When we perform threading on CNC lathes, we usually use one tool for cutting. When machining large-pitch threads, the tool wears too fast, resulting in large changes in thread size and low thread accuracy after cutting. After years of exploration, we have figured out a way to divide rough and fine turning tools when cutting threads on CNC lathes.
During the CNC machining process, when the rough turning insert is worn to the limit, the fine turning insert is replaced with the rough turning tool, and the fine turning tool is replaced with a new insert. In this way, the tool cost can be reduced while ensuring the thread cutting accuracy. This method mainly depends on the tool setting accuracy of the rough and fine thread tools.
- Operation method
Cut both the end face and the outer circle of the workpiece (the end face is flat, and the outer circle is turned), and then measure the diameter D of the outer circle; change the rough threading tool to cut the thread. The specific methods are as follows:
Use the roughing tool (T0X00) with the hand-operated pulse generator to first cut the outer circle D after machining. Shake out the workpiece in the positive direction of Z-axis with the hand-cranked pulse generator, and input the D value (the X-axis of this tool is finished).
Take note of the specific data displayed on the X-axis. Use the manual pulse generator to feed 1-2mm in the negative direction on the data displayed and recorded on the X-axis. Similarly, the manual pulse generator feeds in the negative direction of the Z axis, and the tool can cut to the workpiece.
Enter Z0 (the Z-axis tool setting is complete). At this time, the tool setting of the rough threading tool is completed.
According to this method, the thread is finished, and the operation steps are exactly the same as the rough turning tool setting method. In this way, there will be no random buckle phenomenon during the cutting process. Even if there are more cutting tools, there will be no random buckle phenomenon. - Precautions
1) When each tool is aligned with the X axis, the numbers displayed by the machine tool are different. Be sure to record the actual data of each tool. After exiting the X-axis, the data of the X-axis infeed of multiple thread cutting tools must be the same and cannot be different.
2) In the process of tool setting, when approaching the X-axis and Z-axis of the workpiece, it is recommended that the manual pulse generator should choose the feed rate of 0.001mm.
