From the perspective of machining operation process, CNC machine tool machining can be divided into three major modules: programming, tool setting, and automatic machining. Among them, programming and tool setting are preparatory work for machining operations. Whether the programming is correct, whether the selected cutting amount is reasonable, and whether the input of tool setting parameters is accurate will all be reflected in actual machining.

Therefore, in order to ensure the accuracy of CNC machining operations, it is usually necessary to conduct trial machining to test whether there are any problems with the automatic machining of CNC machines. In trial machining, strictly following the machining principle of "three looks, two demands, and one stop" can greatly reduce collision problems during machine operation.

1. Three looks

Take a look at the program

All operations of CNC machine tools are controlled by program instructions. By checking program statements and program names, problems are identified and corrected in a timely manner. When checking programs, in order to avoid duplicate or missed checks, a certain order of checks should be followed: first, starting from the program name, as the completion of basic CNC operations requires a large number of program instructions for control, a large number of program files will also be stored inside the microcontroller system. The program name will be automatically called out, and special attention should be paid to checking the suffix and program format of the program name; Secondly, check the program fragments. Using computer software simulation to detect whether there are errors in specific program statements. If there are problems with the logic of the statement writing, the simulation software will automatically point out the existing problems, so that programmers can make timely program modifications until there are no problems with the operating program.

Looking at the coordinates of the workpiece

The screen will display detailed information such as the machine tool coordinates and workpiece coordinates of the current tool. When checking, it is important to compare the screen values with the actual tool tip position to ensure that the coordinate values between the two correspond one-to-one. Due to factors such as machine tool fixtures and tool wear, there is often a certain degree of error in the workpiece coordinates. If the error exceeds the standard range, it will affect the machining progress of the machine tool and cause collision problems. Therefore, by comparing the coordinates of the workpiece, this problem can be effectively avoided.

Check the position of the blade tip three times

The machining and cutting operations of CNC machine tools are completed by the cutting tools, so when inspecting the machine tool, the focus should be on checking the position of the tool tip. After using the tool tip for a period of time, wear may occur. On the premise of not affecting the machining quality of the machine tool, the machine tool operator should regularly adjust the tool position to prevent the tool from colliding with the workpiece or chuck. In addition, the actual position of the tool tip should be compared with the displayed data on the screen. If there is a significant error between the two values, the machining operation should be stopped. After stopping the machine, the tool should be exited and reinstalled and adjusted.

2. Second requirements

To execute in a single segment

CNC machine tools all have a single stage SBL execution function. After activating this function, the microcontroller will automatically terminate the machining operation after each control program is completed. The CNC machine operator needs to manually start the next program before the machining operation can be carried out. The advantage of single stage execution lies in providing operators with sufficient inspection time, including tool inspection, coordinate inspection, and program inspection, thereby greatly avoiding the occurrence of collision accidents. Although single stage execution reduces the efficiency of CNC machining, it can significantly improve machining quality and avoid collision problems, resulting in better overall machining performance.

Secondly, low magnification is required

By adjusting the speed adjustment knob of the CNC machine tool and reducing the feed rate of the tool, it is possible to observe whether the position of the tool tip is consistent with the displayed coordinate values before machining the workpiece. If the two values are not equal, the equipment can be stopped in a timely manner to avoid collision problems. Especially during the machining of inner holes in workpieces, it is easy to encounter errors in feed or retract, which not only affects the quality of inner hole machining, but also leads to serious deviations in the size of inner holes in workpieces, as well as problems such as cutting and collision. Therefore, choosing a low magnification processing speed can effectively avoid the above-mentioned processing problems.

3. One stop

To be precise, there should be multiple pauses during the automatic machining process. By pausing, the operator can have sufficient mental preparation to observe and compare the position of the tool tip and the display of screen coordinates, especially when the chips wrap around the workpiece or tool, the cycle stop button can be pressed to use this time to solve problems that occur during CNC machining and prevent errors caused by panic during operation.