Seagull Models DECATHLON ARTF User manual

MadeinVietnam.
“Graphics and specifications may change without notice”.
Kit features.
• Ready-made—minimalassembly&finishingrequired.
• Ready-coveredcovering.
• Photo-illustratedstep-by-stepAssemblyManual.
Specifications
Wingspan--------------------------------------70.9in------------------------------180cm.
Wingarea--------------------------------------837sq.in------------------------54sq.dm.
Approximate flying weight------------------7.5-8.8 lbs---------------------3.4-4.0kg.
Length------------------------------------------47.6in-------------------------------121cm.
Recommended engine size-------------- .75cu.in-------------------------- 2-stroke.
.91cu.in--------------------------4-stroke.
Radio System required 4 channels with 6 servos
Flying skill level Intermediate/advanced.
ASSEMBLY MANUAL
MS: 86

DECATHLON _ CODE SEA 86.Instruction Manual
2
INTRODUCTION.
Thank you for choosing the DECATHLON ARTF by SEAGULL MODELS. The DECATHLON
wasdesignedwiththeintermediate/advancedsportscaleinmind.Itisasemiscale airplane which
iseasytoflyandquicktoassemble.Theairframeisconventionallybuiltusingbalsa,plywoodtomake
itstrongerthantheaverageARTF,yetthedesignallowstheaeroplanetobekeptlight.Youwillfind
thatmostoftheworkhasbeendoneforyoualready. Themotormounthasbeenfittedandthehinges
are pre-installed . Flying the DECATHLON 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 DECATHLON. 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
proceduresdesignedtohelpthenewpilotonhiswaytosuccessfulR/Cflight. They will also be able
to advise on any insurance and safety regulations that may apply.
ADDITIONAL ITEMS REQUIRED.
.75cu.in 2-stroke engine
.91cu.in 4-stroke
4 channel with 6 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
Modellingknife
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
PARTS LISTING.
FUSELAGE ASSEMBLY
(1) Fuselage
WING ASSEMBLY
(1) Right wing
(1) Left wing
(1) Aluminium dihedral brace
Tail section assembly
(1) Horizontal stabilizer/ elevator
halves.
(1) Rudder halves.
Some more parts.
HARDWAREPACK
COWLING
Landinggear.....

www.seagullmodels.com
3
1) Carefully remove the aileron from one
of the wing panels. Note the position of the
hinges.
2)Removeeach hinge fromthewing panel
and aileron and place a T-pin in the center of
each hinge. Slide each hinge into the wing
panel until the T-pin is snug against the wing
panel. This will help ensure an equal amount
ofhingeis on eithersideofthe hinge linewhen
the aileron is mounted to the aileron.
3) Slide the wing panel on the aileron 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
shouldbe maintained betweenthe wingpanel
andaileron.
The control surfaces, including the
ailerons, elevators, and rudder, are
prehinged with hinges installed, but the
hinges are not glued in place. It is
imperativethat youproperly adhere the
hingesin placeper thesteps thatfollow
using a high-quality thin C/A glue.
Note:
4)Deflect the aileron and completely
saturate each hinge with thin C/A glue. The
aileronsfrontsurface should lightlycontactthe
wing during this procedure. Ideally, when the
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: The hinge is constructed of a special
material that allows the C/A to wick or
penetrateanddistribute throughout the
hinge, securely bonding it to the wood
structureof the wingpanel andaileron.
To avoid scratching your new aero-
plane we suggest that you cover your work-
benchwith anold towel. Keepa coupleof jars
orbowlshandytoholdthesmallpartsafteryou
open the bags.
Pleasetrialfitallparts.Makesureyouhavethe
correct parts and that they fit and are aligned
properlybeforegluing!Thiswillensureproper
assemblyasthe DECATHLON ismadefrom
natural materials and minor adjustments may
havetobemade. Thepaintandplasticparts
usedinthiskitarefuelproof.However,theyare
not tolerant of many harsh chemicals includ-
ingthefollowing:paintthinner,cyano-acrylate
glueaccelerator,cyanoacrylategluede-bonder
andacetone.Donotletthesechemicalscome
incontactwiththecoloursonthecoveringand
the plastic parts.
NOTE:
HINGING THE AILERONS.
Hinge.
T- pin.
Hinge.
T- pin.
C/Aglue.

DECATHLON _ CODE SEA 86.Instruction Manual
4
8)Afterbothailerons are securelyhinged,
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.
TURNBUCKLE INSTALLATION.
Installing the turnbuckle for the wing as
same as pictures below.
Work the aileron up and down several
times to “work in” the hinges and check
for proper movement.
Note:
5)Turn thewing panel overand deflect the
aileron in the opposite direction from the
opposite side. Apply thin C/A glue to each
hinge,makingsurethattheC/Apenetratesinto
both the aileron and wing panel.
6) Using C/A remover/debonder and a
papertowel, remove anyexcess C/A gluethat
may have accumulated on the wing or in the
aileronhinge area.
Theholelocationof turnbuckles showninpic-
ture below .
Washer.
washer. Turnbuckle.
3x20mm.
TURNBUCKLE INSTALLATION.
Theholelocationof turnbuckles showninpic-
ture below .
The mounting holes of turnbuckle was
pre-drilled at factory.
Turnbuckle.
388mm.

www.seagullmodels.com
5
HINGING THE RUDDER.
Glue the rudder hinges in place using the
same tectniques used to hinge the ailerons.
Aileron control horn: See pictures below.
AILERON CONTROLHORN
ELEVATOR CONTROL HORN.
M3LOCK
NUT.
ALUMINUMWASHER.
ALUMINUMWASHER.
CONTRONLHORN
M3 SCREW.
16mm.
Epoxy.
Wing
Epoxy.
Wing
Hinge.
Install the elevator control horn using the
same method as with the aileron control
horns.
2 sets.
3x35mm.
Wing. Aileron.
Installingthe turnbucklefor tailstrut ofhori-
zontal fin as same as pictures below.
Horizontal fin bottom.
Turnbuckle.
Tail fin bottom.
2 sets.
3x40mm.

DECATHLON _ CODE SEA 86.Instruction Manual
6
16mm.
See pictures below.Make yourself the
template of your engine on paper.
ENGINE MOUNT INSTALLATION.
4x30mm.
Rudder control horn:
Usingthesametectniquesusedaileroncontrol
horn. See picture below.
2 sets.
3x35mm.
EPOXY.
Rudder control horn.
Rudder.
FUSELAGE.
RUDDER CONTROL HORN.
Elevator control horn.
CONTRONL HORN
M3 SCREW.
M3 LOCK NUT.
ALUMINUMWASHER. EPOXY.
FUSELAGE.
ALUMINUMWASHER.
Rudder.
Aluminum Washer.
16mm.
CONTRONL HORN M3
M3LOCKNUT.
Epoxy.
Epoxy.
Aluminum Washer.
Horizontal
Stabilizer.
Horizontal
Stabilizer.

www.seagullmodels.com
7
Mark and drill 4 holes for engine mount.
Insert 4 blind nuts to firewall.
2) Usinga modelingknife, cut one length
ofsilicon fuel line. Connectone end ofthe line
tothe weightedfuel pick up and the otherend
to the nylon pick up tube.(The silicon tube is
not included).
3) Carefully bend the second nylon tube
up at a 45º angle. This tube is the vent tube.
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.
Thread locker glue.
Venttube. Fuel pick up tube.
Fuel fill tube.
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.
5) With the stopper assembly in place,
the weighted pick-up should rest away from
therear of thetank 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.
Important: When the stopper assembly is in-
stalled in the tank, the top of the vent tube
should rest just below the top surface of the
tank. It should not touch the top of the tank.
Carefully use a lighter or heat gun to
permenently set the angle of the vent tube.
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.

DECATHLON _ CODE SEA 86.Instruction Manual
8
Fuel pick-up tube.
Fuelfill tube.
Venttube.
Blow through one of the lines to ensure
thefuel lines have not becomekinked in-
side the fuel tank compartment. Air should
flowthrough easily.
FUEL TANK INSTALLATION.
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.
C/Aglue attched.
Fueltank.
Plastic tape.
Balsa Block.
2) Follow diagram below for wheel pant
installation:
wheel collar.
wheel.
Axle.
Washer. M3.
wheel Pant.
wheel.
M3.
M3.
wheel collar.
nut. Axle.
Washer.
1) Assembleand mounting thewheelpants
as shown in the following pictures.
WHEEL AND WHEEL PANTS
INSTALLATION.
M3.
12mm.
5mm.

www.seagullmodels.com
9
1) The blind nuts for securing the landing
gearare already mountedinside the fuselage.
2) Using the hardware provided, mount
the main landing gear to the fuselage.
INSTALLING THE MAIN LANDING GEAR.
M4 x 10mm.
M4 x 20mm.
M4 x 10mm.
3) A drop of C/A glue on the wheel collar
screws will help keep them from coming lose
duringoperation.
Repeat the process for the other wheel.
LandingGear. wheel Pant.
Lockerglue.
MOUNTING THE ENGINE.
3) Remove the engine. Using an drill bit,
drill the mounting holes through the engine
mount at the four locations marked.
 1) Place your engine onto the engine
mount. Adjust the engine is centered of the
edges of the engine case.
 2) When you are satisfied with the align-
ment, mark the locations of the engine
mounting.
AlumiumSpar.
AlumiumSpar.
140mm
.
AlumiumSpar.

DECATHLON _ CODE SEA 86.Instruction Manual
10
COWLING INSTALLATION.
MachineScrew 3x10mm.
1.5mmwere
(needlevalve).
Trim and cut.
Trim and cut.
Pushrodwire.
Trim and cut.
 4) Bolttheenginetotheenginemountusing
the four machine screws. Double check that
all the screws are tight before proceeding.
4.2 mm diameter.
MachineScrew 4x30mm.
Pushrodwire.

www.seagullmodels.com
11
 2) Secure the servos with the screws pro-
vided with your radio system.
INSTALLING THE FUSELAGE SERVO.
1) Installthe rubbergrommets andbrass
colletsonto thethrottleservo. Testfittheservo
into the aileron servo mount.
Because the size of servos differ, you
mayneedtoadjustthe size oftheprecutopen-
ing in the mount. The notch in the sides of the
mount allow the servo lead to pass through.
Switch.
INSTALLING THE SWITCH.
Installthe switch intothe precut holein the
side of fuselage. AdjustableServo
connector.
Servoarm.
Loctite secure.
1 pcs.
THROTTLE SERVO ARM INSTALLATION.
Install adjustableservoconnectorinthe servo
arm .
Elevatorservo.
Rudderservo.
Elevatorservo. Throttleservo.

DECATHLON _ CODE SEA 86.Instruction Manual
12
Remove covering.
When cutting through the covering to re-
move it, cut with only enough pressure
toonly cut through the coveringitself. Cutting
into the balsa structure may weaken it.
Throttleservoarm.
Elevatorservo.
Elevatorservo.
Rudderservo.
Epoxy.
Hingeslot.
INSTALLING THE HORIZONTAL
STABILIZER.
INSTALLING THE VERTICAL STABI-
Hingeslot.
Remove covering.
Remove covering.
Epoxy.
Draw center line.

www.seagullmodels.com
13
Epoxy.
Putthe vertical stabilizerinto thein thetop
of the horizontal fin. The bottom edge of the
stabilizershould also befirmly pushed against
the top of the horizontal stabilizer.
When cutting through the covering to re-
move it, cut with only enough pressure
toonly cut through the coveringitself. Cutting
into the balsa structure may weaken it.
Epoxy.
90º
Vertical
Stabilizer.
Horizontal
Stabilizer.
Epoxy.
C/Aglue. Hinge.
INSTALLING THE AILERON SERVOS.
String.
Small weight.
Servos. Smallweight.
Thread.
Electric wire. Aileron
servo.

DECATHLON _ CODE SEA 86.Instruction Manual
14
Attach the string to the servo lead and carefully thread it though the wing.
INSTALLATION THE PUSHROD.
Wing. Aileron.
String. Small Weight.
Wing. Wing rib.
String.
Small Weight.
M2 lock nut.
M2clevis.
75mm.
Repeat the procedure for the other wing.
Wing.
Aileron.
110mm.
Aileron.
Aileron.
Elevator control horn.
Rudder control horn.
M2lock nut.
ELEVATOR - RUDDER PUSHROD
INSTALLATION.

www.seagullmodels.com
15
 1) Elevator and rudder pushrods assembly follow pictures below.
Throttle. Elevator.
Rudder.
Attach to servo arm in fuselage. Attach to elevator - rudder control horn.
M2 Lock nut.M2clevis.
Rudder pushrod.
Control horn.
Elevator Pushrod.
Metalclevis.
Elevator pushrod.
M2lock nut.
 2) Install servos arm to servos. Notice the
position of the servo arms on the servos. See
picture below.
Rudder pushrod.

DECATHLON _ CODE SEA 86.Instruction Manual
16
70mm.
3x10mm.
Alumium
trap.
Fuselage bottom.
Bottom.
1
22
INSTALLING TAIL STRUT SUPPORT
The tail strut system assembly follow pic-
tures below.
Elevator.
Elevator.
Rudder.
Throttle.
3x10cm(2pcs).
Alumium trap.
1
22
1
175mm. 7mm.
Snapkeeper.
Bottom.
70mm.

www.seagullmodels.com
17
1
2
2
21
1
1
2
2
1
MOUNTING THE TAIL WHEEL.
See pictures below.
M2 x 20mm.
M3 x 12mm.

DECATHLON _ CODE SEA 86.Instruction Manual
18
Wing bolt.
2) Wrap the receiver and battery pack in
the protective foam rubber to protect them
from vibration.
 3) Routethe antennain the antennatube
inside the fuselage and secure it to the bot-
tom of fuselage using a plastic tape.
INSTALLING THE BATTERY-RECEIVER.
Battery.
Receiver.
1) Plug the six servo leads and the switch
lead into the receiver. Plug the battery pack
lead into the switch also.
ATTACHMENT WING-FUSELAGE.
Attach the aluminium tube into fuselage.
Insert two wing panels as pictures below.
Antenna.
3x50mm.
Wing tube.
Aluminum tube.
Plastic Screw.
.
C/Aglue.

www.seagullmodels.com
19
Parts requirement.See pictures below.
INSTALLING THE WING STRUT.
M3 x 15mm.
M3x50mm.
M3x50mm.
5mm diameter pilot horn.
Turnbuckle.
60mm.
85mm.

DECATHLON _ CODE SEA 86.Instruction Manual
20
M3x15mm.
1) It is critical that your airplane be bal-
anced correctly. Improper balance will cause
yourplaneto losecontroland crash. Thecen-
ter of gravity is locate 8.7cm back from the
leading edge of the wing, measured at wing
tip.
BALANCING.
13
3
2
1