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Small Flying Wing Model Aircraft of my own design and construction
This flying wing model aircraft was inspired by the control line combat wings, now dubbed the Little Nit.
When designing this flying wing I had the intention of using a 1cc I.C. engine (AP.06). However when building began I opted to go down the brushless electric motor route instead.
A very simple to build project is this one, utilising a symetrical NACA wing section of about 26 inch span including the wing tips and 16% thickness. The flying wing has no taper except for the elevons. The wing is constructed on two spars, with a substantial leading edge supplying a large amount of additional strength. A false trailing edge is also employed with sheet elevons.
Hollowed out block wing tips are used (actually three layers of quarter sheet balsa on this example). The fin is made from 1/8 thick balsa wood, rear strake and the underfin is from quarter sheet (heavily sanded and profiled) and the front sub-fuselage is a liteply and balsa box.
This particular airplane is covered in Solarfilm and trimmed with Solartrim on the top only so I can easily tell which side is up while flying (very useful with such a small and aerobatic aircraft).
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The Corona 35mhz receiver is in the wing under the yellow patch which can be seen on the picture to the left. Some spare GWS horns are used on the elevons, these coming with one of their foam warbirds.
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The radio control gear consists of two cheap 9g micro servos mounted in the centre section (one for each elevon), A Corona lightweight 35mhz receiver mounted in the left half of the wing and a Futaba computer transmitter to mix the elevon servos.
A Tower Pro BM2408-21 brushless outrunner motor spins a Towerpro 8x6 propeller. This is powered by a 2 cell 1000mah lipo battery. The ESC is a 20 amp type from BRC Hobbies.
The battery pack slots into the front underside of the model, this being accessed via an underside hatch as pictured. The ESC sits in front of the battery and is also accessed from this hatch.
The aerial is left full length and is routed to the fin. From here the aerial floats in the breeze. No glitching from the model so far after many flights!
This little flying wing is extremely aerobatic and quite fast considering the cheap power system. Vertical climbs with rolls, brisk acceleration and deceleration due to the very low inertia, a massive roll rate which I tamed a little with lower rates. Loops can be huge due to the high power to rate ratio, or the wing can be pulled up tight to the point of an accelerated stall (this wing just starts nodding under this condition and doesn't violently snap out like some aircraft I've flown). The wing is balanced on the front spar which is around 20% from the L.E.
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Here's the underside of the Little Nit. Front hatch for easy battery access. The brushless motor is epoxied in place, a method which has proven very satisfactory on this small model aircraft. The underfin is there largely to give a hand grip while launching, this is the easiest model I've ever hand launched with no greasy oil making the plane slippery.
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With some up elevon the wing can be slowed down for some low slow passes, full power and the model can be pointed upward and will quickly turn to a distant dot if allowed to. Inverted is OK but either needs down trim or down elevator to supply the wings reflex, outside loops are also good. This particular flying wing has only elevon and motor control so no knife edge or other manouvers which need a rudder are possible, the next one will feature a rudder as will this one at some stage, providing it stays in one piece long enough.
Great stuff, one of the best flying models I've flown and about the cheapest to build and operate. A breeze to transport and takes up very little storage space, plus no ear bashing for oil stains on the axminster. The very quite electric motor/prop combo also sounds a bit like an early military jet at times while flying (that cool whistling sound of many 40s and 50s jets), I don't think thats just my eager imagination!
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