Instrumentation • Electronics
STL printer files. Each printer has a specific file format but essentially it breaks the geometry down into lots of small triangular pieces.”
Muir explains: “For a small product such as a UAV, you generally do not want to optimise for a particular environment or profile. The majority of small scale UAVs tend to have rectangular wing sections that use a single chord profile – if you take a slice through the wing and look at it end-on from the wing, you would see a 2D plan form of the wing called the chord profile.
Wing chord profiles
“Historically, wing design has used the US National Advisory Committee for Aeronautics (NACA) group of chord profiles, which are determined by a four-digit number like NACA 0012 for example, which specifies the thickness of the chord at a certain profile and whether it is symmetrical. “In an Airbus A350 for example, there would be several
chord profiles that make up the wing, so you would have one at the root, one a little further out, another further out still, and so on until last profile at the tip. They allow the wing to be twisted and contoured in a specific way as it moves outboard from the fuselage. “On a UAV, you do not tend to do that – you would
Fig. 3. The Koenigsegg Agera was partially designed using a Stratasys 3D printer.
In the case of EADS, using ALM opened the possibility for aerodynamic optimisation such as wing twist, which would otherwise be difficult and expensive to realise for an aircraft of this scale. Different, detachable wings can be ‘printed’ in a relatively short time to adapt the UAV to missions with different requirements using EADS proprietary ScalmalloyRP material, which provides exceptional mechanical properties useful in the production of structures with complex shapes. Martin Muir, research engineer at EADS acknowledges that ALM design cost can be spread more widely on larger aircrafts, and reasons that putting more complexity into the design is worthwhile because the fuel savings achieved can be justified.
often have the same chord profile at the root as at the tip, in a similar as you would on a light aircraft like a Cessna for example, which has a simple wing profile. Otherwise it becomes very complex to design, and even more so to manufacture. With ALM, the cost of complexity is removed because the cost is all in the size of the product.” The STL files to drive the ALM process came in part from
students using Solidworks and from EADS using CATIA, both of which come from the Dassault aerospace group. Muir describes the EADS printed drone as a static demonstrator rather than a working prototype. Professor Keane derides EADS’s Farnborough display,
saying: “I think what they are doing catching us up is. We have moved on since last year and built two more UAVs. We do not use printed nylon for everything on the latest designs, but only where it is most useful. “Printed nylon is not the best material to use for wings and
Cleanroom-compatible HMI systems R
STAHL is offering a variety of operating and monitoring systems for installation in cleanrooms in the
pharmaceutical sector as well as in other industries. Suitable solutions covering various performance classes range from simple operating equipment for machine control up to Remote HMIs and Thin Clients with large displays, which support process control with complex plant visualisation requirements. All models can be installed in
cleanroom environments without any special provisions. The products have no detrimental effect on the cleanroom classifications under relevant regulations,
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eg standardised procedures according to VDI directive 2038, the EU’s GMP directive, ISO 14644-1, or other market-specific and industry-specific standards. These systems are all available either in standard industrial design or as versions suitable for hazardous areas (zones 2/22 or 1/21). Sealed pharmaceutical and cleanroom
HMIs with ingress protection up to IP66 can be supplied both as stand-alone solutions or as complete wall-panel mountable elements. Wall-panel versions are recommended
for installation in cleanrooms of the highest category, so that the operating systems will not affect air circulation and no particles will settle on them.
All enclosures are made of conductive
materials, making static charges impossible. The devices are designed with smooth
lines and without any dead spaces or dirt traps, making cleaning easy. The HMIs are available with surfaces of
stainless steel or of a dirt-repellent polyester membrane for display and keyboard. Both these materials can withstand powerful jets of water as well as most solvents or cleaning agents. The stainless-steel surface is polished to a very low surface roughness of 0.8µm (N6). Alternative options are anodised front frames and electropolished enclosures. ●
For more information, visit
www.stahl.de
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