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To reduce production costs and increase accuracy when producing complex parts requiring rotational as well as prismatic machining, Hermle has introduced a 5-axis machining centre capable of turning components in the same clamping.

Called C 50 U MT dynamic, the machine is available in the UK through Geo Kingsbury Machine Tools, sole agent for the German manufacturer.

To enable turning operations, a workpiece weighing up to one tonne is rotated at up to 500rpm on the integral table (C-axis), which is mounted on a +30°/-115° swivelling trunnion (A-axis). The table has a 1,000mm diameter clamping surface and sits within a 1,000mm x 1,100mm x 700mm working envelope.

Taper options for the main spindle are HSK-T, sizes 63 and 100, providing 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 toolholders to be used and opening up a wealth of new machining options.

The MT version is a derivation of the Hermle C 50 U machining centre and offers identical 5-axis prismatic metalcutting functionality, but is not simply an upgrade. Technological and safety requirements that apply to lathes have been taken into account 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 3D touch probes.

The construction of the C 50 U lends itself to the addition of high precision turning and 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 mid way between and set back from the outer two, halving the Y-axis span. Production potential is high owing to 6m/s² acceleration to traverse rates of 60m/minute in the X and Y axes, 55m/minute in Z.

Bearings for the A-axis are set directly into the cast iron bed, promoting stable, vibration free machining, particularly as the trunnion is driven from both sides by motors positioned on the axis centreline. The table with integral balancing system is driven by a high torque motor optimised for comparatively high speeds, making it possible to perform combinations of robust roughing and light finishing operations. Compared with competitive machines, Geo Kingsbury claims that the C 50 U MT has a significantly larger maximum collision contour, which means that a larger workpiece can be machined in one hit, without having to waste time and lose accuracy by repositioning and re-clamping.

Hermle has developed a modular, 42 position tool magazine that can be added to supplement the internal magazine of similar capacity. It allows a sufficient number of cutters to be deployed for complex work and/or where long machining cycles require the use of sister tools.

Designed as a compact rack, the extra magazine is installed behind the machining centre and the operator has unrestricted access at ground level for ease of loading and removal. Tools may be up to 250mm in diameter, 430mm in length and 30kg in weight.

Geo Kingsbury
www.gkholdings.com