1. Analysis of the cause of over-cutting of the CNC workpiece

1. Workpiece edge seeking deviation or error

(1) On-site personnel negligence;

(2) The dimensions of the drawing are not clearly marked x, y, and z are not marked in the usual way;

(3) The processing origin of the program list does not coincide with the origin of the drawing.

2. Wrong tool or wrong writing of the program sheet (this error often occurs during program copy)


(1) Fill out the procedure sheet while writing the procedure;

(2) After the program is written, the size of the tool must be checked one by one;

(3) Manually add the program number and tool size to the beginning of the program CNC code.

3. When rough milling, the margin is too little or the tool diameter is not accurate


(1) The programmer should have an in-depth understanding of the cutting performance and material of the tool. Make allowances according to the actual situation;

(2) The tool must be accurately measured before clamping the tool.

CNC Machining Process

4. The tool is not firmly clamped or extended too long to cause over cutting


(1) The clamping tool must be firm;

(2) The elongation of the tool generally does not exceed 2/3 of the total length of the tool;

(3) The tool must be extended under special circumstances (more than 2/3). The cutting volume must be reduced accordingly, and the speed and speed must also be reduced;

5. Excessive cutting amount causes over cutting of broach

When cutting, the processor should consider the material and hardness of the workpiece, the rigid feed rate of the tool and the machine and the adjustment of the speed.

6. Over-cutting due to wrong procedures on site


(1) The site should follow the specified Path on the procedure sheet to capture the procedure;

(2) On-site understanding of the operating system of the program design class and the coding principles of program codes;

Program code = the last two codes of the module number + the workpiece code (two codes) + the electrode serial number (if electrodes are used) + the program serial number.

7. Program writing error (for example: input error of boundary margin Floor surface)

2. Reasons for tool collision

1. CNC code writing error;

For example: the zero point of the work piece is at the bottom or the center of the work piece, but not on the top surface of the work piece. After the program is written, the default height of the post processing program is = 50.0. The work piece may be 50.0 when the distance between the required point of the work piece and the top of the height is 50.0 Or hit the knife.

2. Inaccurate tool measurement;

Preventive measures: Use the most accurate prosthesis for tool measurement as much as possible.

3. The program is garbled (bumping knife due to transmission error);

The program number call is wrong or the program has been modified but the old program is still used for processing and writing date;

When the procedure list is changed, the old diagram and the procedure list should be destroyed by the principle of replacing the old with new ones;

On-site processors try to check the detailed data of the program below.

4. The wrong tool or the wrong tool in the program list;

Prevention: Add the program number and tool diameter to the program header of the program.

5. The safety plane setting is not high enough, and the tool is moved when it is not allowed to reach and hits the tool;

For example: When a knife is processing multiple parts with raised islands between two parts, in order to save the time of lifting the knife on site, set two safety planes (the higher safety plane is greater than the height of the workpiece). The lower safety plane is lower than the height of the workpiece and higher than the part to be processed).

When the tool finishes processing a part, it is raised to a lower safety plane (due to the limitation of the software) when preparing to process a part, the middle lifting tool crosses the boss because the height is lower than the boss and the knife hits.