Unmanned Systems Technology 023 I Milrem Multiscope I Wireless charging I Logistics insight I InterGeo, CUAV London & USA show reports I VideoRay Defender I OS Engines GR400U-FI I Ultrabeam Hydrographic Ultra-2 I IMUs

64 Dossier | OS Engines GF40U-FI Development of the UAV derivative featured the introduction of a port fuel injection system, an anti-vibration mounting system and a bespoke 100 W generator. The camshaft timing was revised to reduce noise (aero modellers relish ‘authentic’ sound whereas UAV operators value quietness) while the exhaust valve seat specification was changed to maximise durability. The UAV engine project began in 2015, and a major step was made in 2017 with the arrival of a downsized, smaller and lighter but no less capable version of the in-house ECU. The prototype had already been shown at the AUVSI (Association for Unmanned Vehicle Systems International) annual Xponential event in 2016 at New Orleans, Louisiana. The definitive GF40U- FI with downscaled ECU was on display at the same event at Denver, Colorado, in May 2018. The GF40U-FI The GF40U-FI has a crankcase diecast from aluminium alloy. It is produced in one piece aside from the rear end cover, which is attached by four 15 mm M5 studs with an O-ring at the interface. The barrel is machined from aluminium alloy while the head is diecast from aluminium alloy. The rocker cover closing the head is likewise diecast from aluminium alloy. The two steel main ball bearings are carried by the crankcase as a push fit. The crankcase also carries as a push fit the pair of ball bearings in which the camshaft runs. Integral with the rear cover is the front of a pair of mounting plates that sandwich four anti-vibration brackets that connect the engine to the fuselage (in cantilevered fashion). A generator mounting plate is attached to the front of the crankcase. Four (two lower side and two underneath) tubular reinforcement beams are run between the generator mounting plate and the front engine mounting plate. The generator mounting plate and the front engine mounting plate incorporate the front and rear mounts for the generator that allow it to be positioned to the lower left of the crankcase, to the lower right, or underneath the crankcase. The barrel is attached to the crankcase by four 15 mm M4 studs, with a ring gasket at the interface. The head is attached to the barrel by five 30 mm M4 studs, with a metal ring gasket at the interface. The rocker cover is attached to the head by three 12 mm M3 studs, with a metal gasket at the interface. The barrel carries a liner, of which the material and bore plating used are undisclosed details. The steel crankshaft has journal diameters of 17 and 10 mm for the two main bearings. It is heat treated but not coated. The crank pin and part of the single counterbalance web are made in one piece with the machined- from-billet crankshaft – the rest of the counterbalance web is a separate item attached using screws. There is no vibration damping system for the crankshaft or the valvetrain. December/January 2019 | Unmanned Systems Technology Fuel consumption data for the GF40U-FI