High-Accuracy Rotating Tables for Large-Dimension Workpieces

Oct. 8, 2014
Rückle Werkzeugfabrik introduced a new swiveling worktable, combining turning and swiveling to achieve multi-face accessibility for machining large workpieces.

The Rückle MRT 800 2xs swiveling table meets the demand for maximum quality in heavy precision machining of aerospace parts.

The extraordinary volume of orders for new aircraft is guiding developments in machining, cutting tools, and automation, in the latter case particularly for systems that handle high-value, large-dimension parts with care, reliability, and efficiency.

Rückle Werkzeugfabrik introduced a new swiveling worktable recently, the MRT 800 2xs, combining turning and swiveling to achieve multi-face accessibility for machining large, workpieces with one clamping. With its rigid mounting and parallel feed, the milling table also gives users extremely good geometric workpiece accuracy and low set-up costs.
The Rückle MRT 800 2xs sets standards in this segment.

Heavy workpieces, e.g., jet engine turbine casings, are put into position at an angle. This is a more efficient set-up and makes the machining process safer than angling the tool relative to the workpiece. Thanks to the combined turning-swivel unit, complex geometries like undercuts and oblique drill holes can be executed with accuracy.

The MRT also offers distortion-free pallet clamping, maintaining dimensional precision for machining workpieces up to 1,600 mm diameter and 1,000 mm high, and for loads weighing up to 4,000 kg.

The uncompensated positioning accuracy of the rotary tables is less then ± 2 arc seconds; the axial and radial run-out accuracy is under 10 µm. The table’s tilting and swivel axis is driven by bevel gear or spur gear units in a master-slave configuration. They are particularly torsionally stiff, and unlike torque motors also provide a high level of safety even in the event of a power failure, according to Rückle.

The rotary actuator consists of a worm gear or torque motor and can be adapted to the requirements of the application. A specially engineered rolling bearing mounting is used in the rotary axis that provides greater degrees of stiffness and accuracies than conventional arrangements.

Another advantage of the swiveling table is the exchangeable middle section. It allows the rotary axis for positioning and milling operations to be replaced with an axis for combined turning and milling operations.

Rückle's modular design principle also allows operators to align the table geometrically following a crash, or to perform repairs on site without having to dismantle the entire unit. Repair costs are manageable thanks to variable exchange of identical spares.