Development of a tandem-table-type CNC lathe with four-axis synchronized control

In the present study, we describe a newly developed CNC lathe for realizing non-axisymmetric curved-surface-turning (NACS-turning). The newly developed lathe can be controlled along four axes (X1, X2, Z, and C) and has a three-linear-motor drive system for the X1, X2, and Z axes to control precise, high-speed motion. The tandem table unit, which moves along the X1 and X2 axes, can move at a maximum acceleration of 98.1 m/s² synchronously with the spindle rotational position. Therefore, in order to realize high-speed cutting motion of a machining curved surface as well as suppress the vibration transmission, the inertial forces are made to cancel each other. In the present study, the fundamental dynamic performance and vibration suppression effects of the tandem table were examined.