GREAT PLANES TWINSTAR EP Instruction Manual

INSTRUCTION MANUAL

SPECIFICATIONS

Wingspan:

47.5 in [1205 mm ]

Weight:

Length: 42.5 in [1080 mm]

Wing

Loading:

Wing Area: 392 in

2

[25.3 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 modi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 nal assembly or
material used for nal assembly, no liability shall be assumed nor
accepted for any damage resulting from the use by the user of
the 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 buyer is advised to return

4-4.25 lb
[1810-1930 g ]

24-25 oz/ ft
[73-76 g/dm2]

Radio:

4-channel minimum with 4 servos
and standard size receiver

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.

Motor:

3002 N. Apollo Dr. Suite 1

Champaign IL 61822 USA

RimFire .10 (35-30-1250) x 2

Hobby Services

READ THROUGH THIS MANUAL BEFORE STARTING CONSTRUCTION. IT CONTAINS IMPORTANT

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

© 2015 Great Planes Model Mfg. A subsidiary of Hobbico,® Inc.

Champaign, Illinois

[phone], Ext 5

[e-mail]

GPMA1609 v1.1

TABLE OF CONTENTS

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

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

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

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

Radio Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Brushless Motor Recommendations . . . . . . . . . . . . . . 3

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

Adhesives and Building Supplies . . . . . . . . . . . . . . . . 3

Optional Supplies and Tools . . . . . . . . . . . . . . . . . . . . 4

Building Stand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

IMPORTANT BUILDING NOTES . . . . . . . . . . . . . . . . . . . 4

KIT INSPECTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

KIT CONTENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

ORDERING REPLACEMENT PARTS . . . . . . . . . . . . . . . . 5

PREPARATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Check the Pre-Installed Hinges . . . . . . . . . . . . . . . . . . 6

ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Build the Wing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Assemble the Fuselage . . . . . . . . . . . . . . . . . . . . . . . 12

Apply the Decals . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

GET THE MODEL READY TO FLY . . . . . . . . . . . . . . . . . 17

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

Set the Control Directions . . . . . . . . . . . . . . . . . . . . . 17

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

Balance the Model Laterally . . . . . . . . . . . . . . . . . . . 19

PREFLIGHT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

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

Charge the Batteries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Balance Propellers. . . . . . . . . . . . . . . . . . . . . . . . . . . 19

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

MOTOR SAFETY PRECAUTIONS . . . . . . . . . . . . . . . . . 20

AMA SAFETY CODE (excerpts) . . . . . . . . . . . . . . . . . . . 20

General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Radio Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

CHECK LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

FLYING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Takeoff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Flight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Landing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

INTRODUCTION

Congratulations on your purchase of the Twinstar EP! Now
you can experience dual motor  ight in a smaller package.
It's perfect for practicing up for scale twin engine models
or just to have some fun throwing it around in the air. The

Twinstar EP is plenty thrusty and capable of aerobatics and

is also extremely easy to  y. This would be a good 2nd or
3rd plane after a trainer has been mastered and you have
some low wing experience. Best of all, this model can be
tossed in the backseat of a car fully assembled to get a
quick  ight over lunch.

For the latest technical updates or manual corrections to the
Great Planes Twinstar EP visit the Great Planes web site at
www.greatplanes.com.

Open the “Airplanes” link, then select the Twinstar EP. 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 governing body of model
aviation and membership is required to  y at AMA clubs.

Though joining the AMA provides many bene ts, one of the

primary reasons to join is liability protection. Coverage is not
limited to  yin g at contests or o n the clu b  eld. It even applies
to  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 country. 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  ying near full-scale aircraft and avoid  ying near or
over groups of people.

SAFETY PRECAUTIONS

Protect Your Model, Yourself & Others...

Follow These Important Safety Precautions

1. Always disconnect the power on the model before
switching off the transmitter. Without a signal to the
receiver, the ESC may command the motor to rotate
which could cause injury to yourself or surrounding
property. Always turn the transmitter on before plugging
the  ight battery into the ESC.

2. Your Twinst ar EP sho uld not b e con side red a toy, but rather
a sophisticated, working model that functions very much like
a full-size airplane. Because of its performance capabilities,

2

the Twinstar EP, if not assembled and operated correctly,
could possibly cause injury to yourself or spectators and
damage to property.

3. 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 un yable model. In a few
cases the instructions may differ slightly from the photos.
In those instances the written instructions should be
considered as correct.

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

5. You must use an R/C radio system that is in  rst-class
condition, and a correctly sized motor and components
(battery, servos, etc.) throughout the building process.

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

7. You must check the operation of the model before every
 ight to ensure 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.

8. If you are not an experienced pilot or have not  own
this type of model before, we recommend that you get
the assistance of an experienced pilot in your R/C club for
your  rst  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.

9. While this kit has been  ight tested to exceed normal use,
if the plane will be used for extremely high stress  ying, or if
a motor larger than one in the recommended range is used,

the modeler is responsible for taking steps to reinforce the

high stress points a nd/or substituting hardwar e more su itab le

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  yability of your  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.

mini servo as an optional higher torque servo for the rudder
and it is shown in the building section of this manual.

In addition, two 12" [305mm] servo extensions are required
for the aileron servos. Two Y-harnesses will also be required
for the ailerons and the ESCs.

Recommended part numbers for the radio components are
provided below:

❍ Futaba S3115 Micro Precision Servo (FUTM0415)
❍ Futaba S3150 Slim Digital Servo (FUTM0303)
❍ Hobbico 12" Extension Futaba J (HCAM2100)
❍ Futaba Dual Servo Extension 6" J (FUTM4130)

Brushless Motor Recommendations

We recommend two RimFire .10 brushless motors and two
25A ESCs. Other motors may work  ne. However, the motor
mount holes are spaced for the RimFire .10 and this motor
has been extensively  ight tested and performs well in the

Twinstar EP. Two 8x8E electric propellers are recommended

with the RimFire .10. Many batteries will work as a  ight
battery. We suggest the 11.1V 3800mAh FP30 FlightPower
pack. Part numbers are provided below:

❍ Great Planes RimFire .10 35-30-1250 Outrunner

Brushless (GPMG4595)

❍ Great Planes Silver Series 25A Brushless ESC 5V/2A

BEC (GPMM1820)

❍ APC 8x8 Thin Electric Propeller (APCQ4116)
❍ FlightPower LiPo FP30 3S 11.1V 3800mAh 30C

(FPWP3383)

If you need a charger for your  ight battery, we suggest either
the Triton EQ or Triton 2 EQ. Both are very versatile chargers
that can charge virtually any hobby battery currently available.

❍ Great Planes ElectriFly Triton EQ AC/DC Charger

(GPMM3155)

❍ Great Planes ElectriFly Triton2 EQ AC/DC Charger

(GPMM3156)

ADDITIONAL ITEMS REQUIRED

Adhesives and Building Supplies

REMEMBER: Take your t i m e and follow the i nstructio ns

to end up with a well- built model t h at is straight and t r u e.

DECISIONS YOU MUST MAKE

This is a pa r tial list of item s re quir ed to  nish the Twinstar EP

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

Radio Equipment

The Twinstar EP requires a minimum 4-channel radio

system with four 39 oz.-in. [2.8 kg-cm] minimum torque
micro sized servos.

Because the motors are mounted on the wings, rudder

authority is important. We recommend the Futaba S3150

This is the list of Adhesives and Building Supplies that are

required to  nish the Twinstar EP:

❍ 1/2 oz. [15g] Thin Pro CA (GPMR6001)
❍ Pro 6-minute or 30-minute epoxy (GPMR6045 or

GPMR6047)

❍ Threadlocker thread locking cement (GPMR6060)
❍ Denatured alcohol (for epoxy clean up)
❍ Drill bits: 1/16" [1.6mm], 5/64" [2mm]
❍ Rotary tool with cutting bit
❍ Revell Premium Soft Handle Knife w/Blades (5)

(RMXR6900)

❍ Top Flite MonoKote sealing iron (TOPR2100)
❍ Top Flite Hot Sock iron cover (TOPR2175)
❍ Panel Line Pen (TOPQ2510)
❍ Small clamps
❍ Masking tape
❍ Household oil

3

Optional Supplies and Tools

IMPORTANT BUILDING NOTES

Here is a list of optional tools that will help you build the

Twinstar EP:

❍ 1/2 oz. [15g] Thick Pro CA- (GPMR6013)
❍ 1/2 oz. [15g] Medium Pro CA+ (GPMR6007)
❍ 2 oz. [57g] spray CA activator (GPMR6035)
❍ 4 oz. [113g] aerosol CA activator (GPMR6034)
❍ CA applicator tips (HCAR3780)
❍ CA debonder (GPMR6039)
❍ Epoxy brushes 6, (GPMR8060)
❍ Mixing sticks (GPMR8055)
❍ Mixing cups (GPMR8056)
❍ Pliers with wire cutter (HCAR0630)
❍ T.A. Emerald Performance Duster Compressed Air

(TAEC1060)

❍ Servo horn drill (HCAR0698)
❍ Hobby Heat micro torch II (HCAR0755)
❍ Dead Center™ Engine Mount Hole Locator

(GPMR8130)

❍ DuraTrax Ultimate Body Reamer (DTXR1157)
❍ Precision Magnetic Prop Balancer (TOPQ5700)
❍ AccuThrow De ection Gauge (GPMR2405)
❍ CG Machine™ (GPMR2400)
❍ Hobbico Flexible 18" Ruler Stainless Steel

(HCAR0460)

❍ Top Flite MonoKote trim seal iron (TOPR2200)
❍ Top Flite MonoKote heat gun (TOPR2000)
❍ Hobbico Pin Vise 1/16 Collet w/6 Bits (HCAR0696)
❍ Hobbico 8-Piece Ball Tip Hex L Wrench SAE

(HCAR0520)

❍ Hobbico 7-Piece Ball Tip Hex L Wrench Metric

(HCAR0521)

❍ Great Planes Clevis Installation Tool (GPMR8030)
❍ Great Planes Precision Prop Reamer Standard

(GPMQ5006)

Building Stand

● When you see the term test  t in the instructions, it means

that you should  rst position the part on the assembly

without using any glue, then slightly modify or custom
 t the part as necessary for the best  t.

● Whenever the term glue is written you should rely upon

your expe rienc e to decide w hat t ype of glue to use. Wh en
a speci c type of adhesive works best for that step, the
instructions will make a recommendation.

● Whenever just epoxy is speci ed you may use either

30-minute epoxy or 6-minute epoxy. When 30-minute
epoxy is speci ed it is highly recommended that you use
only 30-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 stabilizer and wing incidences and motor thrust angles

have been factory-built into this model.

● The Twinstar EP is factory-covered with Top Flite MonoKote

 lm. Should repairs ever be required, MonoKote can be
patched with additional MonoKote purchased separately.

Following are the colors used on this model and order
numbers for six foot rolls.

Royal Blue TOPQ0221 Black TOPQ0208
Jet White TOPQ0204 Missile Red TOPQ0201

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
acceptab le quality, or if you need assistance with a ssembly,
contact Product Support. When reporting defective or
missing parts, use the part names exactly as they are written
in the Kit Contents list.

A building stand or cradle comes in handy during the build.
We use the Robart Super Stand II (ROBP1402) for all our

pr ojec ts in R&D, an d it can be seen in p ictures in this m anua l.

Great Planes Product Support

3002 N Apollo Drive, Suite 1 Ph: [phone], ext. 5
Champaign, IL 61822 Fax: [phone]

E-mail: [e-mail]

ORDERING REPLACEMENT PARTS

Replacement parts for the Great Planes Twinstar EP 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.

4

KIT CONTENTS

2

1

4

7

10

3

5

8

9

11

13

6

12

14

Kit Contents

1 Nose Cone
2 Battery Hatch
3 Fuselage
4 Horizontal Stabilizer and Elevator
5 Vertical Fin and Rudder
6 Wing Joiner
7 Right Wing Panel with Aileron

To locate a hobby dealer, visit the Hobbico web site at www.

ho bbic o.com. Ch oos e “Where to B uy” at the bo t tom 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 Hobby Services
and payments by 3002 N Apollo Drive, Suite 1
personal check to: 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.

8 Nacelle Covers
9 Nacelle Frames
10 Left Wing Panel with Aileron
11 Nylon Spinner
12 Wheels
13 Nose Gear
14 Main Gear

REPLACEMENT PARTS LIST

Order No. Description

GPMA4390
GPMA4391
GPMA4392
GPMA4393
GPMA4394
GPMA4395
GPMA4396
GPMA4397
GPMA4398
GPMA4399
GPMA4400

WING SET TWINSTAR EP ARF
FUSELAGE TWINSTAR EP ARF
TAIL SET TWINSTAR EP ARF
SPINNER TWINSTAR EP ARF
NACELLE FRAME L/R TWINSTAR EP
NACELLE COVER (2) TWINSTAR EP
LANDING GEAR TWINSTAR EP ARF
NOSE CONE TWINSTAR EP ARF
DECAL SET TWINSTAR ARF
BATTERY HATCH TWINSTAR EP ARF
ESC Y-HARNESS TWINSTAR EP ARF

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

5

PREPARATIONS

CUT OFF

UNUSED

ARMS

❏ 1. If you have not done so already, remove 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 4.

❏ 2. Use a covering iron with a covering sock on high heat
to tighten the covering if necessary. Apply pressure over

sheeted areas to thoroughly bond the covering to the wood.

Take c are when applying heat onto tr im cove ring applied ove r

the base color. Move the iron at a rate slow enough to get
the covering hot but not so slow that the top color shrinks
on top of the base color causing the edges to pull away.

❏ 2. If you  nd a control surface with loose hinges, you will
need to add thin CA glue to the hinges. Push the control
surface back into place. De ect the control surface all the
way in one direction in order to expose the center of the
hinge. Apply 6 to 7 drops of thin CA glue to each hinge. Do
NOT use accelerator! The CA glue must be allowed to slowly
wick into the hinge and surrounding wood. When the glue has
dried,  ip the model over and add 6 or 7 drops to the other
side of each hinge. It is recommended that you reinforce
every hinge on the model with CA glue if you found even
one loose hinge. Con rm the control surfaces move freely
and are well secured.

ASSEMBLY

This model has all of the control surfaces pre-hinged at the

fa cto r y. No additional glue is typi cally nec essar y; however, all
of the hinged surfaces must be carefully checked to con rm
they are securely attached. This procedure should be part
of your pre- ight check each and every time you  y.

❏ 1. Grasp each control surface at one end, taking care

not to dent or puncture the covering or the wood structure

beneath. Pull the control surface away from the hinge line.
Move your hand along the surface and repeat the check for
the entire length of the surface.

Check the Pre-Installed Hinges

Build the Wing

❏ 1. Center your aileron servos with your radio system. Test
 t four-armed servo arms onto the servos to determine

6

their best orientation so that the arms are closest to being

Hinge Line Hinge Line

Correct Incorrect

perpendicular with the servo case. Cut three arms from each

servo arm leaving one arm on each servo that matches the

photo. Enlarge the hole closest to 9/16" [14.3 mm] to the
center of the servo arm of each remaining arm with a 5/64"
[ 2 mm] drill bit. Attach a 12" [305 mm] servo extension to each

servo. Secure the connection using the pieces of included

heat shrink tubing. Install the rubber grommets and eyelets
onto the servo mounting tabs.

❏ 4. Fit the servos into the servo openings and drill 1/16"
[1.6mm] holes through the mounting tabs on the servo cases
into the rails. Thread a servo mounting screw (included with
the servo) into each hole and remove it. Apply a drop of thin
CA to each hole to harden the surrounding wood. When the
CA has hardened, install the servos into the openings as
shown using the screws supplied with the servos.

❏ 2. Tie the string ends that are taped inside the wings at
the aileron servo bays to the servo extension connectors.

❏ 3. Pull the strings through the root ribs. Be careful not to
damage the wing ribs as you pull the servo leads through them.

❏ 5. Thread a nylon clevis onto two 6" [150mm] aileron
pushrods 20 complete turns.

❏ 6. Separate the back plates from two control horns using
a knife or sprue cutters. Connect the clevises on the aileron

7

pushrods to the outer holes of the control horns. Position

Servo Arm

1/16" [ 1.6 mm]

Pushrod Wire

FasLink

the control horns over the hardwood plates in the ailerons
(if you cannot see them, hold the aileron at a shallow angle

in good lighting or use a small pin to puncture the covering)

being sure the pushrods are lined up with the enlarged holes

in the aileron servo arms.

❏ 8. With the ailerons in the neutral position (use tape or
small clamps to hold them in place), mark the pushrod wires
where they cross the enlarged holes in the servo arms.

❏ 7. Use a felt-tip pen to mark the location of the control

horn mounting holes onto both ailerons.

Drill 5/64" [2mm] holes at the marks you made. Thread 2-56
x 1/ 2" [13m m] m achine s crews into each hole and secure the
control horns into place with the control horn back plates.

❏ 9. Make a 90 degree bend at the mark on each pushrod

and cut off the excess pushrod 1/4" [6mm] beyond the bends.
Attach the pushrods to the servo arms using nylon FasLinks.
Thread the clevises in or out on the pushrods as necessary

to center the ailerons with the servo arms still perpendicular

to the servo cases. (Never center the servo with the power

on.) When satis ed, slide silicone clevis retainers onto the

ends of the clevises to secure them.

8