Miniaturized parallel kinematic machine tool for the machining of small workpieces

Machining small workpieces with large scale machine tools has several disadvantages such as high costs, low efficiency and higher sensitivity to errors. Miniaturizing the machine to workpiece scale is a suitable approach to overcome certain limitations. However, this measure also leads to significant changes in machine properties even if the kinematic structure remains unchanged. On the basis of a parallel kinematic machine tool the paper investigates size effects and machine characteristics during dimensioning and design process. Static stiffness of joint bearings and overall dynamic behaviour are analysed to derive and prove certain design measures. Furthermore the influence of miniaturization on structure synthesis and feed drive dimensioning is shown. The paper concludes with final design and specifications of the developed parallel kinematic machine tool.