GROB introduces the G750 and enhances the performance of its universal machines
GROB is relaunching the drive concept of its G350 and G550 universal machines; the axes of these machines have been comprehensively improved and redesigned with respect to dynamics, acceleration and speed. GROB has created not only a new generation of universal machines with an impressive drive concept; the newly-developed G750 is another milestone which tops off the G-series.
Mindelheim/Hanover. At the GROB-WERKE in Mindelheim, the universal machine business is increasingly growing in importance. Now GROB engineers have further enhanced the performance of their G350 and G550 universal machines and are displaying the new machine generation for the first time at the EMO in Hanover. The G-modules were completely revamped with respect to the drive concept in the workpiece-carrying A and Y NC axes. In addition to the B axis, the A axis was likewise equipped with a non-wearing torque motor, thus increasing acceleration by a factor of 2. The drive of the Y axis was divided into two recirculating ball screw drives lying symmetrically to the center of the A axis; the drive force application points were moved considerably toward TCP (Tool Center Point). In this way both the static and dynamic rigidity of the machine’s workpiece-carrying assembly could be significantly increased. This is an advantage that has already been proven in a practical trial by a reduced peak time during a 5 axis simultaneous machining operation.
After GROB’s earlier successful market introduction of the G350 and G550 universal machines, it was logical that this innovative machine concept should advance in a version with greater dimensions. The G750 tops off the G-series. It features an X, Y, Z workspace of 1,000x1,100x1,170 mm; the result is that large workpieces for mold-making, the aerospace industry and general machine manufacturing can be ideally machined. Like all G-modules in the universal machine sector, the G750 has spacious free access to the workspace. A hydraulics-free pallet changer can be added as an option. The machine is available in 340 and 575 Nm (40% ED) spindle variants using a HSK-A100 tool holder. The tool magazine holds 60 tools; this can be expanded to 212 tools by an additional magazine.
As an option, GROB also offers a version with a HSK-A63 tool holder with 46 and 206 Nm (40% ED), as well as a spindle providing 30,000 rpm and 63 Nm. In the milling/lathing version with the HSK-T100 interface, the motor spindle provides 340 Nm and can be fixed in position for turning. The special feature: fixing in position relieves the spindle bearing from the machining forces. For a workpiece diameter of 1,280mm, the rotary table will allow a max. speed of 500 rpm and generates a drive torque of max. 4,050 Nm.
The drive concept of the workpiece-carrying A, B and Y axes corresponds to the smaller G350 and G550 machines. The spindle-side X and Z feed axes use linear motor technology in the G750 machine. These non-wearing drives achieve a consistently high positioning accuracy and control precision. The rigidity of the entire machine construction
Mrs. Grob visits the EMO