Computer numerical control (CNC) technology plays a vital role in modern manufacturing. In the CNC machining process, calibration is a key link, which plays an indispensable role in ensuring machining accuracy, improving product quality and ensuring production efficiency. So, what is calibration in CNC?
Calibration in CNC mainly refers to adjusting and confirming various parameters of the machine tool to achieve the best working state. This is like debugging a precision instrument to ensure that it can accurately perform the predetermined task.
First of all, position calibration is an important part of CNC calibration. During the machining process, the axes of the machine tool need to be accurately moved to a specific position to achieve accurate machining of the workpiece. If there is a deviation in the position, the size of the machined part will not meet the requirements, and even scrap may occur. By using high-precision measuring tools such as laser interferometers, ballbars, etc., the coordinate axes of the machine tool can be calibrated. These tools can accurately measure the actual movement distance of the machine tool axis and compare it with the command value in the control system to determine whether there is an error. If an error is found, the error can be eliminated by adjusting the machine tool parameters, such as lead screw pitch compensation, backlash compensation, etc., to ensure the position accuracy of the machine tool.
Secondly, tool length and radius calibration are also essential. In CNC machining, different tools have different lengths and radii. If these parameters are inaccurate, the machining depth and contour accuracy will be affected. Tool length calibration is usually done using a tool setting instrument. The tool setting instrument can quickly and accurately measure the length of the tool and input the measurement results into the machine tool control system. Tool radius calibration can be done by making a trial cut on the machine tool, then measuring the size of the processed workpiece, and comparing it with the theoretical size to determine the error of the tool radius and make corresponding adjustments.
In addition, the geometric accuracy calibration of the machine tool is also very important. During the long-term use of the machine tool, geometric deformation may occur due to various reasons, such as guide rail wear, lead screw bending, etc. These deformations will affect the machining accuracy of the machine tool. By using professional measuring equipment, such as a three-coordinate measuring machine, the geometric accuracy of the machine tool can be fully tested. The inspection content includes the straightness, flatness, verticality, etc. of the machine tool. If it is found that the geometric accuracy does not meet the requirements, the machine tool needs to be repaired or adjusted to restore its accuracy.
Calibration in CNC is not just a one-time activity, but an ongoing process. As the machine tool's usage time increases, the environment changes, and the processing tasks are different, the machine tool's parameters may change, so regular calibration is required to ensure that the machine tool is always in the best working condition.
In short, calibration in CNC is an important means to ensure processing accuracy and product quality. By calibrating the position, tool and geometric accuracy of the machine tool, the performance of the machine tool can be effectively improved, the scrap rate can be reduced, and production efficiency can be improved. In modern manufacturing, more and more companies have begun to pay attention to CNC calibration work and regard it as one of the important measures to improve competitiveness.
