Development of a reconfigurable micro machine tool for microfactory

Recently, there have been several interesting researches on the microfactory especially in Japan, U.S., and Korea. Since the microfactory possess the advantage of flexible manufacturing system and/or reconfigurable manufacturing system, we introduced the concept of modular reconfigurable machine structure in our micro machine tool design for microfactory. Modular reconfigurable machine tools can easily perform machining processes of different kinds such as milling, turning, drilling and or grinding by simply adding or exchanging machine tool units or modules. In this study, we have developed a reconfigurable micro machine tool for microfactory, which can be reconfigured from a milling machine to a tuning lathe or vice versa. In structural design of the machine tools, we already studied a new theoretical method of creating machine configurations of modular-reconfigurable machine tools (MRMT) in the preliminary design stage. According to our design methodology, we designed the structural modules and RMTs after reviewing all feasible configurations in the preliminary design stage. By using some modules, we have built RMT based the micro milling machine with enough stiffness. The 3-axis micro milling machine of RMT has a mini-desktop size of 300 mm x200 mm x320 mm and its travel volume is 10x10x10 mm. Dynamic characteristics including natural frequencies and dynamic stiffness of the developed MRMT were analyzed and examined by using F.E.M. and impact hammer test. And we carried out positioning control test and cutting test using a motion controller. Consequently, we successfully developed reconfigurable micro machine tool with reconfigurable structures of milling machine and turning machine for microfactory by means of configuration simulation, structure and module design, FE analysis, and dynamic characteristic tests such as a modal test and dynamic compliance test.