CNC machining center 850 coordinate system includes machine tool coordinate system and workpiece coordinate system. Different machining center coordinate systems are slightly different.
1. Machine tool coordinate system
(1) The Z coordinate is parallel to the spindle, and the direction of the tool leaving the workpiece is positive.
(2) The X coordinate is perpendicular to the Z coordinate, and the tool rotates. When looking at the direction of the column facing the tool spindle, the right is positive.
(3) Y coordinate, after the Z and X coordinates are determined, the Y coordinate is determined by the right-handed rectangular coordinate system.
The origin of the machine tool coordinate system is also called the mechanical origin, reference point, and zero point. It is a very important datum point for machine tool debugging and processing. Usually, the machine tool zero return is used after the machine is turned on or when the tool is automatically changed. The so-called zero return is to return the moving parts to the mechanical origin. The mechanical origin is generally set at the maximum stroke of the tool or worktable, and in the positive direction of the machine tool standard coordinate system. The tool change position of some machining centers does not coincide with the mechanical origin, the mechanical origin is called the first reference point, and the tool change position is called the second reference point. It should be noted that after the machine is assembled, the second reference point can not be changed after debugging.
2. Workpiece coordinate system
The workpiece coordinate system is the coordinate system established on the workpiece when the programmer is writing the program. The origin of the workpiece coordinate system is the workpiece origin, also called the programming origin. Theoretically, the setting of the workpiece origin is arbitrary, but in fact, it is set by the programmer based on the features of the part for the convenience of programming and the intuitiveness of the size. For the machining center, the workpiece coordinate system can be established only after accurately selecting the origin of the workpiece.
Selection criteria for workpiece origin:
(1) The origin of the workpiece should be coincident with the design basis of the part.
(2) The calculation when compiling the NC program should be the simplest to avoid the calculation error of the dimensional chain.
(3) The processing error caused is the smallest.
(4) The origin of the workpiece should be selected at a position that is easy to be corrected and easy to measure during processing.
The position of the workpiece origin is specified when the part is mathematically processed. After the part is clamped on the machine tool, this point is also determined, but it changes with the different clamping positions of the workpiece. Therefore, the workpiece coordinate system can be changed on the machine tool as required.
