29 Dec 11 - Update on problems experienced
N° of launches / Time | 0 | 0h 0m |
Wingspan | 13.5" | 342 mm |
Wing Area | 144 □" | 9.3 dmē |
Flying Weight | 1.21 oz. | 34.3g |
Wing Loading | 1.21 oz. / □' | 3.7 g/dmē |
Wing Cube Loading | 1.2 - Glider (ultralight at that) | |
Motor | HobbyKing Micro Power brushless system with Gearbox (GPS-C03) | |
Propeller | GWS DD 5" x 3" (EP-0503) | |
Batteries | 1S1P Li-Po 120mAh to 160mAh | |
Speed Controller | XP-3A Brushless Speed Controller - 3A - 1S LiPo | |
Receiver | Spektrum AR6300 - 6ch (micro-connector) - 2.4GHz - 1S LiPo only | |
Servos | Elevons - 2 x HK-282A Single-Screw - 2g - 2 Nm - 0.08s | |
Static Performance | Not testable as yet | |
Flight Performance | Not yet flown |
29 Dec 11 - Some time ago I went to fly this and during the pre-flight check the elevons deflected proportionally to the throttle setting, and tried several batteries; on returning home I tried it again with the same results. A few weeks ago I tried again and the effect seemed to have disappeared, only to return when a different pack was tried. I determined that the effect must be voltage related as it only occurred with smaller (120mAh) packs and never with larger ones (150mAh - 180mAh). I need to make a testing rig so I can find out what current is being drawn by the motor.
2 Jun 11 - A friend sent me link to the Firefly thread on RC Groups. The original Firefly is a 24" span EPP model which uses a Kline Fogleman section. I decided that a smaller version would be interesting for indoor flying and I could use the micro-geared brushless set-up sat around idle. The Kline Fogleman section is basically a stepped section with a strip under the leading edge for approx 35% of the chord. The model was scaled to match the propeller size the motor wanted, which resulted in a 13.5" (342mm) span. The model was assembled from 3mm Depron with the lower mainplane piece and rear of the fin cut from a black sheet for contrast. I was originally going to build it using a UHF RX but swapped to the AR6300 which was also spare. The speed controller is an amazing little device and rated at 3A, far more than the battery can deliver. I originally fitted 3g servos, but one failed during set-up so they were removed and replaced with some 2g servos. When using a 160mA LiPo it balances without ballast, but a 6mm washer is required for smaller cells.