Seagull Models ZLIN 50 User manual

www.seagullmodels.com
MS: SEA 118
“Graphics and specifications may change without notice”.
Specifications:
Wingspan-----------------------------67.7in(172cm).
Wingarea------------------779.7sq.in(50.3sqdm).
Weight-------------------------8.6-9.7lbs(3.9-4.4kg).
Length--------------------------------49.1in(124.6cm).
Engine ----------------.75-.91cu.in---------2-stroke.
.91 - 1.00cu.in ------4-stroke.
Radio--------------6channelswith5digitalservos.
ASSEMBLY MANUAL

ZLIN 50. Instruction Manual
2
INTRODUCTION.
Thankyou forchoosingtheZLIN50 ARTF bySEAGULLMODELS.TheZLIN50 wasdesigned
with the intermediate/advanced sport scale in mind. It is a semi scale airplane which is easy to fly
andquick toassemble.Theairframeisconventionallybuiltusingbalsa,plywood tomakeitstronger
thantheaverage ARTF,yet thedesignallows theaeroplaneto be keptlight. You willfindthat most
oftheworkhasbeendoneforyoualready. Themotormounthasbeenfittedandthehingesarepre-
installed . Flying the ZLIN 50 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 ZLIN 50. 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
proceduresdesigned tohelp thenewpilotonhiswaytosuccessfulR/Cflight.They willalso beable
to advise on any insurance and safety regulations that may apply.
KIT CONTENTS
1
2
9
3
4
5
5
8
6
7
10
11
12
8.2
12 12
12
12 12
8.1
12
12
12
12
12
13

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ADDITIONAL ITEMS REQUIRED.
.75- .91 cu.in 2-stroke engine
.91- 1.00 cu.in 4-stroke
5 digital 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
1 Fuselage
2 Canopy
3 Left wing panel
4 Right wing panel
5 Tail set
6 Aluminum wing tube
7 Scale pilot
8 70mm wheels (2)
8.1 Tail wheel gear
8.2 Main landing gear
9 Wheel pants (2)
10 Decal sheet
11 EP conversion pack
12 Hardware bag included
13 Fiberglass cowl
2)Removeeachhingefrom thewingpanel
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
ofhingeisoneithersideof thehinge linewhen
the aileron is mounted to the aileron.
The control surfaces, including the
ailerons, elevators, and rudder, are
prehinged with hinges installed, but the
hinges are not glued in place. It is
imperativethatyou properly adherethe
hingesinplace per thestepsthat follow
using a high-quality thin C/A glue.
Note:
HINGING THE AILERONS.
Hinge.
T- pin.
1) Carefully remove the aileron from one
of the wing panels. Note the position of the
hinges.
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.Agap of 1/64” or less
shouldbemaintained betweenthewing panel
andaileron.
KIT CONTEN.TS

ZLIN 50. Instruction Manual
4
HINGING THE ELEVATOR.
8)Afterbothailerons aresecurely 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.
Glue the elevator hinges in place using the
same techniques used to hinge the ailerons.
Work the aileron up and down several
times to “work in” the hinges and check
for proper movement.
Note:
4)Deflect the aileron and completely
saturate each hinge with thin C/A glue. The
aileronsfrontsurfaceshouldlightly contactthe
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
penetrateanddistributethroughoutthe
hinge, securely bonding it to the wood
structureofthe wingpaneland aileron.
5)Turn the wingpanelover anddeflectthe
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.
6) Using C/A remover/debonder and a
papertowel,remove anyexcessC/A gluethat
may have accumulated on the wing or in the
aileronhingearea.
Hinge.
T- pin.

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5
HINGING THE RUDDER.
Glue the rudder hinges in place using the
same techniques used to hinge the ailerons.
INSTALL THEAILERONS CONTROL HORN.
Hinge.
2 sets.
3x40mm.
Wing
bottom.
M3LOCK
NUT.
ALUMINUMWASHER.
ALUMINUMWASHER.
CONTROLHORN
M3 SCREW.
Epoxy.
Epoxy.
18mm.
Aileroncontrolhorn.
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. INSTALL ELEVATOR CONTROL HORN.
Install the elevator control horn using the
same method as same as the aileron control
horns.
2 sets.
3x35mm.

ZLIN 50. Instruction Manual
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AluminumWasher.
CONTROL HORN M3
M3LOCKNUT.
Epoxy.
AluminumWasher.
16mm.
Epoxy.
INSTALL RUDDER CONTROL HORN.
Horizontal
Stabilizer.
Elevator control horn.
Horizontal
Stabilizer. Elevator.
2 sets.
3x50mm.
CONTROL HORN
M3SCREW.
ALUMINUMWASHER.
ALUMINUMWASHER.
M3LOCK NUT.
EPOXY.
FUSELAGE Rudder
18mm.
EPOXY.
Fuselage. Rudder.
3mm.
Repeatstepstoinstall theruddercontrolhorn
as same as steps done for ailerons.
3mm.

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Ruddercontrolhorn.
Thread locker glue.
ENGINE MOUNT INSTALLATION.
M4 x 30mm.
Diameter =5.5mm.
1) Locate the items necessary to install the
engine mount included with your model. .
2) Usefour4x30mmheadbolts andfour 4mm
washers to attach the engine mount rails to
thefirewall.Tighten the screws.Makesure to
use threadlock on the screws to help prevent
them from vibrating loose.
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 STOPPERASSEMBLY.
Battery.
Tie Wrap.
2) Usingamodeling knife,cutone length
of silicon fuel line. Connect one end of the
linetothe weighted fuelpickup and theother
endtothe nylonpickup tube.(Thesilicontube
is not included).
A.
INSTALLING THE BATTERY.

ZLIN 50. Instruction Manual
8
Vent tube. 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
therearofthe tank and movefreelyinsidethe
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.
FUEL TANK INSTALLATION.
Fueltank.
A.
A.
C/Aglue.
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.
 8) Use plywood template to hold in place
the fuel tank with C/A glue to secure the fuel
tank inside the fuselage. To help prevent
moveable from transferring to the fuel tank.
 7) Slide the fuel tank into the fuselage.
Guide the lines from the tank through the hole
in the firewall.

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 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.
WHEEL AND WHEEL PANTS
INSTALLATION.
Fuel pick-up tube.
Fuelfill tube.
Venttube.
10mm.
4.2mm.
Blow through one of the lines to ensure
thefuel lines have not become kinked in-
side the fuel tank compartment. Air should
flowthrough easily.
1) Locate the items neccessary to install
the wheel and wheel pants as shown.
2) Follow diagram below for wheel pant
installation:
Use a drill and 4.2mm drill bit to drill a hole in
the wheel pants.
Drill a hole.
3) You have to trim each axle using a tool
cutting and cut-off wheel.
Caution when cutting the axles and
wear protective goggles.
46mm

ZLIN 50. Instruction Manual
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Lockerglue.
4) Slidethecollar to the axleandsetscrew
the collars to secure the collar to the axle and
thensliderthe wheel onthe axle witha drop of
oilontheaxlesothewheelwillspinfreelywhen
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.
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.
wheel Pant.
wheel.
M3.
wheel collar.
Lite-Plywood
block.
nut.
Axle.
Washer.
LandingGear. wheel Pant.
C/Aglue.
wheel collar.
wheel.
Lite-Plywood
block.
Axle.
Washer. M3.

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11
M4x20mm.
Lockerglue.
INSTALLING THE MAIN LANDING GEAR
TO FUSELAGE.
 8) The blind nuts for securing the landing
geararealready mounted insidethe fuselage.
 9) Using the hardware provided, mount
the main landing gear to the fuselage.
Repeat steps as above to attach remain-
ing wheel pants to the landing gear.
 10) Place the fuselage inverted on the
workbenchina suitable stand.Set the landing
gear in place and use a screwdrive to secure
the landing gear to the fuselage using bolts
M4x20mmandwashers.Make sure to usethe
threadlock on the bolts so they don’t vibrate
loose.
INSTALLING THE FUSELAGE SERVO.
Throttleservo.
Elevatorservo.
Rudderservo.
1) Installthe rubber grommets and brass
colletsontothethrottleservo. Testfitthe 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
mayneedtoadjustthesizeoftheprecutopen-
ing in the mount. The notch in the sides of the
mount allow the servo lead to pass through.
INSTALLING THE SWITCH.
Installtheswitch into theprecut hole inthe
side of fuselage.
Cut.
THROTTLE SERVO ARM INSTALLATION.
AdjustableServo
connector.
Servoarm.
Loctite secure.
1PCS.
Throttleservoarm.
Elevatorservo.
Rudderservo.
Installadjustableservoconnectorinthe servo
arm as same as picture below:

ZLIN 50. Instruction Manual
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MachineScrew M4x30mm.
Pushrodwire.
140mm.
Switch.
MOUNTING THE ENGINE.
2) Use a pin drill and drill bit to drill a small
indentation in the mount for the engine mounting
screw.
 1) Positiontheenginewith thedrivewasher
(140mm) forward of the firewall as shown.
3) Use a drill to drill the four holes in the engine
mount rails.
4.2 mm diameter.
4) On the fire wall has the location for the
throttle pusshrod tube (pre-drill).
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.

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Becauseofthe size ofthe cowl, itmay be nec-
essaryto use a needle valveextension for the
highspeedneedle valve. Make this outof suf-
ficient length 1.5mm wire and install it into the
end of the needle valve. Secure the wire in
placeby tightening theset screw in the sideof
the needle valve.
Trim and cut.
COWLING INSTALLATION.
Trim and cut.
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.
1) Slide the fiberglass cowl over the
engine and line up the back edge of the cowl
withthemarks you madeon the fuselagethen
trim and cut as shown.
3) Installthemufflerand mufflerextension
onto the engine and make the cut out 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 .
2) While keeping the back edge of the
cowl flush with the marks, align the front of
thecowlwiththecrankshaftoftheengine. The
front of the cowl should be positioned so the
crankshaft is in nearly the middle of the cowl
opening.Use the spinnerbackplateasaguide.
Hold the cowl firmly in place using pieces of
masking tape.
MachineScrew M3x10mm
.
Needlevalve.

ZLIN 50. Instruction Manual
14
Epoxy.
- Model size: .75-.90 size models
- Motor: 50mm 310 rev per volt
- Propeller: 14x10 ~ 15x10
- ESC: 60A
- Lipo Batteries: 8 cell 3200mA
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.
Needlevalve.
Balsa block.
Epoxy.

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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.
5.2mm.
Epoxy.
Epoxy.
140mm.
5.2mm.
M3x15mm.
4) Locate the plywood battery tray to the
fuselage. Tighten the screws using machine
screws M3x15mm to secure the tray in position.
Blind nut.
Battery.
M4x15mm.
Balsa block.

ZLIN 50. Instruction Manual
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SPINNER INSTALLATION.
MachineScrew M3x10mm
Needlevalve.
speedcontrol.
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) Usinga small weight(Weighted fuelpick-up
workswell) andstring, feed the string through
the wing as indicated.
2) Place the servo between the mounting
blocksand spaceitfromthehatch. Useapencil
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.
Servos. Smallweight.
Thread.
INSTALLING THEAILERON.
Because the size of servos differ, you
mayneed toadjustthesizeoftheprecut open-
ing in the mount. The notch in the sides of
themountallowthe servoleadtopassthrough.

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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. Pull thelead through the
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.

ZLIN 50. Instruction Manual
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Wing.
Aileron.
M3lock nut.
1) Mark the control wire where it crosses the
servo arm hole.
Bend at the mark.
AILERONPUSHRODHORNINSTALLATION
9) Set the aileron hatch in place and use a
Phillips screw driver to install it with four wood
screws.
Mark.
Pen.
Snapkeeper.
Servoarm.
3) Connect the linkage as shown and secure
the control wire with a snap keeper.
8mm Snapkeeper.
2)Make a 90-degreebend at themark and cut
offtheexcesswireleaving8mmpastthe bend.
M2 lock nut. Metalclevis.

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WING ASSEMBLY.
2.5mm.
1.
2.
Repeat the procedure for the other aileron servo.
1.
3.
1) Locate the items necessary to attach the
wing.
2) Slide the aluminum wing tube into one of
the wing panels. Only slide the tube in as far
as it will easily slide. Forcing the tube could
possibly damage the wing.
3) Slide the wings onto the tube and connect
the aileron leads from the wing to the servo
extension leads from the receiver.
4) To help strengthen the wing tube, use
machinescrew M3x2.5mmto secureand lock
the wing tube at end of wing tube as position
already marked and predrilled, please see
below pictures.

ZLIN 50. Instruction Manual
20
Removethecovering.
INSTALLING THE HORIZONTALSTABILIZER.
Center line.
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
thismark down the back of the trailingedge of
the stabilizer.
2) Using a modeling knife, carefully re-
movethecoveringat mounting slotofhorizon-
tal stabilizer.
C/Aglue.
C/Aglue.
M3x2.5mm.
2.
Screw.
2. M3x2.5mm.
5) Attach the wood washers in place with C/A
glue.
6) Toinstallthegunonto thewing.Usea hobby
knife to cut a slot at the leading edge of the
wing as shown and glue it with C/A glue for
the gun.
3.