During operation, CNC turntables generate heat due to motor operation, bearing friction, and cutting heat transfer. The accumulation of this heat causes thermal deformation of the turntable structure. From a precision perspective, thermal deformation first affects the positioning accuracy of the turntable. When the turntable expands due to heat, deviations occur from the originally set positioning, making it difficult to guarantee the dimensional accuracy of the processed parts. For example, in precision boring, minor thermal deformation of the turntable may cause the center of the bore to shift, resulting in a hole diameter that does not meet the design requirements.

　　Simultaneously, thermal deformation also damages the turntable's repeat positioning accuracy. In multiple positioning operations, due to the uncertainty of thermal deformation, the results of each positioning may fluctuate. This is extremely unfavorable for batch processing tasks requiring high-precision repeat positioning. For example, in the mold manufacturing industry, the high precision of the mold cavity requires the turntable to have stable repeat positioning accuracy, but thermal deformation can cause deviations in this process, affecting the quality of the mold.

　　In addition, thermal deformation reduces the rotational accuracy of the turntable. During rotation, uneven expansion caused by thermal deformation can cause eccentricity in the rotating shaft, affecting the surface roughness and shape accuracy of the workpiece. In turning, this reduction in rotational accuracy may cause defects such as taper or out-of-roundness on the cylindrical surface.

　　To address the impact of CNC turntable thermal deformation on accuracy, a series of compensation measures have emerged. During the design phase, optimizing the turntable structure can reduce thermal deformation. For example, using a thermally symmetrical structure design allows the turntable to expand uniformly when heated, thereby reducing the impact of thermal deformation on accuracy. The choice of turntable material is also crucial; using materials with low thermal expansion coefficients can suppress thermal deformation to some extent.

　　During processing, temperature monitoring and control are important compensation methods. By installing temperature sensors at key points on the turntable, real-time temperature changes are monitored. When the temperature rises to a certain level, cooling methods such as air cooling and water cooling are used to dissipate heat from the turntable, keeping the turntable temperature within a reasonable range to reduce thermal deformation.

　　Furthermore, introducing a thermal error compensation algorithm into the CNC system is also an effective method. By establishing a mathematical model between thermal deformation and temperature and turntable operating parameters, the CNC system can calculate the amount of thermal deformation based on real-time temperature data and automatically compensate in the processing instructions, ensuring that the actual movement position of the turntable meets the processing accuracy requirements.

　　Thermal deformation of a CNC turntable has multifaceted effects on its accuracy. However, through reasonable structural design, effective temperature control, and advanced compensation algorithms, the accuracy loss caused by thermal deformation can be significantly reduced, ensuring high-quality CNC machining.