The Picomax 825 Versa was developed right from the start as a 5-axis machine designed to meet the most demanding requirements. The heart of the machine is the Fehlmann HSC motor spindle.

Among the outstanding features of the 825 Versa are the extremely sturdy portal design, the integrated tilting rotary table along the X axis and the optimum operating ergonomics. The portal design of the machine, including the guide and drive systems, is ideal for handling the modern high-performance machining processes that users expect today.

Precision linear guides with direct travel measurement systems in all axes, broadly supported guide blocks and ball screws guarantee high axis feed rates and acceleration for practical, extremely precise HSC machining. The FEM-optimised structure of the machine with 3-point support is made of grey cast iron. The mounting surfaces of the machine’s structural components are shaved to create the best possible geometries. Other advantages of this choice of material are optimum damping properties and homogenous thermal conductivity, which in turn ensures that the operating temperature is quickly reached, combined with consistent 24-hour accuracy, highest geometrical precision and great rigidity.

The Picomax 825 Versa was developed right from the start as a 5-axis machine designed to meet the most demanding requirements. The tilting rotary table is integrated longitudinally into the machine concept, thus allowing tilt operation that is wholly unaffected by the linear axes (no cross torque). The table has dynamic torque drives, mechanical clamps and direct travel measurement systems on both axes. Outstanding characteristics of the 5-axis simultaneous processing capability are the high dynamics and the very large tilt range of 230° (+/- 115°). The highly rigid tilting rotary table with 3 carriages per guide rail is able to take loads of up to 350 kg, and can handle parts with pallet sizes of up to 400×400mm resp. diameters up to 560 mm. The new machining centre can be equipped with zero point clamping systems from various manufacturers (EROWA, 3R, Schunk, etc.)

The heart of the Picomax 825 Versa is the Fehlmann HSC motor spindle. Whether with HSK-A63 and 14’000 or 20’000 rpm or with HSK-E50 and 30’000 or 36’000 rpm – all spindle types grant low-vibration and precise concentricity for best surfaces and maximum tool life.

In the standard version, the tool changer with chain magazine offers room for 44 tools up to Ø 130mm max.  An extension magazine with up to 250 pockets is optionally available.

Chip removal is designed for both dry (minimal-volume lubrication) and wet machining operation (cooling lubricant / oil). Removal of the chips and coolant is via two spiral conveyor units installed to the left and right of the table.

Careful attention has been paid to creating a thermo-symmetric machine structure as well as other specific measures for additionally enhancing precision, including thermo-compensation and positional correction of the main spindle through the use of direct measuring systems. Thus, the heat-producing components are actively cooled, and the lining of the interior space (also with stainless steel) prevents direct transmission of the heat from the chips and cooling water to the machine structure.

www.fehlmann.com

Kuka Systems is to supply the new TIG welding cell for the upper stage nozzle of the Ariane 5 launcher to Astrium GmbH- Space Transportation.

TIG stands for tungsten inert-gas welding and is a special form of arc welding, one of the core competencies of Kuka Systems. Astrium is the prime contractor for the Ariane 5 system and delivers all the stages of the launcher, along with the vehicle equipment bay, the flight software and numerous subassemblies.

In the cell, 242 square cooling tubes made of Inconel 600 are welded together without the use of filler material. Before welding, these tubes are bundled together on a copper-coated aluminum core and held together with binding wire, which is unwound step by step as welding proceeds. The cooling tubes measure four by four millimeters and have a wall thickness of only 0.32 millimeters.

The overall length of weld seam per nozzle amounts to 730 meters, comprising a total of 14,600 individual welds. As the work must be executed with the utmost precision, a vision system is implemented which carries out seam location and tracking, as well as height offset and gap detection, and adapts the welding process accordingly. The weld parameters are automatically selected in accordance with the previously measured gap dimensions.

The system also has a calibration system which aligns the sensor system with the welding torch. This also calculates any deviation of the TCP, which is automatically corrected by the robot.

The advantage of the new cell from Kuka Systems is the fully automated welding process, in which manual production steps are no longer necessary. The operator can observe and monitor the entire process on a screen located outside the cell.

www.kuka.com

The potential of selective laser melting has been demonstrated by researchers at the Fraunhofer Institute for Laser Technology ILT in the EU-sponsored FANTASIA project.

This has been demonstrated by researchers at the Fraunhofer Institute for Laser Technology ILT in the EU-sponsored FANTASIA project. “With this process we can not only make perfect repairs to damaged engine parts but also build complete components that cannot be produced using conventional methods such as milling or casting,” observes Dr. Konrad Wissenbach of ILT.

“This also permits the kinds of geometries and designs we once could only dream of.” Indeed, the figures speak for themselves: with this and other laser-based generative methods, manufacturing cycle times can be reduced by 40 percent or more. In the future, this will mean savings of up to 50 percent of the material required, and at least 40 percent of repair costs. Wissenbach is coordinator of the 6.5 million euro, EU-sponsored FANTASIA project – an acronym standing for “Flexible and near-net-shaped generative manufacturing chains and repair techniques for complex shaped aero engine parts.” The SLM approach is not suitable for every turbine material just yet.

“We have already seen very good results with Inconel 718, a nickel-based superalloy, and with titanium alloys as well,” Wissenbach remarks. “We are not quite as far along with other fissure-prone materials.” Here, ILT researchers are continuing the search for ways of using melting or molding to reseal any cracks a part may have developed during use. Of course it would be even better if cracking could be prevented altogether. This is why the engineers are experimenting with different parameters, varying laser output power, beam geometry and the structure strategy. They are also investigating the effects of construction-platform preheating on product quality.

www.ilt.fraunhofer.de

The new AES fiber, supplied as type 1260 ceramic fleece, is designed for temperatures of up to 1260°C.

They consist of amorphous fibers manufactured through the fusion of a mixture of calcium oxide, magnesium oxide, silicon dioxide and zirconium oxide. Thanks to their properties as technical materials, AES fibers are also utilized in the aircraft and aerospace industries. They are mainly employed as an insulating material suitable for applications with operational temperatures of up to 900 °C.

However, the new AES fiber from Kager, supplied as type 1260 ceramic fleece, is designed for temperatures of up to 1260 °C. This white, lightweight material is a thermal isolator offering great flexibility and high surface resistance (hardly any spalling). It also impresses with high resistance to frequent temperature fluctuations. It is therefore an ideal solution for heat insulation, soundproofing and packaging, and also finds use as a gas filter and sealing material. AES fibers, such as type 1260 ceramic fleece from Kager, support the implementation of lightweight design and construction principles in the manufacture of high-temperature-resistant units. They are not only lightweight themselves, but also enable production with low wall thickness. Kager supplies 600 mm wide roles with lengths of 3.6 m and 7.2 m. Users have the choice between three thicknesses of material – 12.5 mm, 25 mm and 50 mm.

www.kager.de

Gerko Wende, LH Technik: "1000BASE-T standard networks using copper cables are already installed and available on medium- and long-haul planes. But airlines are increasingly turning to 1000BASE-SX/LX standard fiber optic networks.”

Of course there is room for improvement in the IFE on offer. Gigabit Ethernet technology will greatly increase the data transfer capabilities of cabled IFE/CMS networks. “1000BASE-T standard networks using copper cables are already installed and available on medium- and long-haul planes. But airlines are increasingly turning to 1000BASE-SX/LX standard fiber optic networks,” adds Gerko Wende. Future aircraft will also feature wireless WLAN networks that meet the IEEE-802.11n standard that permits data transfer rates of up to 300 Mb per second. This not only entails an improvement in the speed of data transfer, but in the quality. “This standard also uses the 5 GHz range, but it is not yet approved for aviation. However, the FAA and EASA are expected to give their approval this year,” says Gerko Wende.

The 5GHz band has a shorter range than the more commonly used 2.4 GHz band due to the air damping effect, which is a disadvantage on the ground but does not present a problem within the relative confines of an aircraft cabin. Data exchange inside the cabin should function optimally with these technologies, but first of all the data has to reach the aircraft and then return to the ground, and that costs money.

Patrick Brannelly, President of the World Airline Entertainment Association (WAEA): "Given the small screen size, the difference between conventional video and HD is not so noticeable. And anyway, the transition from analogue films to digital media files has already brought a huge improvement in quality."

Patrick Brannelly, President of the World Airline Entertainment Association (WAEA) sums up the problem: “With hotel guests able to use WLANs free of charge and flat rate usage costing very little at ground level, the question is, how much are passengers willing to pay for an onboard service?” No airline can afford to ignore the issue of customer satisfaction – the only successful way to fill seats. Passengers are accustomed to using the Internet and cell phones on a daily basis at minimal cost, and of course they want to do the same on board without having to pay a hefty extra charge. Dave Vernon, Director of Airline Marketing at Rockwell Collins, suspects that passengers flying premium class increasingly expect airlines to offer IFE that interfaces with their own devices.

But the impact of this ground-air convergence will not be equal across the board. For example, Lufthansa Technik will be introducing HD video in the foreseeable future. But for Patrick Brannelly, on-board HD is not an issue: “Given the small screen size, the difference between conventional video and HD is not so noticeable. And anyway, the transition from analogue films to digital media files has already brought a huge improvement in quality.”

For about two years now the ground-based Aircell system has been available in the skies over North America. From the middle of this year Lufthansa will again offer the satellite-based FlyNet service, this time with Panasonic as its partner. Lufthansa has long preferred satellite systems but unfortunately Connexion from Boeing ceased operation in 2007. At that time the necessary technology was installed in almost 70 aircraft with around 30,000 passengers using the service each month.

To expand the range of IFE offerings, Rockwell Collins recently demonstrated the prototype of a 3D interactive moving map. Among other options, the Airshow Interactive 3D allows passengers to choose between multiple map views and flight status information displays.

IFE system costs are hard to justify on medium-distance routes, and the range of offerings is correspondingly limited on medium-haul aircraft in Europe. But this is set to change in future. “As about 70 percent of passengers carry a laptop, there is no additional weight involved, passengers already know how to use the equipment so the crew don‘t need to explain it. All that is missing is the server,” says Mark Janssen of Inflight TV International. On-board equipment is expected to have a service life of about ten years, so no airline can compete with the consumer electronics passengers are carrying themselves. “Servers don‘t have this problem, they can last for 10 years,” Mark Janssen concludes. The new dedicated server can serve 250 passengers at once. An LCD display complete with cables built into the seat is heavy and expensive, and the nine-inch screen provides only a tiny picture. By contrast, current laptops with typically 15 to 17 inch screens generally offer a better image quality.

IFE will become more important
If passengers are to make the most of their electronic accessories via WLAN, a command of the principles of data transfer is required. If large numbers of users in a WLAN try to access the server at the same time, they can block one another. The trick is only to transmit as much data as necessary, which prevents data logjams. Smooth streaming is the name of the game. The new server identifies the bitrates at which passengers‘ laptops can digest data and transmits only what is required.

Patrick Brannelly’s vision for years to come is clear: “There will be an increasing convergence between air and ground, allowing passengers to use their devices to the full in both environments.” The task of the airlines is to guarantee the data infrastructure, the passengers will take care of the rapidly changing electronic periphery. “Improvements in data processing, the use of networks and more efficient data storage will permit progressively smaller on-board systems that are lighter and consume less power,” adds Dave Vernon. He believes that IFE will become steadily more important for the airlines as part of their marketing and branding strategies.
- Barbara Stumpp -

German  Summary
Mit ihrem In-fllight Entertainment-(IFE)-Angebot werden sich die Airlines in den kommenden Jahren zunehmend differenzieren. Fest steht jedoch: Die Unter-haltungs- und Kommunikationsmöglichkeiten werden sich den normalen Gegebenheiten in Büro und privatem Umfeld annähern. Der deutschsprachige Beitrag ist nachzulesen auf www.aerotec-online.com

Safety is one of the paramount requirements that hydraulic drives and control systems for aircraft must satisfy. The big challenge for system and component manufacturers is to ensure an extremely low failure probability. For example, the permissible failure probability for the vertical rudder system stands at one in a billion. In order to meet these demands, the probabilities of failure of the involved elements, such as energy supply, signal supply and actuator, all have to be taken into account.

Overall, this calls for the use of three independent systems for the energy supply (hydraulic or electric), signal supply (computer systems) and actuating elements in order to achieve the stipulated reliability in the rudder positioning drive already mentioned.

But how to supply three independent hydraulic systems in a commercial aircraft that has only two engines, as is common today? Take the Boeing 777 as an example: Each engine supplies one hydraulic system through a hydraulic pump (and an additional electrically driven motor pump). Boeing came up with an idea for providing the third hydraulic system with energy. The American aircraft manufacturer’s solution involves literally “bleeding” both engines and an additional supply unit, the so-called auxiliary power unit, by withdrawing so-called “bleed air”. A pneumatic system uses the bleed air to drive two pneumatically-operated hydraulic pumps.

But what happens if all engines fail, for example, if there is no more fuel? A look at the A380 and its four engines can help. Each of the eight pumps on the four engines normally supplies the so-called green or yellow system with energy. In the extreme case of no fuel, the so-called ram air turbine deploys. This propeller, which is driven by the airstream, generates electricity for the two electric systems. These two systems are capable of supplying all important functions, because the A380 is capable of flying (or, in this case, gliding) completely electrically, meaning without any hydraulics at all, although with reduced performance.

A word about hydraulic system technology: Servo-valves driven by the flight control computer regulate the position of the actuators, which then activate the control surfaces. Position sensors in the actuator report the current position to the flight control computer, and consequently close the control path. The systems are designed with multiple redundancy. If one actuator in the system fails, the actuator is switched into a restraining state by means of a value, while the other actuators working in parallel handle the control tasks with no reduction in function. Safe function stands or falls with the hydraulic actuators, which are characterized by the fact that they block extremely rarely.

Further development for the A380: Liebherr uses electro hydrostatic actuators (EHAs) with a backup system (EBHA), which provides the option of running with the servo-valve or with the motor-pump unit.

Liebherr Aerospace in Lindenberg has developed electro hydrostatic actuators (EHAs) for the A380. An electric motor-pump unit with the associated highly complex power electronics takes the place of a servo-valve. The motor’s rotational speed is a linear function of the volumetric flow rate of the pump that determines the piston’s position.

Possible leaks are seen as a disadvantage, because, over the course of a long service life, these could drain the oil reservoir and consequently cause the drive to fail. As an alternative, Liebherr uses EHAs with a backup system (EBHA), which gives the option of running with the servo-valve or with the motor-pump unit. Although this is a very complex device, it displays a considerably lower risk of failure due to leaks. The system operates very reliably in the A380.

But the experts are also implementing electromechanical solutions. Two examples: An interesting development in drive technology is now in the offing for small, unmanned aircraft, for example, which are not equipped with hydraulic systems. Liebherr has developed a purely electromechanical activation system for the unmanned Barracuda aircraft by EADS. The safety requirements for this aircraft are lower than usual as there is no pilot.

A different electromechanical solution was implemented for the A310’s fueling system: The retractable fuel hose mounted on the aircraft’s tail is aerodynamically controlled using two control surfaces. An electromechanical actuator is responsible for the control. Two 4.2-kilowatt motors control the actively regulated system. In the event of a complete failure, the fuel hose is mechanically anchored to the structure’s underside with a cable.

Control and activate: This active side-stick was also developed in the "Flight Control/Actuation System" product area.

A core problem with electric motor systems is that they can become blocked. The linear movement of the electromechanical system is roughly 100 times less reliable than that of a hydraulic drive. The possible wear of the mechanical construction, which can lead to play and wobble, must also be considered. A number of research projects have been launched in order to eliminate such problems. Engineers are attempting to detect impending failures ahead of time, for example, with the help of structure-borne sound analyses of the device. All in all, there is a lot to be said for hydraulics in aircraft. For example, hydraulically operated surfaces have been in use in transport aircraft for over 50 years. Although aircraft such as the A380 and A350 XWB feature a control architecture with a higher share of electronic systems today, these systems are not a substitute for the hydraulics. To date, not a single hydraulic actuator has been eliminated. There are no current figures indicating the degree to which the targets in weight savings and cost reductions have been reached by omitting a hydraulic system in the A380. But it is acknowledged that the electronics are gaining capabilities in terms of power density and weight. As a fully developed idea, hydraulics can no longer offer such performance leaps.

The increase in operating pressure in the A380 from 207 to 350 bar is the last crucial step forward to be discussed. But as a result, aluminum can no longer be considered as a material for valve blocks, and steel or titanium must be used instead. This means that the advantage of a more compact construction cannot be converted into a weight advantage due to the increased pressure. Nevertheless: Wherever there is a need for cost efficient and reliable solutions dealing with high loads and linear movements, there is just no way of getting around the utilization of hydraulics.

- Nikolaus Fecht -

German Summary
Aller Elektronik zum Trotz: Die Zeiten der Hydraulik im Flugzeugbau sind noch lange nicht vorbei. Ihre Aufgaben reichen in Verkehrsflugzeugen von der Betätigung der Fahrwerke bis hin zur Flugsteuerung. Im Super-Airbus A 380 beispielsweise kommen so genannte elektrohydrostatische Aktuatoren zum Einsatz. Der deutschsprachige Beitrag ist nachzulesen auf www.aerotec-online.com

Kuka demonstrator with twelve cooperating robots for high-precision stringer positioning.

Roughly 80 to 90 percent of the CFRP structures are manufactured today by using conventional, expensive prepreg/autoclave technology. This system uses a prepreg, or semi-finished fiber product that has been pre-impregnated with duroplastic resin, that must be stored at low temperatures. After assembly, it must be cured in an autoclave with the application of pressure and temperature. The method is expensive, as it involves high investment costs for the autoclave and substantial costs for the semi-finished product and its chilled storage. Experts estimate: Even a small CFRP component for an airplane currently costs up to 100 euros per kilogram, and a structural element costs roughly 400 euros per kilogram.

Against this backdrop, technically streamlined methods have become significantly more important in recent years. Instead of pre-impregnated CF textiles, simple, dry, supple textiles are cut from the roll and processed into preforms. Subsequently, special methods are used to infiltrate the forms with resin. At present, however, manufacturing CFRP structures with these techniques is also largely characterized by manual production steps. Although it is still more economical than production in the expensive autoclave, the savings achieved by the less expensive semi-finished product and the more economical storage and process costs are offset by high labor costs. This, in turn, makes it worthwhile to take a look at robots, as industrial robots have made significant progress in recent years, and can now be considered for jobs that used to be the exclusive domain of manual work.

Today’s robot tools contain powerful microsensors and microactuators for intelligent detection, gripping, holding and positioning of the most diverse materials. And so why not use robots to manufacture CFRP parts?
aerotec put this question to Otto Kellenberger, Key Technology Management at Kuka Roboter GmbH in Augsburg, recognized as a competent automation specialist in the automotive industry. In recent years, the firm has been expanding its know-how to branches whose requirements are similarly complex. “Automaton on the basis of flexible and adaptive production systems is the key to our markets of tomorrow. The Kuka Robot Group is more successful here than many of its competitors, and concentrates on progressive solutions to automating the most diverse industrial production processes,” Otto Kellenberger says confidently. He can back up this statement with two projects in the aerospace industry by way of example.

Production with light-weight construction materials calls for the application of new manufacturing techniques. The number of produced units is constantly increasing and, in his opinion, such production levels can only be economically reached if innovative robotic solutions are harnessed in the process automation. One line of attack here is found in adaptive production systems, where a greater number of cooperating robots reaches a level of flexibility similar to that found with human workers in group work processes.

Robot with handling tool for removing the cut parts with any contours from the cutting table.

12 cooperating robots place stringers
Kuka robots offer these capabilities, as open control structures and impressive kinematics has enabled them to penetrate make increasing inroads into extremely sensitive handling areas. Together with Canadian research partners, Kuka has completed the predevelopment and developed an adaptive production system for Airbus as a demonstration project. In this project, 12 cooperating robots place CFRP stringers up to 32 meters long in wing preforms or body parts with the greatest precision and repeat accuracy. As Otto Kellenberger relates, “Human workers cannot handle such long and bendable CFRP parts because the slightest deflection or twisting of the parts can result in damage.

Positioning of workpiece components of this length with one-millimeter accuracy is inconceivable when human labor is used.” And Kuka robots are turning in an impressive performance in a second project, as well. The IWB Anwenderzentrum Augsburg at Technische Universität München and the group for software technology and programming languages at Augsburg University are involved in the “CFK-TEX” research project funded by the Free State of Bavaria and the European Union. VDI /VDE Innovation & Technik GmbH is the organization executing the project.

IMA Ingenieurbüro Anton Abele + Partner GmbH, an engineering office in Augsburg, has likewise taken on an important assignment for this joint project. Bruno Haas, IMA managing director, reports, “We are developing a flat handling tool for removing the cut parts with any contours from the cutting table, and a joining tool for the automated, positionally accurate insertion of the extensive, dry CF textiles of various shapes into three-dimensional molding tools.” This sounds complicated – and it is, too. This is due to the fact that the structure of the fabric is not allowed to be changed under any circumstances – the smallest deviations in the fabric direction or distension of the dry fibers after curing leads to intolerable weak points in the components.

This means that a system has to be initially developed for the robot that makes almost flat gripping possible with a multitude of microgrippers. A robot with this “gripping mat” lifts the two-dimensional cut parts with individually controlled suction cups and places them in a process-controlled storage system. A second robot, with the joining tool that likewise works with suction, picks up the cut parts and places them, one after another, according to the three-dimensional geometry of the preform, using an unrolling movement without displacement, compression or stretching of the individual fibers or the fiber composite.

Bruno Haas says, “We consequently needed two very light tools that integrate a multitude of individually activated microactuators and robots that can drive to any given point in any number of traversing steps according to a complex positioning plan.” The development of the control concept was just as demanding, as could be seen at the Composites Europe trade fair in Stuttgart at the end of last October. The branch unanimously acknowledged the functional model presented as an important element for implementing an intelligent process chain for the economical manufacture of light products made of carbon fiber plastics.

Otto Kellenberger, Key Technology Management at Kuka Roboter GmbH in Augsburg: "Human workers cannot handle such long and bendable CFRP parts because the slightest deflection or twisting of the parts can result in damage."

Otto Kellenberger underlined, “The objective here is to automate the jobs previously handled exclusively by manual production.” As seen in the ‘CFK-Tex’ project, there is a great potential for cost reductions if robot-controlled units are used to pick up the cut parts and build up the layers in the preforms. This process requires a pre-defined sequence with a high level of positioning accuracy. But Kellenberger is certain that “the results achieved to date in the automation of CFRP production are already allowing us to see dramatic reductions in the high manufacturing and quality related costs – in connection high manufacturing speed.”
- Robert Wouters -

German Summary
Um Flugzeuge leichter und sparsamer zu machen, werden immer mehr Bauteile aus kohlefaserverstärkten Kunststoffen (CFK) eingesetzt. Ihr Nachteil: Sie lassen sich bisher nur teilweise von Automaten fertigen. Es dominiert also immer noch die Handarbeit, was auf Kosten der Effektivität und Wirtschaftlichkeit geht. Deshalb eint der Wunsch nach einer umfassenden Automatisierung der einzelnen Fertigungsschritte weite Teile der Branche. Wie sehen die konkreten Fortschritte aus? Der deutschsprachige Beitrag ist nachzulesen auf www.aerotec-online.com

Companies supplying refits and maintenance services have to respond quickly.

Like most companies, airlines strive to offer a better service with less capital equipment and less overall investment. Passenger aircraft are expensive to operate. Unless they are fully utilised, operators can be forced to reduce fleet numbers so they can increase the efficiency of remaining planes. That amounts to fewer aircraft, flying more hours with shorter windows for scheduled maintenance. When these time-pressed aircraft are grounded for annual overhauls – usually for just one or two weeks at a time, companies supplying refits and maintenance services have to respond quickly to ensure they return to service without delay.

“Our customers are very demanding,” says James Deans, director of Airline Components International (ACI) Ltd., a company specialising in the design and manufacture of aircraft interiors. “They send us their statement of requirements or aircraft interior parts and we design, reverse engineer or re-make before the aircraft returns to ope-rational service. The window for doing so may be a matter of days.”

James Deans, Director of ACI: "Our customers send us their statement of requirements or aircraft interior parts and we design, reverse engineer or re-make before the aircraft returns to operational service."

When airlines order a new aircraft from a manufacturer such as Boeing or Airbus, the interior and other fittings are sourced from specialist companies. Often the design and durability of these non-safety critical fittings are, says James Deans, compromised during development in an effort to reduce weight and cost. “A design concept such as a new seat may have been approved by the airline’s marketing department,” he says, “but it can be blocked if they think it’s too heavy or too expensive.” The compromise may be to use a plastic material for parts such as the seat trim items under their recommended tolerance. For example: a 1.2mm instead of 2mm wall thickness can greatly affect the longevity of the parts. The redesigned aircraft seat eventually goes into production but after a while these components will fail. “We fix other companies’ design compromises,” says Deans.

For many years ACI has used its own in-house FDM (fused-deposit-modelling) machine to create design prototypes before committing to external suppliers to produce steel tooling and final injection-moulded parts: this is a great benefit to save when production tooling can be a time-consuming and costly process.

“We found Proto Labs from a trade CAD publication. Initially, we were looking for a company that could produce larger prototype models than we could in-house. We were delighted when we discovered that as well as making prototype injection-moulded parts, Proto Labs could also deliver short production runs that are so much more time-effective than traditional injection-moulding suppliers. That’s when we realised we’d discovered something very significant.”

At the time, ACI was working on creating a project of large injection-moulded parts for the Royal Air Force. “The steel tooling for this one small project was going to cost over £200,000 and the finished parts were going to take 12-16 weeks. Proto Labs told us we could have a finished, injection-moulded part in the same production-intent material without compromising performance, in our hands in one, three, five or 15 business days, which we thought was just amazing!”

Since its first experience, ACI has used Protomold to create a wide-range of parts for its many airline customers. Everything from seat parts to carpet joiners, galley products to overhead bin components and even seat-back video surrounds.

“In the past few years, ACI has invested in its design and testing capabilities,” says Will Matthews, Design Manager.

“In the past few years, ACI has invested in its design and testing capabilities,” says Will Matthews, Design Manager. “This is where we add true value. We have in-house reverse engineering capabilities, finite element analysis and stress, strain, cyclic loading and fatigue testing facilities.

When an ACI part is ready to go into production, it’s considerably better than the original.” Will Matthews was quick to realise the benefit of Protomold intuitive online quoting system, ProtoQuote. The system takes an existing 3D CAD model and uses a super computer cluster to process the model and design tooling but Matthews says that he’s still happy that Protomold have a dedicated project manager to deal with any quirks and is impressed by the company’s commitment to personalised service.

German Summary
Ein Unternehmen für Industriedesign mit Sitz in Oxfordshire, England, nutzt  Schnellspritzguss-Dienstleistungen, um Fluggesellschaften dabei zu unterstützen, die Bodenzeiten ihrer Flugzeuge bei der jährlichen Wartung zu minimieren. Der deutschsprachige Beitrag ist nachzulesen auf www.aerotec-online.com

For protocols and documentation according to ISO 9100: on coordinate measuring machines, modular Renishaw touch probes verify all geometries on the PH10 rotation /swivel head with changeable probe inserts.

Ziegler Feinwerktechnik in Bermatingen by Lake Constance has supplied the aviation industry for over 30 years. The company specializes in the manufacture of sophisticated lathed and milled parts in aluminum alloys, magnesium, titanium, high-quality steels and also fiber-reinforced composite materials for use in fixed-wing aircraft and helicopters. Managed by three brothers who belong to the second generation of the founding family, the company currently employs a workforce of around 40.

“Reliability is the outstanding criterion for aviation. We have to meet these standards on a day-to-day basis,” explains Hubert Ziegler. Within the management trio he is mainly responsible for quality management. “With an average batch size of 35 parts, we produce 80 percent repeat parts.” This applies mainly to components for chassis, control elements for landing flaps and ailerons as well as casings for electronics units. Processing is mainly carried out on three and five-axis Mazak machining centers.

Wolfgang Ziegler describes what is special about this manufacturing process: “Due to the high cost-intensity of the materials and small batch sizes, sound parts have to be produced reliably from the start – waste is taboo. The only way to achieve this is by means of sophisticated measuring technology.” For this reason, the machining centers were fitted with Renishaw  touch probes OMP 40 and OMP60 as soon as they were purchased. “In aviation it’s not only that every thousandth of a millimeter counts, but process reliability is absolutely crucial. Every part has to meet the specifications so as to guarantee faultless operation.”

After mounting, the touch probe detects the precise mounting position. The CNC control system uses this data to correct the zero point. Generally several geometries are then processed, for example a central bore or a bezel. These determine the accuracy of further geometry details. This is where the great benefits of the Renishaw touch probes come into play. They are taken from the rack of the machine center and slotted into the main spindle like a tool. By probing three points, in a bore for example, the control system of the machine identifies the position to accuracies of less than 0.01 mm. The touch probes transfer their data optically to the OMI receiver module. This is located in the working area, usually above the main spindle, and is largely insensitive to cooling water and chippings. Based on the touch probe data, the CNC control system corrects the zero-point for processing further geometries.

Strong believers in sophisticated measuring technology in manufacturing (from left to right): Hubert Ziegler, Fred Hertl (Renishaw), Peter Ziegler, Wolfgang Ziegler.

As Hubert Ziegler explains, this means the company is able to reliably guarantee accuracies of between 0.01 to 0.02 mm on every machined work piece. This accuracy is enhanced by the fact that Ziegler’s touch probes always incorporate the influence of the machine on work piece precision. As Ziegler explains: “We err on the side of caution, especially when it comes to very close tolerances which are difficult to adhere to. Before machining we register geometrical deviations caused by machine axes or travel deviations deriving from temperature influences, i.e. thermal growth of the machine. Here again we use the Renishaw touch probe.”

The OMP40 probe is inserted for this purpose, with a probe sphere providing multidirectional calibration. This significantly increases precision of geometrical data recording in the working area, especially with five-axis machining centers. Peter Ziegler adds: “In addition to process stability, the touch probes also give us economic benefits. We can assume that the parts will be assessed as faultless on the machine. This frequently saves us running a 100 percent check on a coordinate measuring machine, thereby considerably cutting throughput times, increasing flexibility and reducing fixed capital. It minimizes the number of parts which have been fully processed but  not yet released.”  Compared to the increase in process reliability and the advantages it provides, the time required by measurement on the machine is negligible.

Tool measurement and breakage detection at the machining centers ranks as key factors in this high level of process stability. Here, Ziegler relies on Renishaw’s NC4 laser measurement systems. As Wolfgang Ziegler explains, extensive measurement cycles are programmed for virtually every NC program prior to machining. Every piece of the current NC program is inserted and measured by the NC4 laser beam first. The NC control system adopts the individual correction data. Peter Ziegler describes the advantages as follows: “The closer you move tool measurement to the processing station, the more reliably you can eliminate potential errors and inaccuracies. Measuring at the machine completely rules out any transfer errors in setting the tools and programming. This ensures optimum process reliability.”

The aviation supplier further enhances process reliability by subjecting tools to a breakage detection check. “Small, slim tools in particular are inspected by the Renishaw NC4 after every production step in the working area. This means we avoid damage that would otherwise result in expensive and time-consuming scrap, as well as protecting other tools, the machine and the work piece from subsequent damage. Since breakage detection is carried out automatically, the machine operator is relieved of strenuous supervision duties which would require utmost concentration.

What is more, intervention in rapid machining processes was not always fast enough to avoid subsequent damage,” says Wolfgang Ziegler. So by using the touch probes of the OMP product family and the Renishaw NC4 broken tool detection system, Ziegler is able to significantly reduce the costs and time loss caused by scrap. As Peter Ziegler explains, by consistent use of measuring technology in the working area of machining centers it is possible to almost completely eliminate waste created by incorrect mounting position, or by inaccurately measured or broken tools.

Programs can run unmanned
Customers in the aviation sector demand standardized documentation on quality and precision, and Ziegler has three coordinate measuring machines for this purpose. Here again the benefits of the Renishaw touch probes come into play.

The TP touch probes in combination with the PH10 rotation and swivel head have proved ideal for very irregularly shaped parts with numerous bores at random angles, for example. There are various systems, depending on the coordinate measuring machines and the components to be measured. For measuring in very deep bores, for example, it is possible to insert highly rigid extensions between the rotation/swivel head and the probe, as well as between the probe and the probe tip. The coordinate measuring machines have a rack system for automatic exchange of the probes and extensions required. This means that even extensive, lengthy measuring programs can run unmanned.

Aerospace aluminium profile after complete machining.

Lightweight construction is a contemporary issue and accordingly all relevant industrial sectors are in search of materials which combine light weight with high-performance and sturdiness as well as profitability. While in some sectors compromises are the rule, aerospace industry does not follow this course of action. Here security has absolute priority and therefore development and design engineers go to great lengths to balance technical, safety and economical aspects. As far as materials are concerned, aluminium has become first choice in aerospace industry. Typical structural elements are integral aluminium components, milled from the solid, and high-precision extruded aluminium profiles in diverse alloys and grades.

These integral components and extruded aluminium profiles need to be machined with high and reproducible precision, in the least number of clampings possible and in best case the machining is complete, i.e. the parts are ready for assembly. The machining itself is only allegedly not problematic for state of the art machining centers – but it sure is. In view of the predominant dimensions of the work parts which necessitate long traveling paths in the X-axis, the very tight tolerances, and the requirement of different tools for complete machining the offered range of „high-capacity“ milling machines rsp. machining centers is rather limited. But the manufacturers of aerospace components made from aluminium extruded profiles are of course in need of these machines.

Aerospace industry favors suppliers, which offer everything from one source, the complete process chain from the production of the raw material to mechanical processing/ machining to the delivery of modules ready for assembly and quality-documented.

Suppliers as described are not found all over the place – the operational unit Alu Menziken Extrusion AG Division/Alu Menziken Aerospace is definitely one of them. The Swiss Alu Menziken Gruppe produces raw parts like extruded profiles in their in-house smeltery and stud foundry in Menziken and manufactures customized aluminium alloys according to European, American and customer-specific standards. The profiles meet highest demands  on quality – related to straightness, curvature or material thickness, and undergo complete machining according to customer’s demands. This machining service is offered both for small parts and for very long aluminium parts like extruded profiles.

In Alu Menziken’s Mechanical Manufacturing Division 30 qualified employees engage in the manufacturing of work parts on state of the art CNC machining centers. Due to the standard lengths of extruded aluminium profiles of up to 6.000 mm, long-bed milling machines and machining centers are the first choice.

Up to date 12 machines are in use. Five of them carry the sign of the German machine manufacturer matec Maschinenbau, Köngen. The business relationship between Alu Menziken and matec was started in 1997, since then a number of matec traveling column machining centers in diverse configurations have been purchased, at first 2 machining centers matec-30 HV with mounted rotary tables, designed as 4-axis systems for flexible horizontal-/vertical machining.

2005 a traveling column machining center type matec-30 L with a traverse path in X of 6.000 mm and an integrated swivel table for the flexible complete maching in 4 axes followed, 2007 and 2008 again 2 matec-30 HV were ordered, both with traverse paths in X of 6.000 mm, one of which is installed in Menziken, while the other one was shipped to the company’s pressing plant in the USA.

CNC traveling column machining center matec-30 L with traverse paths of X = 6.000 mm, Y = 800 mm and Z = 800 mm for the flexible complete machining of parts of all sizes.

The CNC traveling column machining center matec-30 L purchased in 2005 was the first machine in Alu Menziken’s Mechanical Manufacturing Division with a linear drive in the X-axis, providing a rapid speed of up to 80 m/min. The axes Y and Z have a quite dynamic rapid speed of up to 48 m/min, thus drastically lowering non-productive time, usually caused by long traverse paths – in this case X = 6.000 mm, Y = 800 mm and Z = 800 mm.

For the flexible complete machining of work parts the matec-30 L is equipped with a large tool magazine with a capacity of 128 tools. The tool diameter is 130 mm max. (adjacent places empty), the tool length is 450 mm max., while tool change time (chip-to-chip time) is only 4,5 seconds, which also minimizes non-productive time. The milling head is equipped with a spindle with 18.000 rpm max. and a torque of 100 Nm (190 Nm) at 40% DC, which is more than sufficient for high-performance milling on extruded aluminium profiles of all dimensions. For the complete machining of very long profiles the machine is equipped with two swivel tables size 400 mm x  3.000 mm, the profiles can either be clamped in chucks or be fixed in beam chucks and positioned in a swiveling range of +/-90°. This permits highly flexible machining.

As and when required, the complete machining of small or large parts, very long parts or a number of short parts in a row can be performed. The matec-30 L has a Heidenhain iTCN 530 control, which is known for best results in 4-/5-axis machining and is characterized by a practical, logical, easy-to-operate interface. Practical experience has demonstrated the reliability and precision of the matec machines. matec after sales service has also contributed to customer’s satisfaction. One of the main reasons, why Alu Menziken has chosen matec machining centers is the consequently customer-oriented matec modular system, which permits customer-specific standardized machine solutions. The persons in charge at Alu Menziken Aerospace emphasize: “The customer  gets the optimal solution for his requirements and no trade-off or “compromise” and so in the end really gets what he wants”.
- Edgar Grundler -

German Summary
Alu-Integralbauteile und Strangpressprofile müssen mit hoher und reproduzierbarer Genauigkeit mechanisch bearbeitet werden, und zwar in möglichst wenig Aufspannungen und am Besten komplett, sprich weitgehend montagefertig. Die reine  Bearbeitung stellt an moderne Bearbeitungszentren nur vermeintlich keine größeren Ansprüche. Denn aufgrund der vorherrschenden Werkstück-Dimensionen, der je nach Teil sehr engen Toleranzen, des Bedarfs an verschiedenen Werkzeugen zur Komplettbearbeitung und schließlich der für die oftmals sehr langen Bauteile erforderlichen großen Verfahrwege in der X-Achse, ist das Angebot an entsprechend „gesamt-leistungsfähigen“ Fräsmaschinen bzw. Bearbeitungszentren eher dünn gesät. Aber es gibt sie. Der deutschsprachige Beitrag ist nachzulesen auf www.aerotec-online.com