Troubleshooting methods for common problems in CNC lathe operation

        The CNC lathe is a typical mechatronics product that comprehensively uses advanced technologies such as computer technology, automatic control technology, and measurement technology. Its control system is complex and expensive. Once a failure occurs, many people will stay away from it due to its "expensive value", and will often ask professional maintenance personnel to go out. It is a waste of manpower, material resources and financial resources, as well as delays in working hours. In fact, for some common operation problems, as long as the operator is diligent in thinking, good at summarizing, and focusing on accumulation, it is not difficult to find and solve the problems.

　　 1. In the manual mode, the coordinate axis does not move. In manual operation, the machine coordinate axis does not move, and the coordinate value does not change. The M, S, T functions are executed normally, and the system has no alarm display. Analysis and solution: In this case, the system did not generate an alarm when the failure occurred, and the M, S, and T functions were executed normally. Based on this, it can be preliminarily judged that the CNC system, servo drive, etc. should have no fault. Therefore, it can be analyzed from the manual conditions, carefully check the input of the manual direction keys, the selection of the manual direction, etc. are all normal, and then carefully observe the "Current Position" page of the operation panel, and find that the manual rate, actual rate, and feed rate are all zero. . Confirm that the coordinate axis does not produce manual operation because the manual movement speed is zero. Re-adjust the feed rate percentage, and the manual operation will return to normal.

2. The phenomenon that the automatic operation is not in place: If you want to position the tool tip of No. 1 tool to a known point on the workpiece, after correctly inputting the relevant instructions in the program entry mode (MDI), the M and S instructions will be executed normally, and the machine coordinate axis will be generated. Movement, the CRT screen displays the correct position, but the tool tip does not move to the predetermined position, and the system has no alarm display. Analysis and solution: Because the machine tool returns to the set point in a normal process, it does not reach the set position. Such failures are usually related to tool compensation execution. Checking the execution of tool compensation, it is found that the tool function is T0103, and the tool No. 1 executes the tool compensation value of No. 3 tool, which causes the tool tip to not run to the predetermined position. Re-enter T0101 in the input mode (MDI) to solve this fault.

　　 Third, the thread pitch is irregular: When the CNC lathe is processing the thread, the thread pitch is irregular at the beginning of the thread, that is, the so-called messy thread appears. Analysis and solution: When machining threads on a CNC lathe, the interpolation is performed between the X-axis rotation angle and the Z-axis feed. The chaotic tooth is caused by the inability to synchronize the feeds of the X-axis and the Z-axis, and the hysteresis characteristics of the machine tool servo system itself. GSK980T is an economical CNC system. The spindle speed is open-loop control. Under different loads, the spindle start time is different, and the spindle speed is unstable at the beginning, and the speed will change accordingly. The thread cutting starts from detecting the position on the spindle. The encoder starts after one revolution of the signal, so it may cause the X-axis and Z-axis feeds to fail to achieve synchronization. The above problems can be solved by modifying the program. 1. Change the positioning point of the thread processing program to make it far away from the workpiece. In this way, the unstable change of the spindle speed is completed in the space. After stability, the tool really touches the workpiece, and then the thread processing starts. 2. Add G04 pause command before spindle rotation command M03 and thread processing command to ensure that the spindle speed is stable before starting thread processing.