Fast reacting maintenance of forming tools with a transportable machining unit

In sheet metal forming damages of the free formed tool surfaces occur due to wear or foreign bodies. Fast reacting maintenance is necessary to avoid bottlenecks in workpiece supply of subsequent production steps. A transportable hybrid kinematics machining unit has been developed for repair processing of metal forming tools near the production line. This paper describes strategies to improve the positioning accuracy of the machining unit and methods for optimised surface digitising with an integrated touch probe. Calibration of the hybrid kinematics is based on an enhanced kinematics model which allows the description of geometric errors, compliance and thermal effects.