When we perform thread machining on a CNC lathe, we usually use a cutting tool for cutting. When machining large pitch threads, excessive tool wear can cause significant changes in thread size and low thread accuracy after cutting. After years of exploration, we have developed a method for cutting threads on CNC lathes using coarse and fine turning tools.

In the machining process of a CNC lathe, when the rough turning blade is worn to its limit, the precision turning blade is replaced with the rough turning tool, and the precision turning tool is replaced with a new blade. This can ensure the accuracy of thread cutting while also reducing tool costs. The key to this method is the accuracy of tool alignment for coarse and fine thread cutting tools.

1. Operation method

Cut both the end face and outer circle of the workpiece with a knife (the end face is flat and the outer circle is turned), and then measure the diameter D of the outer circle; Change the coarse thread cutter to cut the thread. The specific methods are as follows:

Use the rough machining tool (T0X00) with a hand operated pulse generator to first adjust the outer circle D after cutting. Use a hand operated pulse generator to shake the workpiece in the positive direction of the Z-axis, and input the D value (after the X-axis alignment of this tool is completed). Record the specific data displayed on the X-axis. Use a hand operated pulse generator to feed 1-2mm in the negative direction on the recorded data displayed on the X-axis. Enter Z0 (Z-axis tool alignment completed). At this point, the coarse thread cutting tool alignment ends.

Follow this method to finish machining the thread, and the operating steps are completely the same as the tool alignment method for rough turning. This way, there will be no disorderly buckle phenomenon during the cutting process. Even if more cutting tools are used for processing, there will still be no phenomenon of disorderly cutting.

2. Precautions

1) When each tool is aligned with the X-axis, the numbers displayed on the machine tool are different. Be sure to record the actual data of each cutting tool. After exiting the X-axis, the data of multiple thread cutting tools entering the X-axis must be the same and there must be no differences.

2) During the tool setting process, when approaching the X-axis and Z-axis of the workpiece, it is recommended to choose a gear with a feed rate of 0.001mm for the manual pulse generator.

The above is an introduction to how CNC lathes can process threads with multiple cutting tools.