G7 VIPER grinder tackles workpiece sizes beyond G5 capacity
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A larger capacity creep-feed 'very impressive performance extreme removal' VIPER grinder is now available. The Makino G7's 730 by 650 by 730 mm XYZ capacity is aimed at the manufacturing requirements of the larger aero-engines and turbine vanes beyond the G5's 300 mm dia limit.
The Viper G7 has a similar specification to the G5, but differs in having dual rolls to dress the bigger grinding wheels. Metal removal rate is of the order of 80 cc/min. Grinding efficiency comes from a number of factors, including linear rapid traverse rate of 48 m/min and rotary workhead speed of 100 rpm.
Built by the Japanese firm Makino, the 5-axis i-Grinder G7 is based on a machining centre platform. This allows other metal cutting tools such as milling cutters, drills, broaches and turning tools to be exchanged automatically between the tool magazine and the spindle, allowing additional machining operations to be carried out in the same cycle.
Programmable coolant nozzles can be positioned by two rotary NC axes anywhere through 360º around the periphery of the grinding wheel. Nozzle positioning is fast and responsive when changing orientation to ensure that coolant continues to be accurately directed towards the point of cutting at all times.
The first G7 sold in Europe will be used for the manufacture of industrial gas turbine blades and vanes at the Årjäng factory of Hanza Precision AB in Sweden. The turnkey cell will be automated with the addition of a Fanuc robot for unattended machining.
