Static–Dynamic Performance Improvement of LV500 Horizontal CNC Lathe via Bed–Saddle Collaborative Optimization and Laser Interferometer Validation

To improve the static and dynamic stiffness of the LV500 horizontal CNC lathe and reduce machining errors, this study focuses on integrated structural simulation, bed–saddle collaborative optimization, and standardized precision evaluation. A whole-machine structural model is established in SolidWorks, and static, modal, and harmonic response co-simulations are performed in ANSYS, followed by multi-objective optimization of the two key weak components. MATLAB is used to process the dynamic simulation data. Based on a Renishaw XL-80 laser interferometer and the accompanying CARTO software, axis accuracy detection and measurement uncertainty evaluation are performed, forming a reproducible full-process engineering analysis system applicable to similar machine tools. The simulation results show that the maximum structural deformation after optimization is 0.016 mm, and the first-order natural frequency increases from 86.99 Hz to 92.55 Hz. Experimental tests demonstrate positioning accuracies of 3.0 μm (U = 0.38 μm, k = 2) for the X-axis and 3.3 μm (U = 0.45 μm, k = 2) for the Z-axis. Owing to the enhanced static–dynamic stiffness after structural optimization, the workpiece machining error can be stably controlled within 0.01 mm. In this study, a unified whole-machine model enables continuous static and dynamic analysis. The coupling stiffness of assembled components is considered in the modeling process, and the static and dynamic performance of the whole machine is improved through dual-component collaborative optimization. The inclusion of metrological-level uncertainty evaluation enhances the reliability of the experimental data. The proposed method provides a standardized engineering scheme for the static and dynamic performance optimization of similar horizontal CNC lathes.