ElectricFlight T
he Flying Aces Club holds a couple of big meets every year. This year was an off year for the FAC Nats in Geneseo, NY. In its place we hold the “Non-Nats”, a slightly shorter meet with somewhat relaxed rules. Usually FAC scale events use an average of three flights for the time. The Non-Nats drop this to the best time of three flights. While most events are rubber powered, we do have a power scale event. We are talking freeflight rather than R/C.
Let’s take a look at the Power Scale event at the Nats. The rules add bonus points for non-electric power since electric power has some advantages. However this year all the winners used electric power. The energy density advantage of Li-Pos make them and a timer more or less a given for a winning model. Well almost.
Ted Allebone, still uses Ni-Cds and Ni- MH cells. The rules for scale events empha- size the scale aspect of the model rather than the flying time; the rubber powered scale events factor the flying time, but the power scale event does not. It uses the time in seconds directly. Over 120 seconds, no ex- tra points—boasting rights only! It’s rather assumed that any power model is capable of a two-minute max. Flights under 20 seconds are non-official and can be reflown. During scale judging, points are awarded for Construction (how much detail of the real aircraft is represented on the model), Markings, and Workmanship. The rules also add bonus points for multi wings, mul- ti engines, floats, and non-conventional configurations.
Don Srull took full advantage of these rules to win the event with his Westland Pterodactyl. He won the event last year at the Nats with the same ship. A four-engined flying wing seaplane is hard to beat on bonus points. His 32-inch span Westland- Hill Pterodactyl Mk VII weighs 104 grams and is a model of a proposed flying wing sea- plane with four motors, two of which are pushers, netting him 43 bonus points.
PHOTO: TED ALLEBONE Ted Allebone’s winning Cavulaunched with the FAC flight line in the background.
Power is supplied by four KP 00s turning 4-inch GWS props, using a single Li-Po cell of 300 mAh capacity. The motor timer is the KP 2-minute version, driving a 20-amp Mikro ESC which is set to a 2.8-volt cutoff. All motors are wired in parallel to the single cell. This is the same setup he used last year including the battery.
Ted Allebone missed last year’s Nats, but competed in several events this year. He won the Half Wakefield rubber event and the Old Time Gas Replica event (electric powered). He entered two WWI twins in power scale, a Vickers Vimy and Gotha. He posted time for the Vimy coming in second. He never officially flew the Gotha as, having qualified the Vimy, he needed to get his flights in for other events while it was rea- sonably calm. When he eventually found time to fly the Gotha, the wind had strength- ened to the point where he didn’t feel it worth the risk. I did see it fly on unofficial fights and it looked great! The Vimy has a 23-inch wing span with a flying weight of 110 grams. It uses Web sur- plus motors (with neodymium magnets) mated to a KP 00 gearbox 2.75:1 driving U 80 props both rotating counterclockwise.
PHOTO: MARK BATTERSON
The battery is 4-cell 110 mAh Ni-MH (1⁄3 AAA). The Gotha has a 26-inch wing span with a flying weight of 90 grams. It uses the same motors as the Vimy driving U 80 props both rotating clockwise (viewed from rear). The battery is a 4-cell 110 mAh Ni-MH (1⁄4 AAA)—lighter weight, but poor heat dissipa- tion! Neither model is fitted with a timer, re- lying purely on a timed charge for duration of run. Both models are wired in parallel. In third place was Martyn Richey’s XB- 42A. I’ll let him describe it: “My XB-42A model is the result of searching the internet for micro contraprop units and finding this brushless unit which weighs 18 grams and produces 160 grams static thrust. My selec- tion of the XB-42A as a subject came quickly because of its unique pusher configuration and wing mounted jet units.
“Built from 3-views, it is smallish for four motors at 27-inch wing span and has a gross weight of 143 grams. The electrical systems consist of the twin brushless motor con- traprop unit, powered by two ESCs, a 2-cell Hyperion 240 Li-Po battery and K&P con- troller. The two 16mm EDF units are full fabrications with 7mm pager type brushed
by stew meyers You can reach Stew Meyers at 8304 Whitman Drive, Bethesda, Maryland 20817, or via e-mail at
stew.meyers@
verizon.net
PHOTO: SAM BURKE
Sam Burke’s Garami Half-Pint (above) is a bit over powered yet flies fine with a gearbox and 8.5mm brushed motor combination from a ParkZone UMX P-51 Mustang. Chris Starleaf’s beautiful Lockheed Model 14 Electra (at right) uses “old school” motors and batteries that would otherwise be tossed.
58 SEPTEMBER 2013
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