Any processing equipment, such as processing route setting, processing programming, processing tool selection, machine tool problems, clamping problems and workpiece material, when  cnc machining parts, will have a certain impact on the final processing accuracy and processing efficiency of the workpiece As a high-precision and high-efficiency processing equipment, vertical machining centers commonly use methods to reduce workpiece machining errors, such as the original error reduction method, error compensation method, error transfer method, error grouping method, error average method, and error synthesis method.

• 1. Error transfer method The essence of the error transfer method is the comprehensive error caused by the collective error, stress deformation and thermal deformation of the transfer process system. For example, the vertical machining center performs some hole processing. The coaxiality of the workpiece is not guaranteed by the rotation accuracy of the machine tool spindle, but by the fixture. When the machine tool spindle and the workpiece are connected by floating, the original error of the machine tool spindle is no longer Affect the processing accuracy, and transfer to the fixture to ensure the processing accuracy.
• 2. Error compensation method The error compensation method is to artificially create an error to cancel the original error inherent in the process system, or to use one original error to cancel another original error, so as to improve the machining accuracy of the workpiece in the vertical machining center purpose. Usually by reducing the machine tool clearance, increasing the machine tool rigidity, using pre-loading, so that the relevant fit produces a pre-tightening force, and eliminate the effect of the clearance. It can also increase the rigidity of the workpiece and tool and reduce the overhanging elongation of the tool and workpiece to increase the rigidity of the process system. It can also use reasonable clamping and processing methods to reduce cutting forces and their changes, choose tool materials reasonably, increase the rake angle and the main declination angle, and perform reasonable heat treatment on the workpiece materials to improve the processing performance of the materials. Several methods.
• 3. Error grouping method In the processing of vertical machining centers, due to the existence of process blank errors, the processing errors of this process are caused. The change of the blank error has two main effects on this process: reaction error and positioning error.
• 4. Error averaging method The error averaging method is to use the mutual comparison and correction between closely related surfaces, or to use each other as the basis for processing, so as to achieve the purpose of eliminating machining errors in the vertical machining center.
• 5. The error synthesis method eliminates the errors of the machine tool itself is the most important method to ensure the final machining accuracy of the workpiece. The error synthesis method requires measuring the original errors of each axis of the machine tool.

The laser interferometer is the main testing instrument of the vertical cnc machining center because of its high measurement accuracy and flexible use.