GREAT PLANES CAP 232 Instruction 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 buyers are not prepared to accept the liability associated with the use of this product,they are advised
to return this kit immediately in new and unused condition to the place of purchase.

READ THROUGH THIS INSTRUCTION MANUAL
FIRST. IT CONTAINS IMPORTANT INSTRUCTIONS
AND WARNINGS CONCERNING THE ASSEMBLY
AND USE OF THIS MODEL.

CAP4P03 V1.0 Entire Contents © Copyright 1998

P.O.Box 788 Urbana, IL 61801 [phone]

www.greatplanes.com

INSTRUCTION MANUAL

MADE IN

USA

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

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

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

Engine Selection............................................................3

Exhaust System.............................................................3

Servo Selection..............................................................3

PREPARATIONS ..............................................................3

Required Accessories....................................................3

Building Supplies & Tools...............................................4

Optional Supplies & Tools ..............................................4

Building Notes ...............................................................5

Types of Wood................................................................5

Common Abbreviations..................................................5

Metric Conversions ........................................................5

Get Ready to Build.........................................................5

DIE-CUT PATTERNS .................................................6 & 7

BUILD THE T AIL SURF ACES............................................8

Build the Stab.................................................................8

Elevator Building Sequence...........................................9

Fin Building Sequence...................................................9

Rudder Building Sequence ............................................9

Hinge the Tail Surfaces ..................................................9

Finish the Tail Surfaces................................................10

BUILD THE WING............................................................11

Make the Wing Sheets.................................................11

Build the Wing Panels..................................................12

Join the Wing Panels....................................................15

Sheet the Wing.............................................................16

Build the Ailerons.........................................................16

BUILD THE FUSELAGE..................................................18

Assemble the Fuselage Former & Sides......................18

Assemble the Fuselage................................................20

Mount the Wing to the Fuselage..................................21

Build the Front Fuselage Deck.....................................25

Mount the Stabilizer to the Fuselage............................26

Build the Turtledeck......................................................27

Mount the Engine.........................................................29

Install the Battery & Tank .............................................30

Install the Servos and Make the Pushrods...................31

Add the Forward & Aft Wing Fairings...........................33

Assemble the Wheel Pants..........................................34

Assemble the Cowl ......................................................36

Prepare the Model for Covering...................................37

COVER THE MODEL.......................................................37

Covering Technique......................................................37

Suggested Covering Sequence ...................................37

BALANCE THE MODEL LATERALLY............................38

PAINTING........................................................................38

FINAL HOOK-UPS AND CHECKS.................................38

Join the Control Surfaces.............................................38

Install the Hardware.....................................................39

Attach the Canopy........................................................39

Set the Control Throws.................................................40

Balance the Model .......................................................40

PREFLIGHT.....................................................................41

Charge the Batteries....................................................41

Balance the Propeller...................................................41

Find a Safe Place to Fly...............................................41

Ground Check the Model.............................................41

Range Check the Radio...............................................42

Engine Safety Precautions...........................................42

AMA Safety Code.........................................................42

FLYING ............................................................................43

Takeoff..........................................................................43

Flight ............................................................................43

Landing ........................................................................43

TWO VIEW DRAWING.................................BACK COVER

Your CAP 232 is not a toy, but rather a sophisticated,
working model that functions very much like an actual
airplane. Because of its realistic performance, the CAP, if
not assembled and operated correctly, could possibly cause
injury to yourself or spectators and damage property.

If this is your first low wing 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 truly
ready to solo.Your local hobby shop has information about
flying clubs in your area whose membership includes
qualified instructors.

You may also contact the national Academy of Model
Aeronautics (AMA), which has more than 2,500 chartered
clubs across the country.

Academy of Model Aeronautics

5151 East Memorial Drive

Muncie, IN 47302-9252

Tele. [phone]

Fax [phone]

Congratulations and thank you for purchasing the Great
Planes CAP 232. The CAP is a rather "square" airplane
with well-defined lines. Coincidentally, this makes it
exceptionally easy to build and cover–especially for a semi­scale sport model. Framing the model is very
straightforward, as most of the structure features
interlocking balsa and lite-ply. The turtledeck sheeting may
look a little intimidating but in actuality it is quite easy to
apply if you follow the instructions.

Flying the CAP 232 is a rewarding experience–as it should
be for such an aerobatic model! It doesn't take much
elevator or aileron throw to put the CAP through its paces.
When you have a feel for your CAP 232, the throws can be
increased to high rates (illustrated in the instructions) to

INTRODUCTION

PROTECT Y OUR MODEL,YOURSELF

& OTHERS...FOLLOW THIS

IMPORTANT SAFETY PRECAUTION

TABLE OF CONTENTS

2

really showcase the aerobatic potential.The CAP performs
surprisingly well on a ball bearing Schneurle por ted .40,
but seasoned experts will surely want to get the most out of
the CAP by bolting on a .46 2-stroke or a .70 4-stroke.

We hope you enjoy building and flying your Great Planes
CAP 232 as much as we did the prototypes.

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
airplane, please call us at [phone]. 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.

Product info – www.greatplanes.com

E-mail – [e-mail]

1. Build the plane 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 are 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. You must properly install all components so that the
model operates properly on the ground and in the air.

5.You must check the operation of the model before every
flight to ensure that all equipment is operating, 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.

Items in parentheses (OSMG2691) 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.

❏ 4 Channel Radio with 4 Servos
❏ Engine -

See

Engine Selection above

❏ Muffler -

See

Exhaust System above

❏ Spare Glow Plugs (O.S.#8 for most 2-stroke engines,

OSMG2691)

❏ Propeller (Top Flite

®

Power Point™) we found that a
11x4 on the O.S. .46FX and the 13x6 on the O.S. .70
Surpass worked the best.

❏ Top Flite Super MonoKote

®

covering (Approximately 2

rolls);

See

Covering (page 37)

Required Accessories

PREPARATIONS

Engine Selection

There are several engines that will work well in your CAP
232, but for unlimited performance we recommend a

hot

2-stroke such as an O.S.®.46FX or SuperTigre™GS-45. If
you prefer a 4-stroke, an O.S. .70 Sur pass™is the ticket.
Your choice of 2-stroke or 4-stroke will determine the
location of the throttle servo and throttle 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 prototype
CAP 232 with the O.S. .46FX we used the Slimline #3218
Pitts Muffler (SLIG2218) without the exhaust extension kit.If
you prefer to use an exhaust extension kit, you can always
purchase #8012 (SLIG5012) for this exhaust. On our
prototype CAP 232 with the O.S. 70 Sur pass, we used the
O.S.short flex pipe (0SMG2684) and the included muffler to
make the exhaust e xit in the scale location.

Servo Selection

During our extensive testing of the CAP 232, we found that
the CAP performs very well with standard Futaba®S3003
servos on all surfaces. However, for all-out 3D aerobatics,
the seasoned expert will want to consider high performance
servos such as the Futaba 9001 for elevator and rudder.
The additional torque, speed and centering capabilities of
these servos will provide crisper performance in everything
from slow rolls to hammerheads, torque rolls, knife edge
loops and beyond.

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

❏ Fuelproof paint;

See

Painting (page xxxx)

❏ Medium Fuel Tubing (GPMQ4131, 3')
❏ 1/4" Latex Foam Rubber Padding (HCAQ1000)
❏ 1/16" Foam Wing Seating Tape (GPMQ4422)
❏ 10 oz.Fuel Tank (GPMQ4104)
❏ (2) 2-1/2" Wheels (GPMQ4223)
❏ (1) 3/16" Wheel Collar (GPMQ4308)
❏ (2) 3/32" Wheel Collars (GPMQ4303)
❏ 2-1/2" Spinner (GPMQ4517 – red)
❏ Pilot (Williams Bros. 1/5 Scale Spor tsman Pilot used

in prototype, WBRQ2626)

❏ Fueling System (Great Planes Top Fueler,

™

GPMQ4160)

❏ Pacer Formula 560 Canopy Glue
❏ 1" Tail wheel (GPMQ4241)

These are the building tools, glue, etc. that we recommend
and mention in the manual.

We recommended Great

Planes Pro™CA and Epoxy

❏ 2 oz.Thin CA (GPMR6003)
❏ 2 oz.Medium CA+ (GPMR6009)
❏ CA Accelerator (GPMR6035)
❏ 30-Minute Pro Epoxy (GPMR6047)
❏ Building Square (HCAR0480)
❏ Plan Protector (GPMR6167)
❏ #1 Hobby Knife Handle (HCAR0105)
❏ #11 Blades (HCAR0311, 100 qty.)
❏ Razor Saw
❏ Small T-pins (HCAR5100)
❏ Medium T-pins (HCAR5150)
❏ Masking Tape
❏ Electric Power Drill
❏ 1/4-20 Tap (GPMR8105, drill bit included)
❏ Drill Bits:1/16", 3/32", 7/64", 1/8", 5/32", #18 or

11/64", 3/16", #10 or 13/64" (unless purchased with
1/4-20 Tap listed above), 7/32", 1/4", 17/64"

❏ Pliers
❏ Monofilament String for aligning wing and stabilizer
❏ Screwdrivers (Phillips and Flat Blade)
❏ HobbyLite

™

Balsa Filler (HCAR3401)

❏ Sealing Iron (TOPR2100)
❏ Bar Sander or Sanding Block and Sandpaper (coarse,

medium, fine grit)

❏ Microballoons

In our busy work shop we use the Great Planes

Easy-Touch

™

Bar Sanders equipped with Great Planes

#80, #150 and #220-grit Easy-Touch Adhesive-Backed

Sandpaper. Great Planes Easy-Touch Bar Sanders are
made from lightweight, rigid, extruded aluminum and can
be found at most hobby shops.

They are available in three sizes–5-1/2" (GPMR6169) and
11" (GPMR6170) for most general purpose sanding and
22" (GPMR6172) 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), 220-grit (GPMR6185) and an assortment
pack 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.

This setup is all that is required for almost any sanding
task. Custom sanders can be made from balsa or
hardwood blocks and sticks for sanding difficult to reach
spots. We also keep some #320-grit wet-or-dry sandpaper
for finish sanding just before covering.

❏ 1 oz.Thick CA- (GPMR6014)
❏ 6-Minute Pro Epoxy (GPMR6045)
❏ CA Applicator Tips (HCAR3780)
❏ Epoxy Brushes (GPMR8060)
❏ Epoxy Mixing Sticks (GPMR8055, qty. 50)
❏ CA Debonder (GPMR6039)
❏ Hot Sock (TOPR2175)
❏ Trim Seal Tool (TOPR2200)
❏ Heat Gun (TOPR2000)
❏ Single Edge Razor Blades (HCAR0312, 100 qty.)
❏ Razor Plane (MASR1510)
❏ Straightedge (Fourmost Non Slip, FORR2149)
❏ 1/8" Brass Tube, see page 17, step 10
❏ 5/32" Brass Tube, see page 33, step 15
❏ Denatured or Isopropyl Alcohol (for epoxy clean-up)
❏ Dremel MultiPro

™

or similar w/Sanding Drum, Cutting

Burr, Cut-off Wheel

❏ Kyosho

®

Curved Scissors for trimming Cowl, Wheel

Pants and Canopy (KYOR1010)

Optional Supplies and Tools

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 #4 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, then slightly modify the part as
necessary for the best fit.

Whenever just “epoxy” is specified you may use

either

30-minute epoxy or6-minute epoxy. When 30-minute epoxy
is specified it is highly recommended that you use only
30-minute (or slower) epoxy because you will need either
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 “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.

Elev = Elevator Fuse = Fuselage

LE = Leading Edge (front) LG = Landing Gear

Ply = Plywood Stab = Stabilizer

TE = Trailing Edge (rear) " = Inches

1. Unroll the plan sheets. Reroll the plans inside out to
make them lie flat.

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 scraps. If
any of the die-cut parts are difficult to punch out, do not
force them! Instead, cut around the parts with a hobby
knife. After punching out the die-cut parts, use your 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 par ts, separate them into
groups, such as fuse (fuselage), wing, fin, stab (stabilizer)
and hardware.

Zipper-top food storage bags are handy for storing your
parts as you sort, identify and separate them into
sub-assemblies.

Get Ready to Build

1/64" = .4mm
1/32" = .8mm
1/16" = 1.6mm
3/32" = 2.4mm

1/8" = 3.2mm
5/32" = 4mm
3/16" = 4.8mm

1/4" = 6.4mm

3/8" = 9.5mm

1/2" = 12.7mm

5/8" = 15.9mm

3/4" = 19mm

1" = 25.4mm
2" = 50.8mm
3" = 76.2mm

6" = 152.4mm
12" = 304.8mm
15" = 381mm
18" = 457.2mm
21" = 533.4mm
24" = 609.6mm
30" = 762mm
36" = 914.4mm

1" = 25.4mm (conversion factor)

Metric Conversions

Common Abbreviations

Balsa Basswood Plywood

Types of Wood

Building Notes

6

DIE-CUT PATTERNS

7

DIE-CUT PATTERNS

❏ 1. Cover the stab portion of the plan with wax paper or

Plan Protector. Pin the die-cut 1/8" balsa stab LE doubler
in position over the plan. Glue the die-cut 1/8" balsa stab
center to the LE doubler with medium CA.

❏ 2. Using two of the 1/8" x 1/2" x 24" balsa sticks, cut and

fit the stab LE, TE, and tips.
Hint: Use a straightedge as a guide to make sure the stab
TE is straight before pinning in place. Glue the stab LE's,
TE, and tips in place with thin CA.

❏3.From the 1/8" x 1/4" x 24" balsa stick, fit and glue the four

cross braces in place. Do the same with a 1/8" x 1/8" x 30"
balsa stick to finish the remaining cross bracing.

❏ 4. 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.

❏❏5. Using medium CA, glue one 1/16" x 3" x 24" balsa

sheet to one side of the stab framework, 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.

❏❏6. Place the sheeted side of the stab on your bench and

trim the sheeting around the outer edges of the framework.

❏7.Repeat steps 5 and 6 to sheet the other side of the stab.

❏ 8. Place the sheeted stab back in place over the plan

and, using the dotted lines as a reference, draw a line on
the stab. Trim the leading edge of the stab on the line you
just drew.

There, that was kind of fun wasn't it? Let's continue to build
the elevators, fin, and rudder.

❏ 9. Make two laminated elevator balance tabs from the

four 1/8" die-cut balsa pieces.Make one rudder balance tab
from the two die-cut pieces.

❏ 10. Build the elevators, fin and rudder from the 1/4" thick

balsa sticks (unlike the 1/8" sticks you used for the stab).
Recommended building sequences follow.

Note: Do not glue the elevator or rudder balance tabs in
place until the leading edges are beveled.

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

BUILD THE T AIL SURFACES

8

A.1/4" x 1/2" LE pin in place
B.1/4" x 1/2" Root rib pin and glue
C.1/4" x 1/2" elevator tip rib fit and glue
D.1/4" x 1/2" TE fit and glue
E.1/4" x 1/4" ribs fit and glue
F. 1/8" x 1/4" diagonal ribs fit and glue
G.1/4" x 1/2" diagonal rib fit and glue
H.Remove the elevator from the plan and inspect all the

glue joints.Add CA where necessary.

I. Sand flat and smooth with bar sander and 220-grit

sandpaper. Note: Do not glue the laminated balance
tab in position until

after

you bevel the leading edge
of the elevator as instructed on page 11. This will
make it easier to sand the bevel.

J. Build the other elevator the same as the first.

A.Laminate the two die-cut 1/8" balsa Fin Bases

together and pin them in place.

B.1/4" x 1/2" TE
C.1/4" x 1/2" Fin tip
D. 1/4" x 1/2" LE (cut taper so it fits against F-9 as

shown on the plan)

E.1/4" x 1/2" center rib
F. 1/4" x 1/8" diagonal ribs
G. 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.

A.1/4" x 1/2" LE
B.1/4" x 1/2" Rudder bottom
C.1/4" x 1/2" TE
D.Two 1/4" x 1/2" ribs
E.One 1/4" x 1/2" diagonal rib
F. Two 1/8" x 1/4" diagonal ribs
G. Remove the rudder from your building board and

sand the top, the LE and TE so they are flush.
Note: Do not glue the laminated balance tab in
position until

after

you bevel the leading edge of the
rudder as instructed on page 11. This will make it
easier to sand the bevel.

H.Inspect all the glue joints. Add CA where necessary.

❏ 1. Place the stab over its location on the plan and

lightly

mark the hinge locations on the trailing edge with a ball
point pen. Mark the hinge locations on the elevators in the
same manner.

HOW TO MARK THE HINGE SLOTS

It's important that the hinge slots are centered and parallel to
the part you are hinging. The best way to start is by accurately
marking the hinge slots.We'll start with the stabilizer.

A. Lay the stabilizer and a ballpoint pen on a flat surface.
Mark a “test line” on the trailing edge of the stab, away from
the hinge locations you marked earlier.

Hinge the Tail Surfaces

Rudder Building Sequence

Fin Building Sequence

Elevator Building Sequence

9

B.Flip the stab over and mark another line in the same location
as the first.If you see only one line, then it is on center.Proceed
and mark the hinge slots at each hinge location. If you see two
lines you will have to adjust the height of the stab until you can
mark only one centerline.

C. Use playing cards or business cards to adjust the height
of the stabilizer until you can mark the centerline. Mark the
hinge slots at each hinge location.

D. Use the same technique to mark the centerline along the
entire length of both elevators.

❏ 3. 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.

❏ 4. Cut 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 in the hinges until you are instructed

to do so.

❏ 5. Retur n 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.

HOW TO BEVEL THE LEADING EDGES

A. Place the leading edge of one of the elevators on your

work surface and use your ballpoint pen to mark a “bevel
to” line on both sides about 3/32" high.

Note: You will probably have to adjust the height of the
elevator with card stock (as you did while marking the hinge
slots) so your “bevel to” line is not too high – making too
sharp of a “V.”

B. Using the “bevel to” lines and the centerline as a guide,
make the “V” on the leading edge of the elevators with a
razor plane or your bar sander and 150-grit sandpaper.

❏ 2. Use the same procedure to bevel the leading edge of

the rudder.

Finish the Tail Surfaces

10

CUT HINGE SLOT

WITH HOBBY KNIFE

AND #11 BLADE

11

❏ 3. Use the plan to make sure the balance tabs are

properly aligned.Then, using medium CA, glue the balance
tabs to both of the elevators and the rudder.

❏ 4. 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
about as strong, and are a nice piece of craftsmanship.
Clean off your work bench and get ready for the wing!

Now while you have a nice clean work bench, let’s start the
wing by making the sheeting.

❏❏1. Glue two 3/32" x 3" x 30" balsa sheets together to

make one 6" wide sheet for the top and bottom leading
edge wing sheeting for one wing half.

HOW TO MAKE WING SHEETS

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 flat. Apply thin CA spar ingly to the seam
between the two pieces, 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 Wing Sheets

BUILD THE WING

❏❏2. Cut the sheet as shown in the photo to make a top

and a bottom LE wing sheet.

❏ 3. Repeat steps 1 and 2 to make the two leading edge

wing sheets for the other wing half.

We’ll start by building the right wing panel upside down over
the left wing panel plan so your progress matches the photos .

❏❏1. Using two large T-pins, cross pin the root end of a

5/16" x 5/16" x 30" basswood main spar over its location on
the plan so it lines up with the wing centerline. This is the

top spar. Cross pin the tip of the spar to the plan with a
piece of 3/32" leftover balsa under the spar past the
location of rib R-10.

❏❏2. Place (do not glue) the die-cut 3/32" balsa wing

ribs R-2 through R-10 on the top spar over their locations

on the plan. Note: The short jig tabs on every rib, should
be contacting the plan.

❏ 3. Using the dihedral gauge to set rib R-2 at the proper

angle, pin the jig tabs in place with small T-pins. Again
using the dihedral gauge, pin ribs R-2 through R-10 to your
building board over their location on the plan.
Note: Inser t the T-pins at an angle from the rear, so they
can be removed after the trailing edge and bottom sheeting
are glued in position.

❏❏4. Place a 5/16" x 5/16" x 30" spar in the notches of the

ribs, using the dihedral gauge to locate this bottom spar.

Note: Due to the decreasing thickness of the wing

towards the tip, the top

main spar

is not pinned directly

to the building board. Instead, the

ribs

are securely

pinned to the building board. You must follow the

instructions closely on where to insert the T-pins in the
ribs so you do not conceal them under the sheeting,
making it very difficult to remove the wing from the
building board.

Build the Wing Panels

12

❏❏5. Glue the main spars to the ribs with thin CA. As

you glue each rib to the spars, simultaneously

pull

the top

spar up into the rib and

push

the bottom spar down into the
rib to make sure the spars are fully seated in the notches.
Make sure all the jig tabs are contacting the work surface.

❏❏6. Lightly r un a sanding bar across the front of the r ibs

to check alignment. Position the shaped leading edge (LE)
on the front of the ribs.The LE should be centered on all the
ribs and the root end should extend past rib R-2 by about
1/16". Make sure all the jig tabs are contacting the work
surface.Use thin CA to glue the LE to the front of the ribs.

❏❏7. Place the 30" balsa shaped trailing edge (TE)

against the rear of the rib tabs and flat on the work bench.

Mark the root end so that it lines up with the centerline of
the wing.Take the TE off your work bench and sand the TE
to the mark you made.

❏❏8. Using the dihedral gauge to correctly position the

TE, use thin CA to glue the trailing edge (TE) to the ends of
the ribs.

❏❏9. Starting at ribs R-8 & R-7, test fit the die-cut 3/32"

cross grain balsa shear webs to the front of the spars.
Note that the shear webs increase in height as they get
closer to the root. Glue them in place with medium CA.
There are two additional shear webs for the rib bays
between ribs 2 & 3 and 3 & 4. Glue these to the back of the
spars between these ribs with medium CA.

❏❏10. Use medium CA to glue the 3/32" x 7/8" x 30"

trailing edge sheeting to the TE and ribs so the end
extends past the wing centerline by approximately 1/8".

❏❏11. Without gluing, fit one of the leading edge sheets

to the bottom of the wing panel by sanding a bevel on the
front edge of the sheet so it matches the leading edge of
the wing.

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❏❏12. Before you glue the LE sheeting in position,

remove the T-pins from the front jig tabs in the wing ribs.

❏❏13.Wet the outside of the leading edge sheeting so it

will bend easier. (Hint: a 50/50 mix of water and alcohol or
ammonia helps break down the wood fibers so the sheet is
even easier to bend). Run a bead of medium CA down the
leading edge of the sheeting. Position the front of the sheet
against the LE of the wing and use accelerator to hold it
there.Wet the sheet once more if needed.

❏❏14. Carefully lift the sheeting away from the ribs.

Working quickly, apply a bead of medium or thick CA to the
top of each rib where the sheeting contacts the spar.

Pull

the sheeting back toward the main spar as you

press

it
down to the ribs and spar. Use masking tape, T-pins or
weights to hold the sheeting to the ribs until the CA cures.

❏❏15. Remove the T-pins, then flip the wing half over on

your building board.

❏❏16. Use a sharp hobby knife to remove the tabs from

the top of the wing. Use a sanding block with 220-grit
sandpaper to clean the edges of the ribs where the tabs
have been removed.

❏❏17. Using a razor saw, trim the spars, LE, TE, LE

sheeting, and TE sheeting flush with R-10.Also trim the LE
and LE sheeting flush with the edges of R-2.

❏❏18. Using the spars and the TE as a guide, sand off

the TE sheeting at the root of the wing.
Note: DO NOT SAND the shaped TE or the spars.

❏ 19. Glue the TE and LE sheeting onto the top of the

wing following the same procedures you used on the
bottom of the wing. (Steps 10-14)

❏ 20. Trim and sand the TE and LE sheeting using the

same procedures you did on the bottom of the wing.
(Steps 16-18)

❏❏21. From the 3/32" x 1/4" x 24" balsa sticks, cut cap

strips and use medium CA to glue them to the top and
bottom of ribs R-4 thru R-10.
Note: Do not put cap strips on R-2 or R-3, as they will be

sheeted after the wing halves are joined.

❏ Repeat steps 1 through 21 to build the left wing panel

over the right wing drawing on the plan.

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