Ultimate sparring partner

Based around two Handtmann 5-axis machining centres with 10 m beds and 110 kW spindles able to achieve metal removal rates of 12 litres per minute, machining cells of this nature are not installed every day. But then producing wing spars is not what you would call 'everyday' machining. Image: The Handtmann machine's spindle removes up to 80 per cent of each billet Aerospace grade aluminium alloy (7000 series) billets, costing thousands of pounds, measure up to 18 m long and 150 mm deep. Weighing over 2,000 kg, a staggering 80 per cent of the metal is removed by machining on both sides to produce a finished wing spar, with a pair of spars created from each billet. With 3,500 employees worldwide, the Canadian-owned Magellan Aerospace Corporation is a rapidly expanding empire, nowhere more than here in the UK. Following its recent acquisitions of Mayflower Aerospace plus Moore's and Verdict Aerospace, Magellan Aerospace (UK) Ltd, which is part of the corporation's Aerostructures Division, now has three UK manufacturing sites, at Wrexham, Bournemouth and Chalfont St Peter, respectively. The success of a recently installed wing rib machining cell at Bournemouth, set the Wrexham site thinking about approaching wing spar machining in the same way, as Paul Rhodes, chairman of the Engineering Technology Group, UK agent for Handtmann, explains: "The aim was to introduce a super-efficient cell, capable of staving-off competition from the Far East," he says. FAST AND COMPETITIVE Magellan sized up a number of suppliers of large, 5-axis machining centres capable of providing turnkey installations, but Handtmann demonstrated very fast cycle times, in combination with an attractive price tag to secure the order. The key here centres round swarf management. Turning 80 per cent of such large aluminium billet into chips presents obvious challenges. The vertical, portal design of the Handtmann PBZ-HD machines score because they feature a travelling table, rather than a travelling gantry, so the point of swarf removal is fixed. This is crucial, because each billet produces around 1.8 tonnes of swarf and, with a value of around £600 a tonne for recycling, the impact on profitability is huge. "The whole system is self-contained," says Haydn Martin, commercial and business development director at Magellan Aerospace UK. "Coolant is separated and re-used, while swarf is collected and compacted by briquetting machines sat behind each Handtmann machining centre." The Handtmann PBZ machines sit side-by-side and are fully linked by an integrated FMS to minimise wing spar changeover times. The automation centres on a palletised system featuring zero-point location to offer up to 12 hours' unmanned running a day and a further 36 hours of unmanned operation at the weekends. Already running at 90 per cent utilisation, the impact of the new manufacturing cell is massive. Back in 1999, front spars for the Airbus A320 were machined on a Henri Liné machining centre in 72 hours floor-to-floor time. Extensive production engineering scrutinising factors, such as loading, machining parameters, cutting tools and workholding, reduced the cycle time to 36 hours by 2007, but this was perceived to be the threshold of what could be achieved. The automated Handtmann machining cell, featuring 70 m/min feed rates and 1G acceleration, has already reduced this by a further 30 per cent, with additional gains anticipated. Moreover, this improvement has been achieved at around 50 per cent of the cost of traditional multi-spindle gantry technology. Other spars to be machined in the new cell include the A330/A340 inner rear and mid-rear spars. PARTNERSHIP PAYS OFF The installation is a £5 million investment that has come about as a result of the partnership between Magellan Aerospace, the Welsh Assembly, Airbus, Handtmann and the Engineering Technology Group. The Welsh Assembly Government invested generously in the project, via its Single Investment Fund. With 180 aerospace firms located in Wales and 20,000 people employed, the Welsh Assembly is keen to build on the Principality's growing reputation for aerospace excellence. Ieuan Wyn Jones, Minister for the Economy and Transport, says: "This significant investment ensures the Magellan facility in Wrexham is in pole position to bid for and win new business. The aerospace sector is highly competitive, which makes this investment so important, providing Magellan Aerospace with one of the most modern and efficient new spar machining facilities in the world." The ribbon on the new facility was cut by local MP David Hanson in front of more than 100 guests, who included representatives from key customers, such as GKN, BAE Systems, Spirit AeroSystems and Airbus. "We needed a good understanding between all parties to put in place a common framework for an investment of this size," underlines Norman Hardie, vice president and head of procurement, Airbus A350. "I congratulate Magellan on their state-of-the-art spar machining facility. As a company, Magellan continues to meet our four main supplier requirements: transparency; maximum support in achieving cost savings; equipment flexibility and adaptability; and the effective management of their own supply chain." The new cell at Wrexham will indeed support orders awarded recently by Airbus for the A350 XWB twin-aisle aircraft. The package consists of a number of large, complex machined aluminium-lithium components for the aircraft centre wing box, including rib 1 and a range of attachment fittings and flange ribs. The orders comprise around 30 machined aluminium details worth $80 million over six years. Comprising an estimated 800 CNC programming hours, delivery of the first parts will commence in May 2010 to meet rising demand. Already with more than 500 orders from over 30 customers, Airbus says that the A350 XWB is shaping up to be the future of air travel. Dave Micklewright, head of facilities management and real estate at Airbus, is equally excited and pleased with the new manufacturing cell at Wrexham. "This is a great example of the UK investing in its manufacturing future," he says. "Going back 10 years, the wing supply base in the UK was a mess, based on failing and fragmented relationships. Since then we've scrutinised and reassessed the whole bill of materials. With Airbus deliveries climbing from 300 to 500 in the past decade, the spar machining cell at Magellan is representative of how far we've come. If you think about it, 40 passenger planes a month is quite staggering, by anyone's standards." Despite all of the fanfare, the new cell is only part of Magellan's journey towards manufacturing excellence, as Mr Martin points out: "The spar machining cell is a significant investment for the company and will enable us to compete on the global stage for aerospace components. However, we are also planning further investment in new equipment during 2010. For example, we are looking to acquire a new high speed machining centre for the production of A350 wing box ribs and a similar machine to produce A320 freighter bulkhead parts. We will also be investing £200,000 in extending the Wrexham facility to add a further 6,000 sq ft." Box Item 1 Securing Magellan's future in Wrexham The Wrexham facility of Magellan Aerospace UK produces parts typically over 3 m in length, with shorter components machined at either Bournemouth (0.5 – 3.0 m) or Chalfont St Peter (up to 0.75 m). Spars, butt straps, ribs and thrust fittings are commonly seen coming off the production lines at the 131,000 ft2 North Wales plant. Image: The Wrexham facility of Magellan Aerospace "We now machine the A320 mid rear spar in just six hours, achieving 12 litres per minute metal removal, which I believe to be a world record," says Adrian Young, operations manager at Magellan Aerospace UK, in speaking about the Handtmann installation. "Our existing Henri Liné machine only removes metal at a rate of 2 litres per minute." Image: Magellan's Adrian Young alongside one of the machined wing spars, with the Handtmann machine in the background It is estimated that the new manufacturing cell will generate £12 million in revenue to help secure the company's future at Wrexham and that of its 340 employees. Around 2,500 spars will be produced every year from 6,000 tonnes of aluminium – approximately 5,000 tonnes of which will be turned to swarf and recycled. Magellan freely admits that components not fitting its core competencies are sub-contracted to either UK or overseas supply chain partners to "get the best deal for customers". Box Item 2 At the sharp end The Handtmann PBZ HD machining centres feature a working envelope of 10 by 1.5 by 1 m. Rotation is ±100° in the A-axis and ±225° in the C-axis. The machines can accommodate 15.5 tonnes of loading capacity (pallet 4 tonnes, payload 11.5 tonnes). The direct driven (torque motor) milling heads are fitted with HSK63A Fischer MFW 2320/30 spindles, giving output of 110 kW and 30,000 rpm. The machines also feature a 36-station disc-type automatic toolchanger and Siemens 840D CNC controls. There are now six Handtmann machining centres in the UK, with three of them purchased by Magellan Aerospace. Cutting tools employed by Magellan on the Handtmann machines are manufactured typically by Mitsubishi Carbide and Technicut, and supplied by Cromwell Tools. The cutters are mounted in Haimer shrink-fit toolholders supplied by Fenn Tool, which Magellan says are selected because they guarantee G2.5 balance at 30,000 rpm. On-machine probing, provided by Renishaw, is used to check tolerances, as tight as 0.02 mm in some instances. Coolant is both supplied and managed at Magellen's Wrexham and Bournemouth sites by Houghton Europe, via its Fluidcare programme of process improvement cost saving initiatives and technical expertise. First published in Machinery, January 2010