SG Models SEA 99N User manual

1
ASSEMBLY MANUAL
Specications
Wing span-------------------- 70.9 in------------ 180 cm
Wing area-------------------- 764.2 sq.in-------- 49.3sq dm
Weight------------------------ 10.1-11 lbs-------- 4.6-5.0 kg
Length------------------------ 56.8 in------------- 144.2 cm
Engine------------------------ 1.2 cu.in----------- 2-stroke
1.2-1.25 cu.in ----- 4-stroke
20-26cc
ELECTRIC CONVERSION : OPTIONAL
Radio------------------------- 7 channels with 8 servos
Code : SEA 99N
Upgrated Dewoitine D-520
71” span 20-26cc

Upgrated Dewoitine D-520 71” span 20-26cc Instruction Manual.
2
ank you for choosing the Upgrated Dewoitine D-520 71” span 20-26cc ARTF
by SG MODELS . e Upgrated Dewoitine D-520 71” span 20-26cc was de-
signed with the intermediate/advanced sport yer in mind. It is a semi scale air-
plane which is easy to y and quick to assemble. e airframe is convention-
ally built using balsa, 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 has been tted and the hinges are pre-
installed. Flying the Upgrated Dewoitine D-520 71” span 20-26cc is simply 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 Upgrated Dewoitine D-520
71” span 20-26cc Use the parts listing below to indentify all parts.
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 ap-
ply.
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 & REPONSIBILITY.
INTRODUCTION
WARNING
KIT CONTENTS
22
1
33
4
5
6
7
10
11
9
12
13
8

3
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.
HINGING THE FLAP
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.
Carefully remove the ap from one of the
wing panels. Note the position of the hinges.
Remove each hinge from the wing panel
and ap 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 ap is mounted to the aileron.
Hinge
1.
2.
Slide the wing panel on the ap until
there is only a slight gap. e hinge is
now centered on the wing panel and ap.
Remove 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 ap.
KIT CONTENTS
SEA99N Upgrated Dewoitine D-520
71” span 20-26cc
1. Fuselage
2. Wing set (2)
3. Tail set (2)
4. Canopy
5. Cowling
6. Wing tube
7. Pilot
8. Wheels
9. Fuel tank
10. Tail wheel
11. Ep Motor box
12. Pushrod set
13. Spinner
ADDITIONAL ITEMS REQUIRED
�20-26cc gasoline engine.
�Computer radio 7 channel with 8
servos.
�Glow plug to suit engine.
�Propeller to suit engine.
�Protective foam rubber for radio
system.
C/A glue

Upgrated Dewoitine D-520 71” span 20-26cc Instruction Manual.
4
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 ap.
Deect the ap and completely satu-
rate each hinge with thin C/A glue. e
ailerons front surface should lightly con-
tact the wing during this procedure. Ide-
ally, when the hinges are glued in place,
a 1/64” gap or less will be maintained
throughout the lengh of the ap to the
wing panel hinge line.
3.
4.
Turn the wing panel over and deect the
ap in the opposite direction from the oppo-
site side. Apply thin C/A glue to each hinge,
making sure that the C/A penetrates into
both the aileron and wing panel.
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 ap
hinge area.
Repeat this process with the other wing
panel, securely hinging the aileron in
place.
Aer both ap 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 care-
fully applying medium pressure, trying to
separate the ap 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 :
5.
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.
Carefully remove the aileron from one of
the wing panels. Note the position of the
hinges.
1.
T-pin
Hinge
C/A glue

5
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.
2.
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.
Remove 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.
Deect the aileron and completely satu-
rate each hinge with thin C/A glue. e
ailerons front surface should lightly con-
tact the wing during this procedure. Ide-
ally, 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.
3.
4.
6.
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.
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.
Hinge
Hinge
T-pin
C/A glue

Upgrated Dewoitine D-520 71” span 20-26cc Instruction Manual.
6
Work the aileron up and down sev-
eral times to “work in” the hinges
and check for proper movement.
Note :
Repeat this process with the other wing
panel, securely hinging the aileron in
place.
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 care-
fully applying medium pressure, trying to
separate the aileron from the wing panel.
Use caution not to crush the wing struc-
ture.
Locate the aileron and ap control horns.
e taller control horn is used for the ailer-
ons, and the shorter horn for the aps.
Use sandpaper to scu the bottom of the
aileron and ap control horns. Use a paper
towel and isopropyl alcohol to remove any
oils or debris from the control horns.
Check the t of the control horns to the
aileron and ap. ey should rest ush
against the control surface as shown.
INSTALL THE AILERONS
CONTROL HORN
1.
7.
2.
3.
4.
Ailerons control horn
Place low-tack tape 1/32 inch (1mm)
from the control horn slot. is will pre-
vent epoxy from getting on the control
surface when the control horns are glued
in place.

7
Apply epoxy to the area of the control
horns that st into the slots. Use enough
epoxy so the control horns will be fully
bonded to the ed surfaces.
Remove the control horns from the
control surfaces. Apply epoxy to the slot
in the aileron and ap. Make sure the
epoxy gets into the slot for a good bond
between the surfaces and control horn.
Epoxy
Before the epoxy fully cures, remove
the tape from around the control horn.
is will allow the epoxy to ow around
the control horn, creating a small let
between the control horn and surface for
a ished look and secure bond.
7.
6.
5.
Epoxy
Install the ap control horn using the
same method as same as the aileron con-
trol horns.
Fiberglass control horn
INSTALL FLAP CONTROL HORN
2.
1.

Upgrated Dewoitine D-520 71” span 20-26cc Instruction Manual.
8
3.
Flap control horn
Epoxy
INSTALLING THE AILERON SERVOS
1.
2.
Ailerons servo Flap servo
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.
Install the rubber grommets and brass
collets onto the aileron servo. Test t the
servo into the aileron servo mount.
Using a small weight (Weighted fuel
pickup works well) and thread, feed the
string through the wing as indicated.
Apply 2-3 drops of thin C/A to each of
the mounting holes. Allow the C/A to
cure without using accelerator.
3.
4.
Minimum servo spec.
Torque : 80 oz-in (5.8 kg-cm) @ 4.8V;
100 oz-in (7.2 kg-cm) @ 6.0V

9
Attach servo lead to the aileron servo.
Attach the string to the servo lead and
carefully thread it though the wing. Once
you have thread the lead throught the
wing, remove the string so it can use for
the other servo lead.
Reinstall the servo into the servo mount
and secure the servo inplace using the
wood screws provided with you radio sys-
tem.
Repeat the procedure for the other wing
half.
7.
5.
6.
8.
9.
INSTALLING THE FLAP SERVO
Repeat the procedure for the ap servo.
1.

Upgrated Dewoitine D-520 71” span 20-26cc Instruction Manual.
10
1.
Locate items necessary to install Sprin
Landing Gear.
You use this fork set JP ER-120-84degree.
INSTALLING RETRACTABLE
LANDING GEAR
AILERON PUSHROD INSTALLATION
Please study images below.
60mm
2.
1.
50mm
M3 clevis
M3 clevis
M3 lock nut
M3 lock nut
1.
3.
2.
4.
3.
INSTALLING THE FLAP PUSHROD
Repeat the procedure for the aileron
pushrod.

11
2.
3.
4.
5.
M3x20mm
6.
7.
8.
9.
M3x10mm

Upgrated Dewoitine D-520 71” span 20-26cc Instruction Manual.
12
10.
11.
12.
13.
14.
M3x4mm
M3x4mm
15.
16.
17.
Collar
M3x4mm

13
19.
20.
21.
22.
23.
18.
WING ASSEMBLY
1.
Please see below pictures.
2.

Upgrated Dewoitine D-520 71” span 20-26cc Instruction Manual.
14
1.
Secure the servos with the screws pro-
vided with your radio system.
Elevator servo
2.
rottle servo
THROTTLE SERVO ARM
INSTALLATION
Install adjustable servo connector in the
servo arm as same as picture below:
1.
2.
INSTALLING THE FUSELAGE SERVOS
rottle servo arm
.
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.
Install the rubber grommets and brass
collets into all servos. Test t the servos
into the fuselage servo mounts.
3.
4.
Rudder servo arm
Elevator servo arm
Elevator servo arm
Elevator servo
Rudder servo
Rudder servo
rottle servo
Elevator servo

15
INSTALLING THE RECEIVER SWITCH
Install the switch into the precut hole in
the side, in the fuselage.
3/32” Hole.
1.
.
2.
3.
INSTALLING THE ENGINE SWITCH
Trim and cut
1.
Switch
2.
INSTALLING THE STOPPER
ASSEMBLY
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.
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.
Trim and cut
1.
2.

Upgrated Dewoitine D-520 71” span 20-26cc Instruction Manual.
16
Carefully bend the second nylon tube up at
a 45º angle. is tube is the vent tube.
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.
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.
3.Vent tube
Fuel ll tube
Fuel pick up tube
When satised with the alignment of the
stopper assembly tighten the 3 x 20mm ma-
chine screw until the rubber stopper expands
and seals the tank opening. Do not over-
tighten the assembly as this could cause the
tank to split.
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.
1.
3.
4.
Slide the fuel tank into the fuselage. Guide
the lines from the tank through the hole in
the ewall.
Use plywood template to hold in place the
fuel tank with C/A glue to secure the fuel-
tank inside the fuselage.
2.

17
5.
6.
Fuel pick up tube Fuel ll tube
Vent tube
2.
Loctite
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.
Blow through one of the lines to ensure
the fuel lines have not become kinked inside
the fuel tank compartment. Air should ow
through easily.
MOUNTING THE ENGINE
Locate the items necessary to install the
engine mount included with your model.
Use four 4x30mm head bolts and four
4mm washers to attach the engine mount
rails to the rewall. Tighten the screws .
Make sure to use threadlock on the
screws to help prevent them from vibrat-
ing loose.
1.
3.
Position the engine with the drive washer
(145mm) forward of the ewall as shown.
4.
145mm

Upgrated Dewoitine D-520 71” span 20-26cc Instruction Manual.
18
Use a pin drill and 4mm drill bit to drill
a small indentation in the mount for the
engine mounting screw.
Use a drill to drill the four holes in the
engine mount rails.
5.
6.
On the e wall has the location for the
throttle pusshrod tube (pre-drill).
Slide the pushrod tube in the ewall and
guide it through the fuel tank mount. Use
medium C/A to glue the tube to the e-
wall and the fuel tank mount.
Connect the Z-bend in the 450mm
throttle pushrod to the outer hole of the
carburetor arm.
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.
7.
8.
9.
M4x30mm
10.
Pushrod wire
4mm
M4 lock Nut
Ignition Modude
M4x30mm

19
11.
13.
12.
14.
16.
15.
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.
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.

Upgrated Dewoitine D-520 71” span 20-26cc Instruction Manual.
20
COWLING
Please see below pictures.
1.
2.
3.
4.
Tape the cowl to the fuselage using low-
tack tape.
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.
5.
Install the muer and muer exten-
sion onto the engine and make the cutout
in the cowl for muer clearance. Connect
the fuel and pressure lines to the carbu-
retor, muer and fuel ler valve. Secure
the cowl to fuselage using the M3x10mm
socket head screws.Putting a small length
of silicon fuel tube under the head of the
screw helps with vibration.
6.