PRO-DESIGN L-39 Albatros 68mm EDF User manual

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L-39 Albatros 68mm EDF
High performance Fiberglass L39 for 68mm electric ducted fan
Specifications are subject to change without notice
Warning !
This model is not a toy and please read the manual carefully before construction and
operating this model aircraft.
Specification
• Flying Weight 1,100-1,200 g
• Wing span 810mm.
• Length 900mm.
• EDF Rotor diameter 68mm

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Radio system for 4 channels or above
1x 40- 60A Electronic speed controllers for brushless motor
1x 70mm fan-units
1x 500-700W 3600-4400kv brushless motors
4x Servo extension wires
3x 9g mini servo
Lithium polymer 3-4 cell, 2200-3200mAh, 20-45c
5 or 30 minute epoxy, CA Glue
Velcro.
Locktite/ threadlock
Drill , drill bit 2mm, 3mm, 5mm
Plier/cutter/ Philip screw driver
2mm , 3mm hex driver
Scissor
Tools needed
Equipment and parts needed

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Fuselage, Main wing, Fuel Tank, Exit ducting sheet, elevator , EDF cover, wing joiner, landing
gear and wheel, canopy, hardware bags ( screw, horn, linkage connector, M3 nut, steering
arm, 3mm collar, mounting plate, magnet).
Find a pre-cut slot at the underside of the wing and cut open the film. Insert the aileron servo
and pass the wire through the hole. You may use servo extension wire. The ailerons have
Inside the Box
Aileron Servo

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been attached to the wing in factory. Before gluing the aileron servo, center the servo horn
by means of a servo tester or with a receiver/ transmitter. Install the servo with epoxy and
balsa wood block if necessary. Mark the horn insertion and cut a 5mm slot in the aileron and
epoxy the control horn. Connect the linkage wire to the servo horn.
Try fitting the wings to the fuselage with the wing joiner and the 3mm carbon rod. Adjust and
orient the joiner such that both wings are in perfect position. 5mm holes can be drilled on the
sides of the fuselage to pass the wires of the aileron servos. Drill two 3mm holes on the
fuselage to connect the carbon rods, that strengthen the wing against torsion.
The wing joiner is made of fiberglass and this guarantee no risk of wing breakage at high
velocity. Sand all contact surfaces to maximize bonding strength.
Glue the main wings with epoxy, then tape the wings firmly to the fuselage. Support the wing
with blocks if necessary. Check for horizontal and longitudinal symmetry.
Main Wing
Main Wing

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Sand away the paint on the fuel tank attachment area. Use 5 mins epoxy to attach the tank to
the main wing. Use clamps/ tape to secure the position.
Detach the aileron from the horizontal plate. Bent the U-shaped wire with a collar fir inside.
Pass the U-shaped wire through the slot on the fuselage. Drill a 2mmx10mm hole in the
Fuel Tank
Elevator

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aileron and try inserting the wire into the hole. Apply CA/ epoxy to attach the elevator to the
horizontal plate after they are in perfect position. Finally, the most important, is to applied
30mins epoxy to secure the horizontal plate to the fuselage. Make sure the horizontal
stabilizer is clamped/ taped such that it lies in the same horizontal plane with the wing.
Ensure it is also perpendicular to the vertical stabilizer. You may use tape to run across the
vertical stabilizer to avoid any position change before the epoxy cured.
The above diagram is for illustration only.
The hex nut under the elevator collar can now be loctited with the push horn in position.
Connect the linkage wire with the linkage connector given.
Cut the exit duct cone and try fitting the EDF unit. The recommended length is 8cm with exit
area equals 85% of fan sweep area. Recommended exit diameter is 55-58 mm.
Elevator Linkage
Exit Ducting

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Test run the EDF unit before installation. Check and mark the ESC connector to ensure air is
blown backward.
Try inserting the EDF unit with the backend first. Apply glue/tape to both end of the EDF
housing. Make perfect sealing to enhance the EDF efficiency. Assemble the ducted fan unit
and anchor the ESC.
Use transparent tape to attach the light EDF cover.
EDF cover
Ducted Fan Unit

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The pre-painted and pre-assembled canopy and cockpit can be a snap on.
The neutral position of the elevator should be the same horizontal level with main wing.
The above photo shows the down elevator stick/ pitch up at low rate.
Elevator throw is 8 mm up 8mm down. Use 50% exponential. Low rate 6mm.
Ailerons throw is 8 mm up 6 mm down. Use 30% exponential. Low rate 5mm.
Control Throws
Cockpit

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Main landing gear assembly. This is a versatile design that can suits all options, including
pilots looking for belly landing, fixed gears or optional electronic retractable gears.
The factory assembled landing gear unit can adapt fixed landing gear. Insert the piano wire
and fixed the position with the provided nylon slab and screw.
Apply sufficient epoxy to make the block strongly attached to the fuselage. Attach the Landing
gears as above.
On the other hand, one can simple install an electronic retractable gear as an option.
Assemble the front gear mount as shown. Apply sufficient epoxy to make the mount strong.
The wooden mount allows use to upgrade to optional electronic retractable gear.
Tighten the steering control arm. Connect the linkage connector to the steering servo (Rudder
Channel)
The height of the front gear is adjusted by the 3mm at the bottom. This is critical for runway
Main Landing gear
Front Landing gear

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take off. The Wing incidence, the attack angle of the main wing to the runway path, will be one
of the factors for the take off distance. It should be slightly positive when the aircraft is loaded
with battery.
The fuselage wheel space is pre-cut in factory. You need to extend the space for the strut as
shown in the diagram above. The ChangeSun electronic retract can be drop fit into the precut
space. You can use Y-cable to connect all 3 electronic retracts. Set the ATV of the
corresponding channel (Gear Ch.) to maximum in both direction.
The fuselage wheel space is pre-cut in factory. You need to extend the space for the strut as
shown in the diagram above. The ChangeSun electronic retract can be drop fit into the precut
space. You can use Y-cable to connect all 3 electronic retracts. Set the ATV of the
Optional Electronic retract
Optional Electronic retract

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corresponding channel (Gear Ch.) to maximum in both direction.
The nose gear slot is pre-cut in factory. The ChangeSun electronic retract can be installed with
ease. You may need some balsa wood to secure the steering servo in place.
The idea C.G. position is 6 cm behind the leading edge measured at where the wing meets
the fuselage. Adjust the battery position to obtain the correct C.G. Check the C.G. before flying.
C.G. setting
Optional Electronic retract

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Assistance from experienced pilot is necessary for beginners.
Pre-flight adjustment and trimming must be done before flying. Check all
linkage, nuts, servo horns, linkage nuts and screws are tightened. Make sure
thread lockers are applied.
Ensure the flying field is spacious and safe to fly.
Bench test the electronic equipment on loading for 5minutes. Check
temperature of the ESC, BEC and battery. This is to ensure the power
system and the BEC are reliable. All EDF should be run in to test for
vibrations and loosen shaft.
Check all electronic equipment. Range check the radio equipment. Test all
control surface are move in the assigned direction.
Check battery voltage before use, even the battery are recently charged.
At the first flight, it is prudent to check the C.G.
In runway takeoff, slight finger pressure at the trailing edge of the elevator
should be able to pitch up the aircraft.
Enjoy!
Take pictures and video of your scale looking,
high performance ProDesign fighter!
Warning for pilot