Seagull Models YAK 52 User manual

YAK 52
“Graphics and specifications may change without notice”.
MS:119
ASSEMBLY MANUAL
Specifications:
Wingspan----------------------------63.4in(161cm).
Wingarea-----------------689.8sq.in(44.5sqdm).
Weight------------------------9.3-10.1lbs(4.2-4.6kg).
Length------------------------------51.7in(131.3cm).
Engine ------------------0.91cu.in---------2-stroke.
1.20cu.in ---------4-stroke.
Radio-------------------6channelswith8 servos.
Retractslandinggear(included).

YAK 52.Instruction Manual.
2
INTRODUCTION.
ThankyouforchoosingtheYAK52ARTFbySEAGULLMODELS.The YAK52 wasdesignedwith
the intermediate/advanced sport flyer in mind. It is a semi scale airplane which is easy to fly and
quicktoassemble.Theairframeisconventionallybuiltusingbalsa,plywoodtomakeitstrongerthan
theaverageARTF,yetthedesignallowstheaeroplanetobekeptlight.Youwillfindthatmostofthe
workhasbeendoneforyoualready.Themotormounthasbeenfittedandthehingesarepre-installed
. Flying the YAK 52 is simply a joy.
This instruction manual is designed to help you build a great flying aeroplane. Please read this
manualthoroughlybeforestartingassemblyofyour YAK52 .Usethepartslistingbelowtoidentify
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.
IfyouareinexperiencedwithbasicR/CflightwestronglyrecommendyoucontactyourR/Csupplier
and join your local R/C Model Flying Club. R/C Model Flying Clubs offer a variety of training
proceduresdesignedtohelpthenew pilotonhisway tosuccessfulR/Cflight. Theywillalsobeable
to advise on any insurance and safety regulations that may apply.
KIT CONTENTS
1
2
9
3
4
5
8
6
7
10
4
12
11
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ADDITIONAL ITEMS REQUIRED.
0.91 2-stroke.
1.20 4-stroke.
Computer radio with 8 servos.
Glow plug to suit engine.
Propeller to suit engine.
Protective foam rubber for radio
system.
Siliconefuel 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.
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)Removeeachhingefrom the wing panel
and aileron and place a T-pin in the center of
each hinge. Slide each hinge into the aileron
untiltheT-pin is snugagainst the aileron.This
will help ensure an equal amount of hinge is
oneitherside ofthehingeline whentheaileron
is mounted to the wing panel.
HINGING THE AILERONS .
Note:
1) Carefully remove the aileron from one
of the wing panels. Note the position of the
hinges.
Hinge.
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
shouldbemaintainedbetweenthewingpanel
andaileron.
T-pin.
1 Fuselage
2 Left wing panel
3 Right wing panel
4 Tail set (2)
5 Canopy
6 Aluminum wing tube
7 Fiberglass cowl
8 Retracts landing gear
9 EP conversion pack
10 Hardware bag included
11 Retract covers
12 Wing fillet
KIT CONTEN.TS

YAK 52.Instruction Manual.
4
8)After both ailerons 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.
6) Using C/A remover/debonder and a
papertowel,removeanyexcessC/Agluethat
may have accumulated on the wing or in the
aileronhinge area.
5)Turnthe wing panel over and deflect the
aileron in the opposite direction from the
opposite side. Apply thin C/A glue to each
hinge,making surethattheC/Apenetratesinto
both the aileron and wing panel.
Workthe aileron upand downseveral
times to “work in” the hinges and
check for proper movement.
Note:
HINGING THE ELEVATOR.
Glue the rudder 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
aileronsfrontsurfaceshould lightly contact the
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.
Thehingeis constructed ofa 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.
Note:
Hinge.

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HINGING THE RUDDER.
Glue the rudder hinges in place using the
same techniques used to hinge the ailerons.
Hinge.
WING TIP ASSEMBLY.
Removecovering.
Fillepoxy.
Covering.
Wing tip.
1) Attach the plastic wing tip to the wing. Use a
hobby knife to remove the covering at the wing
end.
2) Apply the epoxy to the surface of both wing
tip and wing end. The plastic wing tip is held in
position and install it to the wing end. Please
see pictures shown.
Install plastic wing tip to wing end.

YAK 52.Instruction Manual.
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2 sets.
3x35mm.
ALUMINUMWASHER.
ALUMINUMWASHER.
CONTROLHORN
M3 SCREW.
18mm.
Epoxy.
Wing
Wing
Epoxy.
M3LOCKNUT.
Aileroncontrolhorn.
Maskingtape.
INSTALL THE AILERONS CONTROL
HORN.
3) Once the epoxy cures and use a covering
iron to seal the covering on the wing and over
the wing tip.
1) Locate the hardware necessary to install
the control horns for the ailerons.
2) Position the control horn on the bottom of
the aileron. You will see pre-drill hole 3mm for
the horn mounting screw on the aileron.
3) Place epoxy into hole. This will harden the
threads and prevent the crews from pulling
loose.
4) Thread a control horn end with aluminum
washer, lock nut until the top edge of the end is
18mm from the vase of the horn as shown.
3mm.

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Install the flap control horn using the same
methodassameas theaileron control horns.
INSTALL FLAP CONTROL HORN.
Hinge.
Flap control horn.
T-pin.
C/Aglue.
C/Aglue.
T-pin.
C/Aglue.
Install the elevator control horn using the
same method as same as the aileron control
horns.
INSTALL ELEVATOR CONTROL HORN.
CONTROLHORNM3SCREW.
M3 lock nut.
ALUMINUMWASHER. 18mm.
ALUMINUMWASHER.
Epoxy.
Epoxy.
Flap.
Aluminum Washer.
CONTROLHORN
M3 SCREW.
M3LOCK NUT.
Epoxy.
Aluminum Washer.
Flap.
2 sets.
3x30mm.
2 sets.
3x35mm.

YAK 52.Instruction Manual.
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Rudder.
Aluminum Washer.
CONTROLHORN
M3 SCREW.
M3LOCK NUT.
Epoxy.
Aluminum Washer.
Fuselage.
Fuselage.
18mm.
Epoxy.
Rudder.
INSTALL RUDDER CONTROL HORN.
1 sets.
3x50mm.
Aluminum Washer.
CONTROLHORN
M3 SCREW.
M3LOCK NUT.
Epoxy.
Aluminum Washer.
Elevator.
18mm.
Epoxy.
Elevator.
Elevator control horn.
Horizontal
Stabilizer.
Horizontal
Stabilizer.
3mm.
3mm.
Repeatsteps to install the ruddercontrolhorn
as same as steps done for ailerons.

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ENGINE MOUNT INSTALLATION.
Ruddercontrolhorn.
M3 x 15mm.
M3 x 15mm.
1) Locate the items necessary to install the
engine mount included with your model. .
2) Usefour4x30mmheadbolts and four 4mm
washers to attach the engine mount rails to
thefirewall.Tighten the screws . Make sure to
use threadlock on the screws to help prevent
them from vibrating loose.
4x30mm.
Thread locker glue.
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) Usingamodelingknife, cut one length
ofsiliconfuelline. Connectoneendoftheline
totheweightedfuel pick up and the other end
to the nylon pick up tube.

YAK 52.Instruction Manual.
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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
thetankis installed inside the fuselage, it may
be difficult to determine which is which.
Fueltank.
Venttube.
Fuel pick up tube.
Fuel fill tube.
3) Carefully bend the second nylon tube
up at a 45º angle. This tube is the vent 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.
Venttube. Fuel pick up tube.
Fuel fill tube.
5) With the stopper assembly in place,
the weighted pick-up should rest away from
therear of the tank and move freelyinside 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.
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.
Epoxy.
 7) Slide the fuel tank into the fuselage. Guide
the lines from the tank through the hole in the
firewall.
Fueltank.
 8) Use plywood template to hold in place
the fuel tank with C/A glue to secure the fuel
tank inside the fuselage.
Plywood template.
Plywood template.

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Blow through one of the lines to en-
sure the fuel lines have not become kinked
inside the fuel tank compartment. Air
should flow through easily.
9) Connect the lines from the tank to the engine
and muffler. The vent line will connect to the
muffler and the line from the clunk to the
carburetor.
INSTALLING THE FUSELAGE SERVOS.
Servo tray.
Throttle servo.
Elevator servo.
Rudder servo.
M3 x 10mm.
THROTTLE SERVO ARM INSTALLATION.
Installadjustableservoconnectorinthe servo
arm as same as picture below:
AdjustableServo
connector.
Servoarm.
Loctite secure.
1PCS.
Throttleservoarm.
Elevatorservoarm.
Rudderservoarm.
1) Installtherubber grommets and brass
colletsonto thethrottleservo. Testfit 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
mayneedto adjust thesizeofthe precut open-
ing in the mount. The notch in the sides of the
mount allow the servo lead to pass through.
3/32” Hole.
INSTALLING THE SWITCH.
Installtheswitchintotheprecutholeinthe
side, in the fuselage.

YAK 52.Instruction Manual.
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Machinescrew M4x30mm.
Pushrodwire.
Switch.
Trimand cut.
150mm.
MOUNTING THE ENGINE.
2) Use a pin drill and 2mm drill bit to drill a
small indentation in the mount for the engine
mounting screw.
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).
 1) Positiontheenginewith thedrivewasher
(150mm) forward of the firewall as shown.
7) Slide the throttle pushrod wire into the tube.
Position the engine between the mounts. Use
four M4x30mm 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
the fuel tank mount.
6) Connect the Z-bend in the 450mm throttle
pushrod to the outer hole of the carburetor arm.
4.5mm.
Pushrod tube hole.
4mm.

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INSTALLING THE BATTERY.
Epoxy.
Battery.
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.
Battery.
Tie wrap.
COWLING.
Trim and cut.
1)Slidethefiberglasscowloverthe engine
and line up the back edge of the cowl with the
marksyoumadeon the fuselage then trimand
cut as shown.
Becauseofthesizeofthecowl,itmaybenec-
essarytouse a needle valve extension for the
highspeedneedlevalve. Makethisoutofsuf-
ficient length 1.5mm wire and install it into the
end of the needle valve. Secure the wire in
placebytighteningthe set screw in the side of
the needle valve.

YAK 52.Instruction Manual.
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Machine screw M3x10mm.
Needlevalve.
 3) Installthe mufflerandmufflerextension
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 M3x10mm screws.
ELECTRIC POWER CONVERSION.
1) Locate the items neccessary to install the
electric power conversion included with your
model.
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.
Epoxy.
Balsa stick.
Epoxy.
- Model size: .75-.90 size models
- Motor: 50mm 310 rev per volt
- Propeller: 14x10 ~ 15x10
- ESC: 60A
- Lipo Batteries: 8 cell 3200mA
2) While keeping the back edge of the
cowl flush with the marks, align the front of
thecowlwith thecrankshaftoftheengine. The
front of the cowl should be positioned so the
crankshaft is in nearly the middle of the cowl
opening.Use thespinnerbackplateas aguide.
Hold the cowl firmly in place using pieces of
masking tape.

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3) Attach the motor to the front of the electric
motor box using four 4mm blind nut, four
M4x15mm hex head bolts to secure the motor.
Please see picture shown.
M4 x 15mm.
Electric motor.
Epoxy.
150mm. 5.2mm.
5.2mm.
Battery.
4) Locate the plywood battery tray to the
fuselage. Tighten the screws using machine
screws M3x15mm to secure the tray in position.
Blindnut.
Balsa stick.

YAK 52.Instruction Manual.
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INSTALLING THE AILERON - FLAPSERVOS.
Servos. Smallweight.
Thread.
INSTALLING THE SPINNER.
M3 x 15mm.
Battery.
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.
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.
String.
Small weight.
1) Usingasmallweight(Weighted fuelpick-up
workswell)andstring, feed the string through
the wing as indicated.
2) Place the servo between the mounting
blocksand spaceitfrom thehatch.Use apencil
to mark the mounting hole locations on the
blocks.
Because the size of servos differ, you
mayneed toadjustthesizeoftheprecut open-
ing in the mount. The notch in the sides of
themountallowtheservoleadtopassthrough.

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3) Use drill bit in a pin vise to drill the mouting
holes in the blocks.
8) A string has been provided in the wing to
pull the aileron lead through to the wing root.
Remove the string from the wing at the servo
location and use the tape to attach it to the
servoextensionlead.Pulltheleadthroughthe
wing and remove the string.
4) Apply 2-3 drops of thin C/A to each of the
mounting holes. Allow the C/A to cure without
using accelerator.
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.

YAK 52.Instruction Manual.
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1) Mark the control wire where it crosses the
servo arm hole.
Bend at the mark.
AILERONPUSHRODHORN INSTALLATION
9) Set the aileron hatch in place and use a
Phillips screw driver to install it with four wood
screws.
Mark.
Pen.
2)Makea90-degreebendatthe mark and cut
offtheexcess wire leaving 8mmpastthebend.
Cut.
8mm.

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Wing.
Aileron.
M2lock nut.
INSTALLING THE FLAP SERVO.
Repeat the procedure for the other aileron servo.
Snapkeeper.
Servoarm.
3) Connect the linkage as shown and secure
the control wire with a snap keeper.
8mm Snapkeeper.
M2 lock nut. Metalclevis.
M2lock nut.
Wing.
Flap.
Repeat the procedure for the aileron servo.
Cut.
INSTALLING LED LIGHTING SYSTEM.
1) Locate the items necessary to install the
led light included with your model.
2) Please make a hole on the black plastic
mount as shown.

YAK 52.Instruction Manual.
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WING ASSEMBLY.
Maskingtape.
1.
C/Aglue.
C/Aglue.
C/Aglue.
3) Installtheled lighttotheblack plasticmount
to hold the LED in place with C/A glue as
shown.
4) Install the LED and its harness to the wing
andgluetoholdtheplastictothewinginplace
as pictures shown.
5) Use transparent plastic to cover the LED
light with C/A glue as shown.
6) Connect the LED lighting harness to bat-
tery holder in the fuselage.
Installtwo batteriesAA(1.5v)intheholderand
turn the light on.