected tools must correspond to the surface dimensions of the workpiece being machined. In production, tool selection varies based on the machining method of the workpiece. Generally, for machining the peripheral contour of planar parts, end mills are commonly used; for milling planes, carbide insert face mills are preferred; for machining bosses and grooves, high-speed steel end mills are chosen; for rough machining of blank surfaces or holes, corn mills with carbide inserts can be selected; for machining three-dimensional surfaces and variable angle contours, ball-end mills, ring mills, tapered mills, and disc mills are often used.

When machining freeform surfaces, since the cutting speed at the tip of a ball-end tool is zero, to ensure machining precision, a close cutting path is generally used at the tip, making ball-end tools commonly used for surface finishing. Flat-end tools, however, outperform ball-end tools in surface machining quality and cutting efficiency. Therefore, as long as over-cutting is avoided, flat-end tools should be prioritized for both rough and finish machining of surfaces.

In machining centers, various tools are respectively mounted in the tool magazine, and tool selection and tool changing actions are performed according to program instructions. Standard tool holders must be used to ensure that standard tools for drilling, boring, reaming, and milling can be quickly and accurately mounted onto the machine spindle or tool magazine. Programmers should understand the structural dimensions, adjustment methods, and adjustment ranges of the tool holders used on the machine to determine the radial and axial dimensions of the tools during programming, achieving the most convenient and efficient machining path.