Development of movable machine tool with multi spindles and axes (Evaluation of machining accuracy in simultaneous multi spindle machining)

A movable machine tool with multi spindles and axes is newly developed which can efficiently process large-sized parts to expect an additional value. The main specification of the machine tool is not having the major construction such as bed, column and saddle, at all. Instead, the machine tool consists of only linear motor rails and beams to support. The developed machine tool can reduce the cycle time for cutting large size workpieces by means of multi spindles and axes, equipped with 6 to 9 spindles, and can simultaneously control up to 40 axes at maximum. In addition, the installation area of the machine tool is approximately 120% of area that the workpieces occupies. The previous reports explained the basic specification of the machine tool, its concept and performance evaluation, the management of simultaneous movement, the division of NC program for each spindle and interference avoidance, as well as the method of tool path generation to confirm the rapid production of large-sized die and mold. With measured results of parallelism, roughness, squareness, roundness, and bumpness, the study propose a new compensation method to improve the machining accuracy of the machine tool with multi spindles and axes.