Usually, we carry out CNC deep hole machining for a part. First, the CNC programmer analyzes the design drawings of the parts, determines the processing plan, and then selects a point on the workpiece as the original point of the coordinate system, which we call the program coordinate system and the program origin.
The determination principle of this point is easy to determine and convenient programming calculation, generally coincides with the process datum or design datum of the part, so it is also called the workpiece origin, and the coordinate system is also called the workpiece coordinate system. NC programming is based on workpiece coordinate system, and parts machining is done on CNC lathe.
Now we can see that there is no connection between the workpiece coordinate system and the machine tool coordinate system two. In order to link the two, we need to operate the cutter. Let’s take a look at the specific method.
The first is to get the workpiece coordinate system directly by input the cutter offset value through the tool setting. This method is easy to operate and has good reliability. The workpiece coordinate system will not change as long as the cutter deviation and the mechanical coordinate system are not changed. Even if the blade is replaced, the workpiece coordinate system is still in the original position, and the power break and restart the machine tool will not affect the position of the coordinate system.
The second is to specify a value to set the workpiece coordinate system in the program after G50. After the knife, the point on the tool, such as the tip of the knife, can be moved to the coordinates of the G50 set.
The third method is to use MDI to set six coordinate systems, G54~G59, which can change its position through the zero point offset value of the external workpiece or the offset value of the workpiece zero point. Three methods to change the zero point offset value of the external workpiece or the offset value of the workpiece zero point are input from the MDI panel, programmed with G10 or G50, and input with external data.
With the development of numerical control technology, CNC machine tools are widely used. A skilled double head CNC operator must master the basic skill of tool setting. In actual production, the efficiency of tool setting and tool setting error directly affect the efficiency of NC machining and the accuracy of machining parts.
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