Repeatability refers to the accuracy of the turret when it returns to the same tool position multiple times. Generally speaking, the repeatability of high-precision CNC turrets can reach ±0.001mm or even higher. This accuracy is crucial for precision machining. For example, in the mold manufacturing industry, high-precision milling, drilling and other processing operations are required for the mold cavity. If the repeatability of the CNC turret is not accurate enough, it will cause a slight deviation every time the tool returns to the processing position. These deviations accumulate and make the dimensional accuracy and surface quality of the mold unable to meet the requirements, which ultimately affects the performance and service life of the mold.
The high repeatability of CNC turret is the result of the combined effect of multiple factors. From the perspective of mechanical structure, the turret's tool disc, transmission mechanism and tool clamping device all need to have high manufacturing accuracy. The rotation accuracy of the tool disc directly affects the positioning of the tool, and the manufacturing tolerance of its rotating axis and the accuracy of the bearings must be strictly controlled. Transmission mechanisms such as gears and worms need to ensure the accuracy and stability of the transmission and reduce the gap and vibration during the transmission process. The tool clamping device must ensure that the tool can be in the same precise position after each clamping, which requires the clamping device to have high precision, good rigidity, and be able to provide stable clamping force.
In terms of the control system, the CNC turret relies on a high-precision encoder to achieve position feedback. The encoder can accurately measure the rotation angle of the turret and the position of the tool, and feed this information back to the CNC system. The CNC system accurately controls the position of the turret based on the feedback information, and reduces the positioning error through advanced control algorithms such as PID control (proportional-integral-differential control). At the same time, the system can also perform compensation control on the turret, such as compensating for the thermal deformation of the turret according to temperature changes. When the temperature of the turret rises during operation and causes the size to change, the system can automatically adjust the position of the tool to ensure that the repeat positioning accuracy is not affected.
In addition, the working environment of the turret will also affect the repeat positioning accuracy. If there is large vibration, temperature change or dust pollution in the working environment, the accuracy of the turret will be reduced. Therefore, when installing a CNC turret, you need to consider taking shock-absorbing measures, such as installing shock-absorbing pads; controlling the temperature of the working environment to avoid excessive temperature fluctuations; and doing a good job of dust prevention to prevent dust from entering the turret and affecting the normal operation of its mechanical and electrical components.
