Nexa YAK-9 User manual

SPECIFICATIONS
Wingspan 59.8 in.
Length 48.7 in.
Electric Motor 800-900Watt
Glow Engine .46 2-T / .70 4-T
Radio 6 Channels / 6-7Servos
TECHNISCHE DATEN
Spannweiter 1520mm
Lange 1237mm
Elektroantrieb 800-900Watt
Verbrennerantrieb 7.5cc 2-T / 11cc 4-T
Fernsteuerung 6 Kanal / 6-7 Servos
WARNING! This radio controlled model is NOT a toy. If modified or flown carelessly it could go out of controll and
cause serious human injury or property damage. Before flying your airplane, ensure the air field is spacious enough.
Always fly it outdoors in safe areas and seek professional advice if you are unexperienced.
ACHTUNG! Dieses ferngesteuerte Modell ist KEIN Spielzeug! Es ist für fortgeschrittene Modellflugpiloten bestimmt,
die ausreichende Erfahrung im Umgang mit derartigen Modellen besitzen Bei unsachgemäßer Verwendung kann
hoher Personen- und/oder Sachschaden entstehen. Fragen Sie in einem Modellbauverein in Ihrer Nähe um
professionelle Unterstützung, wenn Sie Hilfe im Bau und Betrieb benötigen. Der Zusammenbau dieses Modells ist
durch die vielen Abbildungen selbsterklärend und ist für fortgeschrittene, erfahrene Modellbauer bestimmt.
45 Class
70 Class
2-cycle engine
4-cycle engine
All balsa, plywood construction and almost ready to fly
Or Electric equivalent
YAK
INSTRUCTION MANUAL / Montageanleitung

Minimum 6 channel radio
for airplane with 7 servos
.60 ~.70 - 4 cycle
10.5x6 for .40 - 2 cycle engine
11x6 for .46 - 2 cycle engine
12x6 for .60 - 4 cycle engine
12x7 for .70 - 4 cycle engine
11x8 for Brushless Motor
Silicone tube
Extension for aileron
flap and retract servo.
.46 ~ .50 - 2 cycle
TOLLS REQUIRED
Hobby knife
Needle nose Pliers
Phillip screw driver
Awl
Scissors
Wire Cutters
(Purchase separately) Hex Wrench
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Sander
Masking tape - Straight Edged Ruler - Pen or pencil - Rubbing alcohol - Drill and Assorted Drill Bits
.Motor control x1 .Aileron x2
.Flap x2 (mini servo)
.Elevator x1 .Rudder x1
800-900Watt brushless Motor
ESC:60-65A
Li-Po Battery
CONVERSION TABLE
1.0mm = 3/64”
1.5mm = 1/16”
2.0mm = 5/64”
2.5mm = 3/32”
3.0mm = 1/8”
4.0mm = 5/32”
5.0mm = 13/64”
6.0mm = 15/64”
10mm = 13/32”
12mm = 15/32”
15mm = 19/32”
20mm = 51/64”
25mm = 1”
30mm = 1-3/16”
45mm = 1-51/64”
OPTIONAL ACCESSORIES / BENOTIGTES ZUBEHOR
SILICON
EPOXY A
EPOXY B
CA
GLUE
Epoxy Glue (5 minute type)
Silicon sealer
Cyanoacrylate
Glue Epoxy Glue (30 minute type)
(Purchase separately)
Klebstoff
Epoxy-Klebstoff (30min-Typ)
Epoxy-Klebstoff (5min-Typ)
Low setting
If exposed to direct sunlight and/or heat, wrinkels can appear. Storing the
model in a cool place will let the wrinkles disappear. Otherwise, remove
wrinkles in covering film with a hair dryer, starting with
low temperature. You can fix the corners by using a hot iron.
Bei Sonneneinstrahlung und/oder Wärme kann die Folie erschlaffen bzw. Falten
entstehen. Verwenden Sie ein Warumluftgebläse (Haartrockner) um evtl. Falten aus der Folie
zu bekommen. Die Kanten können Sie mit einem Bügeleisen behandeln. Nicht zuviel Hitze anwenden !
1.5mm
AB
!
CA
L/R
Assemble left and right
sides the same way.
X
Drill holes using the stated
size of drill
(in this case 1.5 mm Ø)
Use epoxy glue
Take particular care here
Hatched-in areas:
remove covering
film carefully
Not included.
These parts must be
purchased separately
Check during assembly that these
parts move freely, without binding
Apply cyano glue
www.motionrc.com

X
Aileron servo
extension
cord
X
Flap servo
extension
cord
Using the thread (pre-installed at
factory) to slide the aileron and flap
extension cord into the wing half.
YAK-9 1- MAIN WING: Extension cord & Servo
3
X
X
X
This model is highly pre-fabricated and can be built in a very short time. However, the work which you have to
carry out is important and must be done carefully. The model will only be strong and fly well if you complete
your tasks competently - so please work slowly, accurately and check every joints, maybe apply more glue to
be safe.
SAFETY NOTES BEFORE ASSEMBLING
Read through the manual before you begin, so you will have an overall idea of what to do.

............2
2mm
Connector
Aileron push rod 2x175mm
............2
.....2
Steel clevis Flap push rod 1.2x120mm
............2
Plastic EZ link
............2
Plastic control horn
............2 set
Plastic control horn
............2 set
2x20mm screw
......4
2 mm
connector
Flap push-rod
1.2x120mm
2- MAIN WING: Control horn & Linkages
4
Secure the plastic control horn
in place using the thin CA glue.
CA
2 mm
YAK-9

Without using Epoxy yet, trial fit the wing joiner
into one of the wing panels.
Next, slide the other wing half onto the dihedral
brace until the wing panels meet. If the fit is overly
tight, it may be necessary to lightly sand the
dihedral brace.
Carefully slide the wing halves together, ensuring that
they are accurately aligned.
Firmly press the two halves together, allowing the excess
epoxy to run out. Using a paper towel, clean off the excess
epoxy.
Draw the center line
on the wing joiner
Coat one half of the dihedral brace with epoxy up
to the center line. Install the epoxy-coated side of
the dihedral brace into the wing joiner cavity up to
the center line.
Hold the wing halves together with paper
clamp and rubber band.
Rubber band
(not include)
Paper clamp
(not include)
Nylon wing bolt
(included)
30 min.
Epoxy
3- MAIN WING: Joining the wing halves
5
CA
6x20mm dowel.
Securely glue together. If coming off during flight,
you lose control of your air plane.
YAK-9

Main landing gear
Gear mount
1
3x20mm
Nylon gear
strap
2mm
2
Ply gear
mount flat
Square
plastic
3
CA
4
2mm
2mm
3x20mm
5
Insert the main landing gear into
the slot on the gear mount, if
necessary, use sander to widen
the slot to make this easier.
3x12mm screw
Ply gear mount
plate x 2 Gear mount x 2
3x20mm screw
......16
Nylon gear strap
.......4
Square plastic x 2
.......8
4- MAIN WING: Fixed gear assembly
.........8
3x12mm screw
2mm
2mm
3x12mm
screw
3x12mm screw
6
YAK-9

2x6mm screw
..........4
....2
...2
4mm collar
Wheel well cover
CA
Step 5A
Step 5B
Step 5C
CA
Plastic track
1.5mm
Attach the plastic wheel well cover in
place and secure it with litter
CA glue or 2x8mm screws.
or
5- MAIN WING: Wheel
7
Step 5E
YAK-9

ON
OFF
GEAR
SWITCH
EXTENDED
RETRACTED
6- MAIN WING: E-retract & strut
Note: Eretract and strut must be purchase separately
www.motionrc.com
Step 6A
Step 6B
Step 6C
Step 6D
Fix the adapter in the retract with hexagon socket
screws supplied with scale oleo strut.
Fix the strut on the adapter....
...then tighten the locking bolt.
8
YAK-9

2mm
7- MAIN WING: E-retract & strut
Step 7A
Step 7B
Step 7C
Step 7D
Drill appropriately sized holes for the hardware
you intend to use (not supplied) then attach the
retract in place (we recommend to use self tapping
screws 3x15mm).
Slip the wheel on the axle with the circlip
pointing away from the strut...
...then attach the axle to the gear and tighten the locking bolt
(use LOCTITE threadlocker on every bolt).
9
YAK-9

6x40mm nylon bolt
.........2
Cut away only
the covering
Using the ABS air scoop (part A) as a template, trace around the outside edge of the ABS air-scoop and then remove it.
Apply the plastic air scoop (part B) in place and secure with CA glue.
A
8- Attach the wing to the fuselage
YAK-9
9- Air scoop
YAK-9
10
CA
Thin CA
B

Using a sharp hobby knife, cut away the covering
inside the lines. Not to cut into the wood.
CA
Thin CA
Cut away only
the covering
Insert the horizontal stabilizer into
the slot on the fuselage, if necessary,
use sander to widen the slot to make
this easier.
If the fit is overly tight, it may be necessary
to lightly sand the top edge of the slot.
Remove the left and right elevator out of the
horizontal stabilizer before insert the horizontal
stabilizer.
10- Air scoop continued
YAK-9
11- Horizontal stabilizer
YAK-9
Note: The hinges are glued to the
elevator only.
Be cautious not to cut into the wood, this will
weaken the structure.
11

Cut away only the
covering both side
BB’
AA’
90O90O
Check the alignment of the horizontal stabilizer When you are satisfied
with the alignment (A=A’ and B=B’), use a pencil to trace around the
top and bottom of the stabilizer where it meets the fuselage.
A=A’ and B=B’
Remove the horizontal stabilizer from the fuselage.
Using the sharp hobby knife, carefully cut away the covering inside
the lines which were marked above.
Be cautious not to cut into the wood, this will
weaken the structure.
Use a small glue faucet, Apply the thin CA glue on
the horizontal stabilizer where it contacts the fuselage
(both the top and bottom sides),and into the slot of the
fuselage as show.
Securely glue together. If coming off during flight,
you lose control of your air plane.
CA
12- Horizontal stabilizer continued
YAK-9
Thin CA
12

Cut away only the
covering both side
Remove the vertical stabilizer from the fuselage.
Using the sharp hobby knife, carefully cut away the covering
inside the lines which were marked above.
Be cautious not to cut into the wood, this will
weaken the structure.
Check the alignment of the vertical stabilizer.
When you are satisfied with the alignment, use
a pencil to trace around the right and left of the
stabilizer where it meets the fuselage.
90 degree measure
12- Vertical stabilizer
YAK-9
Note: The hinges are glued to the
rudder only.
Use a small glue faucet, Apply the thin CA glue on
the vertical stabilizer where it contacts the fuselage
as show.
CA
Thin CA
Securely glue together. If coming off during flight,
you lose control of your air plane.
13

Control horn
................3
2x12mm screw
..........6
Note: Push the elevator push-rod into the fuselage before
attach the elevator control horn.
2mm
Elevator push rod
Elevator push rod
Elevator control horn flat
Elevator control horn flat
2mm
13- Vertical stabilizer
YAK-9
CA
CA
Thin CA
Thin CA
Securely glue together. If coming off during flight,
you lose control of your air plane.
14

1- Insert the tail wheel pushrod into the hole on the tail gear control horn (as show).
2- Install the tail wheel control horn in place.
4- Secure the tail wheel control horn in place using a 2mm screw set,
Ensure smooth non-binding movement.
5- Installing the tail wheel hatch (H) in place using a four 2x10mm self tapping screws.
3
2
3- Instal the tail wheel gear in place.
1
4
5
2x8mm
screw
H
FRONT-VIEW
Remove the engine mount and drill a 5mm hole
through the fire-wall at each of the four marks marked.
Using a pencil or felt tipped pen, mark the fire wall where the four holes are to be drilled.
B
B’
B=B’
! Engine thrust on balk head
is already adjust at factory
Attach the engine mount beams onto the fire-wall so the distance between of two engine mount beams is “A”.
Secure the engine mount beams onto the fire-wall with litter CA glue.
A
...............2
Tail landing gear
..........1
............2
2x3mm screw
............4
2x18mm screw
.....1
Tail wheel control-
horn
2mm I.D collar
1.2x800mm tail wheel push rod
14- Tail wheel
YAK-9
15- Glow engine
YAK-9
15
5mm
! Align the mark on both mounts
with the mark on the fuselage
A
Pull the magnetic top hatch
out of the fuselage.

then reposition the engine mounts on to the fire-wall
and secure them with four 4x25mm hex bolts.
- Reposition the engine on to the engine mounts so
the distance from the prop hub to the fire wall is
127mm
- Mark the engine mounting plate where the four
holes are to be drilled.
Note: Mark the mounting plate through the engine
mounting flanges.
- Reposition the engine on the engine mount beams,
aligning it with the holes. Secure the engine to the
engine mount using four 3x25mm screws.
Attach the four blind-nuts to the fire-wall as show,
3mm
- Remove the engine and drill a 3mm holes
through the beam at each of the four marks made
above.
......4
............4
4x25mm hex bolt
Blind-nut
4mm washer
............4
3x20mm hex bolt
Nut .............4
...4
127mm
16- Glow engine continued
YAK-9
16

Using a wooden motor mounting plate as a template,
mark the fire-wall where the four holes are to be drilled.
Remove the wooden motor mounting plate and drill a 6mm
hole through the fire-wall at each of the four marks marked.
Attach the four 5x80mm bolts
and nuts to the fire-wall as
shown.
3mm bolt / nut...4
Secure the Motor to the wooden
motor mounting plate using the
four 3mm bolts.
5x80mm bolt....4
5mm nut.......12
5mm washer..16
Using a aluminum motor mounting plate
as a template, mark the plywood motor
mounting plate where the four holes are
to be drilled.
Remove the aluminum motor mounting
plate and drill a 1/8”(3mm) hole through
the plywood at each of the four marks
marked .
3mm
! Align the mark on wooden motor
mounting plate with the mark on
the fire-wall.
6mm
17- Electric motor
YAK-9
17
Step 17A
Step 17B
Step 17C
Step 17D
Step 17E
Step 17G

2.5x10mm.....4
Ensure that the fuel tank clunk does not touch
the rear of the fuel tank.
Checking for leaks - block the vents and blow
into the feed, if in doubt submersing the tank
in a blow of water will show up any problems.
Blow
Water
2
X
To muffler
Filler tube
To engine
3x35mm screw
Rubber stopper
1
After confirming the direction . Insert this
assembly, clunk end first, into the fuel tank
and tighten and screw the fuel tankcap on firmly.
1.5mm
LiPo Battery
Battery stand
Battery hatch
18- Fuel tank
YAK-9
19- Cowling & Li-po battery tray
YAK-9
Battery tray
(3mm plywood)
18

Elevator pushrod
Rudder pushrod
Rudder servo
Elevator servo
Throttle servo
NOTE: Place of the servos may be
change depend of engine
(Four-stoke or two-stroke engine)
Tail wheel pushrod
X
Rudder servo
Rudder push rod
Tail wheel push rod
Connector
Elevator servo
X
Connector
Elevator push rod
Elevator push rod
Throttle servo
(in case of glow engine using)
X
Throttle push rod
Connector
........ 3
...... 1
Connector
2x950mm rod with clevis
........ 3 (Elevator x2 , Rudder x1)
1.5x120mm rod....1 (for Elevator linkage)
1.2x500mm rod....1 (for throttle, in case of
glow engine using)
1.2x800mm rod...1 (for tail wheel linkage)
Note: Tighten all screws, if they rotate out, you will lose
control your plane.
Use silicon sealer for all screws.
20- Servo
YAK-9
21- Linkages
YAK-9
19

RUDDER
AILERON
IMPORTANT: Flying your model at these throws will provide you with the greatest chance for successful first flights.
If,after you have become accustomed to the way the Yak-9 flies, you would like to change the throws to suit your taste
that is fine. However, too much control throw could make the model difficult to control, so remember, “more is not always better”.
ELEVATOR
10mm
10mm 25mm
25mm
10mm
10mm
FLAP
15mm
LOW RATE
Aileron : 10mm up / down
Elevator : 10mm up / down
Rudder : 25mm right / left
Flap : 15mm down
HIGH RATE
Aileron : 12mm up / down
Elevator : 12mm up / down
Rudder : 30mm right / left
Flap : 25mm down
right
left
up
down
up
down
down
THE CENTER OF GRAVITY IS LOCATED 107mm BACK FROM THE
LEADING EDGE OF THE WING, AT THE FUSELAGE. BALANCE A PLANE
UPSIDE DOWN WITH THE FUEL TANK EMPTY.
1- Mount the wing to the fuselage. Using a couple of pieces of masking tape,
place them on the top side of the wing (107mm) back from the leading
edge, at the fuselage sides.
2- Lift the airplane. Place your fingers on the masking tape and carefully lift
the plane.
3- If the nose of the plane falls, the plane is heavy nose. To correct this, move
the battery pack further back in the fuselage. If the tail of plane falls, the
plane is tail heavy. To correct this, move the battery forward or if this is not
possible, stick weight onto the firewall.
When balanced correctly, the airplane should level or slightly nose down
when you lift it up with your fingers.
DO NOT try to fly an out-of-balance model !
LATERAL BALANCE:
After you have balanced a plane on the CG, you should laterally balance it. Doing this will help the airplane track straighter.
1- Turn the airplane upside down. Attach one loop of heavy string to the engine crankshaft and one to the tail wheel wire.
With the wing level, carefully lift the airplane by the string. This may require two people to make easier.
2- If one side of the wing fall, that side is heavier than the opposite. Add small amounts of lead weight to the bottom side
of the lighter wing half’s wing tip. Follow this procedure until the wing stays level when you lift the airplane.
IMPORTANT:
Please do not clean your model with pure alcohol, only use liquid soap with water or use glass cleaner
to clean on surface of your model to keep the colour not fade.
107mm
22- Balance
YAK-9
23- Control surface
YAK-9
Position for right diagram
20