Machining centre duo for aerospace specialist

Citation

(2005), "Machining centre duo for aerospace specialist", Aircraft Engineering and Aerospace Technology, Vol. 77 No. 6. https://doi.org/10.1108/aeat.2005.12777fab.001

Machining centre duo for aerospace specialist

Keywords: Aerospace engineering, Machining centres

It is reported that the installation of two long-bed Dugard Hedelius travelling- column style vertical machining centres at specialist aerospace sub-contractor AIM, has not only cut cycle times by at least 15 per cent on a variety of three- axis parts through increased spindle power, but also because components can now be multi-loaded on the machines' expansive beds more components are now being machined in the same set-up through the adoption of pendulum machining routines.

The result is that spindle downtime is minimised, overall output is increased and operators have been freed-up to do other tasks while the machines run unattended.

According to Managing Director Rob Kendall, the potential advantages of the machines' increased spindle power, the pendulum machining opportunities (on parts of suitable size) and improved operator utilisation were immediately realised when the decision was made to replace a pair of ageing, lower- specification milling machines.

“With their respective X axes capacities of 2.5 and 5.8 m, the older machines had served us well,” he says, “but as part of our continual investment programme, it was time they were renewed and replaced by faster, higher-specification equipment.”

“We process a wide variety of components ranging from one-off development prototypes through to tiny turned parts and wing spars measuring 5.5 m long, and while we regularly use the Hedelius machines' full X axes capacities on certain single parts we also knew we could capitalise on the machines' travelling column design/pendulum machining capabilities to enable us to `work smarter' on smaller components.”

AIM's pedigree of continual improvement has, in fact, characterised the Clevedon (North Somerset) operation since its establishment 33 years ago by Rob Kendall's father, Ken, who at 72 years of age is Chairman and continues to play an active role in the 40-employee operation.

With its roots in the design and development of special-purpose machines (hence AIM – Automatic Industrial Machines) the firm evolved into the world of general sub- contracting then into the manufacture of jigs and fixtures for a variety of clients, including aerospace companies.

Its prowess at producing quality work, on time and at the correct price soon saw it become involved in the manufacture of flying parts, and today it quotes global giants such as Airbus UK and BAE Systems among its client list alongside a swathe of blue chip first-tier suppliers who reflect AIM's approvals from Airbus UK, BAE Systems and the GKN Westland Group, as well as its ISO 9002/TS 157 accreditation.

With much of the aerospace work being produced in “component packages” containing any number of parts and involving a mix of both shaft- type and prismatic machining – and occasionally assembly work surrounding test panels for Airbus – AIM'S ability to utilise men and machines to maximum effect has been driven as much by customers' increasing demands for cost- down supply as it has by a personal desire for continual improvement.

Like father like son, Rob Kendall is adamant that continual investment is the way forward, and the shop floor reflects that with an impressive array of high-specification machine tools being used to process the predominantly aluminium workplaces.

“It seems that so many engineering companies are stifled by accountancy – they have no freedom to invest to exploit new markets and new opportunities,” claims Rob Kendall.

“Our philosophy has always been that if we can see a benefit to the business, then we invest because if you don't change and move forward you get left behind. Evidence of this is the fact that not so many years ago this area was home to 30 or more aerospace- orientated subcontractors, whereas today there are only two or three.”

AIM's considerable investment in the Hedelius machines is a case in point. He continues: “Even though when we installed the second machine, the larger capacity 6.5 m model, we were not producing such large parts, we recognised the benefits of pendulum machining and knew the machine would reinforce our policy of always staying one step ahead of the competition by offering a service with which others find it hard to compete.”

“While we know that the machines' increased spindle speeds and traverse rates have cut cycle times, we've never actually measured the time savings gained via increased spindle uptime and improved operator utilisation – but the rewards are clearly visible.”

The benefits generated by the Hedelius duo are being felt across a range of components, including a number of AIM's parts for the A380 Airbus, and particularly in the production of 5.5 m long wing spars. These start life as 2.5 tons slabs of aluminium and when finished machined weigh only 168 kgs.

With a philosophy of always keeping abreast of CMC machine technology developments – AIM used to be a Beta test site for a major machine tool manufacturer, helping in the development of a range of high- specification machines – it did not take long before Hedelius' exclusive UK agent, C Dugard Machine Tools, had arranged for the Kendalls to visit the Hedelius headquarters in Germany, to inspect the machines close-up and to witness at first hand the manufacturing methods employed.

“We were impressed, very impressed,” says Rob Kendall, “not only with the overall build quality but also with the machines' toolchanger design, as well as the style and construction of the doors and covers. When opened up these provide excellent accessibility for part loading/unloading, and we find this very useful.”

Installed in January 2004, the C80/ 3200, with its X axis travel of 3,200 mm, features Y and Z axes travels of 800 and 600 mm, and spindle speeds of 30-8,000 revs/min from a 24 kW spindle that offers a torque of 240 Nm. Feed rate for all axes is 30 m/min. The auto toolchanger accommodates 30/56 tools.

The immediate success of this machine on a variety of parts – and Dugard's after sales support and service – led within 10 months to the installation of the larger capacity BC100/6500, having 6,500 mm in X, 1,000 mm in Y and 770 mm in Z, and 30 m/min traverse rates. With a 50 kW drive providing a torque of 528 Nm, the spindle speed ranges from 30 to 8,000 revs/min, and the toolchanger holds 30/50 tools.

Of box-welded construction, the machines offer superb levels of rigidity and performance, with Siemens digital servo drives and high-torque Celox spindle motors. Both machines feature Heidenhain CMC systems, which is AIM's standardised control system for its machining centre/milling machine applications.

The CNCs' ability to handle the most complex contouring routines is highlighted as being particularly relevant to AIM's high-accuracy applications. The controls receive their programs via Mastercam, which processes the design/manufacturing data often received in CATIA.

AIM's steadfast policy of continual improvement across every company activity has not relied solely on investment in CMC machines or stringent inspection routines based around the use of three co-ordinate measuring machines. It has also been built around a belief of treating employees “in the same way we would like to be treated” and includes profit sharing and a successful apprenticeship scheme that last year saw the company win BEMA's Apprentice of the Year award.

“Our size also allows us to introduce change – in whatever form – very quickly,” adds Rob Kendall, “and we ensure we keep everybody up-to-date with what's happening in the company, sharing both the bad and the good news.” Its a policy that during its 33- year history has enabled the company to never announce any redundancies.

A similar open book management philosophy extends to the customer base, and Rob Kendall is justifiably proud that, without exception, the company's increasing order book is due to customer recommendation.

The strategies have stood the company in good stead and they underpin a continual increase in order intake – this year, for example, the number of A380 aircraft “sets” is double the number processed in 2004 and more investment and improvements are planned to enable the company to stay one step ahead.

Touch probing is being introduced on the Hedelius machines, for toolsetting as well as part inspection, and true five- axis machine is being installed. “Its all about offering customers the service they require,” concludes Rob Kendall. “Its about always aiming higher and investing in the future.”

Details available from: C Dugard Machine Tools, Tel.: +44 (0)1273 732286, Website: www.dugard.com

AIM Limited, Tel.: +44 (0)1275 877695, Website: www.aim-ltd.net