When a single piece of CNC vertical machining center is produced, it is generally processed by blanks. Therefore, there will be interference of excess blanks during the reverse machining and centering, and other tools are needed to meet the requirements. Through many years of practice, it is found that although the ordinary reverse centering method can meet the requirements, it has problems such as cumbersome operation process, long time occupied by the machine, inconvenient observation, low accuracy, and interference of individual types of parts in the jaws of the vise. Greatly affect the processing efficiency and processing accuracy,

• (1) Straight shank round bar tool setting. This method is to mount and clamp a straight shank round bar on the spindle of a CNC vertical machining center. Suppose the X-axis is centered: move the main shaft to slowly approach one side of the workpiece. When approaching, use a parallel block to insert the gap between the round bar and the machined surface of the workpiece. When it feels easy to advance, take out the parallel block and continue Move the spindle, and then insert the parallel block. If it is still easy to insert or cannot insert, then move the spindle again, reciprocating until just enough to insert, and then reset the relative coordinate X axis to zero; then move the CNC vertical multi spindle of the machining center is to the other side of the workpiece, the same operation method is used to obtain the total value of the X axis, and the coordinate system is set after moving the spindle to half of the total value (in the middle of the workpiece). The advantage of this method is simple operation and low value of the tools required; the disadvantage is that the operation steps are many, the process is cumbersome, and the accuracy of tool setting is not high.
• (2) Use a dial indicator to set the knife. This method is a flexible use of several accessories of the lever indicator to achieve the score. The operation method is: put the clamping cap of the lever dial indicator on the spindle, and then install the dial indicator on the clamping cap. Assuming that the X axis is divided, move the machine tool table to slowly press the dial indicator to the machined surface of the workpiece, manually rotate the spindle, and observe the large value of the dial indicator (if it is not an integer, move the spindle to adjust the value of the dial indicator Is an integer), and then reset the X axis of the relative coordinate to zero; then move the spindle to the other side of the workpiece, and use the same operation method to obtain the total value of the X axis. Move the spindle to half of the total value (in the middle of the workpiece). Fixed coordinate system. The disadvantage of this method is that it takes a long time for the machine tool. When the front processing depth is not enough, the edge of the blank will easily interfere with the dial indicator needle or the dial indicator will easily interfere with the vise jaw. In addition, when the Y axis is centered, observe The dial indicator value is inconvenient; the advantage is that the tool setting accuracy is higher.