![\"Research](\"http:\/\/mfgtechupdate.com\/wp-content\/uploads\/2014\/12\/TU2-IMG_4721.jpg\")
<\/a>Research shows cellular machining utilising general-purpose CNC machine tools offers significant advantages over high-end, special purpose machines, with no loss of part accuracy or quality<\/p><\/div>\nThe TU Darmstadt report, entitled \u2018Cellular Manufacturing to enable Lean Machining\u2019, was prepared by Stefan Seifermann, J\u00f6rg B\u00f6llhoff, Eberhard Abele and Joachim Metternich at the university\u2019s Institute of Production Management, Technology and Machine Tools (PTW). Dr. Sven Bechtloff, who has since left the university, was also a key member of the study team.
\nHaas Automation has long-since argued that customers who invest in multiple, affordable CNC machine tools instead of one or two high-end, special purpose machines benefit from greater flexibility, lower investment and running costs and, ultimately, lower cost-per-part. Now, the company\u2019s claim is supported by a recent, independent study on lean machining at the Technische Universit\u00e4t (TU) Darmstadt in Germany.
\nResearch shows cellular machining utilising general-purpose CNC machine tools offers significant advantages over high-end, special purpose machines, with no loss of part accuracy or quality.
\nThe idea for the research was based on a perceived absence of the principles of lean manufacturing applied in widespread machining operations in manufacturing companies of all sizes. Although deployed widely in assembly and process engineering environments (typically in the volume automobile manufacturing sector), the principles of flow as a central element of lean manufacturing have not often been transferred successfully to machining operations, and are rarely to be found at all in Europe.
\n
<\/a>Technische Universit\u00e4t (TU) Darmstadt in Germany carried out the independent study on lean machining<\/p><\/div>\nIn essence, cellular manufacturing is the grouping of heterogeneous equipment (in this case, CNC machine tools) to manufacture a family or group of similar parts. Typically, the concept involves the arrangement of machines in a U-shape to aid flow and balance work-in-progress with \u2018takt\u2019 time (the average unit production time needed to meet customer demand).
\nTo demonstrate the potential advantages, a cellular reference production line has been established at the PTW\u2019s Process Learning Factory (CiP). The \u2018done-in-one\u2019 line features two, high-specification machine tools: a four-axis CNC horizontal machining centre with tombstone fixture, and a CNC multi-axis automatic turning centre. The competing line, a machining cell, features two Haas Super Mini Mill 2 three-axis machining centres and a Haas SL-10 two-axis CNC lathe, as well as two, general purpose CNC machining centres and a CNC lathe supplied by another machine tool manufacturer. The report notes that the investment for the two machines in the \u2018done-in-one\u2019 line totaled \u20ac780,000, while that for the six CNC machine tools in the cell configuration was just \u20ac340,000.
\nAn economic comparison between the two machining line configurations (based on 2000 parts per week, and one worker on each line) drew startling results. The \u2018done-in-one\u2019 line required 15 shifts to complete the 2000 parts. The lead-time was 35 minutes, while the unit cost of each part (without material) was calculated at \u20ac3.95. Using a cellular machining configuration, however, it took just 12.6 shifts to finish the 2000 components to an identical specification, lead-time was reduced to 10 minutes, and unit cost to just \u20ac2.55.
\n