Simply speaking, the common tool alignment methods in CNC machining centers are tool alignment by tool alignment instrument, automatic tool alignment and trial cutting method. Because a complete working procedure of a workpiece may involve several or even dozens of cutters, the trial cutting method is relatively primitive, and the accuracy of the cutter is poor, so it is seldom used. We will focus on the first two typical tool setting methods:1. Automatic tool setting
Automatic tool alignment is realized by the tool detection function of CNC machining center. This device can automatically and accurately measure the length of each tool in each coordinate direction, and can automatically correct the error value of the tool. The whole detection and correction process can be realized on the basis of the normal operation of the machine tool. This tool alignment method is completely realized by electronic control device, which eliminates the error of artificial tool, so the accuracy of tool alignment is higher and the efficiency of tool alignment is better.2. Method of Tool Setting Instrument
Tool alignment with tool alignment instrument is the main method of tool alignment in NC machining center because of its high economic efficiency. Tool alignment is divided into two types: in-machine tool alignment instrument and out-of-machine tool alignment instrument. External tool alignment instrument needs to be pre-corrected outside the machine, and then the tool can be used on the machine tool. In-machine tool alignment instrument is a method of measuring the tool directly installed in a fixed position of the machine tool.3. Preventive Measures of Tool Setting Error
Because the cutters used in CNC machining center are various and the size of the cutter is very different, the tool alignment method should be selected according to the actual processing conditions, the program instructions should be determined, and the tool alignment parameters and tool compensation values should be input well. Even so, there may be some errors in different tool setting methods, which may affect the accuracy of workpiece processing.When using tool alignment instrument, mirror tool alignment and automatic tool alignment, the errors are not mainly due to the manufacturing, installation and measurement errors of the instrument, and the poor skills of using the instrument will also cause errors. Therefore, we should pay attention to the installation and measurement accuracy of the instrument. More importantly, we should master the correct method of using the instrument. Only by using and operating correctly, can we reduce the error to the lowest. At the same time, the quality and rigidity of the cutter and the accuracy of the machine tool itself also affect the error of tool alignment. Therefore, it is also important to select qualified cutters and regularly check the zero drift of CNC machining center.