The invention provides a machine tool eliminating the need of keeping the removed feed-mechanism-protection cover outside the machine. The machine tool comprises a headstock provided with a main spindle for gripping a workpiece; a driving unit provided with a feed mechanism extended along a main spindle axis to move the headstock in a main spindle axial direction; a supporting bed provided with a guide bush in a removable manner; a first cover mounted on the headstock to protect a portion of the feed mechanism with respect to the main spindle axial direction; and a second cover removably mounted on the headstock on the front side of the first cover to protect another portion of the feed mechanism. The second cover is detachably attached to the first cover when removed from the headstock.

A machine tool includes a displacement measuring unit to measure the displacement of a workpiece center-to-blade tip distance which is the distance between a center equivalent position of a workpiece support surface of a workpiece support unit and a blade tip equivalent position of a tool support unit in a direction perpendicular or substantially perpendicular to a spindle axis. The displacement measuring unit measures the displacement by measuring the displacement of a continuous path between the center equivalent position of the workpiece support unit and the blade tip equivalent position and excluding a processing movement region. The displacement measuring unit includes workpiece side and tool side linear position detecting units. A measured value of the displacement measuring unit is used in correcting an X-axis command value.

A lathe control system used for three dimensional curved surface machining includes an input module, a control module, a work table, a feeding module, a first sliding module, a second sliding module, and a cutter. The control module is electrically connected with the input module, the feeding module, the first sliding module, and the second sliding module. The first sliding module drives the feeding module to move along a first direction. The second sliding module drives the feeding module to move along a second direction perpendicular to the first direction. The cutter is positioned on the feeding module. The feeding module is capable of driving the cutter to move back and forth along a third direction under the control of the control module. The third direction is perpendicular to first and second direction.

A lathe control system used for three dimensional curved surface machining includes an input module, a control module, a work table, a feeding module, a first sliding module, a second sliding module, and a cutter. The control module is electrically connected with the input module, the feeding module, the first sliding module, and the second sliding module. The first sliding module drives the feeding module to move along a first direction. The second sliding module drives the feeding module to move along a second direction perpendicular to the first direction. The cutter is positioned on the feeding module. The feeding module is capable of driving the cutter to move back and forth along a third direction under the control of the control module. The third direction is perpendicular to first and second direction.