Great Planes GPMA0236 User Manual
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 this kit immediately in new and unused condition to the place of purchase.
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, the modeler is responsible for taking steps to reinforce the high stress points.
READ THROUGH THIS MANUAL BEFORE
STARTING CONSTRUCTION. IT CONTAINS
IMPORTANT WARNINGS AND INSTRUCTIONS
CONCERNING THE ASSEMBLY AND USE OF
THIS MODEL.
EXT6P03 V1.2© Copyright 2004
P.O. Box 788 Urbana, IL 61803 (217) 398-8970
WWW.GREATPLANES.COM
INSTRUCTION MANUAL
USA
MADE IN
Safety Precautions...................................................................................2
Introduction ..............................................................................................2
Precautions ..............................................................................................3
Decisions You Must Make.......................................................................3
Engine Selection................................................................................3
Exhaust System.................................................................................3
Preparations.............................................................................................3
Required Accessories........................................................................3
Building Supplies and Tools...............................................................4
Optional Tools or Accessories ...........................................................4
Types of Wood...................................................................................4
Common Abbreviations .....................................................................4
Building Notes....................................................................................5
Get Ready to Build.............................................................................5
Inch/Metric Ruler & Conversions .......................................................5
Die-Cut Patterns..........................................................................6 & 7
Build the Tail Surfaces ............................................................................8
Make the Stab Leading Edge Doubler...............................................8
Make the Stab & Fin Sheeting ...........................................................8
Build the Stab ....................................................................................9
Elevator Building Sequence.............................................................10
Fin Building Sequence.....................................................................10
Rudder Building Sequence ..............................................................11
Hinge the Tail Surfaces ....................................................................11
Finish the Tail Surfaces....................................................................11
Build the Wing........................................................................................12
Build the Wing Spars .......................................................................12
Build the Wing Panels......................................................................12
Sheet the Center Section.................................................................14
Servo Mount ....................................................................................14
Join the Wing Panels .......................................................................16
Sheet the Top of the Wing ...............................................................18
Build the Ailerons.............................................................................20
Build the Fuselage .................................................................................22
Assemble the Fuselage Formers & Sides .......................................22
Assemble the Fuselage ...................................................................23
Mount the Wing to the Fuselage......................................................24
Finish the Bottom of the Fuselage ...................................................27
Build the Front Fuselage Deck ........................................................29
Mount the Stabilizer to the Fuselage ...............................................30
Mount the Fin...................................................................................31
Build the Turtle Deck........................................................................31
Mount the Engine & Tank Tray.........................................................32
Install the Servos & Make the Pushrods..........................................33
Assemble the Wheel Pants..............................................................36
Assemble the Cowl ..........................................................................38
Balance the Model Laterally..................................................................39
Prepare the Model for Covering ...........................................................39
Cover the Model with MonoKote Film..................................................40
Covering Technique .........................................................................40
Suggested Covering Sequence .......................................................40
Painting...................................................................................................40
Final Hookups & Checks.......................................................................41
Join the Control Surfaces ................................................................41
Install the Hardware.........................................................................41
Attach the Canopy ...........................................................................42
Set the Control Throws ....................................................................42
Balance Your Model...............................................................................43
Preflight ..................................................................................................43
Charge the Batteries........................................................................43
Balance the Propeller ......................................................................44
Find a Safe Place to Fly ..................................................................44
Ground Check the Model.................................................................44
Range Check Your Radio ................................................................44
Engine Safety Precautions ..............................................................44
AMA Safety Code (excerpt)...................................................................45
General ............................................................................................45
Radio Control...................................................................................45
Flying ......................................................................................................45
Takeoff .............................................................................................45
Flying ...............................................................................................46
Landing ............................................................................................46
2-View Drawing ......................................................................................47
Flight Log................................................................................................48
Fuse & Wing Plans w/Parts List .......................Center Pull-Out Section
Your Extra 300S is not a toy, but a sophisticated, working
model that functions very much like a full-size airplane.
Because of its realistic performance, the Extra, if not
assembled and operated correctly, could possibly cause
injury to yourself or spectators and damage property.
If this is your first sport model, we recommend that you
get help from an experienced, knowledgeable modeler
with your first flights. You’ll learn faster and avoid risking
your model before you’re ready to take the controls for
yourself.
You may also contact the national Academy of Model
Aeronautics (AMA), which has more than 2,500 chartered
clubs across the country. Contact AMA at the address or
toll-free phone number below:
Academy of Model Aeronautics
5151 East Memorial Drive
Muncie, IN 47302-9252
Tele. (800) 435-9262
Fax (765) 741-0057
Or via the internet at: http://www.modelaircraft.org
Congratulations and thank you for purchasing the Great
Planes Extra 300S. We’ve selected the “S” because we feel
it looks the best and it is truly meant to perform aerobatics.
Among a few versions of the Extra 300 out there, another
popular one is the “L” which accommodates two
passengers–one student and one flight instructor.
The Extra is a rather “square shaped” airplane with well
defined lines. Coincidentally, this makes it exceptionally
easy to build and cover–especially for a semi-scale sport
model. Framing the model is very straightforward as most
of the structure features interlocking balsa and lite-ply. The
turtle deck sheeting may look a little intimidating but in
actuality it is quite easy to apply if you follow the
instructions and use the template provided to cut the
sheeting.
Flying the Extra 300S is a thrilling experience–as it should
be for such an aerobatic model! It doesn’t take much
elevator or aileron throw to put the Extra through its paces.
When you have a feel for your Extra 300S, the throws can
be increased to high rates (illustrated in the instructions) to
really showcase the aerobatic potential. The Extra performs
surprisingly well on a ball bearinged, Schnuerle ported .61,
INTRODUCTION
PROTECT YOUR MODEL,YOURSELF
& OTHERS...FOLLOW THIS
IMPORTANT SAFETY PRECAUTION
TABLE OF CONTENTS
2
and even better with a .91 4-stroke, but seasoned experts
will surely want to get the most out of the Extra by
strapping on a .91 2-stroke or a 1.20 4-stroke.
We hope you enjoy building and flying your Great Planes
Extra 300S as much as we did flying the prototypes.
1. Build the model according to the plans and
instructions. Do
not alter or modify the model, as doing so may result in an
unsafe or unflyable model. In a few cases the plans and
instructions may differ slightly from the photos. In those
instances the plans and written instructions should be
considered as correct.
2. Take time to build straight, true and strong.
3. Use an R/C radio system that is in first-class condition,
and a correctly-sized engine and components (fuel tank,
wheels, etc.), throughout your building process.
4. Properly install all components so that the model
operates properly on the ground and in the air.
5. Check the operation of the model before every flight to
insure that all equipment is operating correctly and that the
model has remained structurally sound. Be sure to check
nylon clevises or other connectors often and replace them
if they show signs of wear or fatigue.
6. If you are not already an experienced R/C pilot, you must
fly the model only with the help of a competent, well
experienced R/C pilot.
Remember: Take your time and follow directions to end
up with a well-built model that is straight and true.
Please inspect all parts carefully before starting to build!
If any parts are missing, broken or defective, or if you
have any questions about building or flying this model,
please call us at (217) 398-8970 and we’ll be glad to help.
If you are calling for replacement parts, please reference
the part numbers and the kit identification number
(stamped on the end of the carton) and have them ready
when calling.
We can also be reached by E-Mail at:
productsupport@greatplanes.com
Items in parentheses (GPMQ4243) are suggested part
numbers recognized by distributors and hobby shops and
are listed for your ordering convenience. GPM is the Great
Planes brand, TOP is the Top Flite®brand, and HCA is the
Hobbico®brand.
❏ Four-channel radio with five servos (Optional 6th
servo for twin elevator servos)
❏ Engine – See Engine Selection above
❏ Exhaust – See Exhaust System above
❏ Spare glow plugs (O.S. #8 for most 2-stroke engines,
OSMG2691, O.S. Type-F for most 4-stroke engines,
OSMG2692)
❏ Propeller (Top Flite
®
Power Point™); Refer to your
engine’s instructions for proper size
❏ Top Flite Super MonoKote
®
covering (2 to 3 rolls) –
See Covering (page 40)
❏ Fuelproof paint, See Painting (page 40)
❏ Fuel tank 12 oz. (GPMQ4105)
❏ 3" Medium fuel tubing (GPMQ4131)
❏ 1/4" Latex foam rubber padding (HCAQ1000)
❏ 1/16" Foam wing seating tape (GPMQ4422)
❏ (2) 2-3/4" Wheels (GPMQ4224)
❏ (1) 3/16" Wheel collar (GPMQ4308)
❏ 2-1/2" Spinner (GPMQ4520, White)
❏ Pilot (DGA
®
1/4 scale sportsman pilot used in protype,
DGAQ2010)
❏ Fueling system (Great Planes Easy Fueler
™
,
GPMQ4160)
❏ Pacer Formula 560 canopy glue (PAAR3300)
Required Accessories
PREPARATIONS
Engine Selection
There are several engines that will work well in your
Extra 300S, but for unlimited performance we
recommend a hot 2-stroke such as an O.S.®.91FX or
SuperTigre™G90. If you prefer a 4-stroke, an O.S. .91
Surpass™works well and the O.S. 1.20 Surpass makes
unlimited vertical lines a part of every flight experience.
Your choice of 2-stroke or 4-stroke will determine the
location of the pushrod exit on the firewall, so plan ahead.
Exhaust System
If you choose to use a 2-stroke engine, you will need an
in-cowl muffler for the best appearance. On our protype
Extra 300S with the O.S. .61FX, we used the Slimline
#3217 Pitts Muffler (SLIG2217). With the O.S. Surpass
.91 and Surpass 1.20, we used the stock muffler
included with the engines. The Hobbico exhaust
extension allows the stock muffler to fit inside the cowl.
DECISIONS YOU MUST MAKE
NOTE: We, as the kit manufacturer, provide you with a
top quality kit and great instructions, but ultimately the
quality of your finished 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.
PRECAUTIONS
3
These are the building tools, glue, etc., that we recommend
and mention in the manual.
We recommend Great Planes Pro™CA and Epoxy.
❏ 2 oz. Pro CA (Thin, GPMR6003)
❏ 2 oz. Pro CA+ (Medium, GPMR6009)
❏ 1 oz. Pro CA+ (Thick, GPMR6014)
❏ 6-Minute Pro Epoxy (GPMR6045)
❏ 30-Minute Pro Epoxy (GPMR6047)
❏ CA accelerator (GPMR6035)
❏ Hand or electric drill
❏ Hobby knife handle (HCAR0105, #11 Blades
HCAR0311)
❏ Razor Saw
❏ Pliers (Common and Needle Nose)
❏ Screwdrivers (Phillips and flat blade)
❏ Small T-pins (HCAR5100)
❏ Medium T-pins (HCAR5150)
❏ Masking tape (TOPR8018)
❏ Bar sander or sanding block and sandpaper (coarse,
medium, fine grit)
❏ Easy-Touch
™
(or similar)
❏ Plan Protector (GPMR6167) or waxed paper
❏ Lightweight balsa filler such as Hobbico
®
HobbyLite
™
(Hobbico HCAR3401)
❏ Monofilament string for aligning wing & stabilizer
❏ 90º Building square (HCAR0480)
❏ Builders triangle set (HCAR0480)
❏ 1/4-20 Tap (GPMR8105, drill bit included)
❏ Electric power drill
❏ Sealing iron (TOPR2100)
❏ Heat gun (TOPR2000)
❏ Drill bits: 1/16", 5/64", 3/32", 7/64", 1/8", 5/32", #18 or
11/64", 3/16", #10 or 13/64", 7/32", 1/4", 17/64"
On our workbench, we have three 11" Great Planes
Easy-Touch Bar Sanders, equipped with 80, 150 and
220-grit sandpaper. This setup is all that is required
for almost any sanding task. We also keep some
320-grit wet-or-dry sandpaper handy for finish sanding
before covering.
Great Planes Easy-Touch Bar Sanders are made from
lightweight extruded aluminum and can be found at most
hobby shops. They are available in five sizes – 5-1/2"
(GPMR6169) for those tight, hard-to-reach spots;
11" (GPMR6170) for most general purpose sanding; and
22" (GPMR6172), 33" (GPMR6174) and 44" (GPMR6176)
for long surfaces such as wing leading edges. The
Easy-Touch Adhesive-Backed Sandpaper comes in
2" x 12' rolls of 80-grit (GPMR6180), 150-grit (GPMR6183),
180-grit (GPMR6184) and 220-grit (GPMR6185) and an
assortment of 5-1/2" long strips (GPMR6189) for the short
bar sander. The adhesive-backed sandpaper is easy to
apply and remove from your sanding bar when it’s time
for replacement.
Custom sanding blocks can be made from balsa or
hardwood blocks and sticks for sanding difficult or hard to
reach spots.
❏ CA Applicator tips (HCAR3780)
❏ Epoxy brushes (GPMR8060)
❏ Epoxy mixing sticks (GPMR8055, Qty. 50)
❏ CA Debonder (GPMR6039)
❏ Trim seal tool (TOPR2200)
❏ Hot Sock
™
(TOPR2175)
❏ Razor plane (MASR1510)
❏ Single-edge razor blades (HCAR0312)
❏ Straightedge (Hobbico Non-Slip, HCAR0475)
❏ Denatured or isopropyl alcohol (for epoxy clean-up)
❏ Dremel
®
Moto-Tool®or similar
❏ Cut-off wheel w/mandrel (GPMR8200)
❏ Curved tip canopy scissors (HCAR0667)
Elev = Elevator Fuse = Fuselage
LE = Leading Edge (front) LG = Landing Gear
Ply = Plywood Stab = Stabilizer
TE = Trailing Edge (rear) " = Inches
Bass = Basswood Fin = Vertical Fin
Common Abbreviations
Balsa Basswood Plywood
Types of Wood
Optional Tools or Accessories
Building Supplies and Tools
4
5
There are two types of screws used in this kit:
Sheet metal screws are designated by a number and a
length. For example #6 x 3/4"
Machine screws are designated by a number, threads per
inch and a length. For example 4-40 x 3/4"
When you see the term “test fit” in the instructions, it
means you should first position the part on the assembly
without using any glue and then slightly modify or sand
the part as necessary for the best fit.
Whenever the instructions tell you to glue pieces together,
CA or epoxy may be used. When a specific type of glue is
required, the instructions will state the type of glue that is
highly recommended. When 30-minute epoxy is
specified, it is highly recommended that you use only 30minute epoxy because you will need the working time
and/or the additional strength.
Several times during construction we refer to the “top” or
“bottom” of the model or a part of the model. For example,
during wing construction we tell you to “glue the top main
spar” or during fuse construction “trim the bottom of the
former.” It is understood that the “top” or “bottom” of the
model is as it would be when the airplane is right side up
and will be referred to as the “top” even if the model is
being worked on upside-down (i.e. the “top” main spar is
always the “top” main spar, even when the wing is being
built upside-down).
❏ 1. Unroll the plan sheet. Reroll the plan sheet inside out
to make it lie flat. Place wax paper or a Great Planes Plan
Protector™over the area of plan you are working on to
prevent glue from sticking to the plan. Use tape or tacks to
hold the plan and protector securely in place.
❏ 2. Remove all parts from the box. As you do, determine
the name of each part by comparing it with the plan and
the parts list included with this kit. Using a felt-tip or
ballpoint pen, lightly write the part name or size on each
piece to avoid confusion later. Use the die-cut patterns
shown on pages 6 and 7 to identify the die-cut parts and
mark them before removing them from the sheet. Save all
leftovers. If any of the die-cut parts are difficult to remove,
do not force them! Instead, cut around the parts with a
hobby knife. After punching out the die-cut parts, use your
Easy-Touch Bar Sander or sanding block to lightly sand
the edges to remove any die-cutting irregularities or slivers.
❏ 3. As you identify and mark the parts, separate them
into groups, such as fuse (fuselage), wing, fin, stab
(stabilizer) and hardware.
Zipper-top food storage bags are handy to store small
parts
as you sort, identify and separate them into
sub-
assemblies.
Get Ready to Build
Building Notes
0" 1" 2" 3" 4" 5" 6" 7"
0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180
Inch Scale
Metric Conversions
1/64" = .4 mm
1/32" = .8 mm
1/16" = 1.6 mm
3/32" = 2.4 mm
1/8" = 3.2 mm
5/32" = 4.0 mm
3/16" = 4.8 mm
1/4" = 6.4 mm
3/8" = 9.5 mm
1/2" = 12.7 mm
5/8" = 15.9 mm
3/4" = 19.0 mm
1" = 25.4 mm
2" = 50.8 mm
3" = 76.2 mm
6" = 152.4 mm
12" = 304.8 mm
18" = 457.2 mm
21" = 533.4 mm
24" = 609.6 mm
30" = 762.0 mm
36" = 914.4 mm
6
DIE-CUT PATTERNS
7
DIE-CUT PATTERNS
You may remove the stabilizer and elevator drawing from
the wing plan by cutting along the dashed line. Don’t forget
to cover the plan with a Great Planes Plan Protector so the
glue won’t stick to the plan.
❏ 1. From the 3/16" x 1-1/2" x 24" balsa sheet cut down to
15". Use a ballpoint pen and a draftsmen’s square to
accurately mark the centerline of the 15" balsa sheet stab
LE doubler. Use your pen to make a mark on each end of
the doubler 15/16" from the LE.
❏ 2. Use a straightedge to draw lines connecting the
centerline of the stab LE doubler with the marks on the
ends as shown in the photo.
❏3. Use a hobby knife with a sharp #11 blade to cut along
the lines you drew. If necessary, use a bar sander to true
the leading edges you just cut.
❏ 4. Use the plan as a guide to mark and cut the bevel on
both ends of the stab LE doubler.
❏ 1. See the Expert Tip that follows, then glue three 1/16"
x
3" x 30" balsa sheets together. This will be cut in half
lengthwise creating the sheeting for the stab.
HOW TO JOIN SHEETING
A. Use a metal straightedge as a guide to trim one edge
of both sheets.
B. Use masking tape to tightly tape the two sheets
together joining the trimmed edges.
C. Turn the sheet over and place weights on top of the
sheet to hold it. Apply thin CA sparingly to the seam
between the two places, quickly wiping away excess CA
with a paper towel as you proceed.
D. Turn the sheet over and remove the masking tape,
then apply thin CA to the seam the same way you did for
the other side.
E. Sand the sheet flat and smooth with your bar sander
and 150-grit sandpaper.
Make the Stab & Fin Sheeting
Make the Stab Leading Edge Doubler
BUILD THE TAIL SURFACES
8
❏ 2. Cut the sheet you have made in half making two
sheets 4-1/2" x 30" stab sheets.
❏ 3. Cut the 1/16" x 3" x 36" balsa sheet into four 9"
sheets. Edge glue two of them together to make two sets of
1/16" x 6" x 9" fin sheets.
❏ 1. Pin the stab LE doubler in position over the plan. Fit
and glue a 3/16" x 3/16" x 14" basswood front stab spar,
to the back of the stab LE doubler. Wipe away excess CA
before it cures.
❏2. Test fit the 3/16" x 1-7/8" x 4" balsa stab center in
place.
You will need to trim the stab center down for a perfect fit.
When happy with the fit, glue it to the 3/16" stab spar.
❏ 3. Fit and glue the 3/16" x 3/16" x 14" basswood rear
stab spar to the rear of the stab center.
❏4. Glue the 3/16" x 1/2" x 30" balsa stab TE in place.
❏ 5. Using two 3/16" x 1/2" x 14" balsa sticks, fit and glue
the LE on the stab. Save the ends of the LE sticks for the
gussets at the outer LE corners.
❏6. From a 3/16" x 3/16" x 36" balsa stick, fit and glue the
eight stab ribs in place.
❏7. Using the leftover pieces you saved from the LE stick,
fit and glue two tip gussets in place.
❏ 8. Use your bar sander or a large sanding block and
220-grit sandpaper to sand the entire top and bottom
surface of the stab framework until it is flat and even. Be
careful while sanding so you do not over-thin any one
particular area of the stab or gouge the stab cross braces
by snagging the sandpaper on them.
❏❏9. Using medium CA, Glue the stab framework to one
of the stab sheets you made earlier, aligning the sheeting
parallel to the TE of the stab. Give the CA ample time to
cure before lifting the assembly off the work bench.
Note: It is essential to get a very secure and uniform bond
between the stab sheets and the stab core, especially in
the center.
Note: Refrain from using excessive accelerator. Even
hours after it’s sprayed on, residual accelerator can
prematurely and unexpectedly cure the CA you use later
on nearby glue joints. Unless you must handle or remove
the part from your building board right away we
recommend using no accelerator at all.
Build the Stab
1/16" x 3" x 30" balsa sheets
9
Cut down the middle to make two 4-1/2" sheets.
❏❏10. Place the sheeted side of the stab on your work
bench and trim the sheeting around the outer edges of the
framework.
❏11. Repeat steps 9 and 10 to sheet the remaining side of
the stab.
❏❏1. Make the LE using a 5/16" x 1/2" x 14" balsa stick
(leave 1/16" of length at both ends).
❏❏2. Make the root end, cut from a 5/16" x 1" x 12"
balsa stick.
❏❏3. Make the TE using a 5/16" x 5/16" x 36" balsa stick
(leave 1/16" of length at both ends).
❏❏4. Make the tip and ribs using a 5/16" x 5/16" x 36"
stick.
❏❏5. Make the diagonal ribs using a 1/8" x 5/16" x 36"
balsa stick.
❏❏6. Remove the elevator from the plan and inspect all
glue joints. Add CA where necessary. Sand the LE and TE
flush with ends.
❏❏7. Add 1/8" balsa to both ends of the elevator. Sand
flat and smooth with a bar sander and 220-grit sandpaper.
❏8. Build the second elevator the same as the first.
Note: Because it is not necessary to build on the fuse
plans we reduced them to 75% so that they are easier to
use as a reference while building the fuse. Make sure to
build the fin and rudder over the full-size drawing, not
the reduced plan.
❏1. Make the LE and TE using 3/16" x 1/2" x 14" balsa
sticks.
❏ 2. Make the fin tip using the 3/16" x 1/2" balsa stick
remaining from step A.
❏ 3. Make the fin base using the leftover 3/16" x 1-1/2"
x 9" stick remaining from the stab LE doubler assembly.
❏ 4. Make the 3/16" fin ribs and cross trusses using the
leftover 3/16" x 3/16" stick from the stab rib assembly.
❏ 5. From 3/16" x 3/16" balsa fit and glue the bottom key
in place.
❏ 6. Remove the fin from your building board and inspect
all the glue joints. Add CA where necessary. Use your bar
sander to sand the top of the leading and trailing edges
even with the tip of the fin. Sand the bottom of the leading
edge even with the base. Sand the entire fin flat and
smooth with your bar sander and 220-grit sandpaper.
❏ 7. Sheet both sides of the fin with the 1/16" fin sheets
you made earlier using the same technique you did with
the stab.
❏8. From leftover 1/16" sheeting, sheet the fin post.
❏9. Trim and sand the sheeting flush with the framework.
Fin Building Sequence
Elevator Building Sequence
10
❏ 1. Make the LE using a 5/16" x 1/2" x 14" balsa stick
(leave 1/16" of length at both ends).
❏ 2. Make the balance tab using 5/16" x 1-1/2" x 2-3/4"
balsa sheet.
❏ 3. Make the rudder bottom from the remaining piece of
5/16" x 1" stick leftover from the elevator root assembly.
❏ 4. Make the TE from the 5/16" x 5/16" stick leftover from
the elevator TE assembly.
❏
5. Make three rudder ribs using the remainder of the 5/16"
x 5/16" x 36" balsa stick.
❏ 6. Make the cross trusses and rudder top cap from the
remaining piece of 1/8" x 5/16" remaining from the elevator
assembly.
❏ 7. Using a leftover piece from the LE, glue the corner
gusset in place.
❏ 8. Inspect all the glue joints and add CA where
necessary. Shape the bottom of the rudder as shown on
the plan. Sand the entire rudder flat and smooth with your
bar sander.
❏❏1. Place the stab over its location on the plan and
lightly
mark the hinge locations on the trailing edge with a
ballpoint pen. Mark the hinge locations on the elevators
using the same procedure.
❏❏2. Cut the hinge slots in the elevator and stabilizer
using a #11 blade. Begin by carefully cutting a very shallow
slit at the hinge location to accurately establish the hinge
slot. Make three or four more cuts going a little deeper each
time. As you cut, slide the knife from side to side until the
slot has reached the proper depth and width for the hinge.
❏❏3. Cut twenty four 3/4" x 1" hinges for the elevators
and rudder from the supplied 2" x 9" hinge material, then
snip off the corners. Temporarily join the elevators to the
stab with the hinges, adjusting any hinge slots if necessary
so they all align. Do not glue the hinges in place until
you are instructed to do so.
❏ 4. Return to step 1 and use the same procedures to
hinge the rudder and fin.
❏ 1. Shape the leading edge of the elevators to a “V” as
shown on the plan using a razor plane and bar sander.
❏ 2. Use the same procedure to bevel the leading edge of
the rudder. It will be necessary to sand the bevel at the top
of the rudder hinge line using your sanding block, because
the balance tab will not allow the razor plane to go the
full length.
❏ 3. Use your bar sander and 150-grit sandpaper to round
the tail surfaces as shown on the fuse plan.
That’s about it for the tail surfaces. They’re a little more
work than sheet surfaces but they are much lighter, just as
strong, and a nice piece of craftsmanship. Clean off your
work bench and get ready for the wing!
Finish the Tail Surfaces
Hinge the Tail Surfaces
Rudder Building Sequence
11
1"
1"
3/4"
Note: The following instructions explain how to build the
wing directly over the plans. We’ll start by building the left
wing panel upside-down over the left wing panel plan so
your progress matches the photos.
❏ 1. Before using the 1/4" x 3/8" x 32" basswood spars,
examine them carefully for possible imperfections. Look for
knots, soft spots, diagonal grain and any other
imperfections. If possible, position each spar so the
imperfections (if any) are on the outer half of the wing panel
(toward the tip), where they will be least affected by high
stresses. If the spars are warped slightly, try to “balance
them out” by installing the warped spars in opposite
directions (see sketch).
❏ 2. Find the 1/8" x 3/8" x 18" basswood sticks. Cut the
sticks down to 15-3/4" making the spar doublers. Sand
one end of each of the four spar doublers to a taper as
shown on the plan. Glue the spar doublers to the spars and
sand off any excess glue.
❏ 3. Carefully press out all the die-cut 3/32" balsa wing
ribs. Sand the edges slightly to remove any die-cutting
irregularities.
❏❏1. Tape the left wing plan to your flat work surface,
and cover the wing drawing with Great Planes Plan
Protectors (so you won’t glue the wing to the plan!).
❏❏2. Cross pin a top spar to the plan with the doubler
up and toward the root. Note: The spars are cut slightly too
long. Align them at the root and leave the excess past the
tip rib.
❏❏3. Glue ribs R3 to R10 to the top spar over their
locations shown on the plan, using rib gauge G1 to set the
ribs at the correct angle. Note: One angle on G1 is used as
a rib angle guide and the other angle on it is used for
setting the cockpit rear former at the correct angle.
❏❏4. Place the bottom spar into the rib notches, and use
G1 to position the root end of the spar. When satisfied with
the fit, glue the spar to the ribs with thin CA.
❏❏5. Glue R1, R2 and R2A in place using a leftover
piece of 1/16" ply as a spacer to locate the ribs 1/16" away
from the spars. Do not glue the spacer while gluing the ribs.
Build the Wing Panels
Build the Wing Spars
BUILD THE WING
12
❏❏6. From a 3/32" x 3" x 24" balsa sheet, make shear
webs to fit from ribs R3 through R8, with an additional web
aft of the spars between R3 and R4. Hint: Use a #11 hobby
knife to hold the cut shear webs while putting glue on the
web and put the webs in place.
❏❏7. Glue the 1/8" x 1/4" x 36" balsa bottom rear spar
in place butting it against R1. Remember we are building
the wing upside-down so the bottom spar is on the top now.
Note: It is necessary to bevel the root end of the spar so it
will fit well against R1.
❏❏8. Pull the 1/8" x 1/4" x 36" balsa top rear spar up
into the notches in the ribs and glue in place. Trim the ends
of the rear spars off at the wing tip.
❏❏9. Make marks on the ribs 3/8" forward of the rear
spar.
❏❏10. Glue a piece of 1/16" x 3" x 36" balsa sheet on
the TE of the wing, aligning the LE of the sheeting with the
marks you made in step 9.
❏❏11. Glue the 3/32" x 5/8" x 30" sub LE on the LE of
the ribs, centering it vertically and leaving the excess at the
root of the wing.
❏❏12. Use a razor plane and/or a sanding block, shape
the sub LE so it aligns with the tops of the ribs and the
shape of the airfoil.
❏❏13. Glue a 1/16" x 4" x 32" balsa sheet to the forward
half of the main spar. Note: Make sure the sheeting hangs
over the tip rib and the center of the wing slightly.
13
❏❏14. Carefully lift the sheeting away from the ribs, then
apply a bead of medium or thick CA to the top of each rib
and the sub LE. Working quickly, pull the sheeting forward
as you press it down to the ribs and the sub LE. Use
weights to hold the sheeting to the ribs and sub LE until the
CA cures. Note: It may be necessary to place weights on
the TE of the wing so that the TE of the wing stays down on
the jig tabs.
❏ 1. From a 1/16" x 3" x 36" balsa sheet, cut three 10-1/2"
long sheets. From another 1/16" x 3" x 36" sheet, cut one
more 10-1/2" long sheet. Save the remaining 25-1/2" for
step #3.
❏2. Cut a curve on the end of one of the sheets, using the
plan as a guide. The curve does not have to be an exact
match. Use that one as a template to mark and cut the
three other sheets. These are the forward center sheets.
❏ 3. From a leftover piece of 1/16" x 3" x 25-1/2" balsa
sheet, cut three 7" long sheets. From a 1/16" x 3" x 36"
balsa sheet, cut five 7" long sheets. These eight 7" pieces
are used for the rest of the center sheeting.
❏❏4. Fit and glue one of the four forward center sheets
(from step 2) in place on the wing.
❏❏5. Glue the 7" balsa middle center sheet in place.
❏❏6. Using a 7" balsa sheet, fit and glue the rear center
sheet in place.
❏❏1. Glue the die-cut 1/8" ply aileron servo tray (6A) to
the spar and rib with medium CA.
❏❏2. Glue the die-cut 1/8" ply servo mount support
(6B) in place.
❏❏3. Glue the die-cut 3/32" balsa sub rib (6C) in place.
Servo Mount
Sheet the Center Section
14
❏❏4. Glue a piece of 1/16" balsa to the servo mount
support, aligning it with the top of the sub rib and the top of
R6 as shown in the photo.
❏❏5. Using leftover 1/16" balsa, sheet over the servo
tray area. Note: You will cut the opening for the servo after
the wing is unpinned from your building board.
❏❏6. From a 1/16" x 1/4" x 36" balsa stick, cut and glue
cap strips to all of the exposed ribs. Hint: For easier
positioning of the cap strips, first mark the location of each
rib on the LE and TE sheeting.
❏❏7. Remove the T-pins, then take the wing off your
building board.
❏❏8. Trim the LE sheeting flush with the front of the
sub LE.
❏❏9. Cut the TE sheeting along the outside edge of R4
from the aft edge of the spar to the aft edge of the sheeting.
Trim the TE sheeting flush with the aft spar from R4 to the
wing tip. Note: Save this piece of sheeting for the aileron.
❏❏10. Draw a line 1/2" behind the TE of R2 - R4. Draw
another line 1/2" behind R1 and R2. Trim the TE sheeting
on the lines you just made.
❏❏11. Trim the center sheeting and TE sheeting flush
with R1.
❏❏12. Use a razor saw to accurately cut the spars, sub
LE, LE sheeting and TE sheeting flush with R10.
15
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