Emax BL2826 fitted to John's Stoltac:

emax motor

No. of cells: 3-4 Lipos
Max. efficiency: 86%
Dimensions: 38.5 x 47 mm
Shaft diameter: 5mm
Weight: 182g / 6.4oz
Cost: £44 each

John Swain's flapped Stoltac

(Steep Take Off and Landing TACtical aircraft).

Now Andrew Gibbs' 'Model of the Month' in his 'Talking Electrics' column, AMI Feb 09.
Also featured in Chris Gold's 'Light Fantastic' column in QEFI Oct and Nov 2008.

Details

Span - 72". Chord - 11". Area - 5.5sq.ft. W/loading - 28 oz/sq.ft.Weight - 9lb 8oz.
Power - 2 x Emax BL 2826 brushless. ESC -2 x Emax 50amp.
Batteries - 2 x 6400ma 3s. Props - 12 x 6 APC Slowfly.
Current draw - 38 amps per motor at full "chat".
Wiring - 2 separates ccts., ESC's Y leaded to Rx.
Static Thrust - measured on an "Electronic spring balance" type scale - 8lb 9oz.

Some pictures

 

stoltac picture 1

Partially constructed wing
showing the thick blue foam ribs with sheet top and bottom skins. Photo shows the blown, slotted flap in the 40° landing position. The flaps are "hinged" (pivoted) at their mid chord position to facilitate the opening of the blown slot when more than 20° of flap is selected. The hinge pivots are all ball-bearing mounted to provide virtually friction-free flap movement.
stoltac picture 2

The Stoltac "in the white".
stoltac picture 3

The completed model
with the "radar nose".
stoltac picture 4

A steep take off.
20deg of flap is used on t/o.
Acceleration is "more than adequate".
stoltac picture 5

Centre section.
Air intakes feed cooling air to the ESC; then channelled to the motors.

(Photo: Andrew Gibbs of GibbsGuides.com)
stoltac picture 6

Flap servo.
Sits in the rear of the engine nacelle.

(Photo: Andrew Gibbs of GibbsGuides.com)
stoltac picture 7

Flaps 20°.
20° flap deployment for take-off.

(Photo: Andrew Gibbs of GibbsGuides.com)
stoltac picture 8

Flaps 40°.
40° flap deployment for landing. Slot now open so the flap is blown by the prop.

(Photo: Andrew Gibbs of GibbsGuides.com)
stoltac picture 9

Flaps 80°.
80° barn-door flap deployment for high-drag steep approaches.

(Photo: Andrew Gibbs of GibbsGuides.com)

More Stoltac photos>>
<<Return to main projects page