Respective amounts of movement of feed axes corresponding to first and second position controllers are determined, and if a value obtained by dividing a smaller amount of movement by a larger amount of movement, in the two amounts of movement, falls within a prescribed reference range, a position controller for the feed axis with the smaller amount of movement selects a detected motor position as a position feedback value and a position controller for the other feed axis selects a detected object position as a position feedback value.

A machine tool includes: a plurality of machining units, each including: a first saddle movable in a right-left direction; a second saddle supported by the first saddle and movable in an up-down direction; and a spindle device supported by the second saddle and movable in a front-rear direction. The plurality of machining units are arranged in the right-left direction such that spindles provided in the respective spindle devices are parallel to each other. The machining tool further includes an X-axis moving mechanism that moves the first saddle in the right-left direction; and a control device that controls an operation of the X-axis moving mechanism during machining of a workpiece and during correction of a spindle spacing between the machining units. A plurality of the X-axis moving mechanisms are provided corresponding to the respective machining units.

Respective amounts of movement of feed axes corresponding to first and second position controllers are determined, and if a value obtained by dividing a smaller amount of movement by a larger amount of movement, in the two amounts of movement, falls within a prescribed reference range, a position controller for the feed axis with the smaller amount of movement selects a detected motor position as a position feedback value and a position controller for the other feed axis selects a detected object position as a position feedback value.

A computer controlled machining system is provided, and includes a multi-axis machining device that is configured to produce a workpiece based on a part print, which outlines nominal dimensions for the workpiece. A dimensional measuring device is configured to take or determine measured dimensions of the workpiece. A compensation processor is configured to take the measured dimensions from the dimensional measuring device and compare them to the nominal dimensions, and to determine a plurality of deviation sets from such comparison. The compensation processor transfers the deviation sets to the multi-axis machining device, which shifts a machine coordinate system based on the deviation sets.

A machine tool includes: a plurality of machining units, each including: a first saddle movable in a right-left direction; a second saddle supported by the first saddle and movable in an up-down direction; and a spindle device supported by the second saddle and movable in a front-rear direction. The plurality of machining units are arranged in the right-left direction such that spindles provided in the respective spindle devices are parallel to each other. The machining tool further includes an X-axis moving mechanism that moves the first saddle in the right-left direction; and a control device that controls an operation of the X-axis moving mechanism during machining of a workpiece and during correction of a spindle spacing between the machining units. A plurality of the X-axis moving mechanisms are provided corresponding to the respective machining units.