Seagull Models KA8-B User manual

Specifications:
Wingspan--------------------------------------------118.1in(300cm).
Wingarea----------------------------------------899sq.in(58sqdm).
Weight ----------------------------------------------------6.2lbs(2.8kg).
Length --------------------------------------------------57.1in(145cm).
Radio ---------------------------------------------------------6channels.
Servo ---------------------------------------------4MN48miniservos.
3 servos flying skill level intermediate/advanced.
ASSEMBLY MANUAL
MS:137
“Graphics and specifications may change without notice”.
(Glider)

2
KA8-B Instruction Manual.
INTRODUCTION.
Thankyouforchoosingthe KA8-B ARTF by SEAGULL MODELS. The KA8-B wasdesigned with
thesportstrainer flyerinmind.ItisaHigh-wing aeroplanewhichiseasytoflyandquicktoassemble.
The airframe is conventionally built using balsa, plywood and veneer to make it stronger than the
averageARTF,yetthedesignallowstheaeroplanetobekeptlight.Youwillfindthatmostofthework
hasbeendoneforyou already.Thepushrodsarepre-made tothecorrect lengths,themotormount
has been fitted and the hinges are pre-installed and pinned for security. Flying the KA8-B is simply
ajoy.
This instruction manual is designed to help you build a great flying aeroplane. Please read this
manual throughly before starting assembly of your KA8-B. Use the parts listing below to identify all
parts.
WARNING.
Pleasebeawarethatthisaeroplaneisnotatoyandifitisassembledorusedincorrectlyitwillcause
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
proceduresdesignedtohelpthenewpilot onhiswaytosuccessfulR/Cflight. Theywillalsobeable
to advise on any insurance and safety regulations that may apply.
ADDITIONAL ITEMS REQUIRED.
- 6 channels radio with 7 servos.
- Glow plug to suit engine.
- Propeller to suit engine.
- Protective foam rubber for radio
system.
- Silicone fuel line.
- Stick-on weights for balance
(If necessary).
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 half with pre-installed
aileron.
2) Left winghalf withpre-installedaileron.
TAIL SECTION ASSEMBLY
1) Vertical stabilizer with pre-installed
rudder.
2) Horizontal stabilizer withpre-installed
elevartor halves.

3
Instruction Manual.
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)Removeeach hingefromthewing panel
and aileron and place a T-pin in the center of
each hinge. Slide each hinge into the aileron
untiltheT-pin is snugagainsttheaileron.This
will help ensure an equal amount of hinge is
oneithersideofthe hingelinewhentheaileron
is mounted to the wing panel.
HINGING THE RUDDER .
Note:
Hinge.
T-pin.
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.Agap of 1/64” or less
shouldbemaintainedbetween the wing panel
andaileron.
1) Carefully remove the aileron from one
of the wing panels. Note the position of the
hinges.
4)Deflect the aileron and completely
saturate each hinge with thin C/A glue. The
aileronsfrontsurface shouldlightlycontact 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 constructedof aspecial
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.
C/Aglue.

4
KA8-B Instruction Manual.
8)Afterbothailerons aresecurelyhinged,
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.
Workthe aileronup anddown several
times to “work in” the hinges and
check for proper movement.
Note:
6) Using C/A remover/debonder and a
papertowel,removeany excess C/Agluethat
may have accumulated on the wing or in the
aileronhingearea.
5)Turn the wing paneloverand 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.
HINGING THE ELEVATOR .

5
Instruction Manual.
Aileroncontrol horn.
INSTALL THE AILERON CONTROL
HORN .
2 sets.
3x35mm.
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 6mm 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
9mm from the vase of the horn as shown.
6mm.
ELEVATOR CONTROL HORN
INSTALLATION.
2 sets.
3x35mm.
Install the elevator control horn using the
samemethodassameas theaileroncontrol
horns.

6
KA8-B Instruction Manual.
Rudderservo.
SERVO ARM INSTALLATION.
Installadjustableservoconnectorinthe servo
arm as same as picture below:
AdjustableServo
connector.
Servoarm.
Loctite secure.
1PCS.
Elevatorservo.
Elevatorcontrolhorn.
6mm.
INSTALLING THE FUSELAGE SERVO.
1) Installtherubbergrommetsandbrass
colletsonto thethrottleservo. Test fittheservo
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
mayneedtoadjustthesizeofthe precutopen-
ing in the mount. The notch in the sides of the
mount allow the servo lead to pass through.
Throttleservo.

7
Instruction Manual.
2) Usingasmallweight (Weighted fuelpick-up
workswell) and string, feedthe string through
the wing as indicated.
String.
Small weight.
Installtheswitchinto the precutholeinthe
side of fuselage.
INSTALLING THE SWITCH.
Switch.
Servos.
Because the size of servos differ, you
mayneed toadjustthesizeoftheprecutopen-
ing in the mount. The notch in the sides of
themountallowtheservoleadtopassthrough.
AILERON SERVO INSTALLATION.
Rudderservoarm.
Elevatorservoarm.
Trimand cut.
Throttleservoarm.

8
KA8-B Instruction Manual.
Snapkeeper.
Servoarm.
8mm Snapkeeper.
M2 lock nut. Metalclevis.
8mm
Cut.
AILERONPUSHROD HORN INSTALLATION
FLAP SERVO INSTALLATION.
Attach the string to the servo lead and carefully thread it though the wing.
M2x6mm.
Wing rib.
Wing.
Small weight.
String.
Flap servo.
M2x6mm. Aileronservo.
Aileronservo.
Flapservo.

9
Instruction Manual.
AIRBREAKES PUSHROD CONTROL
HORN INSTALLATION.
M2x6mm.
Repeat the procedure for the other
aileron servo.
C/Aglue.
C/Aglue.

10
KA8-B Instruction Manual.
ELEVATOR PUSHROD INSTALLATION.
M3x30mm.
M3x30mm.
678mm.
Cut.
THE HORIZONTAL STABILIZER
INSTALLATION.

11
Instruction Manual.
8mm
Cut.
Pen.
8mm
Snapkeeper.
3mm
3mm

12
KA8-B Instruction Manual.
RUDDER PUSHROD.
M2x12mm.
Snapkeeper.
Servoarm.
8mm Snapkeeper.
M2 lock nut. Metalclevis.
Pen.
8mm
Cut.

13
Instruction Manual.
SERVO INSTALLATION.
The tow hook.
The above is the tow hook position.
C/Aglue.
C/Aglue.
Cut.
Cut.

14
KA8-B Instruction Manual.
Receiver. Battery.
ATTACHMENT WING -FUSELAGE.
Wing bolt.
BALANCING.
 1) It is critical that your airplane be
balanced correctly. Improper balance will
cause your plane to lose control and crash.
THE CENTER OF GRAVITY IS LOCATED
60 MM BACK FROM THE LEADING EDGE
OF THE WINGAT THE WING ROOT.
 3) Turn the airplane upside down. Place
yourfingerson the maskingtapeandcarefully
lift the plane .
 2)Mountthe wing to the fuselage. Using a
couple of pieces of masking tape, place them
on the top side of the wing 60 mm back from
the leading edge of the wing at the wing root.
INSTALLING THE RECEIVERAND BATTERY.
1) Plugthefive servoleadsandthe switch
lead into the receiver. Plug the battery pack
lead into the switch also.
 3) Route the antennain theantenna tube
insidethefuselageandsecureit to the bottom
of fuselage using a plastic tape.
2) Wrap the receiver and battery pack in
the protective foam rubber to protect them
from vibration.

15
Instruction Manual.
CONTROL THROWS.
Ailerons: 15mm up 15mm down.
Elevator: 15mm up 15mm down.
Rudder: 25mm right 25mm left.
60mm.
*Ifpossible,firstattempttobalance the model
bychangingthepositionof thereceiverbattery
and receiver. If you are unable to obtain good
balance by doing so, then it will be necessary
toaddweighttothenoseortail to achieve the
proper balance point.
Withthewingattachedtothefuselage, allparts
ofthemodel installed(readyto fly),andempty
fuel tanks, hold the model at the
markedbalancepointwith the stabilizer level..
Lift the model. If the tail drops when you lift,
the model is “tail heavy” and you must add
weight* to the nose. If the nose drops, it is
“nose heavy” and you must add weight* to
the tail to balance.
Accurately mark the balance point on the top
of the wing on both sides of the fuselage. The
balance point is located 60 mm back from
the leading edge of the wing at the wing root.
This is the balance point at which your model
should balance for your first flights. Later, you
maywishto experimentbyshifting thebalance
up to 10mm forward or back to change the
flying characteristics. Moving the balance
forward may improve the smoothness and
arrow- like tracking, but it may then require
more speed for take off and make it more
difficult to slow down for landing. Moving the
balance aft makes the model more agile with
alighter andsnappier ”feel”.In anycase,please
start at the location we recommend .

16
KA8-B Instruction Manual.
E) Check the throttle. Moving the
throttle stick forward should open the carbu-
retor barrel. If it does not, flip the servo re-
versing switch on your transmitter to change
the direction.
FLIGHT PREPARATION.
C) Check the elevator first. Pull back
on the elevator stick. The elevator halves
shouldmoveup. Ifit they donot,flipthe servo
reversingswitchon your transmittertochange
the direction.
D) Check the rudder. Looking from
behind the airplane, move the rudder stick to
theright. Theruddershould move totheright.
Ifitdoesnot, flip the servoreversingswitchon
your transmitter to change the direction.
A) Check the operation and direction
of the elevator, rudder, ailerons and throttle.
B) Plug in your radio system per the
manufacture’sinstructions andturneverything
on.
F) From behind the airplane, look at
the aileron on the right wing half. Move the
aileron stick to the right. The right aileron
should move up and the other aileron should
move down. If it does not, flip the servo re-
versing switch on your transmitter to change
the direction.
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 KA8-B to ensure that everything is tight
and well bonded.
4) Checkthecontrolsurfaces. Allshould
move in the correct direction and not bind in
any way.
5) If your radio transmitter is equipped
withdualrateswitches double check thatthey
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.
7) Check the receiver antenna. It should
be fully extended and not coiled up inside the
fuselage.
We wish you many safe and enjoyable
flights with your KA8-B.
8) Properlybalancethepropeller. Anout
of balance propeller will cause excessive vi-
bration which could lead to engine and/or air-
frame failure.
3) Double check the balance of the air-
plane. Do this with the fuel tank empty.