Great Planes GPMA0110 User Manual
READ THROUGH THIS INSTRUCTION
BOOKLET FIRST. IT CONTAINS IMPORTANT
INSTRUCTIONS AND WARNINGS CONCERNING THE BUILDING AND USE OF THIS
MODEL.
WARNING!
This R/C kit and the model you will build is not a toy! It is capable of serious
bodily harm and property damage. IT IS YOUR RESPONSIBILITY AND YOURS
ALONE — to build this kit correctly, properly install all R/C components and flying
gear (engine, tank, pushrods, etc.) and to test the model and fly it only with experienced, competent help in accordance with all safety standards and common
sense as set down in the Academy of Model Aeronautics Safety Code. It is suggested that you join the AMA and become properly insured before you attempt to
fly this model. IF YOU ARE JUST STARTING R/C MODELING, CONSULT YOUR
LOCAL HOBBY SHOP OR WRITE TO THE ACADEMY OF MODEL AERONAUTICS
TO FIND AN EXPERIENCED INSTRUCTOR IN YOUR AREA.
Academy of Model Aeronautics
5151 East Memorial Dr.
Muncie, IN 47302-9252
(800) 435-9262
PO BOX 721 URBANA ILLINOIS 61801
TABLE OF CONTENTS
INTRODUCTION 2
PRECAUTIONS 3
KEEP IT LIGHT' 3
RADIO SELECTION 3
BATTERY SELECTION 3
BATTERY CHARGER SELECTION 3
PROPELLER SELECTION 3
SELECTION OF WHEELS 4
GLUES (ADHESIVES) 4
OTHER ITEMS REQUIRED 4
SUPPLIES AND TOOLS NEEDED 4
COMMON ABBREVIATIONS USED IN
THIS BOOK AND ON THE PLANS 4
PARTS IDENTIFICATION DRAWINGS 5
GET READY TO BUILD
FUSELAGE
PREPARE THE LANDING GEAR PLATE 7
PREPARE THE HATCH 7
PREPARE F1 9
PREPARE F2 9
MAKE THE FUSE SIDES 10
ASSEMBLE THE FUSELAGE 11
BUILD THE FIN 13
BUILD THE RUDDER 13
BUILD THE STABILIZER 14
BUILD THE ELEVATORS 15
MAKE THE HINGES 16
TEMPORARILY INSTALL HINGES 16
TEMPORARILY MOUNT CONTROL
HORNS 17
INSTALL SERVOS 18
INSTALL THE MOTOR AND SWITCH
HARNESS 19
INSTALL ON-OFF SWITCH PUSHROD 20
MOUNT THE RECEIVER SWITCH 21
CUT PUSHROD EXIT SLOTS 21
MOUNT THE STABILIZER 22
TRIAL FIT THE FIN AND RUDDER 22
MAKE THE PUSHRODS 23
INSTALL PUSHRODS 25
COMPLETING THE FUSELAGE 25
WING .................................. 27
..........
6
PREDICTING THE FINISHED FLYING
WEIGHT .. ............................. 30
COMPLETE THE STRUCTURE .......... 31
TRIAL FIT THE WING IN THE SADDLE 31
MOUNT THE ELEVATOR 31
MOUNT THE FIN 32
TRIAL FIT THE MOTOR BATTERY 32
COVERING ........................ 32
COVER THE FUSELAGE 32
ADD WASHOUT AT THE WING TIPS 35
ADD TRIM 35
FINAL ASSEMBLY ...................... 36
BALANCE YOUR MODEL 36
FINAL HOOKUPS AND CHECKS 37
PRE.FLIGHT ........................... 37
CHARGE THE BATTERIES 37
TEST THE MOTOR OPERATION 37
FIND A SAFE PLACE TO FLY 37
GROUND CHECK THE MODEL 38
RANGE CHECK YOUR RADIO 38
MOTOR SAFETY PRECAUTIONS 38
AMA SAFETY CODE 38
FLYING ................................ 38
TRIM OUT THE MODEL 39
YOUR FIRST FLIGHTS 39
THE TAKEOFF 39
FLYING WITH 3 CHANNELS 40
FLYING WITH 2 CHANNELS 40
LANDING 40
APPENDIX ............................. 40
PROPER CARE OF YOUR
THRUSTMASTER MOTOR 40
WHEN YOU BLOW A FUSE 41
HOW TO ACHIEVE THE BEST
PERFORMANCE FROM YOUR ELECTRICPOWERED MODEL 41
WEIGHT 41
THRUST 42
OTHER FACTORS 42
SUMMARY 43
PARTS
LIST
............................
44
INTRODUCTION
Hello' My name is Jim Schrmdt On behalf of
Great Planes Model Manufacturing thank you for
choosing the PT-Electnc I will show you step bystep how to build this airplane Follow these instructions as they are written and you will end up with
a great flying airplane, plus you will have learned
the basics of R/C model building
I'll try to make your building experience as
enjoyable and "snag free as possible If you have
any questions about building or flying this
airplane, please call us at (217) 398-8970 and we'll
be glad to help.
2
PRECAUTIONS
1 You must build the plane according to the
plans and instructions. Do not alter or modify the
model as represented by the plans, as doing so may
result in an unsafe or unflyable model.
2 You must take time to build straight, true
and strong
3 You must use a proper R/C radio that is in
first class condition, the correct size motor and correct components (fuel tank, wheels, etc.) throughout your building process
4 You must properly install all R/C and other
components so that the model operates properly on
the ground
5. You must test the operation of the model
before the first and each successive flight to insure
that all equipment is operating and you must make
certain that the model has remained structurally
sound.
6. You must fly the model only with compe-
tent help from a well experienced R/C pilot if
you are not already an experienced and knowledgeable R/C pilot at this time.
We will give you tips throughout this book on
how to keep the structure light, and we urge you to
follow them
RADIO SELECTION
If you are a beginner, we recommend that
you purchase a radio system that has a built-in
Trainer
training for your first flights using the "buddy box"
system, in which two transmitters (yours and your
instructor's) are connected with a "trainer cord"
PT-Electnc, the ideal radio system is one that employs a small 225 mAh battery pack, a miniature
receiver and 2 or 3 "micro" servos, such as Futaba's
S-33 servos We have, however, done most of our test
flying using 3 standard Futaba S-38 servos and a
225 mAh battery pack, and this combination has
proven to be satisfactory
to use it, rather than purchasing a new one just to
save a couple of ounces, however, we do recommend
that you use a 225 mAh battery pack rather than
the 550 mAh pack that comes standard with most
radios Be aware, however, that a smaller battery
pack means fewer flights between charging.
System
Because weight is an important factor in the
If you already have a radio, we encourage you
If
you
do,
you
will
be able to receive
Note We, as the kit manufacturer, can provide
you with a top quality kit and great instructions,
but ultimately the quality and flyability 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.
Remember: Take your time and follow directions to end up with a well-built model that
is straight and true.
KEEP IT LIGHT!
Because the electric motor and motor battery
are relatively heavy, and because electric motors do
not produce as much thrust as glow engines (when
compared to their weight), it is essential that the
basic structure of the airplane be kept as light as
possible In doing so, you will help insure that the
finished airplane will not be too heavy to fly well
One way to prevent excess weight build- up is
to use only as much glue as needed for good glue
joints. Do not apply extra "fillets" of glue thinking
that it will make your plane stronger' All that extra
glue adds ounces to the weight of your plane, and
will detract from the performance.
Please make sure you select a radio system
that
is
on
a frequency
craft use only", and one that meets current FCC standards.
BATTERY SELECTION
The PT-Electnc was designed to fly with a standard 6-cell 7 2 volt 1200 mAh battery pack for motor
power, and it does so very well' If you want additional
power and a super climb rate, you may wish to use
a 7-cell 84 volt 1200 mAh pack ("flat" type) The
Thrustmaster switch harness uses a connector that
is made to fit batteries with "Kyosho"-type connectors We think the best all-around battery for the
PT-Electnc is the Kyosho 6-cell 1200 mAh Racing
Battery.
BATTERY CHARGER SELECTION
You may use any of the commercially available
battery chargers that are designed for charging 6 or
7 cell nicad battery packs Some chargers have a
"peak detector" which sense when the battery is fully
charged and automatically shut off at the right time
Some chargers operate from 110 volt house current,
12 volt DC (automobile battery), or both
PROPELLER SELECTION
(channel)
designated"
for
air-
The finished PT-Electnc, ready to fly, should
weigh-in right at 3 lbs (48 ounces) as an ideal weight
It will, however, perform quite well at weights up to
3-1/4 lbs We have successfully flown the PT-Electnc
at 3-1/2 lbs , but the performance was marginal
The propeller type size and pitch seem to affect
the performance of the PT-Electnc more than any
other single factor For use with the Thrustmaster
and similar motors we recommend the Grish 8x4
Nylon Propeller over any others we tested in direct
3
drive operation You may wish to experiment with
various other prop sizes in nylon and wood, to best
match your motor, but the Gnsh 8 x 4 is the best
place to start
SELECTION OF WHEELS
Because weight is such an important factor in
electric powered models, we strongly recommend
that you purchase lightweight wheels, such as Dave
Brown "Lite Flite" wheels or Zinger lightweight
wheels
GLUES (ADHESIVES)
If you look at the "ITEMS NEEDED" list you
will see that we recommend only two basic types of
glue for building the PT-Electnc.-.CA glue and
epoxy.
CA (Cyanoacrylate) glues are great for model
building because they set fast Rather than pinning
glued joints together and waiting for hours while the
glue dries, CA glues will harden in a few seconds
while you hold the parts together Thin CA runs
right into a good fitting joint, so you can assemble
the parts first, then apply thin CA Thick CA is
more like syrup and it will not harden until you
press the two parts together squeezing the glue out
to a thin layer A related and very handy product is
CA Accelerator spray (Zip Kicker or Hot Shot),
and is used to instantly harden CA glue When using
CA glues " trial fit" the parts to make sure they
fit well before gluing because they don't give you
a second chance The most common mistake made by
new modelers is using too much CA glue Rather
than squeezing the bottle, it is usually sufficient to
touch the tip of the applicator spout to the joint being
glued and allow a few drops of CA to flow into the
joint.
If you need time to position glued pieces cor-
rectly or need extra strength, use epoxy glue Epoxy
is normally used in the firewall and motor mount
area and when gluing the two wing panels together.
Five
minute
epoxy
starts
to harden in 5 minutes)
is great for most applications If you need longer time
use 15 or 30 minute epoxy You need not use large
amounts of epoxy Squeeze out the amounts of epoxy
and hardener that your particular brand requires.
For example, some epoxies use equal amounts and
some use a 1 to 2 mixture Mix these together Coat
one piece with epoxy, squeegee the excess glue off
with scrap wood The epoxy glue will work better if
there isn't too much oozing out at the edges of the
glued piece Wipe off any of this excess glue with a
tissue.
In any case, glue is never a substitute for a
good-fitting joint, once the Joint is formed, use a
minimum amount of glue and wipe off the excess
with a tissue Clamp, pin or hold the Joint while the
glue is drying.
OTHER ITEMS REQUIRED
General:
Radio, Batteries (See above comments on these
items)
2- 2" Diameter Main Wheels
1- 1-3/4" Diameter Nose Wheel
6- 1/8" Wheel Collars
Iron-on Covering Material (Super Monokote or
Similar)
Roll of 1/8" x 1/4" self-adhesive foam wing seating tape (Rocket City #38, or Sonictronics
#232)
Foam Rubber Padding, 1/4" thick (Goldberg
#291 FR25 or similar)
SUPPLIES AND TOOLS NEEDED
2 oz - Thin CA Adhesive
1/2 oz - Thick CA Adhesive
Instant Glue Accelerator (optional)
2 5 oz - 30 Minute Epoxy
Hand or Electric Drill
Drill Bits 1/16", 5/64", 3/32", 7/64". 1/8", 11/
64",
1/4")
Sealing Iron (for covering)
Heat Gun (optional, for shrinking covering)
Hobby Saw (X-Acto Razor Saw)
X-Acto Knife, #11 Blades
Pliers
Screw Drivers
Flat File
T-Pins
Straightedge 01 Ruler
Masking Tape
Sandpaper (100 grit and 220 grit)
T-Bdi Sanding Block, or Similar
Waxed Paper
Lightweight Balsa Filler
COMMON ABBREVIATIONS USED IN THIS
BOOK AND ON THE PLANS:
Elev = Elevator
Fuse = Fuselage
LE = Leading Edge (front)
LG = Landing Gear
Lt = Left
Ply = Plywood
Rt = Right
Stab = Stabilizer
TE = Trailing Edge (rear)
" = Inches
Remember: Take your time and follow directions to end up with a well-built model that
is straight and true.
4
TYPES OF WOOD
BALSA BASSWOOD PLYWOOD
Study this perspective drawing to become familiar
with the parts of the PT-Electric.
5
GET READY TO BUILD
D 1. Unroll the plan sheet. Re-roll it inside out to make
it lie flat. Note: The fuselage plan is printed on Side
1 and the wing plan is printed on Side 2.
terns shown below to identify the die cut parts and
mark them before punching out. Save all scraps. If
any of the die-cut parts are difficult to punch out, do
not force them! Instead, first cut around the parts
with an Xacto knife.
D 2. Remove all parts from the box. As you do, figure
out the name of each part by comparing it with the
plans and the parts list. Using a felt tip pen, write
the part name or size on each piece to avoid confusion later. Be especially careful to identify the sticks
correctly, as there are several sticks having the same
width but differing thicknesses. Use the die cut pat-
NOTE: After punching out the die cut parts, use your
T-Bar or sanding block to lightly sand the edges to remove
any die-cutting irregularities.
D 3. As you identify and mark the parts, separate them
into groups, such as fuse (fuselage), wing, fin &
stab (stabilizer), and hardware.
6
FUSELAGE
PREPARE THE LANDING GEAR PLATE
D 1. Find the following items: 3/16" x 1-27/32" x 2-3/4"
plywood landing gear plate, three nylon landing gear
brackets, six #2 x 3/8" screws, and the 1/8" wire
main landing gear.
#2x3/8" SCREW
LANDING GEAR STRAP
(NYLON)
D 5. File the screws off flush with the surface of the
landing gear plate to prevent damage to the battery
pack.
D 6. Drill several 1/4" holes in the landing gear plate
as shown on the plan. These holes are for lightness,
and provide cooling air exit for the battery compart-
ment.
D 2. Hold the landing gear on the ply plate in the
position shown on the plan and put the nylon brac-
kets in place. While holding, use a pencil down
through the bracket holes to mark the screw hole
locations.
D 3. Drill 1/16" pilot holes at the above locations.
TIP: Anytime you drill a hole in wood, use a T-pin to start
the hole (for accuracy), and use a scrap wood backing underneath. This will prevent splitting out the back side of
the wood and will protect your work surface. The landing
gear screws will go in easier if you lightly scrape the screws
on a bar of soap to lubricate the threads.
D 4. Temporarily attach the landing gear to the ply
plate using the #2 x 3/8" screws and nylon straps.
D 7. Remove the landing gear and sand the ply plate
smooth. Set the 6 screws aside in a bag marked "LG
SCREWS".
PREPARE THE HATCH
D 1. Find the following items 4 length of hinge strip
material, Die-cut 1/8" ply fuse bottom and hatch,
1/32" x 1- 3/4" x 2" ply, five #2 x 3/8" screws, and
the #2 washer.
#2x3/8"
SCREW
7
1/32" PLY CUTTING PATTERN
D 2. Using the pattern given here, mark the 1/32" x
1-3/4" x 2" ply plate for cutting. Cut out the small
pieces with a scissors or Xacto knife. The two 1-1/4"
x 1/2" pieces are the wing plates. Set them aside
until later. The two 1/4" x 3/4" pieces will be used
in the "PREPARE F-l" section.
D 3. From the 1/32" x 5/16" x 11/16" ply piece that you
previously cut, make the hatch locking tab according to the following sketch: (be sure to drill into a
wood backing to prevent splitting).
D 6. Lay the 1" hinge in place on the hatch and fuse
bottom, and mark the locations of the screw holes.
D 7. Drill 1/16" pilot holes at the marked locations.
HATCH LOCKING TAB
1/32 PLY
D 4. Using thin CA, Glue the remaining 1/32" ply pieces
to the 1/8" ply hatch and fuse bottom in the locations
shown on the plan. Note that the two side pieces and
the front piece extend 1/16" into the hatch opening.
D 5. Cut off a 1" length of hinge strip material and
drill four 3/32" holes as shown in the following
sketch.
D 8. Attach the hinge with four #2 x 3/8" screws.
D 9. Cut or file off the portion of the screws that would
protrude into the battery compartment. NOTE: Protect your eyes from flying metal when cutting off
screws.
HATCH HINGE
D 10. Drill a 1/16" pilot hole in the fuse bottom for the
hatch locking tab, at the location shown on the plan.
8
D 11. Temporarily mount the 1/32" ply hatch locking
tab using a #22 x 3/8" screw and the #2 washer,
and cut off the portion of the screw that protrudes
into the battery compartment.
D 12. Check the operation of the hatch Sand the edges
of the hatch slightly to provide a close but non-binding fit.
D 13. Disassemble the above and set the hatch, hinge,
locking tab and screws aside until later.
PREPARE F- 1
NOTE: The PT-Electric has a "fixed" (non-steering) nose
gear which you will rigidly attach to Former F-l. At first
you may
the airplane on the ground with this setup We just want
to assure you at this time that it actually does steer quite
well' Because there is very little weight on the nose wheel,
the wind moving past the tail of the airplane enables the
rudder to turn the airplane almost as if the nose wheel
were steerable.
D 1. Find the die- cut 1/8" ply former F-l, two nylon
be
thinking
landing gear brackets, four #2 x 3/8" screws, the
1/8" wire nose gear, and the two 1/32" x 1/4" x 3/4"
ply pieces which you previously cut.
that
it
will
not be possible to
steer
D 4. Glue the 1/32" ply screw backplates to the back
of F-l, using the pilot holes you previously drilled
to determine where to locate the ply backplates.
D 5. Now re-drill the pilot holes.
D 6. Temporarily mount the nose gear to F-l using the
nylon brackets and screws.
D 7 Disassemble the above parts, and set the nose
gear, brackets and screws aside until later.
PREPARE F-2
D 1. Find the die cut ply former F-2.
D 2. From the detail drawing of F-2 determine the lo-
cation of the on-off switch pushrod.
#2x3/8"
D 2. Study the detail drawing of F-l on the plan, and
position the nose gear and nylon brackets While
holding them in place, mark the locations of the
screw holes.
D 3. Drill 1/16" pilot holes at the marked locations.
SCREW
D 3. Drill an 11/64" hole in F-2 at the above location.
PREPARE F-4 AND F-5
D 1. Find the die-cut 3/32" balsa formers F-4 and F-5,
and the two 3/32" x 3/8" x 17-7/8" balsa sticks
D 2. Cut a 9-1/8" length from each of the 3/32" x 3/8"
x 17-7/8" sticks, mark them "Wing Saddle Dou-
bler", and set them aside.
9
D 3. From one of the remaining 3/32" x 3/8" balsa sticks,
cut cross-braces for F-4 and F-5. Glue these crossbraces to the formers with thin CA as shown on the
plan. Use only a few drops of glue to avoid excess
weight build-up.
MAKE THE FUSE SIDES
D 1. Find the 1/8" die- cut balsa fuse sides and the
1/8" x 3/8" x 23-7/8" balsa sticks. Inspect the balsa
sticks and pick out the four straightest ones which
you will use for the middle and lower longerons.
D 2. Tape the fuse plan to your flat work surface, then
tape a piece of waxed paper over the fuse side view.
D D 5. From one of the remaining short 1/8" x 3/8" sticks,
cut the tail post to match the plan.
D D 6. Hold or pin the parts accurately in place on the
plan, then glue the middle and lower longerons to
the fuse side and to the tail post using thin CA.
D D 7. Cut a third 1/8" x 3/8" balsa stick to match the
upper longeron on the plan (the upper longeron
extends back to the rear edge of F-6), and glue it to
the fuse side and to the middle longeron.
D D 3. Accurately position one of the 1/8" balsa fuse sides
on the plan and hold it firmly in place with a heavy
book or with "shot bags" (A handy shot bag can be
made by partially filling a sock with lead shot or
BB's).
D D 4. Lay the middle and lower "longerons" (1/8" x 3/8"
sticks) in place and draw a straight line at the front
of the tail post. Cut the longerons off at these lines
using a razor saw.
D 8. While the fuse side is still in place on the plan,
use a straightedge and a pen to mark the locations
of formers F-4, F-5 and F-6. (Skip this step when
building the second fuse side.)
D D 9. Sand the fuse side smooth using a T-bar sander
with 100 grit sandpaper.
D 10. Now repeat steps 3-7 and 9 to build another
identical fuse side.
D 11. Put the two fuse sides together and line them up
at the front and the bottom edges. Then check to
make sure they are exactly the same all the way
around. Sand the edges as necessary until the two
fuse sides match. It is especially important that the
overall length be the same, so sand the tail post as
necessary.
10
D 12. Lay the two fuse sides flat on the table, with the
bottom edges touching. Then, using a straightedge
and a pen, extend the former location lines onto the
fuse side that does not have them.
ASSEMBLE THE FUSELAGE
D 1. To begin, you'll need the following parts: The two
fuse sides you just built, Formers F-1A, F-l, F-2, F-3,
and the 1/8" ply fuse bottom.
D 2. Lay one of the fuse sides down flat on the table.
Insert the tabs of formers F-1A, F-l, F-2 and F-3 into
the slots in the fuse side. Check the plans and make
sure the formers are right side up. (Do not glue).
D 4. Press the 1/8" ply fuse bottom in place. Notice
that the interlocking parts automatically square-up
and align the front portion of the fuselage.
D 5. Lay a piece of waxed paper on your flat table, then
set the fuse assembly upright on the waxed paper.
Make sure that all tabs are fully seated into the
slots and notches. While holding the assembly to-
gether, apply thin CA glue to all joints.
D 3. Lay the left fuse side in place on the formers,
working the tabs into the notches. (Do not glue).
D 6. Turn the fuse upside down, and glue the 3/16" ply
landing gear plate in place in the notches in the
fuse sides (sand the ply plate, if necessary, for a good
fit). Add thick CA glue to the joint between the LG
plate and the 1/8" ply fuse bottom.
D 7. Turn the fuselage right side up, pull the tail posts
together, and apply thin CA glue to the tail posts.
11
D 8. Now get the following parts together: Die-cut 3/32"
balsa fuse bottom, formers F-4, F-5 and F-6, and
the die-cut 3/32" balsa stab saddle.
D 9. Work the 3/32" balsa fuse bottom into place
between the bottom longerons. The front of the fuse
bottom must touch the rear of the landing gear plate.
With the fuse upright on a piece of waxed paper,
make sure the fuse bottom is even with the bottom edge of the fuse sides and bottom longerons,
then apply thin CA glue along the bottom joints,
pulling the bottom longerons together. Note: If you
have small hands and are unable to hold the stringers
together, you may use books or other square weights
to hold the longerons together.
D 12. Find the two die-cut 3/32" balsa pushrod exit
fillers, sand them to fit between the middle and lower
longerons just behind F-6. Glue them in place, flush
with the outside edge of the longerons.
D 13. Find the 3/32" x 1-1/4" x 2-1/2" balsa battery
box rear, and glue it to the landing gear plate, 5/16"
forward of the rear edge of the landing gear plate.
D 10. Slide the 3/32" balsa stab saddle into place be-
tween the middle longerons. The front edge of the
stab saddle must line up with the marks you made
for the rear edge of F-6. Make sure the top edge
of the stab saddle is even with the top of the
longerons, and glue it in place with thin CA.
D 11. Install formers F-4, F-5 and F-6 at the locations
you previously marked. Note: you may have to sand
the
sides
of
the formers
the formers to the fuse bottom, then pull the longerons together and glue them to the formers.
slightly
for a good
fit.
Glue
D 14. Find the 3/32" x 2-1/2" x 4-1/16" balsa battery
box top. Position it so the bottom front edge is even
with the bottom edge the cross-brace on F-2. Glue it
to F-2, the fuse sides and to the battery box rear.
12
D 15. Find the two 3/32" x 3/8" x 9-1/8" balsa sticks
which you previously marked "Wing Saddle Dou-
bler". Sand the ends of these pieces slightly, to fit
between F-2 and F-3. Glue these doublers in place
with the edge flush with the top edge of the fuse sides.
NOTE: This completes the fuselage assembly for now.
Leaving off the top sheeting will make it easier to install
the other components later.
BUILD THE FIN
1. Find the following parts: 3/16" x 1/2" x 5-1/2" balsa
stick, five 3/16" x 3/8" x 24" balsa sticks, and a 3/32"
x 3/16" x 24" balsa stick. Select the straightest 3/16"
x 3/8" x 24" balsa stick and set it aside for later use
as the stabilizer trailing edge.
D 4. From the 3/32" x 3/16" x 24" balsa stick cut ribs
to fit between the framework, as shown on the plan.
Glue the ribs to the framework.
D 5. Sand both sides of the fin smooth using your T-bar
and 100 grit sandpaper. Sand the leading edge and
top of the fin to a rounded shape as shown in the
typical cross-section.
BUILD THE RUDDER
1. You'll need the following parts: Die-cut 3/16" balsa
D
rudder bottom, 3/16" x 3/8" x 24" balsa stick, 3/16"
x 3/16" x 24" balsa stick, and a 3/32" x 3/16" balsa
stick.
2. Working over the separate FIN drawing on the
D
plan, mark and cut the balsa sticks to make the
outer framework of the fin.Begin by laying one of
the sticks in place, then use a straightedge to mark
the cut-off lines. Cut the stick off with a razor saw,
then proceed to the next part.
3. Hold or pin the parts over the plan and glue the
D
outer framework pieces together with thin CA, working on waxed paper to prevent gluing to the plan.
13
2. In the same manner as the fin, cut the outer
D
framework pieces for the rudder.
3. Glue the outer framework and the rudder bottom
D
together with thin CA. Be sure to work on waxed
paper to avoid gluing the parts to the plan!
4. From the 3/32" x 3/16" balsa stick, cut ribs to fit
D
between the rudder leading edge and trailing edge.
Glue the ribs in place.
5. Sand both sides of the rudder smooth and flat.
D
Sand the upper rear corners of the rudder to a round
shape as shown on the plan. Sand the trailing edge
and rudder bottom to a rounded shape as shown in
the typical cross-section.
D 6. Draw a centerline down the full length of the
rudder leading edge, then use your T-bar sander to
sand the leading edge to a "V" shape as shown in
the typical cross-section.
BUILD THE STABILIZER
D 3. From 3/16" x 3/8" balsa sticks, cut the outer
framework pieces and glue them together. Note:
The straightest 3/16" x 3/8" balsa stick should be
used for the trailing edge.
D 4. Cut the triangular corner braces from the 3/16"
x 5/8" x 7" balsa stick and glue them in place.
D 5. Cut the stabilizer ribs from the 3/32" x 3/16" balsa
sticks and glue them in place.
D 6. Cut out the fin notch in the leading edge, and trim
the front edge as shown on the plan.
D 1. Get the following items together: Die-cut 3/16"
balsa stab center front and stab center rear, 3/16"
x 3/8" x 24" balsa sticks, 3/32" x 3/16" x 24" balsa
sticks, and the 3/16" x 5/8" x 7" balsa stick. (Note:
The photo also shows the elevator parts).
2. Tape a piece of waxed paper over the separate
STABILIZER drawing on the plan, then lay the
die-cut 3/16" balsa stab center pieces on the plan
and pin in place. NOTE: These die-cut pieces may
have irregular edges, so you should sand the edges
with your T- bar first, until they fit the plan exactly.
Edge glue these stab center pieces together with thin
CA.
D 7. Sand both sides of the stabilizer smooth with your
T-bar, then sand the stabilizer leading edge and ends
to a rounded shape as shown in the typical cross-section.
NOTE: If the 3/16" balsa stab center pieces supplied in
your kit are soft balsa (easily dented with your fingernail),
do not perform the next step.
D 8. Now you may lighten the stabilizer by trimming
the stab center along the dashed line as shown on
the stabilizer drawing. Use your ruler to transfer
the trim lines from the plan to your stabilizer, then
use a Dremel Moto Tool sanding drum or a piece of
sandpaper wrapped around a dowel to sand away the
excess balsa.
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