Goldwing RC Extreme Series User manual

GOLDWING RC
68in SBACH300 90E & 20CC
Instruction Manual
Two version to choice: 90 Electric or 20CC

Dear Customer,
Thanks for purchasing this newly designed aerobatic RC airplane. Goldwing RC
proudly presents 68in SBACH300 90E & 20CC, Extreme Series, which is a premium
product line of electric & gas RC airplanes designed for unlimited 3D performance.
The new 68in SBACH300 90E & 20CC adopts cutting edge aerodynamic features,
such as streamlined canopy, aileron counterbalance, removable side force generators
(SFGs) .The 68in SBACH300 is also loaded with high-end accessories including
genuine Oracover, CF landing gear, tail wheel assembly and control horns. KUZA
brand CNC Alloy Backplate Hollowed-out Spinner is included as bonus (limited
quantities) for 90E version. And KUZA new fuel Tank Assembly is included for
20CC version.
A QUICK WORD ABOUT SAFETY AND RADIO
CONTROL FLYING MODELS
With radio control aircraft, like any hobby or sport, there are certain risks. The operator of
these models is responsible for these risks. If misused or abused, you may cause serious bodily
injury and/or damage to property. With this in mind, you will want to be certain that you build
your model carefully and correctly. If you are not an experienced flier, have your work checked
and ask for help in learning to fly safely. This model aircraft is not a toy and must be operated
and flown in a safe manner at all times. Always perform a pre-flight check of the model
including all control surfaces, proper function of the radio gear, structure, radio range, and any
other area relating to the safe operation of this aircraft.
Models are not insurable but operators are. You can obtain coverage through membership in
the Academy of Model Aeronautics (AMA). For an AMA information package call
1-800-435-9262, ext. 292 or visit the AMA website at "www.modelaircraft.org".
By the act of using the final assembled model, the
purchaser/operator accepts all resulting liability.
ARF MODELS WARRANTY AND RETURN POLICY
We guarantee that the plane is in perfect condition at purchase. The warranty
will be voided after modifications and usages. If you have any questions or find any
issues, please contact the distributors in your area.

SPECIFICATIONS
Wing Span: 68"(1720mm)
Length: 65"(1650mm)
Wing Area: 946sq in(61sq .dm.)
Flying Weight: 8-8.8lbs(3600-4000g) Depending on battery size used
Engine:.70-.91（2C）.91-.110（4C）20-26cc gas
Electric Power：
Hacker A50-16S with 6S 3800-44000mAh 17x8 or 18x8 prop
DUSKY XM5060EA-470KV with 6S 3700-4400 mAh 17x8 prop
Or other 1500-1800Watt electric motor
ESC：80A
RADIO:4CH/4-5S
Features:
Improved axles (the material of the axle is stainless steel )
Flat nylon hinges for better flying strength
High-quality durable rubber wheels
Pre-hinged control surfaces
Larger aileron and elevator design. Up to 60 degrees of throw on all control
surfaces for excellent 3D aerobatic flying
Extra covering provided for small repairs and covered in genuine Ultracote /
Oracover
Canopy extended into cowl

KUZA RTF clear Fuel Tank with Alloy cap for 20CC version
Alloy Backplate Hollowed-out Electric Spinner included for 90E version
(Excellent cooling effect for brushless motor)
Side force generators

Quick release canopy.
Carbon Fiber accessories version：
Extra strength carbon fiber control horns
One piece air foiled carbon fiber landing gear

New Carbon fiber tail wheel assembly
Strengthened fuselage by carbon fiber rods
Carbon fiber wing tube
Scheme A white/ red / black

Scheme B white/ red / blue
Scheme C yellow/ red / black

Items Required to Complete This Model:
1500-1800Watt electric Motor or
20-26CC Gas
Appropriate propeller for your Motor
All required engine and exhaust
mounting hardware
Ignition battery and switch
One quality throttle servo and
appropriate servo arm
5-6Pcs high quality metal gear servos or
better for the ailerons and elevators
Appropriate servo arms for the above
Servo wire extensions. recommends five
12”
Two switches with charging jacks for
the Rx
Two high quality Rx batteries of
significant capacity to power your
choice of servos.
One Receiver of your choice
Shop Supplies/Tools
Covering Iron and heat gun
Assortment normal hobby tools such as
screwdrivers, hobby knife, drill and
drill bits, pliers, etc.
Thick and Thin CA adhesives
30 minute Epoxy
Isopropyl alcohol
Ruler or tape measure

Blue thread-lock or equivalent

Note: As with all kits, it’s a good idea to read all the instructions
and study the parts before you begin construction. Handle the parts
of this kit with care so you do not damage any of the structure or
covering. Inspect all the parts for any shipping damage and report
any issues to as soon as you can. Make sure you have a flat and
sturdy workbench and follow all safety advice for the tools and
adhesives you plan to use.
AIRCRAFT COVERING
1. With all ARFs, varying temperatures and storage delays can cause covering
material to loosen over time and transportation. recommends lightly going over all
the covering with a covering iron set at medium temperatures. Be sure to use a
soft cover over your iron so you do not scratch the covering surface. Be sure you
go over all seams and edges of the covering to assure it is secure to the airframe
and other covering. Be careful not to apply too much heat or you may cause
bubbles or damage to the covering. A heat gun may also be used along with a
soft cotton cloth to shrink and adhere the covering. Again, be extremely careful
when using a heat gun.
2. Be sure to seal any exposed wood with a thin coating of epoxy to prevent engine
oil from soaking in. This is especially important around the engine compartment
and servo openings with exposed areas.
3. Some modelers prefer to seal the hinge gaps using strips of appropriate covering
or clear trim tape. We have found this to be helpful with models intended for
higher speed flight or models with unusually large hinge gaps. aircraft utilize a
very tight double beveled hinge line and do not normally require this step.
Sealing the hinge gaps is therefore left as an option for the modeler.
Please verify the accessories before assemble:

Fiber glass servo horns: 4 single horns for ailerons and elevator. 1 dual horns for
rudder.
Sand the area of the horn that will be glued to help adhesion.
KUZA 260cc RTF clear Fuel Tank with Alloy cap for 20CC version
KUZA 75mm(3in) Alloy Backplate Hollowed-out Electric Spinner for 90E version

Pushrods: Two 2.5x60mm for aileron. Two 2.5x110mm for elevator & rudder
（Pull-push style）
Ball links: 8 for aileron and elevator.
Pull-pull setup for the rudder.
5 Servo extension safety connector clips

New Carbon fiber tail wheel assembly
Screews for landing gear: 4(4x20mm) Hexagon bolts & 4mm stainless steel
Self-locking nuts & washers
Screews & Washers for cowl: 4(2.5x12mm) Hexagon socket screws & 4 PTFE Washers
4 Hexagon socket screw wrenches

Motor mounting hardware set
Engine mount for nitro and gas engine
Wing Assembly
NOTE: There are pictures of different planes in this manual, however, this plane’s
wings is assembled the same way.
1. It is much easier to install the CFl horns before installing the wing. Locate the
CF aileron control horns, ball links, and associated bolts and nylon-insert lock nuts.
Use some fine sandpaper to roughen up the center areas of the control horn so that the

glue adheres better. Using a sharp hobby knife cut the covering away from the slots
in the rudder and trial fit the control horn.
2. Mix up some 30 minute epoxy and coat the inside of the slots and the center of
the control horn. Hint: a scrap piece of 1/16” ply, tooth pick, or old hobby blade
can be used to coat the inside of the aileron slots. Slide the control horns in place
and make sure they are centered perfectly by using a ruler to measure between the
pivot holes and the hinge line. Wipe any excess glue off with isopropyl alcohol and
paper towels. Install the ball links, bolts and nuts into the holes to help assure
alignment of both control horns while the glue cures. Set aside until cured.
3. The slots for the supplied hinges are pre cut. Locate the hinges and dry fit the
hinges and aileron into place and test the operation. The hinges should seat fully
into the slots so that the hinge line gap is minimal while still allowing full aileron
deflection.
4. Before gluing the hinges in you must first clean the hinges of any mold release
agent using isopropyl alcohol. also recommends scuffing up the plastic with light
sandpaper for maximum glue adhesion.
5. Mix up some 30 minute epoxy and using a toothpick or small wooden dowel coat
the inside of each hinge slot with epoxy. Also put a thin layer of epoxy on one side
of the hinges. Install this end into the slots of the rudder and make sure each hinge is
properly aligned at exactly 90 degrees to the hinge line.
6. Now coat the other end of the hinges with epoxy and install the aileron into the
trailing edge of the wing. Again, make sure the hinges remain in proper alignment.
Using paper towels and some isopropyl alcohol clean off any excess epoxy from the
hinges and surrounding areas.

7.Make sure the aileron is fully seated so that the hinge gap is minimal while still
allowing full deflection of the aileron. When satisfied, use some masking tape to
hold the aileron in place along the bottom and counterbalance. After the epoxy has
cured, remove the masking tape and check for proper operation. If the hinges are
dry some light oil carefully placed on each hinge will help greatly.
8. Cut the covering from the aileron servo slots from corner to corner and iron down
inside the openings. Connect servo wire extensions to your servos and secure the
connections with the supplied clips. Feed the servo wires into the wing and out the
root. The screw holes for servo mounting are laser pre-drilled, it is advisable to
apply some thin CA to strengthen them, Install the servos and screw firmly in place.

9. Use your radio to set the centers of each servo and then assemble and adjust the
length of each control rod. The servo arm should be as close to perpendicular to the
control rod as possible while the aileron is at neutral. Double check all screws, bolts
and nuts to assure proper installation and operation without binding.Once satisfied,
permanently attach the ball link to the servo arm with the supplied screw and nut.
10.Check the final radio operation of the ailerons and make sure there is no binding or
servo fighting of each other. Also check to make sure all linkage bolts and nuts are
secure.
(Below long ALU arm is not included)
Elevator Assembly
NOTE: There are pictures of different planes in this manual, however, this plane’s
elevators is assembled the same way.
1. Find the control horn slots on bottom side the elevators, use the method described
in 1.2-1.4 to install control horns for elevators.
2. Elevator horn slot is located on the left side of elevator. Remove covering over the
hole for horizontal stabilizer on fuselage. Removing covering on the central part of
horizontal stabilizer is recommended for better glue bonding. Insert the horizontal
stabilizer into fuselage, make sure it’s centered. Apply thin and gap-filling medium
CA to glue it in place.

3. Glue the hinges for the elevator with CA glue.
4. After installing the elevator, use supplied balsa pieces to fill gap behind the
elevator as shown below

5.Locate the slots for elevator servo, remove covering. Connect wire extension to
your servos before feeding the wire into fuselage. Install servo with screws supplied
by servo manufacturer.
6.Use your radio to set the servo center position and install the large control horn onto
the servo. Assemble the control rod and ball links and adjust the control linkage for
proper geometry. When satisfied, screw the ball link to the servo arm and control
horn. KUZA 1.5” aluminium CNC servo arm is recommended for elevator control,
the servo arm should be as close to perpendicular to the control rod as possible while
the elevator is at neutral. Double check all screws, bolts and nuts to assure proper
installation and operation without binding.

Tail Wheel Installation
1. Start tail wheel assembly installation.For safety, please remove all screws and
then re-assemble with thread locker.
2. Drill 2 mm holes on the bottom rear of the fuselage, secure the tailwheel bracket
with the provided screws. For best results, the pivot point of the assembly should
be over the hinge line of the rudder.
3. Drill a hole on the bottom of rudder, 130-145mm away for the hinge line. Secure
the tail wheel spring with provided self-threading screw.

NOTE: One spare tail wheel spring is included in the spare hardware pack.
Rudder Assembly
NOTE: There are pictures of different planes in this manual, however, this plane’s
rudder is assembled the same way.
1．Install the fiberglass control horns in the same way as you did the elevator horns.