Eagle x-tail electric version - Introduction

Evolution F3B sailplane

The electro version of the Eagle F3B allows, in addition to other advantages of electromodels, the fast setup of the model, without the need of a winch to get into the air.

Eagle F3B sailplane


With the electroversion you can do more starts with one battery charge, then you would using a winch in the same time. The drag of the propeller is so small, making the flight performance of the electroversion and the glider version nearly the same. The weight with a Li-Pol battery is about 300 grams more, then the basic flying weight of the glider. The electroversion is even lighter then a glider with additional ballast for the speed task. The setup and training for speed task was the main subject for the creation of the electro version.

Eagle x-tail as sailplane version is here...

Eagle x-tail electric version - Details

Evolution F3B sailplane


Category: F3B,F3F with electric propulsion
Conception: Two part wing, two part elevator, x-tail
Wing span: 3200 mm
Length: 1540 mm
Wing area: 63,88 dm2
Elevator area: 5,42 dm2
Wing airfoil: HQ 1,6/7,5 mod
Elevator airfoil: SD8025
Empty weight: from 2350g
Flight weight: cca 2770g
Ballast: 800g
Maximum servo width: wing center: 13 mm (Futaba S3150 or Airtronics 94761Z) , wing tip: 10 mm (Futaba S3150), fuselage: 15 mm (Graupner 3871)
Wing carbon-rohacel-glass or carbon-rohacel-carbon
Spar UMS Carbon
Tailplane glass-balsa-glass
Fuselage carbon-glass
Equipment and parameters:
Electro motor: Kontronik Drive 600
Accumulator: 3200mAh 4S Li-pol
Flight Weight: 2770g
Current drain: 32-36 A
Run time motor: 180 - 300 sec.
Number of climbs: 8-10
Gear ratio: 6,7:1 part of the motor
Propeller: Freudenthaler 17x10


Measurement and altitude logs

With a current drain of 33A, the consumption is about 2700 mAh in 5 minutes. Achived height from particular climbes in total is cca 3000m (estimated) - record from altitude meter-loger Alti:

First climb Following climb Fast down flying 7th climb
last, 13th climb Total flight
Altitude loger Alti file iconSource Alti log file from flight

For view this file you need Alti software. It's download free here

Eagle x-tail electric version - Settings

Evolution F3B sailplane

Settings table for Eagle

Trim positions Flaps Ailreons Elevator Rudder
Normal 0 0 0 0
Termik 4 in line with flap 0 0
Speed -1,5 in line with flap 1 0
Start 12 in line with flap 1 0
Butterfly max down 5 5 0
Deflections Flaps Ailreons Elevator Rudder
Normal 30%/30%
(% of ailreon)
(on tip)
12/10 8/8
(on tip)
Termic 0 6/3 12/10 8/8
(on tip)
Speed 50%/50%
(% of ailreon)
(on tip)
12/6 0
Start 0 25/0
(on tip)
8/7 15/15
Butterfly 0 10/6
(on tip)
12/6 8/8
Towhook: 128 mm from end of cabin.
Center of gravity: from the leading edge 95 mm
up deflection/down deflection

Eagle x-tail electric version - Pictures

Evolution F3B sailplane

Eagle x-tail electric version - Reference

Eagle F3B sailplane

More info and pictures:

Desing and Programing: Michal Michna - 2009
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