OTHER:Helicopter - Inside - Intermeshing - Dragonfly/SynchroLite General Arraignment
This page is to record a possible configuration for the Dragonfly Rotor / Drive-train.
Uses the SynchroLite's Fuselage, with modifications. See:
Uses the Dragonfly's Rotor / Power-train. See:OTHER: Helicopter - Inside - Intermeshing - Dragonfly Principal Assy
Pictures of Mockup:
For additional pictures of cockpit see;DESIGN: SynchroLite ~ Fuselage - Cockpit - Layout
Engine ~ 2-cylinder, inline
Engine ~ 4-cylinder, horizontally opposed
The Hirth H 32 2-cylinder inline is 70 lbs. and the Hirth H 30ES 4-cylinder horizontally opposed is 92 lbs. The difference is only 22 lbs.
Bill of Material 0870
Information Related to a Complete Craft (based on using the SynchroLite fuselage):
Dragonfly Rotor Specifications ~ for a complete 550# GW craft
Power required to hover = 33 HP. = 16.8 lbs / HP
Blade Element Method
Theta is 7.6 degrees for lift of 550 lbs. in hover.
Power required to hover = 35 HP. = 15.7 lbs / HP
Hollmann Program "Dragonfly Hperf.BAS"
The following is based on single disk with 6 blades: (for the fun of it)
Maximum speed is 83 mph at 48 hp.
Maximum endurance is 40 mph at 30 hp.
Maximum range at 69 mph at 38 hp.
Maximum climb rate 18 fps at 37 mph.
Many of these ideas have come from the UniCopter.
The synchro gearbox and the two secondary planetary reductions in the SynchroLite have been replaced by the UniCopter type X-over reduction and synchronization unit.
A torque tube is located between the engine and the primary gearbox to absorb the vibration.
Fuel Tank and Storage:
The fuel tank will be located behind the seat and below the engine. It should be aerodynamic The very aft portion should be flat and parallel to the torque tube. The two, three or four cylinder engine can be mounted directly to this fuselage back via vibration mounts.
Make the fuel tank and integral part of the fuselage and have it located between the pilot's lower back and the engine. This will allow the fuselage to be attached to the back of the tube, provide a means of mounting the engine and give aerodynamics to the aft portion of the fuselage, which will deliver better cooling to the engine.
The volume for the tank appears to be greater than 5 gallons. This additional space can be used for;
The tail boom will be shorter than that of the SynchroLite because the rotor disks are smaller. In addition, the boom, which is part of the fuselage, protrudes back further. Therefore, the detachable boom will be shorter.
The tail might be braced by having a pair of tubes run from each of the two of the drive-train mounts to the tail. Ref;
Have added the Hirth F-30 4-cylinder engine to drawing. At very low power, it should offer more reliability, but the craft will weigh more than the 254 lb Ultralight limit.
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Last Revised: December 4, 2003