[Canberrauav] Hybrid Hex cleanup
jpittar at bigpond.net.au
Fri May 1 12:03:52 AEST 2015
The following is to clean up the discussions on the Hybrid Hex.
Thanks to all for your interesting discussions.
After lots of fiddling around with different physical formats, I have settled on the following for the prototype:
A 2.2 metre wingspan ARF model - the MaxiLift or Porter - will have a fore and aft boom fitted to each wing. Each boom will have motor and 25" horizontal propeller mounted on each end, making a traditional quad.
The horizontal stabilizer will be moved to the top of the vertical stabilizer for clearnce of the quad propellers.
The motor will be a standard tractor mounted 40cc petrol twin (because I already have it).
A tricycle undercarriage will be fitted to allow normal aircraft takeoffs and landings.
The intention for the prototype is to experiment with the aircraft handling in vertical and horizontal flight and in transitioning, beginning at the minimum weight of 13Kg.
The cost and size of the quadcopter parts, to make the aircraft operate as calculated for in eCalc, were a significant roadblock. This was cleared when Stephen pointed out that the quadcopter components only have to lift and maneuver. The Hobby King cost of these parts will be $360 without batteries. One 5Ah 6 cell battery ($105,0.85 Kg) is eCalc'd to bring a hovering and maneuvering time of 2 minutes or so. 5 batteries, 8 minutes.
The requrement to have all propellers stopping will be dealt with later.
With thanks particularly to Ben and Daniel, the generator concept sounds quite feasible. It would save on making a mechanical clutch mechanism at the expense of making a synchronous rectifier and power controller. Depending on conversion efficiencies, a bigger engine would probably be required if it is to allow for continuous hovering and maneuvering.
Rather than a "Hybrid Hex" I suppose it should be described as a "Quad-plane Hybrid".
A good name for it would be the "Vampire", although that name should be reserverd for whichever aicraft we take to the OBC.
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