Derivation of Design Guidelines for Miniature Machine Tools

As has been demonstrated the “microfactory”, which is a miniature manufacturing system proposed by the author and his research group, small machine tools that are comparable in size to their target products lead to large reductions in energy consumption and occupied space. They also increase the flexibility of system reconfiguration because of their low weight and small size. Although it had been thought that micro machine tools might not have sufficient metal cutting capability, experiments showed that were capable of micro mechanical fabrication. However, the design of miniature machine tools has not been fully optimized. For example, the design target of the first prototype, a performable miniature machine (“Micro lathe”), was to make the overall size as small as possible. The author proposed a design evaluation method to roughly estimate machine tool performances during its early design stage. In this paper, the above-mentioned design tool is applied to find suitable miniaturizing strategies. By applying the design tool to the miniaturization of machine tools, it is possible to determine which of the design candidates have the best theoretical performance and which of the local error factors would significantly affect machine performance. From the results of calculation, the tool can clarify the difference of effect of error sources on performances between normal machine tools and miniature machine tools. This leads to some suggestions regarding structures, sizes and suitable machine components. Design guidelines for miniature machine tools can be obtained from the information.