A servo control apparatus which includes: a difference calculation unit that calculates difference between an integral value of speed deviation of a master axis and an integral value of speed deviation of a slave axis; a filter unit that performs filtering of the difference by way of a low-pass filter; and an addition unit that adds a result of the filtering to the integral value of the speed deviation of the slave axis, in which a current command for driving the master-axis motor is calculated for the master axis by using the integral value of the speed deviation of the master axis; and a current command for driving the slave-axis motor is calculated for the slave axis by using an integral value after addition by way of the addition unit.

A lathe capable of shortening a cycle time of workpiece machining. A lathe includes a first spindle, a second spindle opposite the first spindle, a tool post on which a cut-off tool is provided, and a control unit which controls rotation of the first and the second spindles and further controls relative movement of the first and the second spindles and the tool post to cut-off the workpiece. The control unit adds a rotation speed fluctuation to a rotation speed of the first spindle after rotating the first spindle and the second spindle synchronously and detects a rotation speed of the second spindle. The control unit determines that the workpiece is normally cut-off upon determining that a detected fluctuation in the rotation speed of the second spindle is within a predetermined range.

A servo control apparatus which includes: a difference calculation unit that calculates difference between an integral value of speed deviation of a master axis and an integral value of speed deviation of a slave axis; a filter unit that performs filtering of the difference by way of a low-pass filter; and an addition unit that adds a result of the filtering to the integral value of the speed deviation of the slave axis, in which a current command for driving the master-axis motor is calculated for the master axis by using the integral value of the speed deviation of the master axis; and a current command for driving the slave-axis motor is calculated for the slave axis by using an integral value after addition by way of the addition unit.