Small machine tools for small workpieces

The industrial micro manufacturing is changing! The trend is moving away from the one-dimensional mass production to an increasing variety of products coupled with falling numbers and shorter innovation cycles. Today’s ultra-precision machines are rarely operated economically under these conditions. Here, in micro manufacturing the demand rises for new, size-adjusted machine tools that operate more economical and ecological than before. These needs can be derived from a consideration of simple parameters, such as the installation space, size of the working space and need for operating power or the moving masses of machine tools. These parameters are in considerable disproportion to the volume or mass of small workpieces of only few millimeters with structures in micrometer range.

This is where a completely new concept of industrial micro production is set, which was developed in the Priority Program SPP 1476 ”small machine tools for small workpieces” funded by the German Research Foundation (DFG). Under the coordination of Institute of Production Engineering (LaFT) of Helmut Schmidt University in Hamburg, 18 leading production technology institutions of various German universities investigated on new machine tools for micro production.

The idea of the SPP: We make the machines so small, light and flexible, as they can be to be rebuilt and converted for changing needs in shortest times. Therefore the machine tools are introduced and positioned to the workpiece depending on the machining task – and not vice versa as before. What is new is that their work space can interfere with the space section of the workpiece. This allows multiple machines to work simultaneously on a workpiece and, as required, placed flexible side by side, one above the other or in a row. Nevertheless, the technology works accurately and precisely.

Just like a Lego game, companies can respond to changing ideas, processing technologies and requirements at any time. If new parts are needed, they can be easily attached to the machine via multifunctional interface. So an ad hoc change between micro tool spindles, laser processing optics or EDM electrodes is possible. The control operates via a laptop or PC. It also followed by the idea of Open Production – the user community constantly develops the system further. The advantage of this completely new technology: it not only saves time, resources and space, it uses a worker more targeted and effective. The first prototypes are developed. With mass production of such a machine, costs drop down to just under a fifth of conventional production systems.

The aim of the Priority Program is the development and prototype testing of scientific methods for building new machine tools for micro production, which are adapted to characteristic technological and technical parameters of the corresponding micro workpiece. In the Priority Program the main focus is on machine tools for material removal process utilising mechanical (machining), thermal (laser), electro thermal (electrical discharge machining) and electrochemical energy. These new machines have technical, economic and ecological benefits. They enable production of complex parts with higher accuracy from a large range of materials and are also characterised by a higher inherent variability in structure and location of the installation site. Economic and ecological advantages are realised by low costs and lower consumption of resources for the development and operation of the machine. In particular, steep improvements of the mentioned properties are achieved by bringing down the critical size of the developed manufacturing equipment.

After falling below a certain size, small machine tools enable the introduction of new or known but still unused machine tool technologies and elements. As opposed to today’s evolutionary development of the machines, these technologies enable innovative leaps, i.e., revolutionary steps in the development and operation of the machines.

At the Hanover Fair desktop-size machine tools are presented, which were composed in exemplary configurations of the newly developed tool, feed and additional modules. The modules have been designed so that different machine tools can be assembled and disassembled ad hoc and task oriented from the mentioned modules.