UAVE 120 cc four-stroke | Engine dossier into stabilised 5 V, 12 V and 24 V output buses to safely and efficiently power the subsystems across the Prion Mk.3. “We’ve worked with Sullivan since 2006, back when they only made single-phase systems; of course, three-phase is far better,” Slater says. “Using a starter-alternator is a nice idea, but, frankly, we’ve not had a commercial reason to do so, and I’m not sure I like the idea of putting such a heavy-duty device as a starter-alternator on a 120 cc single-cylinder engine. “It could work on a twin-cylinder Boxer 60 cc unit, because the torque output and vibration would be smoothed out via the nature of the four-stroke. But kickstarting a large, 500 cc, single-cylinder, two-stroke motorcycle engine is quite hard; trying to use a pancake starteralternator to start a 120 cc single-cylinder four-stroke is probably quite hard as well.” Future While the core technology of the DS120 is mature by now, UAVE is presently working on a slightly modified version that will function with a tractor propeller, with the end goal of making a dual-engine Prion Mk.3, running on both a tractor prop engine and a pusher prop engine. “Customers want more and more payload capacity per flight, so that’s how we’ll go from carrying 20 kg of payload to 50 kg of payload,” Slater says. “We’re in the process of adapting the cylinder-head design so we can swap our manifolds around and then just turn the engine to face its propeller forwards, with one or two other components inside the engine mirrored to optimise performance. Each propeller will counter-rotate relative to the other, which will enhance flight stability as an added benefit.” Beyond that, UAVE is looking to expand the size of its company and potentially experiment with optimisations ideal for defence applications. These include finding ways to reduce steel content in the engine, being a strongly visible material on radar, as well as aluminium (the Prion Mk.3 or Dragon is otherwise mostly fibreglass, a radar transparent material, ideal for stealthcritical applications). With its wealth of experience as backing, multiple hubs of engineering expertise supporting it and a tightly honed engine at its core, UAVE can be expected to continue flying its aircraft far and wide to new heights and greater extremes across the planet. 79 Uncrewed Systems Technology | December/January 2025 DS120 Single cylinder Four-stroke Naturally aspirated Spark ignited Air cooled Dry sump RON90 gasoline with 2.5% oil mix (JP-8 version also possible) Displacement: 120 cc Weight: 4.5 kg Maximum power: 8 hp (at 4600 rpm with 28x14 three-blade propeller) Maximum speed: 5000 rpm TBO: 1000 hours (maintenance intervals at 50 hours and 200 hours) Some key suppliers OEM & principal design: DGS Engineering Crankshaft balancing: AMB Engineering CNC milling & fabrication services: OLLE Precision Engineering Metal milling, turning & fabrication services: Fenrich Engineering Vapour blasting: Cardigan Powder Coating Cylinder heads: JS Engineering Valves: G&S Valves Fuel injectors: Consolidated Motor Spares B.V. ECU: GEMS Performance Electronics Exhaust downpipe materials: Merseyside Metals Cylinder liners: Laystall Engineering Company Limited Specialist metals: Ultimate Metals Bearings: Henderson Bearing Honda piston components: Vision Spares Ltd (trading as DIY Spare Parts) Alternators & power management units: Sullivan Acutronic Key specifications UAVE is now working on a D50 configuration of its UAV, which will run on two DS120s; one in tractor configuration, one in pusher, for a 50 kg payload capacity
RkJQdWJsaXNoZXIy MjI2Mzk4