B-25 Mitchell
1/48 Scale
8 Channels
P-51 Mustang
1/48 Scale
6 Channels
2.65", 0.495 gram
Martin's Midge
3.2", 0.98 gram
4", 1.3 gram

September, 2004

Martin's Bipe is my second pager-powered plane, 8" wingspan. I've always liked bipes, and the frame-profile fuselage looks better than a stick. The pilot helps too. With the lessons learned from the Mono, the Bipe flew quite well from the outset.

The tricky part of this one is the rudder and elevator actuators. They are "in surface" for lightness. However, with carbon rod construction you can't let them in to slots in the control surfaces as you can with balsa. I also wanted to use thread hinges and mutual centering. The final arrangement turned out quite neat, but is not easy to assemble. There are pictures below, and there is some information about it in the Techniques section. I have several hours of flight time on this plane and the motor is still going strong.

Bipe Pictures

Martin's Bipe

Bipe on carpet

Bipe in flight

Bipe in flight 2

Actuator detail

Tail section

Bipe Video

Martin's Bipe

Bipe Specifications
Wingspan 7.75" (19.7 cm) [8" flat]
Chord 2.0" (5.1 cm)
Wing Area 30.0 sq.in (193 sq.cm)
Weight 0.36 oz (10.3 grams)
Wing Loading 1.73 oz/sq.ft (5.34 g/sq.dm)
Motor MK06-4.5, 6mm, 4.5 ohms
Gears 6.5:1 Falcon MOD 0.25 in homemade gearbox with two ball bearings
Propellor 3.1" (80mm) Homemade carbon, based on modified U80
Battery 80mAH LiPoly
Radio JMP Combo
Antenna 1 piece 38 awg copper, 6cm + 28 turns around 5mm straw + 18cm
Actuators Homemade coil 4mm ID, 44awg, 50 ohms, 3mm x 1mm N45 Neodymium magnet
Construction Carbon Rod, mainly 0.020" (0.5 mm) and foodwrap covering (Reynolds Wrap)
Control Rudder, Elevator, Throttle

Bipe Plans
Plans in PDF format
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