Great Planes GPMA1412 User Manual

INSTRUCTION MANUAL

Wingspan: 77 in [1950mm]
Wing Area: 1155 sq in [74.5 dm2]
Weight: 13 – 15 lb [5900 – 6800 g]
Wing Loading: 26 – 30 oz/sq ft [79 – 91 g/dm2]
Length: 70 in [1780mm]
Radio: 4+ channel, 6 to 7 servos
Engine / Motor: 1.6 – 1.8 cu in [26 – 30cc] two-stroke,

1.8 – 2.1 cu in [30 – 34cc] four-stroke,

1.9 – 2.6 cu in [32 – 43cc] gas engine,
63-62-250 RimFire out-runner motor

Great Planes
This warranty does not cover an y component parts damaged by use or modifi cation. In no case shall Great Planes’ liability exceed the
original cost of the purchased kit. Further, Great Planes reserves the right to change or modify this warranty without notice.

In that Great Planes has no control over the fi nal assembly or material used for fi nal assembly, no liability shall be assumed nor accepted
for any damage resulting from the use by the user of the fi nal user-assembled product. By the act of using the user-assembled product,
the user accepts all resulting liability.

If the buyer is not prepared to accept the liability associated with the use of this product, the b uy er is advised to return th is kit
immediately in new and unused condition to the place of purchase.

To make a warranty claim send the defective part or item to Hobby Services at the address below:

Include a letter stating your name, return shipping address, as much contact information as possible (daytime telephone number, fax
number, e-mail address), a detailed description of the problem and a photocopy of the purchase receipt. Upon receipt of the package
the problem will be evaluated as quickly as possible.

®

Model Manufacturing Co. guarantees this kit to be free from def ects in both material and workmanship at the date of purchase.

WARRANTY

Hobby Services

3002 N. Apollo Dr., Suite 1

Champaign, IL 61822 USA

READ THROUGH THIS MANUAL BEFORE
STARTING CONSTRUCTION. IT CONTAINS
IMPORTANT INSTRUCTIONS AND WARNINGS
CONCERNING THE ASSEMBLY AND USE OF
THIS MODEL.

Entire Contents © Copyright 2007 GPMZ1412 for GPMA1412 V1.0

Champaign, Illinois

[phone], Ext 5

[e-mail]

TABLE OF CONTENTS

INTRODUCTION ....................................................................2

AMA .......................................................................................2

IMAA ......................................................................................3

SAFETY PRECAUTIONS ......................................................3

DECISIONS YOU MUST MAKE .............................................3

Building Stand ...................................................................3

Radio Equipment ..............................................................4

Engine Recommendations ................................................4

Glow Engine Requirements ..............................................4

Brushless Motor Requirements ........................................5

Gas Engine Requirements ................................................5

Propeller ...........................................................................5

ADDITIONAL ITEMS REQUIRED .........................................6

Adhesives & Building Supplies .........................................6

Optional Supplies & Tools .................................................6

IMPORTANT BUILDING NOTES ...........................................6

ORDERING REPLACEMENT PARTS ...................................7

COMMON ABBREVIATIONS ................................................7

METRIC CONVERSIONS ......................................................7

KIT INSPECTION ...................................................................8

KIT CONTENTS .....................................................................8

PREPARATIONS ....................................................................9

ASSEMBLE THE WING .........................................................9

Install the Ailerons ............................................................9

Install the Aileron Servos & Pushrods .............................10

Join the Wing Panels .......................................................11

ASSEMBLE THE TAIL SECTION & LANDING GEAR .........13

Install the Stab, Elevators & Rudder ................................13

Install the Tail Gear Assembly ..........................................15

Install the Elevator Servos & Pushrods ............................16

Assemble and Install the Main Gear ................................17

GLOW ENGINE INSTALLATION ..........................................18

Mount the Engine .............................................................18

Install the Fuel Tank (Glow Engine) .................................19

Install the Throttle Servo (Glow Engine) ..........................20

GAS ENGINE INSTALLATION .............................................22

Mount the Engine .............................................................22

Install the Fuel Tank (Gas Engine) ...................................23

Install the Ignition Equipment (Gas Engine) ....................25

Install the Throttle Servo (Gas Engine) ............................26

BRUSHLESS MOTOR INSTALLATION ................................28

Mount the Motor ...............................................................28

Install the Battery & ESC Trays ........................................29

INSTALL THE RUDDER SERVOS ........................................31

Install the Rudder Servos in the Forward Position ...........32

Install the Rudder Servos in the Aft Position ....................34

FINISH THE MODEL .............................................................35

Install the Radio System ..................................................35

Install the Cowl.................................................................37

Install the Canopy Hatch ..................................................39

Install the Belly Pan, Prop & Spinner ...............................40

Apply the Decals ..............................................................41

GET THE MODEL READY T O FL Y .......................................41

Battery Precautions .........................................................41

Check the Control Directions ...........................................42

Set the Control Throws ....................................................42

Balance the Model (C.G.) ................................................43

Balance the Model Laterally.............................................43

PREFLIGHT ..........................................................................44

Identify Your Model ...........................................................44

Charge the Batteries ........................................................44

Balance the Propellers .....................................................44

Ground Check ..................................................................44

Range Check ...................................................................44

ENGINE SAFETY PRECAUTIONS .......................................44

MOTOR SAFETY PRECAUTIONS .......................................45

AMA SAFETY CODE (excerpts) ..........................................45

IMAA SAFETY CODE (excerpts) .........................................46

CHECK LIST .........................................................................47

FLYING ..................................................................................48

Fuel Mixture Adjustments ................................................48

Takeoff .............................................................................48

Flight ................................................................................48

Landing ............................................................................48

3D FLYING ............................................................................49

ENGINE/MOTOR MOUNTING TEMPLATES ........................51

INTRODUCTION

For the latest technical updates or manual corrections to
the Sukhoi SU-31 1.60 ARF visit the Great Planes web site
at www.greatplanes.com. Open the “Airplanes” link, then
select the Sukhoi SU-31 1.60 ARF. If there is new technical
information or changes to this model a “tech notice” box will
appear in the upper left corner of the page.

AMA

We urge you to join the AMA (Academy of Model Aeronautics)
and a local R/C club. The AMA is the gov erning body of model
aviation and membership is required to fl y at AMA clubs.
Though joining the AMA provides many benefi ts, one of the
primary reasons to join is liability protection. Coverage is not
limited to fl ying at contests or on the club fi eld. It e v en applies
to fl ying at public demonstrations and air shows. Failure to
comply with the Safety Code (excerpts printed in the back of
the manual) may endanger insurance coverage. Additionally,
training programs and instructors are available at AMA club
sites to help you get started the right way. There are over
2,500 AMA chartered clubs across the countr y. Contact the
AMA at the address or toll-free phone number below.

Academy of Model Aeronautics

5151 East Memorial Drive

Muncie, IN 47302-9252

Tele. [phone]

Fax [phone]

Or via the Internet at:

http://www.modelaircraft.org

IMPORTANT!! Two of the most important things you can do

to preserve the radio controlled aircraft hobby are to avoid
fl ying near full-scale aircraft and avoid fl ying near or over
groups of people.

2

IMAA

The Great Planes Sukhoi SU-31 1.60 ARF is an excellent
sport-scale model and is eligible to fl y in IMAA events. The
IMAA (International Miniature Aircraft Association) is an
organization that promotes non-competitive fl ying of giant­scale models. If you plan to attend an IMAA event, obtain
a copy of the IMAA Safety Code by contacting the IMAA at
the address or telephone number below, or by logging on to
their web site.

IMAA

205 S. Hilldale Road

Salina, KS 67401

[phone]

www.fl y-imaa.org/imaa/sanction.html.

PROTECT YOUR MODEL, Y OURSELF

& OTHERS....FOLLOW THESE

IMPORTANT SAFETY PRECAUTIONS

8. While this kit has been fl ight tested to exceed normal use,
if the plane will be used for extremely high-stress fl ying, such
as racing, or if an engine larger than one in the recommended
range is used, the modeler is responsible for taking steps to
reinforce the high-stress points and/or substituting hardware
more suitable for the increased stress.

9. WARNING: The cowl and wheel pants included in this kit
are made of fi berglass, the fi bers of which may cause eye,
skin and respiratory tract irritation. Never blow into a part
(wheel pant, cowl) to remove fi berglass dust, as the dust
will blow back into your eyes. Always wear safety goggles, a
particle mask and rubber gloves when grinding, drilling and
sanding fi berglass parts. Vacuum the parts and the work
area thoroughly after working with fi berglass parts.

We, as the kit manuf acturer , pro vide you with a top quality,
thoroughly tested kit and instructions, but ultimately the
quality and fl yability of your fi nished model depends
on how you build it; therefore, we cannot in any way
guarantee the performance of your completed model,
and no representations are expressed or implied as to the
performance or safety of your completed model.

1. Your Sukhoi SU-31 1.60 ARF should not be considered
a toy but rather a sophisticated, working model that
functions very much like a full-size airplane. Because of its
performance capabilities, the Sukhoi, if not assembled and
operated correctly, could possibly cause injury to yourself or
spectators and damage to property.

2. Y ou must assemble the model accor ding to the instructions.
Do not alter or modify the model, as doing so may result in an
unsafe or unfl yab le model. In a few cases the instructions may
differ slightly from the photos. In those instances the written
instructions should be considered as correct.

3. You must take time to build straight, true and strong.

4. You must use an R/C radio system that is in fi rst-class
condition, and a correctly sized engine and components
(fuel tank, wheels, etc.) throughout the building process.

5. You must correctly install all R/C and other components
so that the model operates correctly on the ground and in
the air.

6. You must check the operation of the model before every
fl ight to insure that all equipment is operating and that the
model has remained structurally sound. Be sure to check
clevises or other connectors often and replace them if they
show any signs of wear or fatigue.

Remember: Take your time and follow the instructions to
end up with a well-built model that is straight and true.

DECISIONS YOU MUST MAKE

This is a partial list of items required to fi nish the Sukhoi SU-31

1.60 ARF that may require planning or decision making before
starting to build. Order numbers are provided in parentheses.

Building Stand

7. If you are not an experienced pilot or have not fl own
this type of model before, we recommend that you get the
assistance of an experienced pilot in your R/C club for
your fi rst fl ights. If you’re not a member of a club, your local
hobby shop has information about clubs in your area whose
membership includes experienced pilots.

A building stand or cradle comes in very handy during the
build. We use the Robart Super Stand II (ROBP1402) for
most of our projects in R&D, and it can be seen in pictures
throughout this manual.

3

Radio Equipment

The Sukhoi SU-31 1.60 ARF requires a minimum 4-channel
radio system with a standard receiver.

Since the Sukhoi SU-31 1.60 ARF is a large model capable
of extreme aerobatics, standard servos should not be used to
operate the control surfaces. Servos with a minimum torque
rating of 98 oz-in [7.1kg-cm] are required except for the
throttle servo which may be operated by a standard servo.
The servos shown in this manual that are used for all of the
control surfaces are Futaba® S3305 servos. A minimum of
six high-torque servos and one standard servo (used for
throttle when installing a glow or gas engine) are needed to
complete the Sukhoi SU-31 1.60 ARF.

❏ Futaba S3305 Servo High-Torque Standard w/Metal

Gears (FUMT0045)

❏ Futaba S3003 Servo Standard (FUTM0031)

Because of heavy loads on the control surfaces, heavy duty
servo arms should be used on all of the control surface
servos. The throttle servo can use the servo arm supplied
with the servo. This manual shows the installation of Great
Planes 2" [51mm] aluminum single-sided servo arms. If the
rudder servos will be installed in the aft location, six arms will
be needed. If the rudder servos are installed in the forward
position, only four arms will be needed. See the building
instructions for details on the rudder servo positions.

Note: The list of servo e xtensions and Y-harnesses is based
on the equipment we used to setup the Sukhoi SU-31 1.60
ARF as detailed in the manual. The length or quantity may
vary depending on the actual equipment being used, radio
locations, etc.

A battery pack with a minimum of 1500mAh capacity should
also be used. When fl ying large models such as the Sukhoi
SU-31 1.60 ARF, ALW AYS check the battery condition before
each fl ight. If you are installing a gas engine with an electronic
ignition module, a separate battery pack (the EI pack does not
need to be high capacity) will also be required in addition to
the battery pack used to power the receiver and servos.

❏ Hobbico HydriMax™ 4.8V 3600mAh NiMH Flat Rx

U (HCAM6333)

A heavy duty receiver switch and charge jack will also
be needed:

❏ Futaba Heavy Duty Switch Harness w/Charge

Cord (FUTM4385)

❏ Ernst Charge Receptacle Futaba J FM (ERNM3001)

If installing a gas engine, an additional switch (standar d
size) and charge jack will also be needed:

❏ Futaba SWH13 Switch Harness & Charge Cord Mini

J (FUTM4370)

Engine Recommendations

❏ Great Planes Large Scale 2" Single Side Servo

Arm (GPMM1110)

The following servo extensions and Y-harnesses were
also used to build the Sukhoi SU-31 1.60 ARF as shown in
the manual:

❏ (2) 36" [914mm] servo extensions for elevator servos

(HCAM2726 for Futaba J-connector)

❏ (2) 36" [914mm] servo extensions for rudder servos

when installed in the optional aft location (HCAM2726
for Futaba J-connector)

❏ (2) 24" [610mm] servo extensions for aileron servos

(HCAM2721 for Futaba J-connector)

❏ (2) 6" [152mm] servo extensions for rudder servos when

installed in the forward location (HCAM2701 for Futaba
J-connector)

❏ (1) 6" [152mm] servo extension for receiver battery pack

(HCAM2701 for Futaba J-connector)

❏ (1) 12" [305mm] servo extension for brushless ESC if

applicable (HCAM2711 for Futaba J-connector)

If using a radio system that does not support mixing
of the elevator, rudder, and ailer on servos, the following
items will be required:

The recommended engine size range for the Sukhoi SU-31

1.60 ARF is 1.6 to 1.8 cu in [26 to 30cc] two-stroke glow engine,

1.8 to 2.1 cu in [30–34cc] four-stroke glow engine , or 1.9 to 2.6
cu in [32 to 43cc] gasoline engine. We recommend either the
O.S.® 1.60 FX glow engine (OSMG0661) or the Fuji-Imvac™
BT-43 EI-2 43cc gasoline engine (FJIG0144). The Sukhoi
SU-31 1.60 ARF is also designed to accept a Great Planes
63-62-250kV RimFire™ out-runner brushless motor. All
of these power systems will allow the Sukhoi SU-31 1.60
ARF to perform the 3D maneuvers it was designed for and
installations are covered in this manual.

Glow Engine Requirements

The only required accessory needed to install a glow engine
is a Pitts style muffl er. If using the O.S. 1.60 FX glow engine,
the order number for a Pitts style muffl er is Bisson O.S. 1.60
FX Pitts Muffl er (BISG4116).

❏ (2) Hobbico

servos (HCAM2751 for Futaba J-connector)

®

Pro™ HD Y-Harnesses for rudder and aileron

❏ (1) Reversing Y -Harness for ele vator servos (EMOM0027

for Futaba J-connector)

4

Brushless Motor Requirements

If installing the Great Planes 63-62-250kV RimFire out­runner brushless motor (GPMG4795), you will also need
to purchase:

❏ Great Planes Brushless Motor Mount Extra

Large (GPMG1265)

❏ Great Planes SS100 100A Brushless ESC (GPMM1870)
❏ 9- to 12-cells (3 or 4 11.1V packs) 3200mAh

LiPo Batteries:

❏ Great Planes LiPo 11.1V 3200mAh 20C Discharge

w/Balance (GPMP0623)

❏ Great Planes Series Deans U 2 to 1 Adapter (GPMM3143)
❏ (2) Great Planes Velcro

1" x 6" (GPMQ4480)

®

Hook & Loop material

❏ LiPo compatible battery charger such as the Great Planes

PolyCharge4 ™ DC only 4 output LiPo charger (GPMM3015)

❏ Great Planes ElectriFly Equinox

Balancer (GPMM3160)

™

LiPo Cell

❏ Great Planes Charge Lead Banana Plugs/Deans Male

Ultra (GPMM3148)
The included spinner adapter nut is designed specifi cally to

fi t into the tapered prop nut used on the O.S. 1.60 FX glow
engine. Because of this, an adapter nut must be purchased
to work with the RimFire prop adapter. You can use Tru-Turn™
Adapter Kit O.S. 1.08 (TRUQ3065) or Dave Brown X-Long
Adapter Nut 3/8-24 (DAVQ6324). Both of these adapter nuts
require a 10-32 spinner bolt that will need to be purchased
separately. The length of the bolt will depend on the adapter
nut being used. We suggest purchasing a 10-32 x 2-3/4"
[70mm] spinner bolt and cutting it to the necessary length.
Another option is to purchase the nut and prop washer
set for the O.S. 1.60 FX engine, O.S. lock nut set 1.60 FX
(OSMG6688). Using the O.S. prop nut will allow you to
also use the adapter nut included with the kit as well as the
included 5mm prop bolt.

Note: The total recommended voltage for the LiPo battery
pack confi guration is 33.3V to 44.4V. This can be done in
combinations of battery packs ranging in voltage. Be sure
that the capacity (mAh) of all packs used are the same value
(example: do not mix 3200mAh packs with 5000mAh pac ks).
The battery pack combination should be connected together
using the recommended series adapter. The actual quantity
of adapters needed depends on the number of packs being
used. Each adapter will connect tw o packs together in series.
If three 11.1V packs are joined to make 33.3V, two series
adapters will be needed (one series adapter will join two

11.1V packs together to make 22.2V, and the second adapter
will combine that 22.2V with the remaining 11.1V pack for a
total of 33.3V). If four 11.1V packs are combined for a total
of 44.4V, then three ser ies adapters will be needed. Other
voltage combinations may require more or fewer adapters.

the battery tray, and securing the ESC to the ESC tray.
One package of Great Planes hook and loop contains
12" [305mm] of material. We suggest purchasing at least
two packages.

The recommended PolyCharge4 will charge up to four LiPo
packs simultaneously. A set of charge leads is required for
each pack that you plan to charge simultaneously. We suggest
purchasing a set of charge leads for each battery pack used
in the power system. The PolyCharge4 is a DC-only charger,
so a suitable DC power source will also be required.

Gas Engine Requirements

The fuel tank included with this kit is suitable for use with
glow fuel. However, if using a gas engine, the fuel tank
must be converted to work with gasoline. This can be
done by purchasing a Sullivan #484 Gasoline/Diesel fuel
tank conversion kit (SULQ2684), two packages of Du-Bro
#813 1/8" [3.2mm] I.D. fuel line barbs (DUBQ0670) and at
least 3' [914mm] of gasoline compatible fuel tubing (such
as Tygon). Without the fuel line barbs, some types of gas­compatible fuel line may slip off the metal fuel tubes. If the
Sullivan conv ersion kit is not a vailable, the Du-Bro #400 gas
conversion stopper (DUBQ0675) and one package of K&S
1/8" [3.2mm] soft brass tubing (K+SR5127) could also be
used to make the conversion.

Also, the hardware needed to mount a gas engine to the
fi rewall is not included with the kit. The hardware that is
detailed in the building instructions of this manual for m ounting
the Fuji-Imvac BT-43 EI-2 engine includes four 10-32 x 1-1/4"
[32mm] SHCS, four #10 fl at washers, four #10 lock w ashers
(split washers), and four 10-32 blind nuts. This hardware
can be purchased at a hardware store, home center , or y our
hobby supplier.

Propeller

Choose the propeller that is appropriate for the power system
you are using. If installing the Great Planes 63-62-250kV
RimFire out-runner motor, the propeller choice will depend
on the battery voltage being used. A 9-cell (33.3V) pack
will require a 20" x 10" prop (APCQ2200). A 12-cell (44.4V)
pack will require a 18" x 8" prop (APCQ3010). If installing an
O.S. 1.60 FX glow engine, we recommend using a 18" x 6"
W prop (APCQ1806). If installing the Fuji-Imvac BT-43 EI-2
engine, we recommend using a 20" x 8" prop (APCQ2080).

The recommended hook and loop material is used to join
the individual battery packs together, securing them onto

5

ADDITIONAL ITEMS REQUIRED

IMPORTANT BUILDING NOTES

Adhesives & Building Supplies

This is the list of Adhesives and Building Supplies that are
required to fi nish the Sukhoi SU-31 1.60 ARF.

❏ Pro

™

30-minute epoxy (GPMR6047)

❏ 1/2 oz. [15g] Thin Pro CA+ (GPMR6001)
❏ 1/2 oz. [15g] Medium Pro CA+ (GPMR6007)
❏ Hobbico 60 watt soldering iron (HCAR0776)

or

❏ Hobby Heat

™

Micro Torch II (HCAR0755)

❏ Silver solder w/fl ux (STAR2000)
❏ Petroleum jelly (Vaseline

®

)

❏ 3' [900mm] Standard silicone fuel tubing (GPMQ4131)

(for glow engine only)

❏ R/C foam rubber (1/4" [6mm] – HCAQ1000)
❏ Drill bits: 1/16" [1.6mm], 3/32" [2.4mm], 7/64" [2.8mm],

9/64" [3.6mm] 7/32" [5.6mm], 3/16" [4.8mm]

❏ Denatured alcohol (for epoxy clean up)
❏ 8-32 Tap and drill set (GPMR8103) (for glow engine only)
❏ Tap handle (GPMR8120) (for glow engine only)
❏ #1 Hobby knife (HCAR0105)
❏ #11 Blades (5-pack, HCAR0211)
❏ Masking tape (TOPR8018)
❏ T-pins (HCAR5150)
❏ Great Planes Pro Threadlocker (GPMR6060)
❏ Dead Center

™

Engine Mount Hole Locator (GPMR8130)

❏ Panel Line Pen (TOPQ2510)
❏ 1" [25mm] Double-sided foam mounting tape (GPMQ4442)
❏ 220-grit Sandpaper (GPMR6185)
❏ 21st Century

®

sealing iron (COVR2700)

❏ 21st Century iron cover (COVR2702)

Optional Supplies & Tools

Here is a list of optional tools mentioned in the manual and other
items that will help you build the Sukhoi SU-31 1.60 ARF.

❏ Fuel fi ller valve for glow fuel (GPMQ4160)
❏ Fuel fi ller valve for gasoline (GPMQ4161)
❏ 1/2 oz. [15g] Thick Pro CA- (GPMR6013)
❏ Stick-on segmented lead weights (GPMQ4485)
❏ Epoxy brushes (6, GPMR8060)
❏ Mixing sticks (50, GPMR8055)
❏ Mixing cups (GPMR8056)
❏ Builder’s Triangle Set (HCAR0480)
❏ 36" Metal ruler (HCAR0475)
❏ Pliers with wire cutter (HCAR0630)
❏ Hobbico Duster
❏ Rotary tool such as Dremel

™

can of compressed air (HCAR5500)

®

❏ Rotary tool reinforced cut-off wheel (GPMR8200)
❏ Servo horn drill (HCAR0698)
❏ CG Machine

™

(GPMR2400)

❏ #64 Rubber bands (1/4 lb [113g] box, HCAQ2020)

• There are two types of screws used in this kit:

• Self-tapping screws are designated by a number and
a length. For example #6 x 3/4" [19mm]

This is a number six screw that is 3/4" [19mm] long.

• Machine screws are designated by a number, threads
per inch, and a length. For example 4-40 x 3/4" [19mm]

This is a number four screw that is 3/4" [19mm] long

with forty threads per inch.

• When you see the term test fi t in the instructions,
it means that you should fi rst position the part on the
assembly without using any glue, then slightly modify
or custom fi t the part as necessary for the best fi t.

• Whenever the term glue is written you should rely upon
your experience to decide what type of glue to use. When
a specifi c type of adhesive works best for that step, the
instructions will make a recommendation.

• Whenever just epoxy is specifi ed you may use either
30-minute (or 45-minute) epoxy or 6-minute epo xy. When
30-minute epoxy is specifi ed it is highly recommended
that you use only 30-minute (or 45-minute) epoxy,
because you will need the working time and/or the
additional strength.

• Photos and sketches are placed before the step they
refer to. Frequently you can study photos in following
steps to get another view of the same parts.

• The Sukhoi SU-31 1.60 ARF is factory-covered with high
quality heat-shrink fi lm. Should repairs ever be required,
this fi lm can be patched with Top Flite® MonoKote®
purchased separately. MonoKote is packaged in six-foot
rolls, but some hobby shops also sell it by the foot. If
only a small piece of MonoKote is needed for a minor
patch, perhaps a fellow modeler would give you some.
MonoKote is applied with a model airplane covering iron,
but in an emergency a regular iron could be used. A roll
of MonoKote includes full instructions for application.
Following are the colors used on this model and order
numbers for six foot rolls.

True Red – TOPQ0227
Metallic Blue – TOPQ0402
Cub Yellow – TOPQ0220
White – TOPQ0204
Metallic Charcoal – TOPQ0407

6

• The stabilizer and wing incidences and engine thrust
angles have been factory-built into this model. However,
some technically-minded modelers may wish to check
these measurements anyway. To view this information
visit the web site at www.greatplanes.com and click on
“Technical Data.” Due to man ufacturing tolerances which
will have little or no effect on the way your model will fl y,
please expect slight deviations between your model and
the published values.

ORDERING REPLACEMENT PARTS

Replacement parts for the Great Planes Sukhoi SU-31

1.60 ARF are available using the order numbers in the

Replacement Parts List that follows. The fastest, most
economical service can be provided by your hobby dealer or
mail-order company.

COMMON ABBREVIATIONS

Fuse = Fuselage
Stab = Horizontal Stabilizer
Fin = Vertical Fin
LE = Leading Edge
TE = Trailing Edge
LG = Landing Gear
Ply = Plywood
" = Inches
mm = Millimeters
SHCS = Socket Head Cap Screw
ESC = Electronic Speed Control

METRIC CONVERSIONS

To locate a hobby dealer, visit the Hobbico® web site at
www.hobbico.com. Choose “Where to Buy” at the
bottom of the menu on the left side of the page. Follow the
instructions provided on the page to locate a U.S., Canadian
or International dealer.

Parts may also be ordered directly from Hobby Services by
calling [phone], or via facsimile at [phone],
but full retail prices and shipping and handling charges will
apply. Illinois and Nevada residents will also be charged
sales tax. If ordering via fax, include a Visa® or MasterCard®
number and expiration date for payment.
Mail parts orders and payments by personal check to:

Hobby Services

3002 N. Apollo Drive, Suite 1

Champaign, IL 61822

Be certain to specify the order number exactly as listed in
the Replacement Parts List. Payment is by credit card or
personal check only; no C.O.D.

If additional assistance is required for any reason contact Product
Support by e-mail at [e-mail],
or by telephone at [phone].

1" = 25.4mm (conversion factor)

1/64" = .4mm
1/32" = .8mm
1/16" = 1.6mm
3/32" = 2.4mm
1/8" = 3.2mm
5/32" = 4.0mm
3/16" = 4.8mm
1/4" = 6.4mm
3/8" = 9.5mm
1/2" = 12.7mm
5/8" = 15.9mm

3/4" = 19.0mm
1" = 25.4mm
2" = 50.8mm
3" = 76.2mm
6" = 152.4mm
12" = 304.8mm
18" = 457.2mm
21" = 533.4mm
24" = 609.6mm
30" = 762.0mm
36" = 914.4mm

Replacement Parts List

GPMA3070 Wing Kit
GPMA3071 Fuse Kit
GPMA3072 Tail Set
GPMA3073 Cowl
GPMA3074 Canopy
GPMA3075 Landing Gear
GPMA3076 Wheel Pants
GPMA3077 Decals
GPMA3078 Spinner

7

KIT INSPECTION

KIT INSPECTION

KIT CONTENTS

Before starting to build, take an inventory of this kit to make sure it is complete and inspect the par ts to make sure they
are of acceptable quality. If any parts are missing or are not of acceptable quality, or if you need assistance with assembly,
contact Product Support. When reporting defective or missing parts, use the part names exactly as they are written in
the Kit Contents list.

Great Planes Product Support:

3002 N Apollo Drive, Suite 1

Champaign, IL 61822

Telephone: [phone], ext. 5

Fax: [phone]

E-mail: [e-mail]

KIT CONTENTS

1

4

6

5

7

8

9

15

2

3

11

10

11

12

16

13

14

1 Cowl
2 Canopy
3 Fuselage
4 Spinner
5 Engine Mount
6 Fuel Tank
7 Main Landing Gear (2)
8 Main Wheels (2)
9 Wheel Pants (L&R)
10 Horizontal Stabilizer
11 Elevators (L&R)

Kit Contents

12 Wing Joiner (4 pcs.)
13 Rudder
14 Tail Gear Assembly
15 Left Wing w/Aileron
16 Right Wing w/Aileron

8

8

PREPARATIONS

❏ 1. If you have not done so already , remo ve the major parts

of the kit from the box and inspect for damage. If any parts
are damaged or missing, contact Product Support at the
address or telephone number listed in the “Kit Inspection”
section on page 8.

❏ 2. Carefully remove the tape and separate all the control

surfaces. Use a covering iron with a covering sock on medium/
high heat to tighten the covering if necessary . Apply pressure o ver
sheeted areas to thoroughly bond the cov ering to the wood.

❏ ❏ 2. Apply a small amount of petroleum jelly or something

similar to the center of each hinge to prevent epo xy from sticking
to the joints and keeping the hinge from operating smoothly.

Read all of Step 3 before proceeding.

ASSEMBLE THE WING

Install the Ailerons

Do the left wing fi rst so your work matches the photos
the fi rst time through. You can do one wing at a time, or
work on them together.

❏ ❏ 1. Test fi t the included hinge points into the pre-drilled

pockets in the wing panel and aileron. The hinge points
should seat into the hinge pockets all the way to the metal
pin in order to minimize the gap between the aileron and
wing. If necessary, use a hobby knife to enlarge the surface
of the hinge pockets until the proper fi t is achieved. Test fi t
the aileron to the wing. The hinge gap between the aileron
and wing should only be wide enough to allow a small line of
light through. Excessive gap will decrease the effectiveness
of the ailerons.

❏ ❏ 3. Mix up a batch of 30-minute epoxy. Using a toothpick

or wood scrap, apply epoxy to the inside of each hinge point
pocket. The pockets are drilled through to the open cavity in
the wing and aileron, so be careful that you do not apply too
much to the walls of the pockets as it will simply drip into the
wing. Apply a light coat of epo xy to one end of all the hinges f or
one wing panel. Insert the hinge points into the pockets in the
wing panel, wiping away excess epoxy with denatured alcohol
as necessary. Be sure the hinges are inserted in the correct
orientation so that the direction of the hinge pin is inline with the
TE of the wing. Apply epo xy to the other ends of the hinges and
slide the aileron into position over the hinges. Use masking tape
to hold the aileron in place while the epoxy cures.

❏ 4. Repeat these steps for the right wing panel.

9

Install the Ailerons Servos & Pushrods

❏ 1. Installing the servos in the wing will require the use

of one 24" [610mm] servo extension for each aileron servo.
One Y-harness connector is required and is used to allow the
aileron servos to plug into one slot in your receiver. You may
have a computer radio that allo ws you to plug the servos into
separate slots and then mix them together through the radio
transmitter. If you choose to mix them together with the radio
rather than a Y-harness, refer to the manual included with
your particular model radio system.

❏ ❏ 2. Attach the 24" [610mm] servo extension to the

aileron servo and secure it with a piece of the included large
heat-shrink tubing. Only 1-1/2" [38mm] of heat-shrink tubing
is required for each connector.

❏ ❏ 5. Temporarily position the aileron servo into the servo bay.

Drill a 1/16" [1.6mm] hole through the four mounting holes of the
servo, drilling through the plywood mounting plate in the wing.
Install and remove a servo mounting screw into each of the four
holes. Apply a drop of thin CA into the holes to harden the wood.
After the glue has cured, install the servo into the opening using
the hardware that came with your servo. Center the servo with
your radio system and install a servo arm as shown.

The next three images are used for steps 6 and 7

❏ ❏ 3. Cut the covering 1/8" [3mm] inside the opening in

the underside of the wing for the aileron servo. Use a tr im
iron to seal the covering to the inner edges of the opening.

❏ ❏ 4. Tie the string from inside the opening for the aileron

servo to the end of the servo extension. Remove the tape
holding the other end of the string to the wing root rib and
pull the servo wire and extension through the wing.

❏ ❏ 6. The aileron has a plywood plate for mounting the control

horn. You can see the outline of it underneath the covering by

10

looking at the aileron at a shallow angle. If you cannot see it, the
plate is approximately 1-5/8" [41mm] wide and will be inline with
the servo arm. Use a T-pin to lightly puncture the covering to be
sure you are over the plyw ood plate.

❏ ❏ 7. Place a hea vy duty nylon control horn on the aileron,

positioning it as shown in the sketch inline with the outer hole
of the servo arm. Mark the location for the screw holes. Drill
through the marks you made with a 3/32" [2.4mm] drill bit. (Be
sure you are drilling into the plywood plate mounted in the
bottom of the aileron. Drill through the plate only. Do not drill
all the way through the aileron!). Using a #4 x 5/8" [16mm]
sheet metal screw , install and then remov e a screw into each
of the holes. Harden the holes with thin CA. Install the control
horn with four #4 x 5/8" [16mm] sheet metal screws.

❏ ❏ 8. Locate a .095" x 6" [2.4mm x 152mm] pushrod wire

threaded on one end. Screw a 4-40 nut, a silicone clevis
retainer and a threaded metal clevis onto the threaded end
of the wire 20 turns. Tighten the nut against the clevis using
threadlocking compound and then install the clevis on the
outer hole of the aileron control horn.

❏ ❏ 9. Be sure the aileron servo is centered and the servo

arm is parallel to the hinge line. Install a 4-40 metal solder
clevis onto the outer hole in the servo arm. Center the
servo arm parallel with the aileron hinge line and center the
aileron. Using the solder cle vis as a guide, mark where to cut
the pushrod wire. Remove the pushrod and clevis from the
control horn and the solder clevis from the servo arm. Install
another silicone clevis retainer onto the wire and solder the
clevis to the pushrod using the “Expert Tip” that follows.

4. Put a couple of drops of oil onto a rag and wipe the joint.
This will prevent rust from forming on the joint.

❏ ❏ 10. Install the pushrod and cle vises to the outer hole in

the servo arm and the outer hole in the control horn. Adjust the
linkage until the aileron and the servo arm are both centered.
Then, tighten the nut against the clevis with threadlocking
compound. Slide the two silicone clevis retainers to the end
of each clevis.

❏ 11. Repeat these steps for the right wing panel.

Join the Wing Panels

HOW T O SOLDER THE CLEVIS

TO THE PUSHROD

1. Where the pushrod will make contact with the solder
clevis, roughen the wire with 220-grit sandpaper.

2. Use denatured alcohol to remove any oil residue from
the pushrod wire.

Note: Soldering should be done with silver solder, not

an electrical solder.

3. Apply a couple of drops of fl ux to the wire. Slide the
solder clevis onto the wire. Using a small torch or
soldering iron heat the wire, allowing the heated wire to
heat the solder clevis. Apply a small amount of solder to
the joint. When the wire and the clevis are hot enough
the solder will fl ow into the joint. Avoid using too much
solder, causing solder to fl ow out of the joint and clump.
Use just enough solder to make a good joint. Allow the
wire and clevis to cool.

❏ 1. Tr im the covering from the servo lead cutouts in the

top of the wing panels. Feed the aileron servo leads through
the cutouts. Taping the leads to the top of the wing will keep
them out of the way when joining the wing panels.

❏ 2. Glue the 5/16" x 1-1/8" [8mm x 28mm] anti-rotation

pin halfway into one of the wing panels as shown.

11

❏ 3. Locate the two aluminum wing joiner pieces and the

two plywood wing joiner pieces. Use 220-grit sandpaper to
thoroughly roughen both sides of each aluminum wing joiner
piece and remove the sanding dust from the pieces. Glue
the four pieces together using 30-minute epoxy with the two
aluminum pieces being on the inside of the stack. Note that
the joiner has a slight “V” shape that will giv e the wing a small
amount of dihedral when assembled. The point of the “V” shape
is the bottom of the joiner. Wipe a w ay any excess epo xy with
a cloth dampened with denatured alcohol and use clamps to
hold the pieces together while the epoxy cures. Be sure that
the joiner pieces are glued so the edges are fl ush with each
other. Mark a centerline on the assembled wing joiner.

Read all of step 4 and dry fi t the parts together to ensure
a proper fi t before gluing. Sand the wing joiner or root
ribs if necessary to achieve the correct fi t. The root ribs
should join together tightly with no gaps.

30-minute epoxy. Thoroughly coat one half of the wing joiner
with 30-minute epoxy and insert it into the joiner pocket of one
wing panel with the bottom of the “V” shape pointing to the
underside of the wing. Coat the root ribs of both wing panels,
the protruding end of the wing joiner, and the protruding end of
the anti-rotation pin with epoxy. Slide the wing panels together
and use tape to hold them tight while the epoxy cures. Wipe
away any excess epoxy with denatured alcohol.

❏ 5. Bevel the ends of the 3/8" x 1-3/4" [10mm x 45mm]

wing dowels. Use epoxy to glue the wing dowels in place.
Position the dowels so that 5/8" [16mm] protrudes beyond
the front of the wing.

❏ 4. Use a mixing stick or something similar to coat the

inside of the wing joiner pockets of both wing panels with

❏ 6. Trim the covering from the wing bolt holes in the

wing assembly.

12

❏ 7. Draw a centerline onto the plywood wing bolt plate as

shown. Position the wing bolt plate over the wing bolt holes
on the underside of the wing and use a felt-tip pen to trace
around it. (Be sure that y ou center the wing bolt plate o v er the
holes or it may interfere with the installation of the belly pan.)

HOW TO CUT COVERING FROM BALSA

Use a soldering iron to cut the covering from the area
beneath the wing bolt plate. The tip of the soldering iron
doesn’t have to be sharp, but a fi ne-tip does work best.
Allow the iron to heat fully.

Use a straightedge to guide the soldering iron at a rate that
will just melt the covering and not burn into the wood. The
hotter the soldering iron, the faster it must travel to melt a
fi ne cut. Peel off the covering.

❏ 8. Use a sharp #11 hobby knife or use the following

“Expert Tip” to cut the covering 1/16" [1.6mm] inside of the
lines you marked. Use care to cut only in the covering and
not into the wood. Use alcohol to wipe a w a y the lines . Glue
the wing bolt plate in position. Continue the wing bolt holes
through the plate using a 1/4" [6mm] drill bit. Clamp a piece
of scrap wood against the wing bolt plate to prevent tear out
when drilling the holes.

ASSEMBLE THE T AIL SECTION

& LANDING GEAR

Install the Stab, Elevators & Rudder

❏ 1. Just as you did with the ailerons, prepare the hinge

point pockets in the stab and elevators by test fi tting the
hinges and enlarging the holes as necessary.

❏ 2. Locate the stab slots near the aft end of the fuse and

trim away the covering.

13

❏ 3. Temporarily install the wing onto the fuse using two

1/4-20 nylon wing bolts. The wing dowels will fi t into receiving
holes in the former behind the LE of the wing.

❏ 6. Use a felt-tip marker to mark the outline of the fuse onto

the top and bottom of the stab.

❏ 7. Remov e the stab from the fuse and cut the covering just

inside the lines you drew. If using a hobby knife to remove
the covering, use care to cut only in the covering and not
into the wood.

❏ 8. Use 30-minute epoxy to glue the stab into the fuse by

coating the top and bottom of the stab in the area where you
removed the covering. Slide the stab into position. Confi rm
that the stab is centered as was done in steps 4 and 5. Wipe
away any excess epoxy with a paper towel and denatured
alcohol. Do not disturb the model until the epoxy has fully
hardened. With the stab secure, you can now remove the
wing from the plane.

❏ 4. Test fi t the stab in the fuse. Center the stab left and right

in the fuse. Stand back 15 to 20ft [5m to 6m] and check to be
sure the stab is parallel to the wing. If necessary , adjust the stab
saddle as needed until the stab and wing are parallel.

❏ 5. Measure the distance from the tip of each wing to the

tip of the stab. Adjust the stab until the distance from the tip
of the stab to the tip of the wing is equal on both sides.

❏ 9. As you did with the ailerons, use a toothpick or wood

scrap to apply epoxy to the inside of each elevator and stab
hinge point pocket. Apply a light coat of epoxy to one end
of all the hinges for the elevators along with a small amount
of petroleum jelly at the center of each hinge. Insert the
hinge points into the pockets, wiping away excess epoxy
with denatured alcohol as necessary. Be sure the hinges
are inserted in the correct orientation. Apply epoxy to the
other ends of the hinges and slide the elevators into place.
Use masking tape to hold the elevators in position while the
epoxy cures.

14

❏ 10. Attach the rudder in the same manner.

Install the Tail Gear Assembly

❏ 3. Measure 1-1/2" [38mm] back from the LE bevel of the

rudder and make a mark on the underside center of the rudder.

❏ 4. Use a 5/32" [4mm] drill bit to mak e a 1/2" [13mm] deep

hole at the mark. To improve accuracy, drill a smaller pilot
hole at your mark fi rst.

❏ 1. Trim the covering from the fuse for the tail

gear bushing.

❏ 2. Apply CA or epo xy to the outside of the bushing and insert

the bushing into the hole by gently tapping it into place until fully
seated. Be sure not to get glue into the hole in the b ushing.

❏ 5. Slide the tail gear collar and nylon retainer onto the

tail gear assembly as shown. If necessary, use a 1/16"

[1.6mm] drill bit to enlarge the hole in the retainer for the tail
gear guide wire.

❏ 6. Temporarily insert the tail gear assembly into the tail gear

bushing and the nylon retainer into the hole you drilled in the
rudder. Center the tail gear bracket onto the fuse over the tail
gear collar and mark the location of the mounting holes.

15

❏ 7. Drill 1/16" [1.6mm] holes at the marks you made. Thread

a 2mm x 8mm self-tapping screw into each hole and back it
out. Apply a couple drops of thin CA glue to each hole and
allow it to harden.

❏ 8. Apply CA or epoxy to the nylon retainer and reinstall

the tail gear assembly into the bushing and rudder. Do not
glue the nylon retainer to the guide wire. The wire must slide
freely through the hole in the retainer. Gently tap the retainer
in place until approximately 3/16" [4.8mm] protrudes below
the bottom of the rudder. Attach the tail gear bracket using
two 2mm x 8mm self-tapping screws. Thread the 3mm set
screw into the tail gear collar with a drop of threadlocking
compound. Cut off the e xcess guide wire 1/2" [13mm] behind
the nylon retainer.

shrink tubing. Feed the servo extensions through the fuse
and install the servos into the servo bays with the splines
facing forward using the mounting hardware included with
the servos. Be sure to harden the servo mounting screws
with thin CA.

❏ 3. Attach a servo arm to each elevator servo

pointing downward.

❏ 9. Confi rm that the tail wheel rotates freely. Oil the axle and

adjust the position of the 3mm wheel collar if necessary .

Install the Elevator Servos & Pushrods

❏ 1. Trim the covering from the elevator servo bays leaving

1/8" [3mm] around the opening. Use a trim iron to seal down
the covering around the edges of the servo bays.

❏ 4. Just as you did with the ailerons, begin assemb ly of the

elevator pushrods using two .095" x 12" [2.4mm x 305mm]
pushrod wires threaded on one end, two 4-40 clevises and
two 4-40 nuts. Attach the clevis of each pushrod to the servo
arms and use the pushrod as a guide to position the control
horns onto the underside of the elevators. Secure the control
horns to the elevators with #4 x 5/8" [16mm] sheet metal
screws, being sure that you are drilling the screw holes
through the plywood plates in the elevators. Do not drill all
the way through the elevators! Center the elevators and use
a solder clevis to mark where to cut the pushrod wires. Cut
the wires, solder the clevises to the pushrods and attach the
pushrods to the elevators , securing the clevises with silicone
clevis retainers.

Note: The Sukhoi SU-31 1.60 ARF is setup for either forw ard
(pull-pull system) or aft (pushrod system) rudder servo
positions in order to offset ballast that may be required to
balance the airplane. The rudder servos will be installed
after the power system is put in place. After the installation
of the power system, the current C.G. of the plane can be
checked which will determine the optimum location of the
rudder servos.

❏ 2. Attach a 36" [914mm] servo extension to each elevator

servo. Secure the servo extensions with the included heat-

16