Great Planes GPMA1581 User Manual

™

SPECIFICATIONS

Wingspan:

Wing Area:

Weight:

GLIDER WING

Wing

Loading:

55.5 in
[1410mm]

2

400 in
[25.8 dm2]

28 – 29.5 oz
[795–835 g]

10.1 – 10.6 oz/ft
[31–32 g/dm2]

2

Wingspan:

Wing Area:

Weight:

SPORT WING

Wing

Loading:

31.5 in
[800mm]

219 in
[14.1 dm2]

22.5 – 24.0 oz
[640 –680 g]

14.8 – 15.8 oz/ft
[45–48 g/dm2]

WARRANTY

Great Planes® Model Manufacturing Co. guarantees this kit to

be free from defects in both material and workmanship at the
date of purchase. This warranty does not cover any component
parts damaged by use or modification. 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 final assembly or
material used for final assembly, no liability shall be assumed nor
accepted for any damage resulting from the use by the user of
the final 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 buyer is advised to return

INSTRUCTION
MANUAL

2

2

this 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.

Length: 34.5 in

[875mm]

Radio:

4-Channel with 6 micro servos
and standard receiver

Motor, ESC,

Battery

Hobby Services

3002 N. Apollo Dr. Suite 1

Champaign IL 61822 USA

24-33-4040 Ammo

11.1V 1800 – 2200mAh LiPo

™

, 25A ESC

READ THROUGH THIS MANUAL BEFORE STARTING CONSTRUCTION. IT CONTAINS IMPORTANT

INSTRUCTIONS AND WARNINGS CONCERNING THE ASSEMBLY AND USE OF THIS MODEL.

Champaign, Illinois

[phone], Ext 5

[e-mail]

© 2011 Hobbico®, Inc. GPMA1581 Mnl

TABLE OF CONTENTS

AMA

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

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

SAFETY PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . .2

ADDITIONAL ITEMS REQUIRED . . . . . . . . . . . . . . . . . . .3

ORDERING REPLACEMENT PARTS . . . . . . . . . . . . . . . .4

KIT INSPECTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5

ASSEMBLE THE WINGS . . . . . . . . . . . . . . . . . . . . . . . . . .6

Install the Servos . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Hook up the Ailerons . . . . . . . . . . . . . . . . . . . . . . . . . .7

Finish the Wing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8

Mark the C.G. (Balance Point) . . . . . . . . . . . . . . . . . .10

ASSEMBLE THE FUSELAGE . . . . . . . . . . . . . . . . . . . . . 11

Install the Landing Gear. . . . . . . . . . . . . . . . . . . . . . . 11

Attach the Horizontal and Vertical Stabilizers . . . . . .11

Install the Servos . . . . . . . . . . . . . . . . . . . . . . . . . . . .12

Assemble the Ducted Fan . . . . . . . . . . . . . . . . . . . . .13

Test Run the Motor. . . . . . . . . . . . . . . . . . . . . . . . . . .15

FINAL PREPARATIONS . . . . . . . . . . . . . . . . . . . . . . . . .17

Mount the Receiver and ESC. . . . . . . . . . . . . . . . . . .17

Check the Control Directions . . . . . . . . . . . . . . . . . . . 17

Check the Control Throws . . . . . . . . . . . . . . . . . . . . .18

Balance the Model (C.G.). . . . . . . . . . . . . . . . . . . . . .18

Identify Your Model . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Charge the Battery . . . . . . . . . . . . . . . . . . . . . . . . . .19

FLYING THE SYNCRO . . . . . . . . . . . . . . . . . . . . . . . . . .19

Find a Suitable Flying Site . . . . . . . . . . . . . . . . . . . . .19

Ground Range Check . . . . . . . . . . . . . . . . . . . . . . . .19

Set a Flight Timer. . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Take Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

Hand-Launch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20

ROG (Rise off Ground) . . . . . . . . . . . . . . . . . . . . . . . 21

Flying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

Landing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

After Flight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21

INTRODUCTION

Thank you for purchasing the Syncro. The Syncro includes

both a “glider” wing and a “sport” wing. With the glider wing,

the Syncro is more stable and forgiving. This configuration

is better suited to beginners and pilots with little flight

experience, giving them more time to think and react. When

you’re ready to graduate from the glider wing, the sport wing

transforms the Syncro into a more nimble, faster “jet-like”

craft perfect for boring holes in the sky!

For the latest technical updates or manual corrections to the

Syncro visit the Great Planes web site at greatplanes.com.

Open the “Airplanes” link, then select the Syncro. 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.

Academy of Model Aeronautics: If you are not already a

member of the AMA, please join! The AMA is the governing
body of model aviation and membership provides liability
insurance coverage, protects modelers’ rights and interests
and is required to fly at most R/C sites.

Academy of Model

Aeronautics

5151 East Memorial Drive

Muncie, IN 47302-9252

Tele. [phone]

Fax [phone]

modelaircraft.org

IMPORTANT!!!

Two of the most important things you can do to preserve the

radio controlled aircraft hobby are to avoid flying near full­scale aircraft and avoid flying near or over groups of people.

PROTECT YOUR MODEL, YOURSELF

& OTHERS… FOLLOW THESE

IMPORTANT SAFETY PRECAUTIONS

1. Your Syncro 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 Syncro, if not assembled and operated correctly, could
possibly cause injury to yourself or spectators and damage
to property.

2. You must assemble the model according to the instructions.
Do not alter or modify the model, as doing so may result in
an unsafe or unflyable 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. If you are not an experienced pilot or have not flown
this type of model before, we recommend that you get
the assistance of an experienced pilot in your R/C club for

your first flights. 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.

4. While this kit has been flight tested to exceed normal use,
if the plane will be used for extremely high stress flying, 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.

We, as the kit manufacturer, provide 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.

2

ADDITIONAL ITEMS REQUIRED

Adhesives

There are a couple of adhesives recommended for gluing

the special type of foam from which the Syncro is made:
One kind is either foam-safe or regular CA (cyanoacrylate
or “super glue”). CA is best for modelers that already have
experience with it because CA requires special handling. CA
must be used with adequate ventilation and it can harden
quickly, possibly causing some modelers to glue their fingers
to the parts or to each other. Another kind is “canopy glue,”
a craft glue specially formulated for plastics. Canopy glue is
recommended for most builders because it is water soluble,
easy to clean up, emits no fumes and is easier to work with
because it takes longer to dry:

CANOPY GLUES

Zap Adhesives Ric 560 (PAAR3300), OR

❏

J&Z R/C-56 (JOZR5007)

❏

If using canopy, glue Great Planes epoxy brushes (6)

(GPMR8060) are also recommended for spreading the glue.

long as you desire. And the same applies to the 2200mAh

“T-Rex” battery. With this battery the motor draws slightly

more current @ 22 Amps, but will still fall to or below the
maximum rated constant current when in the air. However,
the motor should not be run on the ground with either battery
at full power for more than 30 seconds. Otherwise, the motor
may overheat causing damage.

If using batteries other than the ones recommended, keep

in mind that batteries with higher capacity (mAh) and/or “C”
rating could cause the motor to operate over its maximum

current limit. The recommended 2200mAh 25C battery, is
capable of providing 55 Amps (2.2 Amps x 25 C = 55A). So, if
you were to switch to, say a larger, 2500mAh 25 C battery it
will be capable of 62.5 Amps. This may be okay as long as the

motor does not draw more than 28 Amps, but then the Syncro
should probably not be flown full throttle for extended periods

without lowering the throttle allowing the motor to cool.

If experimenting with batteries different than the ones
recommended, the best way to know if you are operating
the motor within its limits is to connect a Watt meter

(REPL0100) in-line between the ESC and the battery.
This will tell you how much current the motor is drawing

with the battery you are using.

CA AND ACCESSORIES

1 oz. [30g] Medium Pro

❏

2 oz. [57g] spray CA activator (GPMR6035)

❏

CA applicator tips (HCAR3780)

❏

CA debonder (GPMR6039)

❏

™

CA+ (GPMR6008)

Motor and ESC

The motor and ESC (electronic speed control) recommended

for the Syncro are these:

Great Planes 24-33-4040 Ammo Inrunner Brushless

❏

Motor (GPMG5165)

Great Planes Silver Series SS-25 25A Brushless ESC

❏

(GPMM1820)

Note: The recommended 24-33-4040kV Ammo motor is
rated for 18 Amps constant current and 28 Amps surge
current. This means the motor can be run indefinitely as long
as it is not drawing more than 18 Amps, but can be run for no
longer than 30 seconds if drawing the maximum of 28 Amps
before you have to back off the throttle and allow the motor to
sufficiently cool. The closer to 18 Amps the motor operates
the longer it can be run until it gets too hot. And the closer to
28 Amps the motor operates the shorter it may be run until it
gets too hot (again, before reducing the throttle allowing the
motor to cool). The motor must never be operated over 28

Amps. The ElectriFly batteries recommended in this manual

will allow the motor to operate within the specified range:
With the 1800mAh 11.1V (3S) 25C battery, the motor will

draw about 21 Amps on the ground (static) at full-throttle.
Although this is slightly over the constant current limit (of
18 Amps), it will drop to or below this limit when the plane

is in the air, so the Syncro may be flown full-throttle for as

Batteries

There are a couple of batteries recommended for the Syncro.
The ElectriFly 1800mAh 11.1V 25C LiPo (lithium-polymer)

battery (GPMP0515) is smaller, lighter weight and less

expensive, while the ElectriFly 2200mAh 11.1V 25C “T-Rex”

LiPo (GPMG0520) is slightly larger for slightly longer flight time.

Radio Control System

The Syncro requires a 4-channel radio control system with
Futaba S3107 micro servos (or similar). For beginners who

may not already have a suitable radio control system, the
Futaba 6EX 6-channel radio is recommended (FUTK6900).
It features the latest 2.4GHz technology for reliability and
eliminates the need for frequency sharing with other pilots
who may be flying at the same time.

The 6EX does not come with servos, so six servos will also

be required (two for each wing and two for the elevator and

rudder controls in the fuselage). Futaba S3107 micro servos
(FUTM0025) are recommended and illustrated in the manual,

but any servo that is the same size (7/8" x 7/16" x 13/16"

[22mm x 11mm x 20mm]) and torque rating could also be

used. ElectriFly ES-50 Nano servos (GPMM1210) are also

suitable.

A 6" [152mm] servo extension wire (HCAM2000 for Futaba)
will also be required.

3

Charging System

ORDERING REPLACEMENT PARTS

The LiPo batteries recommended for your Syncro require a

special charger capable of charging LiPos. LiPo batteries must
also be “balance charged” so that each of the three individual
cells making up the complete battery are charged evenly.

For pilots who wish to charge several batteries
simultaneously (reducing down time and optimizing flight
time), the Great Planes PolyCharge4™ DC-powered LiPo
charger (GPMM3015) is recommended. The PolyCharge4
can charge up to four LiPo batteries at once. But the
PolyCharge4 does not have an internal LiPo cell balancer,
so for each LiPo battery you wish to charge simultaneously,
one Great Planes Equinox™ LiPo Cell Balancer (GPMM3160)
will also be required. Finally, the PolyCharge4 does not have

AC capability, so if wall-charging from home is important,

a separate A/C 12-Volt power source must be purchased
separately. A suitable power supply for the PolyCharge4 is
the Great Planes 12V 12A DC power supply (GPMP0901).

Another viable battery charging option is the Triton™ EQ
(GPMM3155) featuring the required built-in LiPo cell

balancing. The Triton EQ also features a built-in AC adapter
and wall cord so it can charge batteries from either a wall
outlet or a 12V source. The Triton EQ can charge only one
battery at a time.

Replacement parts for the Syncro 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.

To locate a hobby dealer, visit the Great Planes web site

at greatplanes.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 fax 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

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 by credit card or

personal check only; no C.O.D.

®

or MasterCard® number

Tools and Accessories

Other than common hobby tools such as screwdrivers,
needle-nose pliers, etc., here is the list of items illustrated
in this instruction manual required to assemble the Syncro.

Thread-locking cement (GPMR6060)

❏

Great Planes stick-on lead weight (GPMQ4485)

❏

Masking tape

❏

A standard “L-bend” hex key is included with this kit for

tightening the set screws in the fan rotor adapter (see
page 13), but it’s really only a “one-time” use tool. For any
future disassembly and reassembly, and even for this first­time assembly, a high-quality 1.5mm hex wrench such as
the DuraTrax® 1.5mm Ultimate Hex Driver (DTXR0288) is
suggested.

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

REPLACEMENT PARTS LIST

Order No. Description

GPMA4190
GPMA4191
GPMA4192
GPMA4193
GPMA4194
GPMA4195
GPMA4196
GPMA4197
GPMA4198
GPMA4199

NOTE

Fuselage Set
Glider Wing Set
Sport Wing Set
Tail Set
Foam Fan Duct
Landing Gear Set
Hardware Pack
Canopy Hatch
Ducted Fan Unit
Ducted Fan Rotor

Full-size plans are not available.
You can download a copy of this
manual at www.greatplanes.com.

4

KIT INSPECTION

Before starting to build, take an inventory of this kit to make sure it is complete, and inspect the parts 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

2

17

1. Fuselage/canopy hatch

2. Glider wing halves (R&L)

3. Glider wing spar

4. Glider wing spar covers

5. Jet wing

6. Jet wing spar covers

7. Horizontal stabilizer with elevators

8. Vertical stabilizer with rudder

9. Fan duct (top, bottom)

10. Fan assembly (fan housing, rotor, tail cone)

11. Foam fan cones (5)

6

5

4

9

2

10

4

16

9

8

12

11

3

12. Landing gear (R&L main landing gear, 40mm wheels,
nose gear, 25mm nose wheel)

13. Hardware (Glider wing dowel plate, adhesive-back hook

& loop (2), long (450mm) Y-harness, short (240mm)
Y-harness, motor wire extensions, aileron pushrods, Fan
duct mounting bolt, wing bolt collar, Phillips wing screw,
pinned hinge, 10mm wood screws (2), 3mm fl at washer (for
wing screw), micro screw-locks (4), Faslinks (6), retainers
for screw-locks (6), screws for screw-locks (8),
rotor adapter w/set screws, 5mm hex nut, 3x4mm fl at­head motor mount screws (2)

7

13

2mm fan

5

ASSEMBLE THE WINGS

After the spar covers are permanently glued into place,

the ends of the Y-connector for the aileron servos will no
longer be accessible. The servos may still be removed by
pulling the wires out of the wing, but the wing will no longer
be functional because it will not be possible to re-connect

new servos. So make sure your servos are working properly

before permanently gluing in the spar covers because
there’s no going back.

Install the Servos

Refer to this photo for the next two steps.

Cut off the unused arms

3. Use small wire cutters to cut off the unused arms so

❏

you have two, opposing servo arms. Fasten the arms to the

servos with the servo arm screws that came with your servos.

1. If assembling the glider wing, connect the two servos

❏

you will be using for the ailerons to the longer Y-connector. If
assembling the sport wing, connect the aileron servos to the
shorter Y-connector. Connect the ESC to the throttle channel
in the receiver (channel 3 for Futaba) and the Y-connector to
the aileron channel (channel 1). (If using the ElectriFly SS­25 ESC, note that the brown wire is the negative lead.)

Longer, 3-hole arms

90°

5/16" [8mm]

2. Turn on your transmitter and center the trims. Connect

❏

the motor battery to the ESC to power the servos. Use servo
arms with holes that are approximately 5/16" [8mm] from
center (which are the arms included and shown for the
Futaba servos recommended). Position the arms on the
servos so they will be 90°, or as close to 90° as possible to
the sides of the servo.

90°

4. Disconnect the servos from the Y-connectors. Test-

❏

fi t, then glue the servos into the wings as illustrated for the
wing you are working on: It is recommended to use canopy

glue because the servos will be easier to remove later if ever
necessary (for transferring to another model). Hint: You can
skip ahead to step 1 on page 12 and glue in the elevator and
rudder servos too. Then, you won’t have to wait for the glue to
dry when you get to that part of assembly.

6

Hook up the Ailerons

1. If working on the glider wing (pictured), connect one of

❏

the shorter Z-bend pushrods to the outer hole of the servo
arm on the servo in the right wing panel. Insert a screw-lock
connector into the bottom hole in the aileron control horn
and fi t the pushrod into the connector.

If working on the sport wing, connect one of the longer

Z-bend pushrods into the outer hole of the servo arm on

the servo in the right side of the wing. Insert a screw-lock
connector into the outer hole in the aileron control horn and
fi t the pushrod into the connector.

2. Same as when you were fi tting the servo arms to the

❏

servos, temporarily connect the aileron servo to the receiver
and power up the system so you can move the servo with
the transmitter. Holding the aileron centered, temporarily lock
the pushrod to the screw-lock connector with a 2mm screw.

Move the aileron control

stick to the right

SERVO CONTROL SURFACE

Moving the pushrod outward
increases the control throw

Moving the pushrod inward
decreases the control throw

Move the aileron stick all the way to the right. Measure how

far from center the trailing edge of the aileron moved. For the
glider wing, the aileron should move 3/8" [10mm] up and
3/8" [10mm] down. For the sport wing, the aileron should

move 5/16" [8mm] up and 5/16" [8mm] down. If the aileron

does not move the specifi ed distance, move the pushrod

to another hole in the servo arm or to another hole in the

aileron horn to increase or decrease the throw until you can

get it as close as possible (+/- 1/16" [1.5mm] is acceptable).

Moving the pushrod inward
increases the control throw

Moving the pushrod outward
decreases the control throw

Right aileron deflects

toward the top of the wing

3. Use the control stick on the transmitter to move the

❏

aileron servo. Make sure the servo is moving in the correct
direction; when you move the stick to the right the aileron
should defl ect toward the top of the wing (downward, since
we are working on the wing upside-down). If the aileron
does not respond in the correct direction, reverse the servo
direction in the transmitter.

4. Once we’ve confi rmed that the servo direction is

❏

correct, check the control throw as follows to make sure the
model responds correctly in the air—if the throw is too much
you will end up over-controlling it—if the throw is not enough
the model will respond too slowly.

Retainer

5. Once you have the pushrods where you want them and

❏

the control throw set, press a nylon retainer onto the screw-

lock connector securely holding it to the control horn—be
certain the retainer fi ts tightly and goes all the way on. If you

feel the retainer slipped on too easily, discard that retainer

and replace it with another—a couple of spare retainers are

included with this kit.

7

6. Still with the radio on, remove the screw in the screw-

❏

lock connector, wet the threads with threadlocker, reinstall
the screw and tighten it securely making sure the aileron
remains centered.

7. Connect the other pushrod to the other aileron and

❏

servo the same way.

Finish the Wing

GLIDER WING:

1. Keep a couple of paper towels handy for wiping glue

❏

from your fi ngers and the wing—remember, canopy glue is
preferred because it will be easier to clean up. You’ll also
need some masking tape for holding the halves together
until the glue dries. If using canopy glue, lightly wet the
paper towels with water or window cleaner to make it easier
to wipe up glue.

4. Mate the halves and install the dowel plate. Use strips

❏

of masking tape on the top and bottom of the wing to pull

the halves together. Make certain the dowel plate remains

in position helping to keep the wings aligned. Also install

the wing bolt bushing to align the trailing edges. Use your

paper towels to wipe excess glue from the wing and from
your fi ngers as necessary. Do not disturb the wing until the

glue has set (overnight if using canopy glue).

2. Test-fi t the wing halves using the dowel plate to help

❏

assure alignment.

3. Get ready to glue the wings together. Apply glue to all

❏

joining surfaces of both wing halves—you don’t need much—
just a fi lm, but all surfaces that touch should have glue.

5. After the glue from joining the wing halves has dried,

❏

remove the masking tape and get ready to glue in the spar

and the spar covers. Test-fi t, but do not glue in the spar. Also
connect the Y-connector to the servos. Use a dab of glue to

hold the connectors in the channel so they won’t move around

and interfere with the fi t of the spar covers. If the servo wires

are too long you can double them back into the servo cavity.

8