Seagull Models SEAGULL 40 User manual

Specifications
Wingspan ------------------------------------------ 60 in/ 153cm.
Wing area ------------------------------------ 620 sq.in/ 40dm2.
Length -------------------------------------------- 45 in/ 113.7cm.
Approximate flying weight --------- 5.5 - 6.2 lbs/ 2.5-2.8kg.
Recommended engine size - 0.40 -- 0.46 cu. in 2-stroke.
0.52 cu. in 4-stroke.
Recommended R/C ------------------- 4 channel minimum.
Flying skill level ----------------------------- Low wing Trainer.
Kitfeatures.
• Ready-made-minimalassembly&finishingrequired.
• Factory-installedpushrod.
• Photo-illustratedstep-by-stepAssemblyManual.
Hand-made Almost Ready to Fly R/C Model Aircraft
ASSEMBLY MANUAL
Additionalitems required.
Engine.
4 Channel or greater Radio Control system.
Glues.
Tools.
Starting Equipment.
Madein Vietnam.
SEAGULL 40
LOW WING TRAINER
MS:10
“Graphics and specfications may change without notice”.

SEAGULL 40 LOW WING TRAINER. Instruction Manual.
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WING ASSEMBLY.
NOTE: We highly recommend using 30
minute epoxy as it is stronger and provides
more working time, allowing the builder to
properlyaligntheparts.Usingfastcureepoxy
whenjoiningthewinghalvescouldresultinthe
gluedryingbeforethewinghalvesarealigned
properlywhichmayresultinfailureofthewing
centre section during flight.
 1)TestfittheWingtubeintoeachwinghalf.
The brace should slide in easily up to the
centreline that you drew. If not, use 220 grit
sandpaper with a sanding block and sand
down the edges and ends of the brace until it
fits properly.
NOTE:To avoid scratching your new aero-
plane we suggest that you cover
your workbench with an old towel.
Keepacoupleofjarsorbowlshandy
toholdthesmallpartsafteryouopen
the bags.
Please trial fit all parts. Make sure
you have the correct parts and that
they fit and are aligned properly be-
fore gluing! This will ensure proper
assembly as the SEAGULL 40 is
made from natural materials and
minor adjustments may have to be
made.
The paint and plastic parts used in
thiskitare fuel proof. However, they
arenottolerantofmanyharshchemi-
cals including the following: paint
thinner, cyano-acrylate glue accel-
erator,cyanoacrylategluede-bonder
andacetone.Donotletthesechemi-
calscomeincontactwiththecolours
onthecoveringandtheplasticparts.
INTRODUCTION.
Thank you for choosing the SEAGULL 40 LOW WING TRAINER ARTF by SEAGULL MODELS. The
SEAGULL 40 was designed with the intermediate/advanced sport flyer in mind. It is a low-wing
aeroplanewhichiseasytoflyandquicktoassemble.Theairframeisconventionallybuiltusingbalsa,
plywoodtomake itstrongerthanthe averageARTF,yet thedesignallowstheaeroplanetobekept
light. You will find that most of the work has been done for you already. Flying the SEAGULL 40 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 SEAGULL 40. 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
supplierandjoinyourlocalR/CModelFlyingClub.R/CModelFlyingClubsofferavarietyoftraining
proceduresdesignedto helpthenewpilotonhisway tosuccessfulR/Cflight. Theywillalsobeable
to advise on any insurance and safety regulations that may apply.
Wing tube.

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 3) Peel off the backing from the self adhe-
sivecoveringstrip.Applythestriptothecentre
section of the wing starting from the bottom
trailingedge.Wrapthestripallthewayaround
the wing until it meets the trailing edge again.
Trim off any excess strip.
Carefully slide the two wing halves together
and firmly press them together, allowing the
excess epoxy to run out. There should not be
any gap in the wing halves. Use rubbing
alcohol and a paper tower to clean up any
excess epoxy.
Apply masking tape at the wing join to hold
the wing halves together securely.
2) Remove the brace when satisfied with
its fit ineach wing half. Coat both sides of one
halfofthedihedralbracewith30minuteepoxy.
Next,poursomeepoxyintothedihedralboxin
one wing panel. Make sure you cover the top
andbottomaswellasthesidesofthedihedral
brace. Use enough epoxy to fill any gaps.
Glue attach.
Maskingtape.
Removecovering.
Wing botton.
Epoxy.
INSTALLING THE AILERON SERVOS.
Because the size of servos differ, you
mayneedtoadjust thesizeofthe precutopen-
inginthemount. The notch in the sides of the
mount allow the servo lead to pass through.
1) Install the rubber grommets and brass
collets onto the aileron servo. Test fit the
servo into the aileron servo mount.
2) Usingasmallweight(Weightedfuelpick-
up works well) and thread, feed the string
through the wing as indicated.
Small
weight.
Servos.
Thread.

SEAGULL 40 LOW WING TRAINER. Instruction Manual.
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4) Tape the servo lead to the wing to pre-
vent it from falling back into the wing.
 5) Reinstalltheservointotheservomount
and secure the servo inplace using the wood
screws provided with you radio system.
Thread.
Thread.
Wing bottom. Small weight.
3) Attach servo lead to the aileron servo.
Attach the string to the servo lead and care-
fullythread it though the wing. Once you have
thread the lead throught the wing, remove the
string so it can use for the other servo lead.
Thread.
Electric wire.
String.
Small weight.
Plastic tape.

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2) Locate the two nylon control horns, two
nylon control horn backplates and four
machine screws.
1) Using a ruler & pen to draw a straight
line as below picture.
2) Locate the two nylon control horns,
two nylon control horn backplates and four
machine screws.
3)Positiontheaileronhorn onthebottom
side of aileron. The clevis attachment holes
should be positioned over the hinge line.
(2) 2 x 20mm.
ControlHorn.
MountingScrews. Mounting Plate.
Repeat the procedure for the other wing
half.
Pen.
Straightline.
4) Using a 1mm drill bit and the control
horns as a guide, drill the mounting holes
through the aileron halves.
5)Mount the control horns by inserting
thescrewsthroughthe control hornbasesand
aileron halves, then into the mounting
backplates. Do not overtighten the screws or
the backplates may crush the wood.
6) Thread one nylon adjustable control
hornontoeachaileroncontrol rod. Thread the
horns on until they are flush with the ends of
the control rods.
7) With the aileron servo centered and
the aileron even with the trailing edge of the
wingattachtheclevisto the controlhorn.Mark
the control wire where it crosses the servo
arm hole.
AILERON LINKAGE.
Pen.
Markpoint.

SEAGULL 40 LOW WING TRAINER. Instruction Manual.
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3) The landing gear wire is held in place
using two nylon landing gear straps and four
3mm x 10mm wood screws.
The straps should be located equal dis-
tance from the inside and outside ends
ofthewire.
4) Using the two landing gear straps as
a guide, mark the locations of the four 3 x
10mm mounting screws onto the wing sur-
face.
Gear mounting slot.
Landing gear wire.
8) Make a 90-degree bend at the mark
andcutofftheexcesswire leaving 10mm past
thebend.
9) Connect the linkage as shown and
secure the control wire with a wire keeper.
Repeat the procedure for the other
aileron servo.
INSTALLING THE MAIN GEAR WIRES.
1) Using a modeling knife, remove the
covering from over the two main gear mount-
ing slots located in the bottom of the wing.
2) Insert the 90º bend of one main gear
wire into the predrilled hole in one mounting
slot.
Cut. 3x10mm.
7mm.

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FUEL TANK.
Be careful do not to drill through the
top of the wing!
6) Reinstall the gear wire and install the
straps using the four 3 x 10mm wood screws.
Tighten the screws completely to secure the
gear wire in place.
1) Using a modeling knife, carefully cut
offtherearportionofoneofthetwonylontubes
leaving 1/2” protruding from the rear of the
stopper. This will be the fuel pick up tube.
Pen.
Markpoint.
5) Remove the two straps and the gear
wire. Drillfour1.5mmpilotholesintothewing
for the wood screws.
1.5mm.
3 x 10mm.
Landing gear wire.
2) Usingamodelingknife,cutonelength
ofsiliconfuelline(notincluded)to2-1/4”long.
Connect one end of the line to the weighted
fuelpickupandtheother end to thenylonpick
up tube.
3) Carefully bend the second nylon tube
up at a 45º angle. This tube is the vent tube.
INSTALLING THE STOPPER ASSEMBLY.
4) Carefully heat the vent tube using a
heat gun or lighter to permanently set the
angle of the tube.
Vent tube. Fuel pick up
tube.
Fuel fill tube.
When the stopper assembly is installed in
the tank, the top of the vent tube should rest
justbelowthetop surfaceofthetank. Itshould
not touch the top of the tank.

SEAGULL 40 LOW WING TRAINER. Instruction Manual.
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 2) Place your engine onto the engine
mount. Adjust the engine is centered of the
edges of the engine case.
 3) When you are satisfied with the align-
ment, mark the locations of the engine
mounting.
MOUNTING THE ENGINE.
1) Install the pushrod housing through the
predrilledholeinthefirewall and intotheservo
compartment. The pushrod housing should
protrude 1/4" out past the front of the firewall.
MakeaZ-Bend1/4"fromoneend of theplain
wire pushrod.
4) Remove the engine. Using an drill bit,
drill the mounting holes through the engine
mount at the four locations marked.
Fuel fill tube.
Fuel pick up
tube.
Vent tube.
Battery tray.
C/AGlueattachment.
6) With the stopper assembly in place,
the weighted pick up should rest about 3/8”
awayfromtherearof the tankandmovefreely
insidethetank. The topoftheventtubeshould
rest just below the top of the tank. It should
not touch the top of the tank.
7) When satisfied with the alignment of
thestopperassembly tightenthe3mmx20mm
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.
Using a modeling knife, cut one length of
fuelline20”long. Connectonelinetothe vent
tube and one line to the fuel pick up tube on
the stopper. See picture bellow.
Fueltank.
Blow throughthetubestomakesurethe
lines have not become kinked during
installation.
5) 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.

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3x25mm.
Pushrod wire.
 6) AttachtheZ-Bendinthepushrodwire to
the throttle arm on the carburetor.
 5) Bolttheenginetotheenginemountusing
the four machine screws. Double check that
all the screws are tight before proceeding.
Installing steering arm as below.
NOSE GEAR INSTALLATION.
2.5mm.
3x25mm.
112mm.
Adjust the nose gear steering arm until the
arm is parallel with the fire wall.
Steering arm.
Adjustable connector.

SEAGULL 40 LOW WING TRAINER. Instruction Manual.
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1) Install the rubber grommets and brass
collets onto the elevator, rudder and throttle
servos. Test fittheservosintothepreinstalled
servo tray. Because the size of servos dif-
fer, you may need to adjust the size of the
precut openings in the tray.
INSTALLINGTHEFUSELAGESERVOS.
1) Install the switch into the precut hole
in the fuselage side. Use the two screws pro-
vided with the switch to secure it in place.
INSTALLING THE SWITCH.
Switch.
Install the pushrod wire as shown.
INSTALLINGTHESPINNER.
Install the spinner backplate, propeller and
spinner cone. The spinner cone is held in
place using two 3 x 15mm wood screws.
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.
Adjustable
Connector.

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 6) 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.
2) Position the servos into the servo tray
with the output shafts orientated as shown
below. Drill 1/16” pilot holes through the tray
for each of the mounting screws.
Secure the servos with the screws pro-
vided from your radio system.
Throttle.
Elevator.
Rudder.
Switch.
HORIZONTALSTABILIZER.
1) Using a ruler and a pen, locate the
centerlineofthehorizontalstabilizer,atthetrail-
ing edge, and place a mark. Use a triangle
and extend this mark, from back to front,
across the top of the stabilizer. Also extend
thismarkdownthebackofthetrailingedgeof
the stabilizer.
2)Usingamodelingknife,carefullyremove
the covering from over the vertical stabilizer
mounting slot in the top of the fuselage.
 3) Slide the stabilizer into place in the pre-
cut slot in the rear of the fuselage. The stabi-
lizer should be pushed firmly against the front
of the slot.
 4) 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.
 5) Remove the stabilizer. Usingthelines
youjustdrewasaguide,carefullyremovethe
covering from between them using a model-
ingknife.
When cutting through the covering to
remove it, cut with only enough pressure to
onlycutthrough thecoveringitself.Cuttinginto
the balsa structure may weaken it.
Removecovering.
Center line.
Pen.

SEAGULL 40 LOW WING TRAINER. Instruction Manual.
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2) Slidetheverticalstabilizerintotheslot
in the top of the fuselage. The rear edge of
thestabilizer shouldbeflushwiththerearedge
of the fuselage and the lower rudder hinge
should engage the precut hinge slot in the
lowerfuselage. Thebottomedgeofthestabi-
lizer should also be firmly pushed against the
top of the horizontal stabilizer.
3) While holding the vertical stabilizer
firmly in place, use a pen and draw a line on
each side of the vertical stabilizer where it
meets the top of the fuselage.
4) Remove the stabilizer. Using a mod-
eling knife, remove the covering from below
the lines you drew.
Pen.
Hingeslot.
in the fuselage. Slide the stabilizer in place
and realign. Double check all of your mea-
surementsoncemorebeforetheepoxy cures.
HoldthestabilizerinplacewithT-pinsormask-
ing tape and remove any excess epoxy using
a paper towel and rubbing alcohol.
 8) After the epoxy has fully cured, re-
move the masking tape orT-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.
VERTICAL STABILIZER INSTALLATION.
1) Using a modeling knife, remove the
covering from over the precut hinge slot cut
intothelowerrear portionofthefuselage. This
slot accepts the lower rudder hinge.
Hinge.
 7) When you are sure that everything is
aligned correctly, mix up a generous amount
of 30 Minute Epoxy. Apply a thin layer to the
topandbottomofthestabilizermountingarea
and to the stabilizer mounting platform sides
Remove covering.

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6) When you are sure that everything is
alignedcorrectly,mixupagenerous amountof
30MinuteEpoxy. Applyathinlayertothemount-
ingslotinthetopofthefuselageandtothesides
and bottom of the vertical stabilizer mounting
area. Applyepoxytothebottom and topedges
When cutting through the covering to re-
move it, cut with only enough pressure
toonly cut through the covering itself. Cutting
into the balsa structure may weaken it.
5) Slide the vertical stabilizer back in
place. Using a triangle, check to ensure that
theverticalstabilizerisaligned90ºtothehori-
zontal stabilizer.
90º
Vertical
Stabilizer.
Horizontal
Stabilizer.
of the filler block and to the lower hinge also.
Set the stabilizer in place and realign. Double
checkallofyourmeasurementsonce morebe-
foretheepoxycures.Holdthestabilizerinplace
with T-pins or masking tape and remove any
excess epoxyusinga papertowelandrubbing
alcohol. Allow the epoxy to fully cure before
proceeding.
CONTROL HORN INSTALLATION.
1) Locate the nylon control horns- nylon
controlhornbackplatesand machinescrews.
2)The positionofelevatorcontrolhornon
theleftsideof elevator.Theclevisattach-ment
holesshouldbepositionedover thehingeline.
ControlHorn.
MountingScrews. Mounting Plate.
(2) 2x20mm.
4) Mount the control horns then into the
mounting backplates. Do not overtighten the
screwsorthebackplatesmay crush thewood.
6) Install the rudder control horn using
thesamemethod as with the elevator control
horns.
3) Using a 2mm drill bit and the control
horns as a guide, drill the mounting holes
through the elevator halves.
5)Positiontheruddercontrolhornonthe
left side of the airplane.
Left side.

SEAGULL 40 LOW WING TRAINER. Instruction Manual.
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ATTACHMENT WING - FUSELAGE.
See picture below:
BALANCING.
1) It is critical that your airplane be bal-
anced correctly. Improper balance will cause
yourplanetolosecontroland crash. The cen-
terofgravityislocated9cmbackfromthelead-
ing edge of the wing, measured at the wing
tip.
1)Plugthefiveservo leads andtheswitch
lead into the receiver. Plug the battery pack
lead into the switch also.
2) Wrap the receiver and battery pack in
the protective foam rubber to protect them
from vibration
ELEVATOR-RUDDER PUSHROD
INSTALLATION.
Elevatorpushrod.
Rudderpushrod. Clevis.
Control
horn.
Antenna.
Antennawire.
Receiver.
Battery.
Tiewrap.
Throttle.
Elevator.
Rudder.
Switch.
Wing bolt.
INSTALLINGTHE RECEIVERANDBATTERY.
Adjustable Servo connector.
Servo arm.
(1PCS).
(2PCS).
Threadlocker glue.

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2) If the nose of the plane falls, the plane
is nose heavy. To correct this first move the
battery pack further back in the fuselage. If
this is not possible or does not correct it, stick
small amounts of lead weight on the fuselage
sides under the horizontal stabilizer. If the tail
of the plane falls, the plane is tail heavy. To
correct this, move the battery and receiver for
ward orif this is not possible, stick weight onto
thefirewall. When balanced correctly, the air-
plane should sit level or slightly nose down
when you lift it up with your fingers.
CONTROL THROWS.
1) We highly recommend setting up the
SEAGULL 40 using the control throws listed
atright. Wehavelistedcontrolthrows for both
Low Rate (initial test flying) and High Rate
(aerobaticflying).
2) Turn on the radio system, and withthe
trim tabs on the transmitter in neutral, center
the control surfaces by making adjustments
totheclevisesoradjustable servo connectors.
The servo arms should be centered also.
 4) By moving the position of the adjust-
able control horn out from the control surface,
you will decrease the amount of throw of that
control surface. Moving the adjustable con-
trol horn toward the control surface will in-
crease the amount of throw.
 3) When the elevator, rudder and aileron
control surfaces are centered, use a ruler and
check the amount of the control throw in each
surface. The control throws should be
measured at the widest point of each sur-
face!
FLIGHT PREPARATION.
 A) Check the operation and direction of
the elevator, rudder, ailerons and throttle.
 B) Plug in your radio system per the
manufacturer's instructions and turn every-
thingon.
 D) Check the rudder. Looking from be-
hindthe airplane, move the rudder stick to the
right. Theruddershouldmovetothe right. If it
does not, flip the servo reversing switch on
your transmitter to change the direction.
 C) Check the elevator first. Pull back on
theelevatorstick. Theelevatorhalvesshould
move up. If it they do not, flip the servo re-
versing switch on your transmitter to change
the direction.
INITIAL FLYING/SPORT FLYING
Ailerons: 3/8” up 3/8” down
Elevator: 3/8 ” up 3/8” down
Rudder: 1/2” right 1/2” left
AEROBATIC FLYING
Ailerons: 1/2”up 1/2”down
Elevator: 5/8”up 5/8”down
Rudder: 1” right 1”left
Do not use the aerobatic settings for
initial test flying or sport flying.
 E)Check the throttle. Moving the throttle
stick forward should open the carburetor bar-
rel. Ifitdoes not,fliptheservo reversingswitch
on your transmitter to change the direction.
 F)From behind the airplane, look at the
aileronontherightwing half. Movetheaileron
sticktothe right. Therightaileronshouldmove
upandtheotheraileronshouldmove down. If
it does not, flip the servo reversing switch on
your transmitter to change the direction.
CG=9cm.

SEAGULL 40 LOW WING TRAINER. Instruction Manual.
16
5) If your radio transmitter is equipped
withdualrateswitchesdoublecheckthatthey
are on the low rate setting for your first few
flights.
6) Check to ensure the control surfaces
are moving the proper amount for both low
and high rate settings.
PREFLIGHT CHECK.
1) Completely charge your transmitter
and receiver batteries before your first day of
flying.
2) Check every bolt and every glue joint
in the SEAGULL 40 to ensure that everything
is tight and well bonded.
3) Double check the balance of the air-
plane. Do this with the fuel tank empty.
4) Checkthecontrolsurfaces. Allshould
move in the correct direction and not bind in
any way.
8) Properlybalancethepropeller. An out
of balance propeller will cause excessive vi-
bration which could lead to engine and/or air-
frame failure.
We wish you many safe and enjoyable
flights with your SEAGULL 40 LOW WING
TRAINER.
7) Check the receiver antenna. It should
be fully extended and not coiled up inside the
fuselage.