Four major factors affecting the machining accuracy of CNC lathes and countermeasures

In the field of mechanical processing, CNC lathes, as one of the important mechanical equipment, have been developed to have the characteristics of automation and intelligence, and the overall machining efficiency and quality are more significant. However, there may be a series of factors that will affect the machining accuracy in the actual operation of CNC lathes. If they are not discovered and improved in time, they will definitely affect the machining results.

The impact and optimization strategy of the electrical servo system

In the process of using CNC lathes to process parts, the electrical servo system will have a direct impact on the operation of the lathe.

In the process of processing various parts in the machinery, the focus should be on the position of the parts and tools, and the position needs to be strictly controlled. In this case, the operation of the servo motor can realize the work of moving the ball screw forward or backward. In the process of adjusting the position of the two, if any of the servo drive and the ball screw has a rotation error problem, it will have a great impact on the production accuracy of the parts.

Optimization strategy: Optimizing the performance of the servo system can help significantly reduce the time delay in the processing process, and help the rapid and accurate positioning of complex parts and efficient feedback of the processing process. The use of proportional-integral-derivative (PID) control strategy or adaptive control technology can effectively improve the response speed of the servo system,

enabling it to track instruction changes more quickly and accurately. When using a servo system to process parts such as arcs or rings, the feed axis needs to be accurately designed and designed as an open-loop gain, which can effectively improve the machining accuracy of the contours in the parts.

The influence of tool wear and cutting parameters on the machining accuracy of CNC lathes and optimization strategies

During the machining process of CNC lathes, tools are needed to cut parts. The tool itself has a main deflection angle and a tool tip arc, which easily leads to a certain degree of error when using the tool to cut parts. However, as the number of parts machining increases, this error will continue to increase. The tool will gradually wear during the cutting process, causing the blade to become blunt, the cutting force to increase, and the cutting heat to be generated. This will cause the surface roughness of the workpiece to deteriorate, the dimensional accuracy to decrease, and even vibration and cutting discontinuity may occur, affecting the geometric shape accuracy of the workpiece.

Cutting speed, feed rate and cutting depth are the three main parameters in cutting processing. Unreasonable selection of cutting parameters will affect the processing accuracy. For example, if the cutting speed is too high, the tool wear will be aggravated, the cutting heat will increase, and the workpiece thermal deformation and dimensional accuracy will decrease; if the feed rate is too large, the tool will vibrate during the cutting process, affecting the surface quality and dimensional accuracy of the workpiece.

Optimization strategy: During the processing, the tool wear should be checked regularly, and the tool with severe wear should be replaced in time. In addition, it is necessary to calculate the error in combination with the actual characteristics of the tool, and then combine the error to repair the creation error. In the actual processing process, the various errors existing in the processing are continuously corrected accordingly to ensure the accuracy of each part in the actual processing. At the same time, the cutting parameters can be reasonably selected according to the workpiece material and processing requirements. For example, when processing aluminum alloy, the cutting speed can be appropriately increased, but attention should be paid to controlling the feed rate and cutting depth to avoid excessive wear of the tool. In addition, coated tools can also be used to improve the wear resistance and service life of the tool.

The influence of errors in motor operation on the processing accuracy of CNC lathes and improvement plans

The error problem generated during motor drive and use is a technical factor. The errors generated by the operation of the motor are mainly approximation errors and rounding errors. Therefore, the staff needs to strictly control these two aspects, and increase the stability of the entire mechanical braking function and the control of the motor speed by formulating a control plan.

Optimization strategy: In the specific implementation of error compensation, it is necessary to pay more attention to rounding errors and approximation errors. When controlling rounding errors, hardware processing can be used for prevention and control, and software processing can be used to improve the accuracy of data processing, so as to prevent the risk of errors caused by uncertain factors in the actual operation process as much as possible. For the compensation of approximation errors, it is necessary to improve the accuracy of the application of approximate algorithms and fitting ideas, and achieve accurate outlines of the outer contours of parts through accurate calculations of the outer contours of parts to prevent compensation errors of the control system. For processes and workpieces that require repeated positioning, error measurement should be strengthened before specific CNC machining, and the accuracy of measurement should be improved to prevent errors in subsequent machining. For inevitable errors, they should be controlled in a timely manner, and the errors should be within a reasonable range to ensure the quality of processed products. The error compensation method is used, that is, considering the factors of software and hardware on the basis of considering the system compensation function, combining the two organically, and compensating the coordinate axis again, so as to improve the processing accuracy.

The influence of CNC lathe guide rail offset error on the processing accuracy of CNC lathe and improvement plan

When the CNC lathe is running, there is always an error in the relative position offset of the guide rail, which seriously affects the processing accuracy of the CNC lathe. During the turning operation, the lathe guide rail will wear irregularly, causing the tool tip position to shift slightly later, reducing the accuracy of the final processed workpiece.

Optimization strategy: In the actual operation of the CNC lathe, in order to prevent the accuracy error caused by the body as much as possible, the base and guide rail should be optimized in the initial design stage. For CNC lathes with many functional requirements, they can be set as inclined beds during the bed design process. With the help of a suitable barrel structure, the weight of the lathe can be reasonably controlled, and the manufacturing process can be improved.

The 200MSY CNC lathe of Eastern CNC is worth a look. The machine tool is designed to meet common accuracy challenges with its high precision and high rigidity. The L-shaped bed structure optimizes the mechanical structure, has greater shock damping, support rigidity, thermal balance effect and outstanding stability, enhances the dynamic rigidity of the machine tool, withstands large cutting torque, reduces vibration and thermal deformation, etc. It adopts a 35° bed, a high-rigidity interpolation Y-axis, a 12-station dynamic milling turret BMT55, a built-in spindle (maximum spindle speed 4000 rpm), a hydraulic through-type chuck, and a servo-programmable tailstock spindle. Machine tools equipped with this type of structure have high processing accuracy and high efficiency, and the stable structure and modular design of the machine tool also improve accuracy. Visit east-cnc.com for more details.