Numerical control equipment such as CNC machining center has three coordinate systems, which are called mechanical coordinate system, programming coordinate system and workpiece coordinate system.
The origin of the mechanical coordinate system is the origin of the fixed coordinate system of the manufacturer when manufacturing the machine tool, also called the mechanical zero point. It has been determined when the machine tool is assembled and debugged, and is the reference point for machine tool processing. In use, the mechanical coordinate system is determined by the relative coordinates of the reference point. After the machine tool system is started, perform the operation of returning to the reference point, and the mechanical coordinate system is established. Once the coordinate system is established, the coordinate system will not change as long as the power supply is not cut off.
The programming coordinate system is the coordinate system used when programming, and can also be called the relative coordinate system. Generally, the Z axis is coincident with the workpiece axis, and the X axis is placed on the end surface of the workpiece.
The workpiece coordinate system is the coordinate system used by the machine tool for processing, and it should be consistent with the programmed coordinate system. Whether the programming coordinate system can be consistent with the work coordinate system is the key to operation. The establishment of the workpiece coordinate system is determined by setting the coordinate value of the current position of the tool through the program statement of the system. It is necessary to calibrate the tool before machining, clear the displayed coordinates after the tool is aligned, and write the displayed coordinate value into the corresponding tool compensation parameter when calibrating other tools. Then measure the tool setting diameter Фd, move the tool to the position where the coordinate display X=a-dZ=b, and then you can run the program. Press reset or emergency stop during processing, you can return to the set starting point to continue processing. But if there is an accident such as: X or Z axis no servo, tracking error, power failure, etc., the system can only be restarted. After restarting, the set workpiece coordinate system will disappear and the tool needs to be re-calibrated. Therefore, the workpiece coordinate can also be said to be a relative coordinate system.