In a machine tool, a control device performs control on an axis member rotating device and a stage rotating device such that when part of a placement region RE in a stage is arranged in a position opposite a spindle cutter in a third direction, in a direction which is at least one of a first direction and a second direction and in which accuracy is required, a screw axis length from a connection portion of the screw axis member of a ball screw and an axis member rotating device to a nut portion is minimized and that the part of the placement region RE in the stage is moved to the position opposite the spindle cutter in the third direction.

A headstock assembly for a machine tool includes a mount having a female threaded bore, a headstock mounted slidably relative to the machine base, a drive member mounted on the headstock, a spindle, and a spindle extension. The spindle has an intermediate segment disposed in a chamber of the headstock and coupled to be driven by the drive member so as to permit the spindle to rotate about a spindle axis. The spindle extension is coupled to be rotatable with the spindle, and has a male threaded segment configured to be in threaded engagement with the female threaded bore so as to permit the headstock to be linearly moved relative to the mount.

A headstock assembly for a machine tool includes a mount having a female threaded bore, a headstock mounted slidably relative to the machine base, a drive member mounted on the headstock, a spindle, and a spindle extension. The spindle has an intermediate segment disposed in a chamber of the headstock and coupled to be driven by the drive member so as to permit the spindle to rotate about a spindle axis. The spindle extension is coupled to be rotatable with the spindle, and has a male threaded segment configured to be in threaded engagement with the female threaded bore so as to permit the headstock to be linearly moved relative to the mount.