Unmanned Systems Technology 036

90 approach with moulded carbon fibre composites. Instead of binding millimetre- long carbon fibres in a resin, stress-aligned continuous long fibres give an order of magnitude greater strength and allow composites to be used for cost-effective, mainstream parts with complex shapes. In Additive Moulding, an AM printer is used to deposit the carbon fibre. The stress-aligned fibres concept comes from automated tape layout methods that have been developed over the years, but instead of just fusing sheets of composite materials, 3D-printed fibres are laid in the best place as determined by the stress loading in a mould, and then layers of composite are applied. This uses the whole volume to reinforce against the stresses in the part for complex shapes. Additive Moulding can also use different types of fibres, using metal for example to put wires and circuits inside a structure, especially for wireless charging. It can embed the wireless charging coil closer to the surface of the design and still have it protected, with the connecting wires running through the structure. This can also apply to the antennas for a wireless comms link, which can vary in size and shape depending on the frequencies used, and which can vary from one aircraft to another. This allows a UAV’s antenna and mechanical components to be combined into a single, multi-functional part. The design is broken down into elements, which are built in the moulding process to create pre-formed components, also called pre-preg parts. The parts comprise different regions of the end construction, so software called a slicer is used to divide the design into suitable elements. Similar to the software that creates the layers in 3D printing, it is used for this segmentation. This allows every part of the final system to achieve a single mechanical functional requirement or functions including wireless charging, antenna, thermal management and so on. The technique can deliver accuracy to within 1 mm for smaller elements such as the legs of a UAV. February/March 2021 | Unmanned Systems Technology Focus | Additive manufacturing ITALY ProtoService +39 052 540 1281 www.protoservice.it Sinthesi Engineering +39 331 556 557 www.sinthesieng.it JAPAN Mimaki – www.mimaki.com Ricoh – www.ricoh.com THE NETHERLANDS Additive Industries +31 40 218 0660 www.additiveindustries.com NEW ZEALAND Zenith Tecnica +64  9 213 3784 www.zenithtecnica.com SWEDEN Arcam +46 31 710 32 00 www.arcam.com Sandvik +46 8 456 11 00 www.sandvik.com UK 3DDC +44 1234 391894 www.3ddc.eu 3D Systems +44 845 051 4900 www.3dsystems.com 3T Additive Manufacturing +44 1635 580284 www.3t-am.com ARRK Europe +44 1452 727700 www.arrkeurope.com Betatype +44 7738 238993 www.betaty.pe CA Models +44 1786 464434 www.camodels.co.uk Croft Additive Manufacturing +44 1925 767 070 www.croftam.co.uk EOS +44 1926 623107 www.eos.info Graphite AM +44 1296 482 673 www.graphite.uk.com Laser Prototypes +44 28 9070 6940 www.laserproto.com Laser Lines +44 1295 672500 www.laserlines.co.uk Material Solutions +44 1905 732160 www.materialssolutions.co.uk Performance Engineered Solutions +44 114 321 6375 www.pes-performance.com Examples of additive manufacturing suppliers (continued)