Seagull Models EXTRA EA 300L User manual

Specifications:
Wing span ------------------------------54.9 in ( 139.5cm).
Wing area -----------------517.7 sq.in ( 33.4sq dm).
Weight ------------------------6.6 lbs ( 3.0 kg).
Length ------------------------------44.4 in ( 112.9 cm).
Engine ------------------ 0.46 cu.in -----2-stroke.
0.62 cu.in -----4-stroke.
Radio ------------------- 4 channels with 5 servos.
Electric conversion: optional
MS:199
“Graphics and specifications may change without notice”.
ASSEMBLY MANUAL
SIZE: 46-62

EXTRA EA 300l - 1395mm.Instruction Manual.
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INTRODUCTION.
Thank you for choosing the EXTRA EA300L by SEAGULL MODELS. The EXTRA EA300L was
designed with the intermediate/advanced sport flyer in mind. It is a semi scale airplane which is easy
to fly and quick to assemble. The airframe is conventionally built using balsa, plywood to make it
stronger than the average ARTF , yet the design allows the aeroplane to be kept light. You will find
that most of the work has been done for you already.The motor mount has been fitted and the hinges
are pre-installed . Flying the EXTRA EA300L is simply a joy.
This instruction manual is designed to help you build a great flying aeroplane. Please read this
manual thoroughly before starting assembly of your EXTRA EA300L. Use the parts listing below to
identify all parts.
WARNING.
Please be aware that this aeroplane is not a toy and if assembled or used incorrectly it is
capable of causing injury to people or property. WHEN YOU FLY THIS AEROPLANE YOU
ASSUME ALL RISK & RESPONSIBILITY.
If you are inexperienced with basic R/C flight we strongly recommend you contact your R/C supplier
and join your local R/C Model Flying Club. R/C Model Flying Clubs offer a variety of training
procedures designed to help the new pilot on his way to successful R/C flight. They will also be able
to advise on any insurance and safety regulations that may apply.
KIT CONTENTS
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3
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ADDITIONAL ITEMS REQUIRED.
0.46 2-stroke.
0.62 4-stroke.
Computer radio with 5 servos.
Glow plug to suit engine.
Propeller to suit engine.
Protective foam rubber for radio
system.
Silicone fuel line.
TOOLS & SUPPLIES NEEDED.
Thick cyanoacrylate glue.
30 minute epoxy.
5 minute epoxy.
Hand or electric drill.
Assorted drill bits.
Modelling knife.
Straight edge ruler.
2mm ball driver.
Phillips head screwdriver.
220 grit sandpaper.
90° square or builder’s triangle.
Wire cutters.
Masking tape & T-pins.
Thread-lock.
Paper towels.
The control surfaces, including the
ailerons, elevators, and rudder, are
prehinged with hinges installed, but
the hinges are not glued in place. It
is imperative that you properly
adhere the hinges in place per the
steps that follow using a high-quality
thin C/A glue.
2) Remove each hinge from the wing panel
and aileron and place a T-pin in the center of
each hinge. Slide each hinge into the aileron
until the T-pin is snug against the aileron. This
will help ensure an equal amount of hinge is
on either side of the hinge line when the aileron
is mounted to the wing panel.
HINGING THE AILERONS .
Note:
Hinge.
T-pin.
KIT CONTENTS.
1 Fuselage
2 Wing set
3 Tail set
4 Canopy
5 Pilot
6 Cowling
7 Main landing gear
8 Wheel pants
3) Slide the aileron on the wing panel until
there is only a slight gap. The hinge is now
centered on the wing panel and aileron.
Remove the T-pins and snug the aileron
against the wing panel. A gap of 1/64” or less
should be maintained between the wing panel
and aileron.
1) Carefully remove the aileron from one
of the wing panels. Note the position of the
hinges.

EXTRA EA 300l - 1395mm.Instruction Manual.
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8) After both ailerons are securely hinged,
firmly grasp the wing panel and aileron to
make sure the hinges are securely glued and
cannot be pulled out. Do this by carefully
applying medium pressure, trying to separate
the aileron from the wing panel. Use caution
not to crush the wing structure.
7) Repeat this process with the other wing
panel, securely hinging the aileron in place.
Work the aileron up and down several
times to “work in” the hinges and
check for proper movement.
Note:
HINGING THE ELEVATOR.
Glue the elevator hinges in place using the
same techniques used to hinge the ailerons.
4)Deflect the aileron and completely
saturate each hinge with thin C/A glue. The
ailerons front surface should lightly contact the
wing during this procedure. Ideally, when the
The hinge is constructed of a special
material that allows the C/A to wick
or penetrate and distribute
throughout the hinge, securely
bonding it to the wood structure of
the wing panel and aileron.
hinges are glued in place, a 1/64” gap or less
will be maintained throughout the lengh of the
aileron to the wing panel hinge line.
Note:
Hinge.
6) Using C/A remover/debonder and a
paper towel, remove any excess C/A glue that
may have accumulated on the wing or in the
aileron hinge area.
5) Turn the wing panel over and deflect the
aileron in the opposite direction from the
opposite side. Apply thin C/A glue to each
hinge, making sure that the C/A penetrates into
both the aileron and wing panel.
Epoxy

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HINGING THE RUDDER.
Glue the rudder hinges in place using the
same techniques used to hinge the ailerons.
Hinge.
LEDLIGHT
INSTALL THE AILERONS CONTROL
HORN.
Locate the hardware necessary to install the
control horns for the ailerons.
Aileron Control Horn
Assembling the ledlight as shown below
pictures. C/A glue

EXTRA EA 300l - 1395mm.Instruction Manual.
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Epoxy
INSTALL ELEVATOR CONTROL
HORN.
Install the elevator control horn using the same
method as same as the aileron control horns,
Epoxy
Epoxy
Elevator Control Horn
INSTALL THE RUDDER CONTROL
HORN.
Repeat steps to install the rudder control horn
as same as steps done for ailerons.
Epoxy
Rudder control horn
Elevator
Epoxy
Rudder Control Horn

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ENGINE MOUNT INSTALLATION.
1) Locate the items necessary to install the
engine mount included with your model. .
2) Use four M4x30mm head bolts and four
4mm washers to attach the engine mount rails
to the firewall. Tighten the screws . Make sure
to use threadlock on the screws to help
prevent them from vibrating loose.
M4x30mm.
ENGINE 0.72 : 4 STROKE
1) Using a modeling knife, carefully cut
off the rear portion of one of the 3 nylon tubes
leaving 1/2” protruding from the rear of the
stopper. This will be the fuel pick up tube.
INSTALLING THE STOPPER ASSEMBLY.
2) Using a modeling knife, cut one length
of silicon fuel line. Connect one end of the line
to the weighted fuel pick up and the other end
to the nylon pick up tube.
Thread locker glue
3) Carefully bend the second nylon tube
up at a 45º angle. This tube is the vent tube.
5) With the stopper assembly in place,
the weighted pick-up should rest away from
the rear of the tank and move freely inside the
tank. The top of the vent tube should rest just
below the top of the tank. It should not touch
the top of the tank.
4) Test fit the stopper assembly into the
tank. It may be necessary to remove some of
the flashing around the tank opening using a
modeling knife. If flashing is present, make
sure none falls into the tank.
Vent tube. Fuel pick up tube.
Fuel fill tube.
A

EXTRA EA 300l - 1395mm.Instruction Manual.
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 7) Slide the fuel tank into the fuselage. Guide
the lines from the tank through the hole in the
firewall.
 8) Use balsa plywood to help prevent
moveable from transferring to the fuel tank as
shown.
You should mark which tube is the vent
and which is the fuel pickup when you attach
fuel tubing to the tubes in the stopper. Once
the tank is installed inside the fuselage, it may
be difficult to determine which is which.
6) When satisfied with the alignment of
the stopper assembly tighten the 3 x 20mm
machine screw until the rubber stopper ex-
pands and seals the tank opening. Do not
overtighten the assembly as this could cause
the tank to split.
FUEL TANK INSTALLATION.
Fuel Tank
Rubber
C/A glue A
Vent tube.
Fuel pick up
Fuel fill tube.
INSTALLING THE BATTERY.
Battery.
INSTALLING THE MAIN LANDING GEAR
TO FUSELAGE.
Battery

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 1) The blind nuts for securing the landing
gear are already mounted inside the fuselage.
 2) Using the hardware provided, mount
the main landing gear to the fuselage.
 3) Place the fuselage inverted on the work-
bench in a suitable stand. Set the landing gear
in place and use a screwdrive to secure the
landing gear to the fuselage using bolts
M4x20mm and washers. Make sure to use the
threadlock on the bolts so they don’t vibrate
loose.
C/A glue.
Cut.
Cut.
2) Follow diagram below for wheel pant
installation:
Use a drill and 8mm drill bit to drill a hole in the
wheel pants.
14mm.
8mm.
Drill a hole.
Thread locker glue.
M4x20mm
C/A glue.
M4x20mm.
WHEEL AND WHEEL PANTS
1) Locate the items neccessary to install

EXTRA EA 300l - 1395mm.Instruction Manual.
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4) Slide the collar to the axle and setscrew
the collars to secure the collar to the axle and
then slider the wheel on the axle with a drop of
oil on the axle so the wheel will spin freely when
installed. Prepare a second collar and tighten
the setscrew using hex wrench to secure the
collar to the axle.
5) Place the wheel assembly in the wheel
pants. The threaded portion of the axle will fit
the notch of the wheel pant as shown.
3) You have to trim each axle using a tool
cutting and cut-off wheel.
wheel Pant.
wheel.
M3.
wheel collar.
nut.
Axle.
Washer.
Lite-Plywood
block.
M3.
wheel collar.
wheel.
Axle.
Washer.
M3.
6) Slide the threaded end of the axle
through the hole in the bottom of the landing
gear leg. Use a washer and locknut to tighten
the axle to the landing gear. Make sure to use
threadlock on the nut so it won’t vibrate loose
in flight as shown.
 7) Tighten the setcrews using a hex
wrench to secure the collars on the axle over
the flat spot to retain the wheel as shown.
INSTALLING THE FUSELAGE SERVOS.
1) Install the rubber grommets and brass
collets onto the throttle servo. Test fit the servo
into the aileron servo mount.
 2) Secure the servos with the screws pro-
vided with your radio system.
Because the size of servos differ, you
may need to adjust the size of the precut open-
ing in the mount. The notch in the sides of the
mount allow the servo lead to pass through.
Repeat steps as above to attach remain-
ing wheel pants to the landing gear.

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THROTTLE SERVO ARM INSTALLATION.
Install adjustable servo connector in the servo
arm as same as picture below:
Throttle
Elevator
Rudder
Adjustable Servo
connector.
Servo arm.
Loctite secure.
1 PCS.
3/ 32” Hole.
INSTALLING THE SWITCH.
Install the switch into the precut hole in the
side, in the fuselage.
Throttle
Rudder
Elevator
Switch.
Trim and cut.
MOUNTING THE ENGINE.
 1) Position the engine with the drive washer
(110mm) forward of the firewall as shown.
110mm
2) Use a pin drill and 2mm drill bit to drill a
small indentation in the mount for the engine
mounting screw.

EXTRA EA 300l - 1395mm.Instruction Manual.
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2 mm.
2mm.
3) Use a drill to drill the four holes in the engine
mount rails.
4) On the fire wall has the location for the
throttle pusshrod tube (pre-drill).
6) Connect the Z-bend in the 450mm throttle
pushrod to the outer hole of the carburetor arm.
2mm
7) Slide the throttle pushrod wire into the tube.
Position the engine between the mounts. Use
four M3x25mm machine screws to secure the
engine to the mount as shown.
5) Slide the pushrod tube in the firewall and
guide it through the fuel tank mount. Use
medium C/A to glue the tube to the firewall and
Pushrod wire.
Machine screw M3x25mm.
8) Reinstall the servo horn by sliding the
connector over the pushrod wire. Center the
throttle stick and trim and install the servo horn
perpendicular to the servo center line.
9) Move the throttle stick to the closed position
and move the carburetor to closed. Use a 2.5mm
hex wrench to tighten the screw that secures
the throttle pushrod wire. Make sure to use
threadlock on the screw so it does not vibrate
loose.
Pushrod wire

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COWLING.
1) Slide the fiberglass cowl over the en-
gine and line up the back edge of the cowl with
the marks you made on the fuselage then trim
and cut as shown.
Cut
Cut
Cut
2) While keeping the back edge of the
cowl flush with the marks, align the front of
the cowl with the crankshaft of the engine. The
front of the cowl should be positioned so the
crankshaft is in nearly the middle of the cowl
opening. Use the spinner backplate as a guide.
Hold the cowl firmly in place using pieces of
masking tape.
Because of the size of the cowl, it may be nec-
essary to use a needle valve extension for the
high speed needle valve. Make this out of suf-
ficient length 1.5mm wire and install it into the
end of the needle valve. Secure the wire in
place by tightening the set screw in the side of
the needle valve.
3 x10mm
Needle valve

EXTRA EA 300l - 1395mm.Instruction Manual.
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 3) Install the muffler and muffler extension
onto the engine and make the cutout in the
cowl for muffler clearance. Connect the fuel
and pressure lines to the carburetor, muffler
and fuel filler valve. Secure the cowl to fuse-
lage using the 3x10mm screws.
ELECTRIC POWER CONVERSION.
- Model size: .46 -.52 size models
- Motor: 35mm 830 rev per volt
- Propeller: 12x6 ~ 13x6
- ESC: 60A
- Lipo Batteries: 4 cell 4200mA
2) Attach the electric motor box to the firewall
suitable with the cross lines drawn on the electric
motor box and firewall. Using epoxy and balsa
stick to secure the motor box to the firewall.
Please see pictures below.
1) Locate the items neccessary to install the
electric power conversion included with your
model.
ELECTRIC POWER CONVERSION
4x20 mm

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3 x 15mm
3) Attach the motor to the front of the electric
motor box using four 4mm blind nut, four
M3x15mm hex head bolts to secure the motor.
Please see picture shown.
4) Locate the plywood battery tray to the
fuselage. Tighten the screws using machine
screws M3x15mm to secure the tray in position.
Nut M3
4mm
110mm
Epoxy.
speed control.
5) Attach the speed control to the side of the
motor box using two-sided tape and tie wraps.
Connect the appropriate leads from the speed
control to the motor. Make sure the leads will
not interfere with the operation of the motor.
Epoxy
Speed Control
Balsa

EXTRA EA 300l - 1395mm.Instruction Manual.
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Battery
INSTALLING THE SPINNER.
Install the spinner backplate, propeller and
spinner cone.
The propeller should not touch any part
of the spinner cone. If it does, use a
sharp modeling knife and carefully trim away
the spinner cone where the propeller comes
in contact with it.
2) Place the servo between the mounting
blocks and space it from the hatch. Use a pencil
to mark the mounting hole locations on the
blocks.
3) Use drill bit in a pin vise to drill the mouting
holes in the blocks.
INSTALLING THE AILERON - FLAP SERVOS.
Servos. Small weight.
Thread.
1) Using a small weight (Weighted fuel pick-up
works well) and string, feed the string through
the wing as indicated.
Because the size of servos differ, you
may need to adjust the size of the precut open-
ing in the mount. The notch in the sides of
the mount allow the servo lead to pass through.

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6) Secure the servo to the aileron hatch using
Phillips screwdriver and the screws provided
with the servo.
5) Use dental floss to secure the connection
so they cannot become unplugged.
7) Apply 1-2 drops of thin C/A to each of the
mounting tabs. Allow the C/A to cure without
using accelerator.
4) Apply 2-3 drops of thin C/A to each of the
mounting holes. Allow the C/A to cure without
using accelerator.
C/A glue

EXTRA EA 300l - 1395mm.Instruction Manual.
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2 x 10mm
2x10mm
AILERON PUSHROD HORN INSTALLATION
Fuel Tubing
M2 Clevis
Hex Nut
Pushrod
Mark
INSTALLING THE HORIZONTAL STABILIZER.
1) Using a ruler and a pen, locate the
centerline of the horizontal stabilizer, at the
trailing edge, and place a mark. Use a triangle
and extend this mark, from back to front,
across the top of the stabilizer. Also extend
this mark down the back of the trailing edge of
the stabilizer.
Snap keeper.
Servo arm.
8mm
Snap keeper.
M2 lock nut. Metal clevis.
Bend at the mark
Nylon Snap Keeper
Fuel Tubing

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5) When you are satisfied with the align-
ment, hold the stabilizer in place with T- pins
or masking tape, but do not glue at this time.
4) Install the stabilizer onto the fuselage.
Align the centerline drawn on the top and the
rear of the stabilizer with the centre of the fu-
selage. When that is aligned, hold the stabi-
lizer in that position using T-pins or masking
tape. Align the horizontal stabilizer with the
wing. When viewed from the rear, the hori-
zontal stabilizer should be level with the wing.
If it is not level, use sandpaper and sand down
the high side of the stabilizer mounting plat-
form until the proper alignment is achieved.
The tips of the stabilizer should also be equal
distance from the tips of the wing.
3) Put the stabilizer into place in the
position of the fuselage.
2) Using a modeling knife, carefully remove
the covering at mounting slot of horizontal
stabilizer.
6) With the stabilizer held firmly in place,
use a pen and draw lines onto the stabilizer
where it and the fuselage sides meet. Do this
on both the right and left sides and top and
bottom of the stabilizer.
Remove covering
When cutting through the covering to
remove it, cut with only enough pressure
to only cut through the covering itself. Cut-
ting into the balsa structure may weaken
it.
8) Using a modeling knife, carefully re-
move the covering that overlaps the stabilizer
mounting platform sides in the fuselage. Re-
move the covering from both the top and the
bottom of the platform sides.
7) Remove the stabilizer. Using the lines
you just drew as a guide, carefully remove the
covering from between them using a model-
ing knife.
Pen
Remove the covering.
Cut

EXTRA EA 300l - 1395mm.Instruction Manual.
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Remove covering.
1) Using a modeling knife, remove the
covering from over the precut hinge slot cut
into the lower rear portion of the tail at the fu-
selage.
Epoxy
INSTALLING THE VERTICAL STABILIZER.
Cut
9) When you are sure that everything is
aligned correctly, mix up a generous amount
of 30 Minute Epoxy. Apply a thin layer to the
bottom of the stabilizer mounting area and to
the stabilizer mounting platform sides in the
fuselage. Putting the stabilizer in place and
realign. Double check all of your measure-
ments once more before the epoxy cures.
Hold the stabilizer in place with T-pins or mask-
ing tape and remove any excess epoxy using
a paper towel and rubbing alcohol.
Epoxy
Epoxy
Epoxy
10) After the epoxy has fully cured, re-
move the masking tape or T-pins used to hold
the stabilizer in place. Carefully inspect the
glue joints. Use more epoxy to fill in any gaps
that may exist that were not filled previously
and clean up the excess using a paper towel
and rubbing alcohol.