A new computer numerically controlled lathe containing a carbon fiber-reinforced plastic pipe frame was developed in this study. The pipe frame structure is lightweight and allows the machine size and stiffness to be adjusted by varying the parameters of the frame structure. Furthermore, using carbon fiber-reinforced plastic instead of steel improves the heat deformation properties of the frame.
When employing a pipe frame structure for machine tools, structural vibration can be problematic. In particular, the relative vibration between the tool and the workpiece must be suppressed to improve the accuracy of the machined surface. To achieve this vibration suppression, an actuator driven by piezoelectric elements was installed in the frame of the developed CNC lathe structure to counteract the vibration at specific modes by applying active vibration control. As a result of using the proposed vibration control method, the vibration amplitude was reduced by up to 88.6% compared with that without control. Additionally, the circularity of workpiece was improved by 27%.
