A machine tool of the present embodiment includes: a column that is disposed in a vertically standing manner and has a predetermined linear expansion coefficient; a spindle head that is supported by the column and supports a horizontal spindle for attaching a tool thereto; and a reference bar that is disposed separately from the column and has a linear expansion coefficient that is different from the linear expansion coefficient of the column wherein the column has a column-side measurement target zone, the reference bar has a reference bar-side measurement target zone, and a measurement means measures a distance between the column-side measurement target zone and the reference bar-side measurement target zone.

A method for controlling the motor of a tool magazine that rotates around a horizontal rotation axis is configured so that: at least two indexing positions for the tool magazine are determined; the load torque acting on the tool magazine when stopped at said indexing positions is measured; an unbalance torque, which is the load torque when stopped at the indexing position at which the load torque when stopped is maximal, is calculated from multiple load torques when stopped; and the servo motor for the tool magazine is controlled on the basis of the unbalance torque.

A counterbalance and drive system for a machine slide mechanism includes a counterbalance system having a first flexible connector suspended from a machine mount and interconnecting a slide mechanism and a counterweight and a drive system having a second flexible connector suspended from the machine mount and interconnecting the slide mechanism and the counterweight. The drive system includes both a drive motor operatively engaged along a length of the second flexible connector for vertically displacing the slide mechanism and a compliant connector operating within a limited range of compliance that imparts a regulated amount of tension along at least a portion of the length of the second flexible connector between the engagement of the drive motor and the counterweight.

A transfer center for machining at least one workpiece is disclosed, having a machine frame, having a plurality of preferably stationary machining spindles arranged in the machine frameparticularly in a machining head, having a workpiece carrier on which at least one workpiece to be machined is arranged by means of a respective clamping device, and having a workpiece manipulator arranged in the machine frame, onto which workpiece manipulator the workpiece carrier is flange-mounted and which is movable by drive means in at least one spatial direction in relation to the machine frame. To achieve a high machining accuracy in parallel machining, according to one proposal, the transfer centerin order to compensate for a deviation between the actual position and the desired position of the workpiece or workpieceshas a position compensation system with at least two pressure elements situated between the workpiece or workpieces and the machine frame, whose operating directions enclose an angle with each other.

The present disclosure relates to a sag compensation apparatus of a machine tool and a machine tool including the same, in which in case of sag of a cross-rail occurring due to transfer of a saddle and a ram spindle unit, hydraulic pressure compensates for the sag in real time, thereby improving machining precision and maximizing responsiveness and reliability.

A machine tool includes a base frame, a work spindle for receiving a tool, and a swivelling bridge for receiving a workpiece, wherein the swivelling bridge is configured such that it can swivel about a swivel axis, and wherein the swivelling bridge is received such that it can swivel on a first swivel bearing and a second swivel bearing. A workpiece holder for directly or indirectly receiving the workpiece is provided on the swivelling bridge, wherein the workpiece holder is arranged between the first swivel bearing and the second swiven bearing. The movements of the machine tool are controlled by a digital computer. A deflection compensation device for compensating for tilting of the workpiece due to deflection of the swivelling bridge is provided on the swivelling bridge.