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88, which uses the same combustion process and much of the same componentry. It was designed for aircraft weighing 110-120 lb, while the NW-44 is aimed at 55 lb UAVs. At the time of our visit, the company was fitting spark plugs into an NW-88 in preparation for a 1000 h test run. Harris said, “We also have new coatings on the standard piston rings to alleviate carbon build-up. This is the leading cause of power loss in small engines, and there is a growing demand from end-users for heavy fuel systems. The new coatings eliminate the need to have custom keystone rings manufactured for a piston.” VersaLogic VersaLogic, based in the town of Tualatin, discussed its new Harrier embedded computer. Harrier integrates the latest Intel Apollo Lake Atom processors with error-correcting code (ECC) RAM. Up to 8 Gbytes of ECC RAM can be soldered onto the Harrier board for detecting and correcting the more common forms of internal data corruption. As the company noted, HALE UAVs operating at or near 20 km altitudes are at very high risk of single- bit memory errors owing to cosmic ray interactions, making ECC RAM particularly useful here. The Harrier board measures 95 x 55 x 27 mm, weighs 140 g and consumes between 5.5 and 8.8 W during normal operation. It features dual Gigabit Ethernet ports, as well as one USB 3.0, four USB 2.0 and two serial ports. More recently, the company also unveiled its newest product, the Owl embedded computer. This can be equipped with dual-core or quad-core Apollo Lake Atom processors, and features analogue inputs in addition to the I/O configuration seen on the Harrier. VersaAPI software can also be used for reading and programming Owl through its I/O ports; it runs on Windows or Linux operating systems. The Owl weighs 200 g, measures 95 x 95 x 27 mm and typically consumes 9.4 W (if on a 12 V power supply and integrated with 8 Gbytes of RAM). Both the Harrier and the Owl are tested to Mikl-Std-202H, and feature onboard voltage regulation to ensure stable power supplies from nominal 12 V inputs. KDE Direct Our last stop was the city of Bend, where electric propulsion manufacturer KDE Direct is headquartered and where the company showcased its newest and upcoming systems. “Our 6815XF-205 electric motor was developed with the aim of increasing the rotational speed of our medium to medium-large propellers while keeping a relatively small footprint,” said Tyler Russell. “We have motors that work very well for supplying torque or speed, but this motor is aimed at providing both. “We wanted a motor capable of taking our 24 in propellers at lower voltages, or our 21 in propellers at high voltages and increase the amount of thrust produced without increasing the size of the power plant. “Part of that came from a desire to test our propellers to the maximum possible rpm they can sustain. Another part came from noticing that some customers want to lift heavier payloads with frames of limited size, while other customers want to limit their motor and propeller size while lifting VTOL-transition UAVs for take- off or landing functions,” he said. The motor is kV-rated to 205 rpm/V and a torque constant of 0.047 Nm/A, with the voltage input range running from 22.2 to 52.2 V. It weighs 550 g, and contains 24 stator poles and 20 permanent magnets; neodymium N45UH is used as the magnet material. When equipped with a 21.5 in (54.61 cm) diameter propeller designed with a 7.3 in pitch, and running at full throttle on a 26.1 V battery supply, the 6815XF-205 can produce 4.67 kg (45.82 N) of thrust force while consuming 733.4 W and drawing 28.1 A. KDE has also been producing customised versions of its 13218 electric motor for heavy-lift UAVs and urban air taxi projects, the original version of which was unveiled at AUVSI Xponential 2019. “We’re seeing an increasing number of users wanting custom winding schemes and stator stack sizes to increase the power capabilities of the 13218,” Russell explained. Leslie Koegler commented, “The lead times can vary greatly depending on what customers want to do; they can be up to eight weeks if they’re looking for something pushing the current and temperature tolerances, along with weight constraints and multiple simultaneous projects being handled, but that rarely happens. “Configuring a motor for a specific power output or mounting pattern is easy with one of our designs, so anything like that is turned around very quickly.” Lina Wigington added, “The 35.5 in propellers designed for the 13218 motor are now in full-scale production. They also have a specialised adapter for the folding version, which has been put through significant strength testing.” Acknowledgements The author would also like to thank FLIR, Collins Aerospace and Sierra Olympic for their time and hospitality during the visit, and UST looks forward to getting updates from them in the near future. 75 Unmanned Systems Technology | December/January 2020 Oregon | Tech tour The 6815XF-205 is designed with solid-core copper windings rated to 240 C at continuous operation, 0.2 mm silicon-steel stator laminations and ABEC-7 bearings (Courtesy of KDE Direct)