Thread turning refers to the thread processing process, specifically to the workpiece rotation, turning tool along the axis of the workpiece to move a lead. The blade trajectory formed the thread surface of the workpiece thread processing process. The thread is processed by the position encoder on the spindle of the CNC machine tool and the spindle speed synchronization.

Thread turning

How to use thread machining?

CNC lathes are operated repeatedly from rough cutting to fine cutting on the same tool path when turning threads. When want to change the speed, the need to give a position encoder output of the information on the main shaft, screw knife cut when the trajectory is not changed, due to the input of information access systems have a delay in the response time, the speed of the spindle, the knife cut the thread will be different, that is why change the spindle speed in processing thread will disorderly buckle. The main points to note when the thread is large diameter is: by the turning tool extrusion, the size of the large diameter of the external thread will swell, and the small diameter of the internal thread will shrink. The front diameter of outer thread = nominal diameter D-0.1P (pitch: P). The bottom hole diameter of the inner thread of plastic metal ≈ nominal diameter D-P (pitch: P). Inner thread bottom diameter of brittle metal ≈ nominal diameter D-1.05P (pitch: P). We usually use a tool for thread machining.

thread machining

How to minimize the tolerance of thread?

In the use of CNC machine tools, the processing of large pitch threads will appear in the late processing thread size change, and thread precision is a low phenomenon. The reason is caused by tool wear too fast in the processing of machine tools. So how do you solve this problem? When the coarse lathe blade can not be used to replace, you can change the fine lathe blade to the coarse lathe tool to temporarily replace the tool, and then the fine lathe tool to replace the new fine blade to ensure the accuracy of processing can also save cost. This method also depends on the accuracy of the knife.

machined thread

The thread is processed by the position encoder on the spindle of the CNC machine tool and the spindle speed synchronization. In general, CNC lathes repeatedly operate on the same tool path when turning threads. In the use of CNC lathe mechanical thread parts processing, the encoder number control spindle feed drive device, to control the tool shelf, the final completion of the feed task.

The CNC system can monitor the signal information of the spindle rotation to control the number of motor revolutions. The CNC system will operate in strict accordance with the requirements of the numerical value so that the lathe can cut the same thread parts as required. As the spindle rotates, the encoder also rotates and emits the same pulse signal. To reduce the working delay of the machine tool, when the NC system receives the signal, it starts working synchronously.

How to prepare for thread machining?

To machine, a perfect thread part, knowing how to reduce the tolerance is not enough. Here are three things for you to prepare for a thread process.

1. Choose Right Material

Turning processing steps when the main technical characteristics of a lathe, so the cutting tool material and structure all have strict requirements, such as cutting tool can choose YG types of cemented carbide cutting thread of cast iron material, car and car steel material to make tools to use a type of YT cemented carbide, the material is an important tool of numerical control machine tool, it not only can rough machining or finish machining.

2. Correct Additional Method

CNC turning is an important step for mechanical threads, as well as for deciding whether a part is good or bad at some point. In the selection of appropriate processing methods and digital information processing parts drawings, in the mechanical thread type CNC machine tool turning to process, must meet the requirements of the material, according to the requirements to select materials, and according to the information on the drawings control CNC machine tool for mechanical thread type parts turning to process.

3. Choose the Right Tool 

Buying a ticket lets, you choose the right tool to understand the Angle of the tool and control it during machining. In order to ensure the accuracy of processing parts, but also clear tool selection is very rational and stable performance, determine the planning of the tool life and tool walking route and steps, to ensure that the tool’s use time is longer in a reasonable range.

Linear threading is where the position encoder on the spindle sends out an output message after the lathe turns the thread repeatedly from rough cutting to fine cutting on the same tool path. Thread knife into the system will produce response time spindle speed is different, the cutting thread must be different, this is why in the process of changing the spindle speed thread will buckle the phenomenon. The shaft speed must be kept constant from rough cutting to fine cutting if the thread is not to be screwed.


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