Unmanned Systems Technology 036

84 A dditive manufacturing (AM), or 3D printing, is becoming a key element in a UAV design, achieving lighter and stronger components using a wide range of materials. For example, there are more than 30 printed nylon parts on some of the latest UAVs, and developers are looking at ways to produce these components much faster. There is also a trend for developing tools and techniques to produce components made from different types of materials as single units. This combines the controllability of AM methods for plastics and metals with the speed of those using carbon or glass composites. This is opening up new approaches to designing unmanned systems, such as entire monohull boats for USV applications. Many AM processes allow structures to be built with voids inside the material, and while this is used to reduce the weight of UAVs, it also dramatically increases the buoyancy of a USV design. As the technology matures, so some tools are reaching their practical limits, especially as regards metal AM systems, in both size of components and speed of production. These often use titanium, Inconel (a nickel-chromium ‘superalloy’), steel or aluminium, and have reached the point where it is difficult to justify making larger components. A laser AM printer typically has a workspace, or powder bed, of 1 x 1 x 1 m, which using titanium would weigh 7 t and represent millions of dollars’ worth of metal. The widespread selective laser sintering (SLS) technique uses high- power lasers to melt metal powder in the bed of the workspace layer by layer. The Unmanned systems developers can expect greater productivity and multi-material components from this crucial technology, as Nick Flaherty explains Shape of 3D things to come Binder jetting can produce multiple custom designs in a fully automated process (Courtesy of Desktop Metal) February/March 2021 | Unmanned Systems Technology