Giant Alumax adds to productivity at Airbus UK

Citation

(2002), "Giant Alumax adds to productivity at Airbus UK", Aircraft Engineering and Aerospace Technology, Vol. 74 No. 1. https://doi.org/10.1108/aeat.2002.12774aab.009

Giant Alumax adds to productivity at Airbus UK

Keywords: Aircraft, Wings, Manufacture

A large-capacity Alumax long bed gantry machine from AB Marwin is reported to be dramatically reducing product cycle times for the manufacture of aircraft wings at Airbus UK's Broughton facility. The machine's performance and versatility complement an ability to handle massive components and is said to have earned the Alumax widespread support among its operators (Plate 4).

Plate 4 Large capacity alumax

The state-of-the-art long-bed machine plays a crucial role in the manufacture of the four aluminium panels which together make up the under-side, or "bottom skin", for the wings on Airbus' A340-500/600 long-range airliner, currently the largest aircraft manufactured by Airbus. Built to dimensions specified by Airbus, the Alumax features an X-axis made up of 3m cast iron sections totalling 40.5m, two Y-axes of 3m and a Z-axis of 600mm, making it the largest twin-bed machining centre ever built by the Wolverhampton-based machine tool specialist. Used predominantly for the high speed milling of the wing's surfaces, the Alumax also performs a variety of drilling and profiling operations on the massive 2024 aluminium alloy billets, which are typically 32m long, 3m wide and 35mm thick.

The Alumax's machining operation forms part of a tightly controlled manufacturing process which

also includes deburring, inspection, anodising and crack detection, painting and finally delivery. The machining centre works in conjunction with a dedicated material handling system featuring an overhead monorail and vacuum lift for transporting the enormous aluminium components. The nature of the application required a reliable highspeed machine capable of performing a number of operations on massive components. The Alumax has been designed specifically with this demanding application in mind and has helped enhance manufacturing capabilities at Airbus.

Key operations performed by the Alumax include the precision milling of intricate internal structures on the inside face of each panel, to make way for "stringers", "spars", "ribs" and other components vital to wing assembly. "Skimming" and the creation of "root ends" and "tapers" are also performed on the outside face of panels. Consistent panel thickness is a crucial requirement of wing skin production and despite the enormous size of the components machined on it, Renishaw part probing and X-axis laser feedback enable the Alumax to produce components within a thickness tolerance of ±0.13mm and 0.08mm.

Another important factor in the Alumax's all-round appeal is its innovative dual "Y" axis, which allows the simultaneous machining of both port and starboard wings, reportedly resulting in dramatic reductions in product cycle time. In an application which involves the removal of 80 per cent of the billet's original material volume, the ability to machine a pair of wings simultaneously has proved a major benefit, helping to streamline manufacturing operations considerably.

High metal removal rates also contribute to the Alumax's impressive performance and are thought to be another advantage whose importance is magnified by the sheer scale of metal removal involved. A typical "roughing" metal removal rate approaching 4003 inches (6554.83CM)/Minute has reportedly amounted to an increase in machining feed rates from a previous rate of 5m/minute to 7.5m/minute on the Alumax. Finishing rates are said to have undergone an even greater improvement, reportedly increasing by over 100 per cent from 8m/ minute to approximately 20m/minute. Such performance is stated to be the result of the Alumax's two 85kW Weiss spindles, capable of up to 20,000rpm and working in conjunction with a feed rate of up to 20m/ minute. Each spindle features a dedicated auto tool-changer which has contributed to reductions in cycle time while improving operator safety levels.

Operator safety is paramount at Airbus UK and the Alumax is said to incorporate features designed to minimise the risk to those using the massive machining centre. Firstly, machine operation is performed from an isolated control booth which eliminates the need for users to work from the moving gantry, an important safety factor given the machine's rapid maximum feed-rate of 20m/ minute. Direct contact between the machine and operator is reduced further by the incorporation of state-of-the-art Renishaw part probing and Blum tool probing, both of which increase the machine's level of automation while contributing to its machining accuracy The Alumax's guarding is stated to enclose all moving parts and reportedly complies with current safety legislation.

Control of the Alumax is achieved through a Fanuc 15MB system, a system new to Airbus' Alumax operators but one whose user-friendly windows-based software has proved versatile and easy to learn. Tacoma's Adaptive Control System performs the role of monitoring machine status to provide essential feedback on all major spindle operations and on-line remote diagnostics are an optional extra soon to be added to the Alumax.

AB Marwin Believes that with round-the- clock operation, seven days per week, the Alumax has proved a valuable addition to Airbus' manufacturing operations since its introduction in August 2000. The machining centre came with a full twelve-month service agreement which guarantees a twenty-four hour response time in the unlikely event of a technical problem.

The company considers that Alumax's ability to perform a range of accurate, high- speed machining operations on two enormous components simultaneously, has enabled Airbus to achieve dramatic reductions in product cycle time while maintaining levels of consistency which are crucial to the process of wing skin production. It also believes that the machining centre's safety conscious design and ease-of-use, coupled with the peace-of- mind provided by the company's technical support, has added to the overall appeal of this state-of-the-art long-bed machine.

Details available from, AB Marwin Ltd, Tel: +44 (0) 1902 390400; Fax: +44 (0) 1902 390500; E-mail: sales@abmarwin.com