Hangar 9 J-3 Piper Cub User manual

Specifications
Wingspan: 80-1/8"
Wing Area: 850 sq. in.
Weight (Approx.): 6.5-7.0 lbs.
Recommended Engines:
.40-.46 2-Cycle
.45-.60 4-Cycle
WE GET PEOPLE FLYING
TM
TM
Raising the Standard of Quality in
Almost Ready-To-Fly Aircraft
• Ultra Covering
• Pre-finished Fiberglass Cowl
• Highest Quality Craftsmanship
• 90% Pre-Built
• IMAA-Legal 80-1/8
" Wingspan
ALMOST READY-TO-FLY
PRE-BUILT
90
%
ASSEMBLY MANUAL

2
Table of Contents
Introduction 3
Additional Equipment Required 4
Tools and Supplies Required 4
Section 1: Hinging The Aileron 5
Section 2: Joining the Wing Halves 6
Section 3: Installing the Aileron Servos 8
Section 4: Installing the Aileron Linkage 12
Section 5: Mounting The Wing 14
Section 6: Installing The Tail 17
Section 7: Hinging The Rudder 20
Section 8: Installing The Engine 22
Section 9: Landing Gear Assembly and Installation 25
Section 10: Assembling and Installing the Fuel Tank 26
Section 11: Installing The Radio 28
Section 12: Installing The Linkages 29
Section 13: Attaching The Cowl 34
Section 14: Installing The Windows 35
Section 15: Scale Detailing 35
Section 16: Balancing the J-3 Piper Cub 38
Section 17: Control Throw Recommendation 39
Section 18: Flying the J-3 Piper Cub 39
Pre-Flight Check 40
Pre-Flight at the Field 41
AMA Safety Code 42
Cowl Template (for Saito .50 or .56) 43

3
Throughout aviation history, select few aircraft have achieved
such a level of popularity that they transcend their eras. Such is
the case of the J-3 Piper Cub. This timeless classic is perhaps
even more famous today than when it was first introduced to the
army (then known as an L-4) in the late '30s. 4 out of 5 pilots in
the Second World War are claimed to have gotten their initial
flight training behind the stick of the Cub.
Hangar 9’s J-3 Piper Cub offers traditional scale appearance in
an IMAA-legal size that can be powered with any standard
.40-.46 size 2-cycle engine. Or, for enhanced scale realism,
a .45-.55 4-cycle engine can be used to power this Cub.
Hangar 9’s J-3 Piper Cub comes 90% pre-built to a high level of
craftsmanship and is pre-covered and trimmed in Ultra covering.
This means you can have a large (80-1/8" span), high quality
scale J-3 Piper Cub, showing it to your friends at the field in 20
hours or less. Best of all, they’ll never know it’s an ARF, and
chances are they’ll compliment you on your building and
finishing skill. Don’t worry . . . we won’t tell!
An R/C aircraft is not a toy! If misused, it can cause serious
bodily harm and damage to property. Fly only in open areas,
preferably AMA (Academy of Model Aeronautics) approved flying
sites, following all instructions included with your radio and
engine.
Introduction
Warning

Radio Equipment
4 Channels (minimum)
5 Standard Servos
Standard 450-650 mAh Receiver Battery Pack
Y-Harness
2 Servo Extensions
Engine Recommendations
.40-.46 2-Cycle Engines
.45-.55 4-Cycle Engines
Adhesives
Instant thin CA (cyanoacrylate) glue
Thick CA glue
CA remover/debonder
White canopy glue (e.g., R/C 56 or Formula 560)
6 minute epoxy
12 minute epoxy
30 minute epoxy
Blue Locktite 242
Tools
Drill
Drill bits: 1/4", 1/8", 1/16", 3/32"
Small and medium Phillips screwdrivers
Z-bend pliers
Needle nose pliers
Pliers
Small round file
Adjustable wrench
Razor saw
Heat gun
Moto-Tool with sanding drum
Hobby knife with #11 blade
Mixing stick
Epoxy brush
4
Additional Equipment Required
Tools and Supplies Required
Saito .50GK
Recommended JR Systems
JR F400 FM
JR XF642FM/PCM
JR XP783
JR XP8103 FM/PCM
Recommended 2-Cycle Engines
Thunder Tiger Pro .40
Thunder Tiger Pro .46
Webra Speed .40 Sport
Recommended 4-Cycle Engines
Saito .50GK
Saito .50
Saito .56GK
Saito .56
Thunder Tiger
Pro .40
1/16" x 36" music wire
Medium sandpaper
Masking tape
Straight edge
Measuring device
(e.g., ruler, tape measure)
Scissors
Paper towels
Wax paper
Rubbing alcohol
Pencil
Felt tipped pen
Fuel tubing (optional)
Hobby enamel paint: black, silver
Saito .56GK

Right wing panel with aileron and hinges
Left wing panel with aileron and hinges
Note: The control surfaces, including the ailerons, elevators
and rudder, are pre-hinged with the hinges installed, but the
hinges are not glued in place. It is imperative that you
properly adhere the hinges and ailerons in place per the steps
below using high quality thin CA.
❑1. Carefully remove the aileron from one of the wing panels.
Note the position of the hinges. The J-3 Piper Cub comes
with high quality CA-type hinges, which are manufactured
in the USA.
❑2. Replace the aileron, making sure the hinges slide in place.
Deflect the aileron and apply a few drops of thin CA glue
directly to the center of each of the hinges. The aileron’s
front surface should lightly contact the wing during this
procedure. Ideally, when the hinge is glued in place, a
1/32" gap or less will be maintained throughout the length
of the aileron. The hinge is constructed of a special
material that allows the CA to wick or penetrate and
distribute throughout the hinge, securely bonding it to the
wood structure.
❑3. Turn the wing panel over and deflect the aileron in the
opposite direction and from the opposite side. Apply
several drops of thin CA glue to each aileron hinge,
making sure that the CA penetrates into both the aileron
and the wing.
❑ 4. Using CA remover/debonder and a paper towel, remove
any excess CA glue that may have accumulated on the
wing or in the aileron hinge area.
❑5. Repeat this process with the other wing panel, securely
hinging the aileron in place.
5
Section 1: Hinging The Ailerons
Instant thin CA glue
CA remover/debonder
Paper towels
Parts Needed Tools And Adhesives Needed

❑ 6. After both ailerons are securely hinged, firmly grasp the
wing and aileron to check that the hinges are immovable.
Do this by applying medium pressure, trying to separate
the aileron from the wing.
❑1. Locate the dihedral brace (also called the wing joiner).
Using a ruler, mark the exact center of the brace with a
pencil as shown in the photo below.
❑2. Trial fit the dihedral brace into one of the wing panels.
It should insert smoothly up to the center line marked in
Step 1. Now 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.
6
Section 1: Hinging The Ailerons
Right wing panel from Section One
Left wing panel from Section One
Dihedral brace
Trim Tape
30 minute epoxy
Masking tape
Paper towels
Rubbing alcohol
Wax Paper
Ruler
Pencil
Mediumsandpaper
Mixing stick
Parts Needed Tools And Adhesives Needed
Section 2: Joining the Wing Halves
CONTINUED

❑ 3. Next, check for the correct dihedral angle. Place the wing
on a large, flat surface with one wing panel resting on the
flat surface. The opposite wing tip should be exactly 2"
from the surface (see illustration below). If necessary,
sand the dihedral brace until this is achieved.
❑ 4. Mix up approximately three ounces of 30 minute epoxy.
Note: It is extremely important to use plenty of epoxy
when joining the wing halves.
❑ 5. Smear a generous amount of epoxy into the wing joiner
cavity of one wing half. A scrap piece of wood or mixing
stick is handy here.
❑ 6. Coat one half of the dihedral brace with epoxy up to the
pencil line drawn in Step 1. Note the orientation of the
V side of the dihedral brace; the V must face up. Install
the epoxy-coated side of the dihedral brace into the wing
joiner cavity of the wing half up to the center line, making
sure the V of the dihedral brace is positioned correctly.
❑7. Apply a generous amount of epoxy into the wing cavity of
the other wing half.
❑8. Now apply epoxy to all sides of the exposed area of the
dihedral brace and uniformly coat both wing roots with
epoxy.
7
Section 2: Joining the Wing Halves
CONTINUED
2 inches

❑ 9. Carefully slide the two wing halves together. Firmly press
the halves together, allowing the excess epoxy to run out.
Using rubbing alcohol and a paper towel, clean off the
excess epoxy. There should not be any gap between the
wing halves.
❑10.Apply masking tape at the wing joint to hold the wing
halves together securely. Place the wing on a large, flat
surface. With one wing panel lying flat on the surface, the
opposite wing tip should be propped up exactly 2" from
the surface. Apply more masking tape to the center wing
joint and recheck the 2" measurement. Allow the wing
joint to dry overnight.
Note: It is a good idea to place a sheet of wax paper under the
wing’s center joint so any excess epoxy doesn’t adhere to the
surface of the work area.
❑11.When the wing center joint is completely dry, remove the
masking tape and apply the included trim tape to cover the
center joint.
❑1. Hold the assembled wing up to a strong light. Note the
aileron servo cut-outs on the bottom side of each wing.
Using a very sharp hobby knife, carefully trim away the
covering material where the aileron servos will be
mounted.
8
Section 2: Joining the Wing Halves
Section 3: Installing the Aileron Servos
CONTINUED
Assembled wing
Two standard size servos
w/mounting hardware
Y-harness
Servo extensions (2)
Wood servo blocks
w/screws
Aileron covers
Hobby knife
Small Phillips
screwdriver
Drill
1/16" drill bit
1/16"x36" music
wire
Masking tape
Scissors
Pencil
Felt tipped pen
30 minute epoxy
Parts Needed Tools And Adhesives Needed
2 inches
bottom of the wing

❑2. Install the grommets and eyelets on both aileron servos.
Now place the servo blocks on the servo as shown and
mark with a pencil where the servo screws attach the
servo to the blocks.
❑3. Using a 1/16" drill bit, drill the marked location on the
blocks.
❑4. Mount the blocks to the aileron servo as shown using the
screws included with your servos.
❑5. Using scissors, cut out the aileron cover. Also, using a
hobby knife cut out the opening where the linkage exits
the aileron cover.
❑6. Temporarily install a servo arm with a hole located
between 10-12mm out from the center on the servo as
shown. Now trial fit the servo on the aileron servo cover
as shown with the servo arm aligned in the middle of the
linkage opening in the aileron cover.
❑7. Using a felt tipped pen, trace around the wood servo
blocks where it contacts the aileron cover.
9
Section 3: Installing the Aileron Servos
CONTINUED

Section 3: Installing the Aileron Servos
CONTINUED
❑8. Now mark two equidistant holes as shown on the servo
cover where the servo blocks are to be mounted. Two
sheet metal screws, included with the J-3 Cub, will be
used to mount each block to the servo cover.
❑9. Using a 1/16" drill bit, drill the servo cover at the four
marked locations.
❑10.Holding the servo in place, drill four 1/16" pilot holes into
the wood servo blocks.
❑11.Using 30 minute epoxy, glue the servo blocks in place,
then screw them into position with 4 sheet metal screws.
❑12.Center the aileron cover over the aileron cut-out in the
wing and drill four 1/16" holes at each corner of the
aileron cover through the wing’s bottom surface.
❑13.Screw the aileron cover in place with four sheet metal
screws as shown.
❑14.Now repeat these steps to install the servo on the other
wing half.
❑15.Remove the aileron covers from the wing halves.
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