Hangar 9 Piper J-3 Cub 40 User manual

Wingspan: ....................................... 80" (2032mm)
Fuselage length: ........................... 49.9" (1268mm)
Wing area: ........................ 919 sq. in. (59.3 sq dm)
ASSEMBLY MANUAL
Piper J-3 Cub 40
Weight: ............................ 6.75–7.5 lbs (3–3.4 kg)
Engine: ............ .36–.46 2-stroke, .56–.82 4-stroke
Radio: ................................. 4-channel w/ 5 servos
Specifications

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2
Contents of Kit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Additional Required Equipment. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Covering Colors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Additional Required Tools and Adhesives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Field Equipment Required. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Using the Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Before Starting Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Warranty Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Section 1: Hinge Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Section 2: Engine Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Section 3: Servo Installation (Aileron) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Section 4: Servo Installation (Fuselage) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Section 5: Window Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Section 6: Landing Gear Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Section 7: Installing the Stabilizer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Section 8: Cowling Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Section 9: Wing Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Adjusting the Engine. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Control Throws . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Recommended CG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Preflight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Range Testing the Radio . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
2005 Official AMA National Model Aircraft Safety Code. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Table of Contents

3
Radio Equipment
• 4-channel radio system (minimum)
• 5 standard servos
• Receiver
• Receiver battery
• Switch harness
• 12" Servo Extension (JRPA098) (2)
• “Y” Harness (JRPA135)
• Large Arms/Horns w/Screw (JRPA212)
Recommended JR® Systems
• PCM10X
• XP9303
• XP8103
• X-378
• XP6102
• XF631
• XF421
• Quattro
Recommended Engine
• Evolution® .36–.46
• Saito™ .56–.82 4-stroke
Large Parts:
A. Fuselage HAN4002
B. Wing HAN4001
C. Cowling HAN4004
D. Tail Set HAN4003
E. Landing Gear HAN4005
F. Wing Strut Set HAN4010
G. Window Set HAN4008
Items Not Shown:
Fuel Tank
Tail Wheel Assembly HAN4007
Decal Set HAN4009
Pushrod Set HAN4011
Wheels HAN4006
Top Fuselage Hatch HAN4012
• Cub Yellow HANU884
• Black HANU874
JR XP6102
JR XP9303
Covering Colors
Contents of Kit
Additional Required Equipment
A
B
D
E
C
G
F

4
Tools
• Adjustable wrench
• Crimping tool
• Drill
• Drill bit: 1/16”, 5/64”, 3/32”
• Felt-tipped pen
• Heat gun
• Hobby knife
• Hobby scissors
• Petroleum jelly
• Phillips screwdriver (small)
• Phillips screwdriver (large)
• Pliers
• Rotary tool w/sanding drum
• Ruler
• Sandpaper
• String
• Threadlock
• T-pins
Adhesives
• 6-minute epoxy
• Thin CA
• Medium CA
Other Required Items
• Epoxy brushes
• Felt-tipped pen or pencil
• Measuring device (e.g. ruler, tape measure)
• Mixing sticks for epoxy
• Paper towels
• Petroleum jelly
• Rubbing alcohol
• Sanding bar
• Covering Iron (HAN101)
• Covering Glove (HAN150)
• Sealing Iron Sock (HAN141)
An RC aircraft is not a toy! If misused, it can cause serious bodily harm and damage to property. Fly only in open areas,
preferably at AMA (Academy of Model Aeronautics) approved flying sites, following all instructions included with your
radio and engine.
• Propeller
• Fuel
• Glow Plug Wrench (HAN2510)
• Glow Plug Igniter with Charger (HAN7101)
• Glow Plug (HAN3001/3006)
• Manual Fuel Pump (HAN118)
Field Equipment Required
Additional Required Tools and Adhesives
Warning

5
Before beginning the assembly of your J-3 Cub, remove each part from its bag for inspection. Closely inspect the
fuselage, wing panels, rudder, and stabilizer and for damage. If you find any damaged or missing parts, contact the place
of purchase.
If you find any wrinkles in the covering, use a heat gun or covering iron to remove them. Use caution while working
around areas where the colors overlap to prevent separating the colors.
This manual is divided into sections to help make assembly easier to understand, and to provide breaks between each
major section. Remember to take your time and follow the directions.
Horizon Hobby, Inc. guarantees this kit to be free from defects in both material and workmanship at the date of purchase.
This warranty does not cover any parts damaged by use or modification. In no case shall Horizon Hobby’s liability exceed
the original cost of the purchased kit. Further, Horizon Hobby reserves the right to change or modify this warranty without
notice.
In that Horizon Hobby has no control over the final assembly or material used for the final assembly, no liability shall be
assumed nor accepted for any damage of or caused by the final user-assembled product. By the act of using the product,
the user accepts all resulting liability.
Once assembly of the model has been started, you must contact Horizon Hobby, Inc. directly regarding any warranty
question that you have. Please do not contact your local hobby store regarding warranty issues, even if that is where you
purchased it. This will enable Horizon to better answer your questions and provide service in the event that you may need
any assistance.
If the buyer or user is not prepared to accept the liability associated with the use of this product, they are advised to
return this kit immediately in new and unused condition to the place of purchase.
For any additional questions please contact:
Horizon Hobby Product Support
4105 Fieldstone Road
Champaign, Illinois 61822
[phone]
www.horizonhobby.com
HAN100 – Heat Gun
HAN150 – Covering Glove
HAN101 – Covering Iron
HAN141 – Sealing Iron
Sock
Before Starting Assembly
Using the Manual
Warranty Information

6
Required Parts
• Stabilizer • Elevator
• Fuselage • Rudder
• Wing • Aileron (R&L)
• Tail gear wire • Hinge (17)
Required Tools and Adhesives
• Thin CA • T-pins
• 6-minute epoxy • Petroleum jelly
• Drill • Drill bit: 1/16", 3/32"
• Hobby knife
  Step 1
Locate three hinges. Place a T-pin in the center of
each hinge.
  Step 2
Drill a 1/16" hole in both a stabilizer and elevator half in
the center of the hinge locations.
  Step 3
Place the hinges in the stabilizer.
  Step 4
Slide the elevator and stabilizer together. Remove the
T-pins. There should be a 1/64" gap between the
stabilizer and elevator.
  Step 5
Check that the tips of the stabilizer and elevator are
aligned. Wick thin CA into each of the hinges.
Note: Do not use accelerator in the hinging
process. The CA must be allowed to soak into
the hinge naturally.
Section 1: Hinge Installation

7
  Step 6
After the CA has cured, flex the surfaces several times to
break in the hinges.
  Step 7
Pull on both surfaces to make sure the hinges are secure.
 Step 8
Repeat Steps 1 through 7 for the aileron hinges. Each
aileron will use four hinges. Center the ailerons and make
sure they are not binding before gluing the hinges.
 Step 9
Coat the tail gear wire near the bushing with petroleum
jelly. Work the lubricant into the bearing to prevent epoxy
from entering the bearing, gluing the bearing to the wire.
 Step 10
Drill a 3/32" hole in the rudder 1 1/4" from the bottom.
Section 1: Hinge Installation

8
 Step 11
Cut a groove from the hole to the bottom of the rudder to
allow clearance for the tail gear bearing.
 Step 12
Apply a thin layer of lubricant where the bearing will
ride in the rudder. Use 6-minute epoxy to glue the wire
into the rudder.
 Step 13
Cut a slot in the end of the fuselage to accept the tail
gear bearing.
 Step 14
Install three hinges into the rudder. Test fit the rudder
to the fuselage, sliding the hinges and tail wheel bracket
into position.
 Step 15
Use 6-minute epoxy to glue the tail gear bearing into the
fuselage. Use thin CA for the hinges.
Section 1: Hinge Installation

9
Required Parts
• Fuselage assembly • Fuel tank assembly
• Engine mount
• 8-32 x 3/4" bolt (4) • 8-32 X 1" bolt (4)
• 8-32 lock nut (4) • #8 washer (4)
• 14 1/4" pushrod wire • Clevis
• Clevis retainer
• Engine mount plate (2)
Required Tools and Adhesives
• Engine w/muffler • Threadlock
• Ruler • Phillips screwdriver
 Step 1
Secure the engine mount to the firewall using four
8-32 x 3/4" bolts. Use threadlock to prevent the bolts
from vibrating loose during flight.
 Step 2
Position the engine so the drive washer is 4 1/2"
forward of the firewall. Use the engine mount plates,
8-32 x 1" bolts, 8-32 lock nuts and #8 washers to attach
the engine to the mount. The engine mounting lugs are
sandwiched between the engine mount plates and the
engine mount. Tighten the bolts evenly.
Note: The engine mount plates have texture
on one side, which is placed against the
engine mounting lugs.
 Step 3
Place a clevis retainer onto a clevis. Thread the clevis
onto the 14 1/4" pushrod wire. Slide the wire into the
pushrod tube in the fuselage. Attach the clevis to the
carburetor arm.
Section 2: Engine Installation

10
 Step 4
Attach the muffler to the engine using the hardware
provided with your particular engine.
Note: It may be necessary to rotate the end of
the muffler to point the stinger straight down,
away from the fuselage.
 Step 5
Check the tank and note which fuel line is vent and which
is attached to the clunk. Make a note of the line colors
and which they correspond to. Also note the direction
of the vent line inside the fuel tank so it faces toward the
top of the fuselage.
 Step 6
With the vent line up, slide the fuel tank into the fuselage.
 Step 7
Attach the vent line to the muffler and the line from the
clunk to the carburetor.
 Step 8
A Saito™ 4-stroke can be installed instead of a 2-stroke
engine. You will have to relocate the throttle pushrod to
line up with the throttle arm on the carburetor.
Section 2: Engine Installation

11
Required Parts
• Wing (L&R) • Servo hatch (L&R)
• #2 x 3/8" screw (8) • Control horn (2)
• 2mm x 20mm screw (6) • Clevis (2)
• Clevis retainer (2)
• 4 3/4" pushrod wire (2)
• Pushrod wire keeper (2)
Required Tools and Adhesives
• Phillips screwdriver (small) • 6-minute epoxy
• Felt-tipped pen • String
• Drill • Drill bit: 1/16", 3/32"
• Pliers • “Y” harness
• 12" servo extension (2) • Hobby knife
• Long Servo Arm (JRPA212) (2)
 Step 1
Remove the covering from the servo opening in the
bottom of the wing using a hobby knife. Select the correct
servo hatch by checking the alignment for the servo arm
on the plate with the one on the wing.
 Step 2
Install the recommended servo hardware (grommets and
eyelets) supplied with the servo. Temporarily install a long
half servo arm (JRPA212) onto the servo and position
the servo onto the hatch so the servo arm is centered in
the notch. Once satisfied, mark the location for the servo
mounting blocks using a felt-tipped pen.
 Step 3
Locate the 3/8" x 3/4" x 3/4" servo mounting blocks.
Use 6-minute epoxy to glue the blocks to the hatch. Let
the epoxy fully cure before proceeding to the next step.
Section 3: Servo Installation (Aileron)

12
 Step 4
Place the aileron servo between the mounting blocks and
use a felt-tipped pen to mark the location of the four servo
mounting screws. Note that the servo must not touch the
hatch in order to isolate engine vibration.
Note: Before mounting the servo,
electronically center the servo using the
transmitter, then install the servo arm to
avoid having to remove the servo and center
the arm later. It may be necessary to slightly
trim one of the servo mounting blocks to clear
the servo wire.
 Step 5
Remove the servo and use a 1/16" drill bit to pre-drill
the holes for the servo mounting screws marked in the
previous step. Use the screws supplied with the servo to
mount it to the servo mounting blocks.
 Step 6
Connect a 12" Servo Lead Extension (JRPA098) to the
servo lead. Secure the connectors by tying them in
a knot using dental floss or by using a commercially
available connector clamp to prevent the servo leads from
becoming disconnected.
Note: It is always a good idea to secure
the servo connector and servo extension
together to prevent the wires from
becoming unplugged.
Section 3: Servo Installation (Aileron)

13
 Step 7
Tie a wheel collar onto a piece of string. Drop the wheel
collar into the wing from the root and retrieve it from the
servo opening.
 Step 8
Tie the string onto the servo extension. Gently pull the
extension through the wing using the string. Untie the
string when the servo lead has been pulled through. Use
tape to secure the servo lead to the wing to prevent it from
falling back into the wing panel.
 Step 9
Secure the hatch using four #2 x 3/8" screws.
Section 3: Servo Installation (Aileron)

14
 Step 10
Place a clevis retainer onto a clevis. Thread the clevis
onto a 4 3/4" pushrod wire. Remove the backplate
from a control horn, and then attach the clevis to the
control horn.
 Step 11
Position the control horn on the aileron. Use the
pushrod wire as a guide to align the horn to the servo
arm. Position the horn so the holes align with the hinge
line. Use a felt-tipped pen to mark the positions for the
three mounting bolts.
 Step 12
Drill the locations marked in the previous step using
a 3/32" drill bit.
 Step 13
Place a few drops of thin CA into each of the holes to
harden the balsa. Attach the control horn using three
2mm x 20mm screws and the control horn backplate.
Section 3: Servo Installation (Aileron)

15
 Step 14
Plug in the aileron servo to the radio system. Center the
trims on the transmitter to center the aileron servo. Hold
the aileron in neutral. Use a felt-tipped pen to mark the
pushrod wire where it crosses the servo arm.
 Step 15
Bend the pushrod wire at the mark. Use a pushrod wire
keeper to secure the pushrod wire to the servo arm.
 Step 16
Repeat Steps 1 though 15 for the remaining wing panel.
Required Parts
• Fuselage • Clevis
• Clevis retainer • Control horn
• Wing strut mount (2) • #4 x 3/8" screw (4)
• 19 3/4" pushrod dowel • 6" pushrod wire
• Pushrod wire (32”)
• 2 1/8" heat shrink tubing (2)
• 2mm x 12mm screw (3)
• 7 1/4" pushrod wire (2)
Required Tools and Adhesives
• Phillips screwdriver • Hobby knife
• Drill • Drill bit: 3/32", 5/64"
• Heat gun • Medium CA
• Thin CA • Felt-tipped pen
 Step 1
Remove the covering for the wing strut mount. The
opening is located above the rear landing gear mount.
Section 3: Servo Installation (Aileron)
Section 4: Servo Installation (Fuselage)

16
 Step 2
Slide the wing strut mount into the opening. Secure the
mount using two #4 x 3/8" screws.
 Step 3
Install the recommended servo hardware (grommets and
eyelets) supplied with the servos into the throttle, rudder,
and elevator servos.
 Step 4
Use the hardware provided with the servos to mount them
in the fuselage.
 Step 5
Place a clevis retainer onto a clevis. Thread the clevis
onto a 32" pushrod wire. Remove the backplate from a
control horn, and then attach the clevis to the control
horn. Slide the pushrod into the rudder pushrod tube in
the fuselage. Position the horn so the holes align with the
hinge line. Use a felt-tipped pen to mark the positions for
the three mounting bolts.
 Step 6
Drill the locations marked in the previous step using
a 3/32" drill bit. Place a few drops of thin CA into
each of the holes to harden the balsa. Attach the control
horn using three 2mm x 12mm screws and the control
horn backplate.
Section 4: Servo Installation (Fuselage)

17
 Step 7
Plug in the rudder servo to the radio system. Center the
trims on the transmitter to center the rudder servo. Hold
the rudder in neutral. Use a felt-tipped pen to mark the
pushrod wire where it crosses the servo arm.
 Step 8
Remove the pushrod wire from the fuselage and remove
the clevis. Bend the pushrod wire at the mark. Slide
the pushrod back into the fuselage from the radio
compartment, and then put the clevis back onto the
wire. Use a pushrod wire keeper to secure the pushrod
wire to the servo arm.
 Step 9
Center the throttle stick and trim with both the receiver
and transmitter on. Install the throttle servo arm in the
neutral position.
 Step 10
Move the throttle stick and trim lever down to the throttle
closed position. Manually close the carburetor and mark
the throttle pushrod where it crosses the servo arm.
Section 4: Servo Installation (Fuselage)

18
 Step 11
Remove the pushrod wire from the fuselage and remove
the clevis. Bend the pushrod wire at the mark. Slide
the pushrod back into the fuselage from the radio
compartment, and then put the clevis back onto the
wire. Use a pushrod wire keeper to secure the pushrod
wire to the servo arm.
 Step 12
Check the movement of the throttle to verify there is no
binding at either low or high throttle. If there is, make the
necessary adjustment to eliminate any binding. Install the
throttle servo arm screw when complete.
 Step 13
Locate the 19 3/4" wood pushrod for the elevator. Drill two
5/64" holes through the dowel, 1" and 1 1/4", from one
end. The holes must be parallel to each other.
 Step 14
Cut a groove into the pushrod from the hole to the end
of the pushrod. Repeat for the opposite side so you end
up with two grooves. The elevator pushrod wires will
rest in these grooves.
 Step 15
Locate the two 7 1/4" pushrod wires. Make a bend in one
wire 1/4" from the non-threaded end of one of the wires.
The remaining pushrod is bent 1/2" from the end.
 Step 16
Test fit the two wires. The wire bent at 1/2" is placed in
the hole closest to the pushrod end. You will have to
trim the wire down after the bend so it won’t interfere
with the other pushrod. Once fit, use medium CA to
glue the wires to the dowel.
Section 4: Servo Installation (Fuselage)

19
 Step 17
Slide the 2 1/8" piece of heat shrink over the wires and
dowel. Use a heat gun or lighter to shrink the tubing. Once
the tubing has been shrunk, apply thin CA to each end of
the shrink to complete this part of the pushrod assembly.
 Step 18
Repeat Steps 13 through 17 for the opposite end of
the dowel, but only drill one hole and prepare one 6"
pushrod wire.
 Step 19
Slide the elevator pushrod wire in position into the
fuselage. It may take some time to get it in, so be
patient. Slide a clevis retainer onto two clevises, and
then thread them onto the pushrod wires at the aft end
of the fuselage. This will prevent the pushrod wire from
falling out of the fuselage.
 Step 20
Plug the necessary servo leads into the receiver. This
includes the switch harness and battery leads as well.
Install the flat radio foam into the fuselage, followed by the
die-cut foam. Place the receiver and battery into the foam.
Note: There is a tube located under the
elevator servo for the antenna wire. Route the
wire through this tube to the tail of the aircraft.
 Step 21
Place the remaining flat radio foam over the receiver and
battery. Secure the foam to prevent the receiver and battery
from moving from their location. Mount the receiver
switch to the side of the fuselage.
Section 4: Servo Installation (Fuselage)

20
Required Parts
• Side window (L&R) • Front windscreen
• Support (2) • Fuselage hatch
Required Tools and Adhesives
• Hobby scissors • Canopy glue
• Hobby knife
 Step 1
Use hobby scissors and a hobby knife to trim the side
windows from their sheets. Leave a 1/8" lip to glue the
windows to the fuselage.
 Step 2
Test fit the windows from the inside of the fuselage. Trim
them as necessary so they fit flush to the outside of the
fuselage. Use canopy glue to secure the windows into the
fuselage. Install the window into the fuselage hatch at this
time as well.
Note: You can use epoxy as well, but be
very careful not to get epoxy on the nice clear
windows.
 Step 3
Cut and fit the two supports to the fuselage. Use medium
CA to glue them into position.
 Step 4
Test fit the front windscreen into position. Trim as
necessary. Use canopy glue to secure the front
windscreen to the fuselage.
Section 5: Window Installation