Uncrewed Systems Technology 044 l Xer Technolgies X12 and X8 l Lidar sensors l Stan UGV l USVs insight l AUVSI Xponential 2022 l Cobra Aero A99H l Accession Class USV l Connectors I Oceanology International 2022

30 Dossier | Xer Technologies X12 and X8 they are major technological IP.” Airframe structure and materials As mentioned, rapid prototyping and the supply of composite and metal parts have been critical to the r&d of both UAVs to date. To that end, Xer Technologies uses local suppliers for its CNC-machined metal parts and carbon composite. Both suppliers serve effectively as extended development arms for Xer, which cites geographical proximity, close communication and specialist knowhow as having been key to rapid turnarounds of new parts and hence the speedy evolution of the X12 and X8 designs. “Their considerable competencies and experience serve as a vital first step for any new design direction we’re considering,” Skantze says. “Outsourcing to high-quality materials suppliers isn’t cheap by any means, but we’ve made a conscious decision not to become a prototyping or materials company. Instead our structural parts suppliers provide our engineers with industrial- grade components at almost a moment’s notice along with extremely valuable input as part of a collaborative approach to the engineering of our systems. “Take for example our CNC partner, who supplies precision-cut aluminium parts for the UAVs. In the past, they’ve delivered lots of parts for high-end sportscars, so they’re used to making very high quality components, and we’ve found them to be an extraordinarily good partner.” The carbon composite for the hull’s covers, fairings, tube arms and internal starfish structure from another local partner have been similarly supportive, both with rapid manufacturing turnarounds and extensive consultation regarding new designs of carbon- polymer parts. Critical trade-offs between the weight and rigidity of the metals and composites have been made, with Xer finding that lightness in some areas led to softness and hence dangerous vulnerability to resonances. This trade-off, as well as cost considerations, has informed vital choices such as the number of layers of carbon fabric used in various sections of the hull. “The layers are measured against 3D-printed tooling before being laser- cut to exact measurements,” Skantze says. “More layers means more strength, heaviness and material costs, assuming you’re using the same material all over. There’s also the possibility of using fewer layers if you swap to a more expensive and high-end fabric. “Then there’s the direction of the fibres that you should consider in terms of how stress is transmitted through them. For instance, we could have just made our arms with uniform fibres, but by using non-uniform ones we can better sustain the structure’s rigidity and longevity against the upward lifting force generated by the rotors. Then we compensate for that extra weight in areas such as the hub cover, which suffers no particular stresses and can therefore be made really thin and light.” What greatly determined the material types, layer counts and directions was the distribution of loading points identified throughout the airframe structure from the testing and CAD simulations the team carried out. Wherever there was June/July 2022 | Uncrewed Systems Technology Non-uniform carbon fibre in the UAVs’ arms helps sustain their rigidity against the upward lifting force of the rotors The ability to consistently receive engine data from the ECU, through the autopilot and at the GCS, has been a critical factor in the development of Xer’s UAVs