3D Hobby Shop EPP EXTRA 330SC User manual

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Assembly Manual- 72” Extra 330SC
Designed by Scott Stoops
Thank you for purchasing this 3DHobbyShop ARF RC aircraft. If you have any issues, questions, concerns or
problems during assembly, please contact our tech department at:
[e-mail] or 1-830-990-6978 10am-5pm Central M-F
SAFETY in Assembly
During assembly of this aircraft, you will be asked to use sharp knives and hobby adhesives. Please follow all safety
procedures recommended by the manufacturers of the products you use, and always follow these important guidelines:
ALWAYS protect your eyes when working with adhesives, knives, or tools, especially power tools. Safety glasses are the
best way to protect your eyes.
ALWAYS protect your body, especially your hands and fingers when using adhesives, knives, or tools, especially power
tools. Do not cut toward exposed skin with hobby knives. Do not place hobby knives on tables or benches where they
can roll off or be knocked off.
ALWAYS have a first-aid kit handy when working with adhesives, knives, or tools, especially power tools.
ALWAYS keep hobby equipment and supplies out of the reach of children.
IMPORTANT NOTE – We strive to provide the absolute best-quality ARF aircraft on the planet. However, the ultimate
success or failure of this aircraft is dependent upon proper assembly by you. If you have questions about an assembly
step, please contact us, or read the assembly thread for your airplane on RCGroups.com before proceeding. It is always
better to slow down and be sure of your assembly than to rush through it and make a mistake which can cause a crash.
SAFETY in Flying
SAFETY NOTICE: This is NOT a toy! It is a very high-performance RC airplane capable of high speeds and extreme
maneuvers. It should only be operated by a competent pilot in a safe area with proper supervision.
ONLY fly your aircraft in a safe, open area, away from spectators and vehicles–and where it is legal to fly.
NEVER fly near overhead power or utility lines. If your airplane ever becomes stuck in a line or a tree DO NOT attempt to
retrieve it yourself. Contact the authorities for assistance in retrieving your aircraft. Power lines are DANGEROUS and
falls from ladders and trees CAN KILL!
Never fly too close to yourself or spectators. Spinning propellers are DANGEROUS!
Never run your motor inside a house or building with the propeller attached – Remove the prop for safety.
Always fly within your control.
Always follow manufacturer’s instructions for your radio system.
Always obtain proper insurance before flying – contact the AMA at www.modelaircraft.org

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REQUIRED ITEMS
CA Glue – Thin and Medium or Thick
Hobby Knife
Small Phillips Screwdriver
Set Metric Allen Wrenches
Scissors
Small Pliers
Adjustable wrench
Masking tape
Drill and drill bits
Threadlocker (Blue Loctite)
Polyurethane or 30min epoxy glue
Vaseline/petroleum jelly
Rubbing alcohol
Optional – Heat gun and covering iron
Assembly Instructions – Read completely before starting assembly!
UNPACK
Unpack your airplane and examine the components. Check for damage of any kind. If you have damage,
please contact 3DHobbyShop to discuss.
WRINKLES
Your airplane was packed in plastic at the factory without any wrinkles in the covering. You may notice some
wrinkles now; more likely, you will notice a few in a day or two or the first time you take the plane out to the
flying field. These wrinkles are the result of wood shrinkage and/or expansion. Balsa wood changes size and
shape slightly as it is exposed to varying humidity in the air. This is a natural property of balsa wood. As your
airplane adjusts to the weather in your part of the world, wrinkles may appear and disappear. Wrinkles may be
removed with the gentle application of heat to the covering material on your airplane. The best tools to use are
a heat gun and covering iron. Apply the heat gently: the covering material will shrink as you apply the heat,
and this will remove the wrinkles. BE CAREFUL! Too much heat applied too quickly can damage the
covering, either by causing it to pull away from the wood at seams and corners or even by melting it. The
covering will shrink at low temperature with patient application of heat. Wrinkles in the covering DO NOT
affect flight performance. If you must shrink on a color-seam, use the iron and go slowly and carefully to
avoid any pulling or lifting at the seam.
Remove the canopy before attempting to use heat on your covering! The canopy is made of thermo-activated
plastic and WILL deform with the application of heat. Do not apply heat to the canopy.
PAINT
If you need to clean your airplane, we recommend using a damp towel. The paint used on the canopy and
cowl is not safe for all cleaners. In particular, DO NOT use alcohol on these parts, it will remove the paint.
Let’s get started!

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Install the wheels onto the axles and secure with the wheel collars, as shown.
(1.5mm Metric Allen Wrench/Driver)
Slide one wheel/axle assembly into a wheel pant as shown above. Be sure to orient the wheel pants to face
forward when landing gear is installed on the fuselage.
Tighten the locknut as shown to secure the assembly onto the gear leg. Repeat for other side.
(10mm Ny-Lock Nut)

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Install wood screws through gear into pants as shown.
(Tip: Drilling a 1/16” pilot hole will ease screw installation)
Attach the gear to the fuselage with 4mm screws, use loctite.
(3mm Metric Allen Wrench/Driver)
Install gear cover plate as shown, using thick CA, epoxy glue or clear silicone.

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Install tailwheel onto fuselage as shown, using QTY 2 screws and washers, with loctite.
Note: Rear blind nut hole is located 2.3” from aft vertical stabilizer.
(3/32 Allen Wrench/Driver)
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The 72” SC comes with pre-hinged and pre-gap-sealed wings/ailerons to save time during your build. The
airplane also comes with the hinges pre-glued to the rudder and elevator halves to further lessen the work. All
tail hinges are the same type and work the same way. The below instructions cover the use of polyurethane
and epoxy glue. If you are using a type of specific RC-hinge glue, follow the direction on the hinge glue bottle.
Quick HOW TO use PU ( Polyurethane) glue: (Using hinge installation as the example)
1) Apply Petroleum Jelly to center hinge joint using cotton swab.
2) Lightly ampen all holes with water. (More important in ry climates)
3) Squeeze in a small amount PU glue into all hinge holes.
4) Install hinges.
5) Wipe away glue as it expan s an foams using rubbing or enature alcohol. (Keep an eye on it an
wipe as require for the first 10-20 mins)
6) Allow to fully cure.
2.3”
Builders Tip:
Remove tail wheel assembly
set screws one at a time and
re-torque with loctite. This
will assist in providing a long
service life from your tail
wheel assembly .
1.5mm Metric Allen
Wrench/Driver
Tail Wheel
Rudder Hinging

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1) Apply Petroleum Jelly to center hinge joint using cotton swab.
2) Lightly dampen all holes with water. (More important in dry climates)
Note: Hinges are
factory glued to the
Rudder and
Elevator halves.

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3) Squeeze in a small amount PU glue into all hinge holes.
4) Install rudder. BE SURE to position tail-wheel tiller wire as shown.
5) Wipe away glue as it expands and foams using rubbing or denatured alcohol. (Keep an eye on it and wipe
as required for the first 10-20 mins)

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Remove covering from areas indicated above.
Recommended covering removal tools:
1) Hobby Knife
2) Soldering Iron (Pencil Tip)
3) Hot Knife
Covering Removal
FWD Anti-Rotation
Pin
AFT Anti-Rotation
Pin
Wing Tube
Wing Bolt
Aileron Servo
Extension

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Remove covering over the horizontal stabilizer opening. Insert horizontal stabilizer – DO NOT GLUE YET.
Temporarily install the wings onto the fuselage.
Use a ruler to center and align the stab side-to-side.
Horiz
ontal Stabilizer Installation
Builders Tip:
Use foam material
to hold the
horizontal stabilizer
in place while
aligning.

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Using a tape measure or long ruler, measure from the stab to the wing tips as shown in the diagram. Equalize
that measurement right and left to be sure your stab is aligned. Double check the side-to-site alignment before
proceeding.
When stabilizer is centered and aligned, drip Thin CA glue onto the stab-to-fuselage joint top and bottom.
NOTE: We do not remove any covering form the horizontal stabilizer. This keeps the stabilizer strong, and
thin CA makes an excellent joint to covering material. If your stab joint is not tight enough for thin CA glue, or if
you have to trim the opening to align the stab, you can use thick CA glue as well.

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Install joiner into left elevator half using Medium CA. Press firmly into place to assure proper alignment. Allow
to dry.
Apply glue to left side elevator hinge holes using same method as rudder installation.
Elevator Installation

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Slide elevator into position as seen above.
Insert hinges and temporarily hold elevator in place using a small piece if masking tape.

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Apply Medium CA to right elevator joiner slot. (Test fit before applying glue)
Apply glue and position right elevator in place.

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Make sure the elevator can swing 45 degrees up and down, minimum.
Apply masking tape strips to both elevator counterbalances, allow to dry.

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Temporarily assemble rudder and elevator control horns for your chosen power system as pictured above
without lock nuts.
To help obtain proper CG:
Electric power systems use Pull-Pull rudder set-up.
DLE30/Gas Engines use tail mounted Push-Pull rudder set-up.
Proceed to next page:
Rudder Control Horns for
Electric/Pull-Pull set-up.
(Short Mounting Tabs)
Rudder Control Horn for
Gas/DLE30 Push-Pull.
(Long Mounting Tabs)
Elevator Control
Horn
Rudder and Elevator Control Horn Installation

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Remove covering from just inside of marker perimeter.
Repeat above steps on LEFT elevator.

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Using plenty of epoxy or polyurethane glue, install the rudder and elevator horns as shown. (or on both sides of
the rudder) Use the ball-joint as shown, to hold the rudder horn in perfect alignment while the glue dries. Clean
up any excess glue with alcohol. Allow to dry.
Instructions for pull-pull rudder set-up starting on page: 20
Remove covering from Elevator (Left) and Rudder (Right) servo hole openings as seen above.
Elevator and Rudder Servo Installation

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Install rudder and elevator servos as shown. Note: Use 18-24” servo extension.
A NOTE about servo arms on the 72” SC. The Extra 330SC uses ball-links on its controls for precise control-
surface motion. It is extremely important to make sure that the ball-links have free motion throughout the servo
travel, and do not touch the servo arms. For example, when using Hitec servo arms, this is easily
accomplished by cutting or sanding away the corner of the arm as shown.
Rudder Elevator

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Install elevator and rudder pushrods using hardware pictured above.
NOTE: We recommen the use of one elevator servo with metal gears an at least 100 oz/in of torque.
However, enough har ware is supplie in your kit to install a secon elevator servo, in “mirror image”
fashion, on the other si e of the fuselage. Note that this may result in a tail-heavy con ition unless you
are using a large an heavy power system.
Install the rudder servo, servo arm, and ball links with locking nuts as shown.
Pull
-
Pull Rudder Cable Installation

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The rudder pull-pull cables are assembled as shown in the diagram. Crimp the crimp tubes firmly with pliers, an
use a rop of thin CA glue on each crimp tube after you are one crimping.
Crimp the servo end of the cables first. The cables cross once inside the fuselage to form an “X”.
Use a lock nut to tighten the ball link into the ru er control horn. Assemble the cables onto the pull-wire
en s, pulling the cables snug before crimping. We o not nee the cables to be extremely tight, just snug
an without sagging. Use the threa e pull-cable en s, screwing them into the ball joints as necessary, to
tighten the cables.