How to determine the coordinate system of CNC lathe processing?

CNC lathe processing is a relatively demanding business. When processing the workpiece, if there is a slight deviation in the coordinate setting, the product will be scrapped, and it may even cause a safety accident. So how to determine the coordinate system of CNC lathe processing?

(1) CNC machine tool reference point: The reference point is also a fixed point on the machine tool, which is the limit position of the tool holder movement with mechanical stops or electrical devices. Its main function is to position the machine tool coordinate system.

(2) Machine tool coordinate system: The coordinate system on the CNC machine tool adopts the right-hand Cartesian coordinate system.

(3) Workpiece coordinate system: The workpiece coordinate system is the coordinate system set by the programmer during programming, and is also called the programming coordinate system.

Workpiece coordinate system origin: When performing CNC programming, first set a certain point on the part drawing as the programming coordinate origin according to the shape, feature and size of the processed part. This point is called the programming origin. Theoretically, the origin of the workpiece coordinate system can be selected at any point on the workpiece, but this may represent tedious calculation problems and increase programming difficulties. In order to facilitate calculation and simplify programming, usually the origin of the workpiece coordinate system is selected on the rotation center of the workpiece, and the specific position can be considered to be set on the left end surface (or right end surface) of the workpiece. Try to make the programming reference and design reference and positioning reference coincide.

Tool calibration: The machine tool coordinate system is the only datum of the machine tool, so it is necessary to figure out the position of the program origin in the machine tool coordinate system and complete it through tool calibration. The essence of tool setting is to determine the unique position of the origin of the workpiece coordinate system in the machine tool coordinate system. Tool setting is the main operation and important skill in CNC machining. The accuracy of the alignment determines the machining accuracy of the parts. At the same time, the tool alignment efficiency also directly affects the CNC machining efficiency.

Tool change: When the tool needs to be changed during the machining of the CNC machine tool, the appropriate tool change point should be considered when programming. The so-called tool change point refers to the position of the tool post to change the tool. After the CNC lathe determines the workpiece coordinate system, the tool change point can be a fixed point or an arbitrary point relative to the workpiece origin. The tool change point should be located outside of the workpiece or fixture, so that the tool holder does not touch the workpiece and other parts when changing the tool.