A machine tool comprises: a servomotor feeding a workpiece or a tool; a motor control section controlling the servomotor; and a processor connected to the motor control section, in a parameter adjustment mode while rotating a load by the servomotor with a given speed command issued to the motor control section under a condition where torque is limited, the processor calculating load inertia based on the torque and an angular acceleration of the servomotor that is obtained based on an output from the servomotor, calculating a parameter based on the load inertia, and adjusting a control parameter set to the motor control section based on the parameter.

A machine tool comprises: a servomotor feeding a workpiece or a tool; a motor control section controlling the servomotor; and a processor connected to the motor control section, in a parameter adjustment mode while rotating a load by the servomotor with a given speed command issued to the motor control section under a condition where torque is limited, the processor calculating load inertia based on the torque and an angular acceleration of the servomotor that is obtained based on an output from the servomotor, calculating a parameter based on the load inertia, and adjusting a control parameter set to the motor control section based on the parameter.

To dynamically change the acceleration without trial executions of a machining program, a numerical control device, which controls a motor on the basis of a machining program that specifies a path for a drive target of the motor, includes a changing unit that changes the acceleration of the motor under the control of the motor on the basis of the inertia ratio, the acceleration-deceleration factor that can be externally input, or the current value of the motor.

A numerical controller includes a command analysis unit that generates movement command data by analyzing a program command and an axis travel calculation unit that, when the program command commands movement of a tool in a direction of a first straight axis orthogonal to an axis of rotation of a workpiece, converts a command value based on the program command for the movement of the tool in the direction of the first straight axis into a command value for a rotation angle of a turret, and a position of the tool is controlled in accordance with a rotation command for the turret based on the command value for the rotation angle of the turret calculated by the axis travel calculation unit, instead of the command based on the program command for the movement in the direction of the first straight axis.

A machine tool system has a machine tool with a stationary machine base, support elements connected to the machine base, and a crossbeam connected to the support elements. The crossbeam is adjustable relative to the support elements in a Z-direction or the support elements are adjustable relative to the machine base in an X-direction. A tool holder head is mounted on the crossbeam and adjustable for travel in a Y-direction along the crossbeam. The X-, Y- and Z directions form a cartesian coordinate system. A control facility is connected to the machine tool for controlling travel in the Y-direction and adjustment in at least one of the X- and/or Z-directions based on a kinematic parameter specified as a function of a position of the tool holder head relative to the Y-axis and thus takes into account asymmetric load distribution caused by movement of the tool holder head.