Seagull Models SEA 304 User manual

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Specications:
Wingspan--------------- 80.0 in (203.2 cm).
Wing area--------------- 937.8 sq.ins (60.5 sq.dm).
Weight------------------- 10.4 lbs (4.7 kg).
Length------------------- 57.2 in (145.2 cm).
Engine/Motor size----- 20cc gasoline.
Radio--------------------- 5 channels with 7 servos.
ASSEMBLY MANUAL
Code : SEA 304

DHC-1 CHIPMUNK Instruction Manual.
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ankyouforchoosingthe DHC-1CHIPMUNKARTFbySGMODELS. e DHC-1CHIP-
MUNK was designed with the intermediate/advanced sport yer in mind. It is a semi scale air-
planewhichiseasytoyandquicktoassemble.eairframeisconventionallybuiltusingbalsa,
plywood to make it stronger than the average ARTF, yet the design allows the aeroplane to be
kept light. You will nd that most of the work has been done for you already. e motor mount
hasbeen tted andthehingesarepre-installed.FlyingtheDHC-1CHIPMUNK issimply a joy.
is instruction manual is designed to help you build a great ying aeroplane. Please read
this manual throughly before starting assembly of your DHC-1 CHIPMUNK Use the parts
listing below to indentify all parts.
Please be aware that this aeroplane is not a toy and if assembled or used incorrectly it is ca-
pable of causing injury to people or property. WHEN YOU FLY THIS AEROPLANE YOU
ASSUME ALL RISK & REPONSIBILITY.
If you are inexperienced with basic R/C ight we strongly recommend you contact your R/C
supplier and join your local R/C model Flying Club. R/C Model Flying Clubs oer a variety
of training procedures designed to help the new pilot on his way to successful R/C ight.
ey will also be able to advise on any insurance and safety regulations that may apply.
INTRODUCTION.
WARNING.
KIT CONTENTS
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KIT CONTENTS.
SEA304 DHC-1 CHUPMUNK
1. Fuselage
2. Wing set (2)
3. Tail set (2)
4. Canopy
5. Cowling
6. Wing tube
7. Pilot
8. Wheel pants
9. landing gear
10. Fuel tank
11. Tail wheel
ADDITIONAL ITEMS REQUIRED.
TOOLS & SUPPLIES NEEDED.
in cyanoacrylate glue.
Medium cyanoacrylate glue.
30 minute epoxy.
5 minute epoxy.
Hand or electric drill.
Assorted drill bits.
Modelling knife.
Straight edge ruler.
2mm ball driver.
Phillips head screwdriver.
220 grit sandpaper.
90° square or builder’s triangle.
Wire cutters.
Masking tape & T-pins.
read-lock.
Paper towels.
�20cc gasoline engine.
�Computer radio 5 channel with 7
servos.
�Glow plug to suit engine.
�Propeller to suit engine.
�Protective foam rubber for radio
system.
HINGING THE FLAP.
.
2x10mm

DHC-1 CHIPMUNK Instruction Manual.
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HINGING THE AILERON.
Note : e control surfaces, including the ailer-
ons, 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 us-
ing a high-quality thin C/A glue.
1) Carefully remove the aileron from one
of the wing panels. Note the position of the
hinges.
2) Remove each hinge from the wing 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. is will help ensure an equal amount
of hinge is on either side of the hinge line
when the aileron is mounted to the aileron.
3) Slide the wing panel on the aileron until
there is only a slight gap. e hinge is now
centered on the wing panel and aileron. Re-
move the T-pins and snug the aileron against
the wing panel. A gap of 1/64” or less should
be maintained between the wing panel and
aileron.
NOTE : e hinge is constructed of a spe-
cial 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.
4) Deect the aileron and completely satu-
rate each hinge with thin C/A glue. e ailer-
ons front surface should 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.
Hinge.
T-pin.
Epoxy.
Hinge.

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5) Turn the wing panel over and deect the
aileron in the opposite direction from the
opposite side. Apply thin C/A glue to each
hinge, making sure that the C/A penetrates
into both the aileron and wing panel.
6) Using C/A remover/debonder and a paper
towel, remove any excess C/A glue that may
have accumulated on the wing or in the
aileron hinge area.
7) Repeat this process with the other wing
panel, securely hinging the aileron in place.
8) Aer both ailerons are securely hinged,
rmly grasp the wing panel and aileron to
make sure the hinges are securely glued and
cannot be pulled out. Do this by carefully ap-
plying medium pressure, trying to separate
the aileron from the wing panel. Use caution
not to crush the wing structure.
Work the aileron up and down sev-
eral times to “work in” the hinges
and check for proper movement.
Note :
INSTALL THE AILERONS
CONTROL HORN.
Epoxy.
Epoxy.
Fiberglass control horn
Fiberglass control horn
INSTALLING THE AILERON SERVOS

DHC-1 CHIPMUNK Instruction Manual.
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Because the size of servos dier, you
may need to adjust the size of the precut
opening in the mount. e notch in the
sides of the mount allow the servo lead to
pass through.
1) Place the servo between the mounting
blocks and space it from the hatch. Use a
pencil to mark the mounting hole loca-
tions on the blocks.
2) Use drill bit in a pin vise to drill the
mouting holes in the blocks.
4) Use dental oss or heatshrunk tube to
secure the connection so they cannot be-
come unplugged.
5) Secure the servo to the aileron hatch
using Phillips screwdriver and the screws
provided with the servo.
6) Apply 1-2 drops of thin C/A to each
of the mounting tabs. Allow the C/A to
cure without using accelerator.
3) Apply 2-3 drops of thin C/A to each
of the mounting holes. Allow the C/A to
cure without using accelerator.
1.5mm
C/A glue
Minimum servo spec.
Torqu e : 80 oz-in (5.8 kg-cm) @ 4.8V;
100 oz-in (7.2 kg-cm) @ 6.0V

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7) Remove the string from the wing at the
servo location and use the tape to attach it
to the servo extension lead. Pull the lead
through the wing and remove the string.
8) Set the aileron hatch in place and use a
Phillips screw driver to install it with four
wood screws.
AILERON PUSHROD INSTALLATION.
Please see below pictures.
2x10mm
C/A glue

DHC-1 CHIPMUNK Instruction Manual.
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40mm
80mm
M3 clevis. M3 lock nut.
INSTALLING THE FLAP SERVO.
Repeat the procedure for the ap servo.
INSTALLING THE FLAP PUSHROD.
Repeat the procedure for the aileron
pushrod.
40mm
80mm
M3 clevis. M3 lock nut.
INSTALLING LANDING GEAR.
1)Locate items necessary to install Sprin
Landing Gear.

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Use a 6 to 12
volt battery.

DHC-1 CHIPMUNK Instruction Manual.
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DHC-1 CHIPMUNK Instruction Manual.
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Elevator servo arm .
INSTALLING THE RECEIVER SWITCH.
Install the switch into the precut hole in
the side, in the fuselage.
Rudder servo arm.
rottle servo arm.
2) Secure the servos with the screws pro-
vided with your radio system.
Rudder servo.
rottle servo.
.
INSTALLING THE FUSELAGE SERVOS.
.
Because the size of servos dier, you
may need to adjust the size of the precut
opening in the mount. e notch in the
sides of the mount allow the servo lead to
pass through.
1) Install the rubber grommets and brass
collets into all servos. Test t the servos
into the fuselage servo mounts.
3/32” Hole.
Elevator servo.
.
Switch.
INSTALLING THE ENGINE SWITCH.
Trim and cut.
Switch.
Trim and cut.

DHC-1 CHIPMUNK Instruction Manual.
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INSTALLING THE STOPPER
ASSEMBLY.
1) Using a modeling knife, carefully cut
o the rear portion of one of the 3 nylon
tubes leaving 1/2” protruding from the
rear of the stopper. is will be the fuel
pick up tube.
2) Using a modeling knife, cut one length
of silicon fuel line. Connect one end of
the line to the weighted fuel pick up and
the other end to the nylon pick up tube.
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
dicult to determine which is which.
7) Use balsa block to hold in place the fuel
tank with C/A glue to secure the fuel tank.
3) Carefully bend the second nylon tube up
at a 45º angle. is tube is the vent tube.
Vent tube. Fuel pick up tube.
Fuel fill tube.
4) Test t the stopper assembly into the tank.
It may be necessary to remove some of the
ashing around the tank opening using a
modeling knife. If ashing is present, make
sure none falls into the tank.
6) When satised with the alignment of the
stopper assembly tighten the 3x20mm ma-
chine screw until the rubber stopper expands
and seals the tank opening. Do not overtight-
en the assembly as this could cause the tank
to split.
5) With the stopper assembly in place, the
weighted pick-up should rest away from the
rear of the tank and move freely inside the
tank. e top of the vent tube should rest just
below the top of the tank. It should not touch
the top of the tank.

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ENGINE MOUNT INSTALLATION.
1) Locate the items necessary to install
the engine mount included with your
model.
2) Use four 4x30mm head bolts and four
4mm washers to attach the engine mount
rails to the ewall. Tighten the screws .
Make sure to use threadlock on the screws
to help prevent them from vibrating loose.
8) Use balsa block to hold in place the fuel
tank with C/A glue to secure the fuel tank
inside the fuselage
9) Connect the lines from the tank to
the engine and muer. e vent line will
connect to the muer and the line from
the clunk tothe carburetor.
Fuel pick up tube. Fuel ll tube.
Ven tube.
read locker glue.

DHC-1 CHIPMUNK Instruction Manual.
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3) Use a drill to drill the four holes in the
engine mount rails.
4mm
4mm
Machine screw M4x30mm
4) e rewall has the location for the
throttle pushrod tube (pre-drill).
5) Slide the pushrod tube in the rewall
and guide it through the fuel tank mount.
Use medium C/A to glue the tube to the
rewall and the fuel tank mount.
6) Connect the Z-bend in the 450mm
throttle pushrod to the outer hole of the
carburetor arm.
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.
MOUNTING THE ENGINE.
1) Position the engine with the drive
washer (145mm) forward of the ewall
as shown.
145mm
2) Use a pin drill and 4mm drill bit to drill
a small indentation in the mount for the
engine mounting screw.

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8) Reinstall the servo horn by sliding the
connector over the pushrod wire. Cent-
er the throttle stick and trim and install
the servo horn perpendiular to the servo
center line.
9) Move the throttle stick to the closed po-
sition 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.
Pushrod wire.

DHC-1 CHIPMUNK Instruction Manual.
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COWLING. 1) Tape the cowl to the fuselage using
low-tack tape.
2) Use a drill and drill bit to drill the holes
for the cowl mounting screws. Make sure
the cowl position is correct before drill-
ing each hole.
M3x10mm

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Because of the size of the cowl, it may be nec-
essary to use a needle valve extension for the
high speed needle valve. Make this out of suf-
cient length 1.5mm wire and install it into
the end of the needle valve. Secure the wire in
place by tightening the set screw in the side of
the needle valve.
ELECTRIC POWER CONVERSION.
1) Locate the items neccessary to install
the electric power conversion included
with your model.
2) Recommend the items necessary to in-
stall the electric power conversion parts
included with your model.

DHC-1 CHIPMUNK Instruction Manual.
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3) Attach the electric motor box to the
rewall centered with the cross lines
drawn on the electric motor box and re-
wall. Using M4x25mm to secure the mo-
tor box to the rewall. Please see pictures
below.
4) Attach the motor mount to the front
of the electric motor box using four 4mm
blindnut,fourM4x20mmhexheadboltsto
securethemotor.Pleaseseepictureshown.
M4x25mm and washers.
en, use 5.5mm drill bit to enlarge the
holes on the electric motor box.
Blind nut.
- Motor: 110 - 2000 Watts
- Propeller: 17x8 ~ 19x10
- ESC: 85A
- 8S- 9S Lipo
5.5mm
5mm