A new machining center for five-axis/five-sided machining within an 800 x 800 x 550 mm working envelope has been launched by Hermle of Germany. Designated C 42 U, the machine is ideal for applications in the aerospace, motorsport, tool and mold, and other industries requiring complex, close-tolerance components.
The machine is also offered in MT (mill-turn) version; turning operations at 800 rpm or less can be carried out in the same clamping using the C-axis table mounted on a ± 130° swiveling A-axis trunnion. Parts can weigh up to 700 kg, half the maximum possible (without turning) on machines configured for five-axis machining.
Alternatively, a three-axis machine can be supplied with a fixed table capable of supporting parts more than 1 m long and weighing 2 t.
A modified gantry positions all guideways above the working area. The Y-axis has a tandem drive for high machine dynamics and features a patented arrangement of three staggered guideways, one midway between and set back from the outer two, halving the Y-axis span. Production potential is high owing to 10 m/s² acceleration to traverse rates of 60 m/min in the linear axes.
The spindle features Hermle’s new slimline design to facilitate machining of deep cavities and is available with maximum speeds of 10,000, 18,000, or 25,000 rpm offering up to 29 kW and 200 N•m. The two-part design incorporates six displacement sleeves that collapse to prevent damage to the spindle in the event of a collision.
The SK40 / HSK-A 63 taper provides rigidity for static tooling during turning operations. Unusually, these may be performed not only when the table is horizontal or vertical but also at any intermediate angle, allowing short tool-holders to be used and opening up a wealth of machining options.
Technological and safety requirements that apply to lathes were taken into account in the design of the MT version, and relevant safety standards have been adhered to, notably EN 12417 and EN 12478. Even the upper part of the machine enclosure and roof were considered when designing the guarding.
Another new safety feature is tool measuring and breakage monitoring. Milling tools are scanned by laser and turning tools are measured from two sides by 3-D touch probes.
Construction of the C 42 U lends itself to the addition of high-precision turning. Bearings for the A-axis are set directly into the mineral cast bed, promoting stable, vibration-free machining, particularly as the trunnion is driven from both sides by motors positioned on the axis centerline. The table, with integral balancing system, is driven by a high-torque motor optimized for comparatively high speeds, making it possible to perform combinations of robust roughing and light finishing operations.
The single-lift machine has a three-point support that requires no special foundations and can be transported as a single unit.
Adaptation to partial or full automation is afforded by the entire Hermle range of automation equipment, such as pallet change and storage systems, flexible manufacturing cells including workpiece storage and material flow, or handling systems including robotic configurations. Control system is either the Heidenhain iTNC 530 or Siemens 840 D SL with 19-in screen and 30° tilt. Other options relate to coolant delivery, chip control, and tool management.