Key Considerations for Operating a CNC Machining Center

In mold manufacturing, CNC machining centers are crucial for processing critical components such as mold cores, inserts, and copper electrodes. The quality of these components directly affects the overall mold quality, and copper electrode processing quality influences EDM (Electrical Discharge Machining) operations. To ensure CNC machining quality, preparation before machining is crucial. Besides having abundant machining experience and mold knowledge, effective communication with the production team and colleagues is essential.

CNC Machining Process

1. Read blueprints and program sheets.
2. Transfer the appropriate program to the machine.
3. Check the program header, cutting parameters, etc.
4. Determine the machining dimensions and allowances for the workpiece.
5. Properly clamp the workpiece.
6. Accurately locate the workpiece.
7. Establish precise workpiece coordinates.
8. Select suitable cutting tools and cutting parameters.
9. Properly clamp the cutting tools.
10. Use a safe method for test cutting.
11. Observe the machining process.
12. Adjust cutting parameters if necessary.
13. Provide timely feedback on issues during the machining process.
14. Inspect the workpiece quality after machining.

Precautions Before Machining

1. For new molds, ensure the machining drawings meet requirements and are clear. They should also be signed by a supervisor, and all columns in the drawing should be filled out.
2. The workpiece should have the quality department’s approval mark.
3. After receiving the program sheet, verify whether the workpiece datum coincides with the blueprint datum.
4. Carefully review each requirement on the program sheet and confirm if the program aligns with the blueprint. Any issues must be resolved with the programmer and production team.
5. Based on the workpiece material and size, assess the reasonableness of the roughing or finishing tool selection. If the tool application is inappropriate, promptly inform the programmer to make necessary adjustments to enhance machining efficiency and accuracy.

Precautions During the Machining Process

1. When removing excess material from the workpiece, avoid cutting too deeply during manual operations.
2. The first cut is crucial; careful operation and verification help identify errors in tool length compensation, tool diameter compensation, program, and spindle speed, preventing damage to the workpiece, tools, and machine.
3. Follow this trial cutting process: a) The first point’s height should be raised by the maximum 100mm, to visually inspect its correctness. b) Adjust “rapid traverse” to 25% and feed rate to 0%. c) Pause the machine when the tool is about 10mm away from the workpiece surface. d) Check the remaining travel distance and program correctness. e) Restart the machine with one hand on the pause button and the other controlling the feed rate. f) When the tool is very close to the workpiece surface, pause again and verify the remaining Z-axis travel. g) After ensuring smooth and stable cutting, return all controls to normal settings.

Precautions After Machining

1. Confirm the completion of all required procedures and instructions on the program sheet.
2. After machining, inspect the workpiece’s shape and size against the requirements on the blueprint and conduct a self-check based on the part drawing or process chart to detect any errors promptly.
3. Check for any anomalies in various positions on the workpiece. If in doubt, notify the team leader.
4. For large workpieces, inform the team leader, programmer, and production supervisor before removing them from the machine.
5. Ensure safety when removing large workpieces, especially protecting both the workpiece and the CNC machine.

Conclusion

Operating a CNC machining center requires careful preparation, effective communication, and adherence to key precautions throughout the process. By following these guidelines, you can ensure high-quality CNC machining results and improve overall efficiency in mold manufacturing.