Cut to perfection

Grob says its 5-axis machining centres flawlessly meet the demands of companies in the aerospace industry for perfect machining of complex or extremely fine, difficult-to-machine components.

In the aerospace industry, both aluminium and difficult-to-cut materials, such as titanium and heat-resistant nickel-based alloys are machined. Thanks to its compact design, high productivity and precision, as well as its optimum accessibility, Grob’s universal machining centre is perfectly suited as a milling or mill-turn machining centre for aerospace companies.

In view of the high costs for blanks and the strict tolerances, components in the aerospace industry must be produced in the highest quality right from the very start. The comprehensive documentation of the machining parameters and of the quality characteristics represents a particular challenge for safety components. The batch sizes are relatively small here, which requires machines and systems to be highly flexible and easy to set up – features that the universal machines of Grob provides. In hardly any other industry is the balancing act between economic efficiency and process reliability greater. Grob’s engineers have risen to this complex challenge and developed the powerful 5-axis universal machining centre series, creating an ideal machine concept that meets these criteria while also meeting individual customer requirements. When it comes to the different, specific requirements, it is worth taking a close look in order to make the best choice for a suitable machine solution.

Unique tunnel design

Thanks to the special axis concept of the universal machining centre, the full tool length can be employed in any axis position, even with maximum part sizes. The Grob tunnel design allows the entire work area to be used, since the motorised spindle and tool can fully retract into the spindle shaft. This enables the use of maximum tool dimensions for maximum component sizes, and allows blisks to be machined with no limitations. The interference diameter of the blisk here corresponds to the work area diameter of the Grob universal machining centres, which means that there are no limitations regarding the blade and tool lengths.

As the Z tool axis is located in the stable cross-slide structure, the distance between the runner blocks remains constant throughout the entire Z-axis stroke. Together with the long distance of the guide shoes to the spindle tip, this results in uniform milling conditions and perfect Z-axis stability. With a vertical spindle position, the maximum blisk diameter depends on the blade height, and therefore also on the tool length. This means that the blisks have to be programmed in advance and inspected with a CAM simulator. The unique overhead machining allows for excellent chip fall and reduces the heat load in the component.

Highly dynamic spindles

High cutting volumes in aluminium processing, but also in hard-to-cut materials, are achieved using powerful motorised spindles with rotational speeds of up to 30,000rpm. Using optimised motorised spindles and rotary axis drives, Grob says its machining centres achieve the highest path velocities, even in 5-axis simultaneous machining. The high-torque motorised spindles are used in the heavy-duty cutting of superalloys. Coolant systems with frequency-controlled high-pressure pumps guarantee a reliable process. Perfect chip disposal due to the horizontal arrangement of the spindles and optional overhead machining are said to make the Grob 5-axis universal machining centres unique.

From an individual machine to automated and interlinked systems, as well as from specialised systems to turnkey processes, Grob provides the aerospace industry with the right concept. The G150, G350, G550 and G750 universal machining centre series, optionally available as mill-turn machining centres, provides a broad range of applications for aerospace components up to a diameter of 1,280mm. This ensures that complex and extremely stable components with a wide range of requirements, such as turbine blades, turbine blisks, structural components, structural housings or brake flap fittings, are cut to perfection.

www.grobgroup.com