Page 1
Sportster
20
40
66
Engine
Wing Span
Wing Area
Length
Weight
.19-.25
48"
400
sq.
in.
39-1/2"
3-1/2-4 lbs.
.35..45
56"
550
sq.
43"
5
lbs.
in.
.45-.61
61-1/2"
675
sq.in.
48"
6-7-1/2 lbs.
MATERIALS NEEDED TO COMPLETE THIS KIT:
4 channel radio Wheel collars Covering
Engine Wheels Instant glue
Fiberglass cloth/resins Epoxy White glue
Engine mounting bolts Fuel tank
Propeller Spinner
The Super Sportster was designed for the sport flier The Sportster is fast, stable and aerobatic It has good looks, good performance and
stability at low speeds For the creative builders it can be detailed to resemble a war bird, Formula 1 racer or a CAP 21 type aerobatic ship Materials
are included for both trike gear and conventional gear (taildragger) to help you create your own Sportster
The parts are machine cut and sanded for accurate fit Some parts are razor cut in the 20 size for accuracy Should you notice a difference in
size between plans and parts, it is usually because paper plans change size with moisture Most of the parts are self aligning and do not require
building over the plans except where specified in the instructions
Different types of glues may be used such as epoxy, Cyanoacrylate or aliphatic (white) resin Be careful when using any kind of glue Make sure
you have enough ventilation CA glues (instant) are especially harmful if not used correctly
We suggest that you build on a flat surface to insure a straight wing and fuselage When you build over the plans, cover them with waxed paper
so the wood parts are not glued to the plans'
The following tools will be helpful when you build and X-Acto knife, razor plane, saw sanding block, flat building board T Pins hinge slotting
kit, drill and drill bits, tap and tap holder, covering iron and heat gun, Dremel tool and cutter tor wire and router bits, soldering iron, screw drivers, needle
nose pliers, files, clamps and a good square or right triangle
We recommend a plastic heat shrink covering such as Super Monokote to keep your Sportster light Follow the manufacturer's instructions
concerning the use of this covering material
Please read through this step by step instruction book before you start building so you will get an overall idea of the construction steps and avoid
mistakes Since these instructions do pertain to the 20, 40 and 60 size Sportsters, refer to the plan and parts list to help you identify the various parts
Any differences in the instructions for the various size models will be noted at the appropriate steps with a star (•*)
These instructions and plans were intended tor 2 cycle engine use However starting on page 26 of this booklet, you will find adaptation
instructions for the installation of 4-cycle engines
Please inspect all parts carefully before starting to build! If any parts are missing, broken or defective, or it you have any questions
about building or flying this airplane, please call us at (217) 398-8970 and we'll be glad to help. It you are calling tor replacement parts,
please look up the part numbers and the kit identification number (stamped on the end of the carton) and have them ready.
WARRANTY
Great Planes Model Manufacturing Co., Inc. guarantees this kit to be free of 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, he Is advised
to immediately return this kit in new and unused condition to the place of purchase.
READ THROUGH THIS INSTRUCTION BOOK FIRST. IT CONTAINS
IMPORTANT INSTRUCTIONS AND WARNINGS CONCERNING THE
ASSEMBLY AND USE OF THIS MODEL.
(SEE WARNING ON BACK COVER)
POBOX788 URBANA, ILLINOIS 61801 (217)398-8970
Page 2
BUILDING THE TAIL SECTION
1. D PREPARE THE FIN AND RUDDER
Prepare the forward and rear fin sections by sand-
ing if necessary for a good fit. Working over the plans, butt
glue the fin section together. After the glue is dry, sand
both sides of the fin. Also sand both sides of the rudder.
* The 20 size fin is in one piece.
* The 60 size rudder is in two pieces. Glue these together.
Note: Specific instructions for tricycle gear installation are
in italics.
2. D CUT THE HINGE SLOTS IN THE FIN AND RUDDER;
CUT OUT RUDDER FOR JOINER CLEARANCE
Draw centerlines down the trailing edge of the fin
and the leading edge of the rudder. Mark and cut the hinge
slots. Two hinges are used above the stabilizer. For conventional gear (Tail dragger) the third hinge should be just
below the stab and above the tailwheel strut tab. (For tri-
cycle gear the third hinge should be near the bottom of the
rudder. Check the plans.) Relieve (cut out) the leading edge
of the rudder for elevator joiner wire clearance. (Shape the
rudder leading edge to a "V"now for tricycle gear.) For con-
ventional gear wait to shape the leading edge until the
hole is drilled for the tailwheel tiller arm later.
3. D GLUE THE STAB PARTS TOGETHER; SAND THE
STAB AND ELEVATORS
Check the fit and butt glue the stabilizer forward and
rear sections together. Sand both sides of the stabilizer
and elevator halves.
* The 20 size stab is in one piece.
4. D DRILL HOLES IN THE ELEVATOR HALVES FOR
ELEVATOR JOINER WIRE
Draw a front to back centerline down the top side of
the stab and a centerline down the leading edges of the
elevator halves. Mark the center of the elevator joiner wire.
Align the stab, elevator and joiner wire and mark the hole
locations for the joiner wire arms on the centerline of the
elevator leading edge. Drill the holes.
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5. D GROOVE OUT THE ELEVATORS FOR JOINER WIRE
CLEARANCE
Cut a groove in the elevator leading edge inboard
(inside) of the hole so when the joiner wire is installed it
will be flush with the leading edge of the elevator. Groove
both elevator halves.
6. D TRIAL FIT THE JOINER WIRE
Temporarily install the elevator joiner wire into the
elevator halves. Check to make sure that this assembly is
aligned properly. Bend the joiner arms if necessary for a
perfect fit. DO NOT GLUE THE JOINER WIRE TO THE ELEVATOR HALVES UNTIL AFTER THE PIECES ARE COVERED
LATER.
7. D CUT HINGE SLOTS FOR THE STAB AND ELEVATOR
Mark and cut the hinge slots for the stab and eleva-
tor halves as you did with the fin and rudder. See the plans
for locations. Shape the leading edges of the elevator
halves to a "V".
BUILDING THE WING PANELS
READ THIS FIRST BEFORE YOU START BUILDING THE
WING PANELS: It is very important that you build a straight
wing with no warps or twists or you will get some flying
characteristics you didn't expect! Be very careful when
you align the ribs, spars, leading edges and trailing edges
and sheeting at the various steps below. All these parts
should be in their correct positions before you glue them in
place. Hold or pin the parts in place, then glue. Use the
following instructions to help you build the wing straight
and warp free.
Remember: Anyone can build a wing. Only a careful builder
can build a straight wing.
1. D NOTCH THE RIBS FOR LANDING GEAR BLOCK
CLEARANCE
Notch the ribs to be installed at locations 2 and 3 for
the hardwood main landing gear blocks. Conventional
gear block notches are forward on the ribs. (Tricycle gear
notches are the rear cutouts.) Check the fit with the block.
Number these ribs 2 and 3. Cut the notches in the ribs for
the other wing panel at the same time. (Conventional gear
cut outs are shown.)
* 20 size ribs are notched already. Glue the scrap back into the notch you will not use.
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2. D GLUE THE 1/16" PLYWOOD LANDING GEAR SUPPORTS TO THE RIBS
Start on the right wing panel by gluing the 1/16 ply
brace on the left side of rib 2 and on the right side of rib 3.
(For the left panel the brace glues on the right side of rib 2
and on the left side of rib 3.) When the glue is dry sand the
braces to the rib contour. Note that the landing gear block
will be flush with the bottom sheeting not the bottom of
the rib. (Conventional gear locations are shown throughout the instructions.)
3. D PIN THE BOTTOM SPAR OVER THE PLANS; PLACE
RIBS ON THE SPAR
Pin the bottom spar on the waxed paper covered
plans. Temporarily install all the ribs to the spar making
sure they are 90 degrees to the building board and that the
landing gear notches are down. (Waxed paper is not shown
for clarity.)
4. D GLUE THE TRAILING EDGE TO THE RIBS; GLUE
THE RIBS TO THE BOTTOM SPAR
For the 40 size, align the top edge of the trailing
edge stock to the top edge of the building shim (see size
below). For the 20 and 60 size, align the trailing edge to the
top of the shim as shown in the drawing below. Use waxed
paper in between the shim and the trailing edge and pin
them together. Center the trailing edge to the rib ends.
Glue the trailing edge to the ribs with the shim pinned to the
work surface. Glue the ribs to the bottom spar. DO NOT
GLUE THE SHIM TO THE TRAILING EDGE! USE THE
SHIM AGAIN WHEN YOU BUILD THE LEFT WING PANEL.
Shim Sizes:
20 = 1/4 x 5/8
40 = 3/32 x 7/8
60 = 1/4 x 3/4
5. D GLUE THE RIBS TO THE LEADING EDGE
Use a straight edge and draw a straight line on the back
of the leading edge about 3/32" from the top. Using 1/4 x 1/4 x 36
balsa stock as a shim under the leading edge (for the 40 size),
align the top of the ribs to the line and glue them in place to the
leading edge. The leading edge is intentionally wider than
necessary to allow for slight warpage. Do not fight a slight warp
but instead glue the leading edge to the ribs making sure there is
at least 3/32" above and below the ribs for sheeting. Later the
excess will be carved off.
* Use an 1/8" shim for the 20 size.
* Use a 5/8" shim for the 60 size.
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6. D ADD THE TOP SPAR, TOP LEADING EDGE SHEETING AND TOP TRAILING EDGE SHEETING
Glue the top spar in place. Glue the top leading
edge sheeting between the leading edge and the dotted
line on the top spar shown on the plans. Align the top trailing edge sheeting even with the back of the trailing edge
and glue it in place.
7. D ADD THE TOP CENTER SECTION SHEETING AND
CAP STRIPS
Glue the top center section sheeting in place. Glue
the front piece on first. Then cut the rear piece to fit and
glue it in place. Add the top cap strips. Note that the cap
strip on the tip rib (outer end of the wing) is offset so the
outer edge is flush with the outer edge of the rib. After the
glue sets up, remove the wing from the building board and
check all the glue joints. Add more glue if necessary. Now
remount the wing upside down reversing the trailing edge
shim on your work surface.
8. D PREPARE THE MAIN LANDING GEAR BLOCK
Glue the torque block to the inboard (inside) end of
the ungrooved side of the landing gear block. The grooved
side of the torque block should face toward the other end
of the long landing gear block. After the glue dries, drill a
5/32" hole down through the landing gear block, using the
groove in the torque block as a guide. Epoxy is recom-
mended for the above procedure.
9. D TRIAL FIT THE LANDING GEAR BLOCK ASSEMBLY
Temporarily install the landing gear support assembly into the wing. Custom fit the assembly as follows.
Shape the bottom end of the torque block to fit the contour
of the wing sheeting to which it mates. The top of the long
grooved block should be flush with the bottom sheeting (not
yet installed).
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10. D
TRIAL
temporarily install the landing gear wire. The torque arm
should slide into the hole you drilled earlier with the long
arm resting in the groove in the long block. Custom fit as
necessary. Remove the wire.
11. D GLUE THE LANDING GEAR BLOCK AND GUSSET
block in place. Add the small gusset under the outer (outboard) end of the long block. Fill the groove at both ends of
the long block with scrap balsa so foreign matter does not
get into the wing.
* Go to step 13 for the 20 size model.
FIT THE
BLOCK
Remove the landing gear block from the wing and
IN PLACE
Use 5 minute expoxy to glue the main landing gear
MAIN
GEAR WIRE
INTO
THE GEAR
12. D (40 and 60 SIZE ONLY) GLUE THE HARDWOOD
HOLD DOWN PLATE AND BALSA FILLERS TO
THE WING PANEL
Add the maple wing hold down plate and balsa
fillers behind the leading edge between ribs 1 and 2.
Custom fit as necessary. Use 5 minute epoxy after you are
sure of the fit and glue the pieces in place.
13. D (20 SIZE ONLY) GLUE THE TWO 1/8" PLYWOOD
DOWEL PLATES TO THE WING PANEL
Remove the 1/8" Plywood dowel plates from the
razor cut sheet. The smaller dowel plate glues to the rear
of the wing panel leading edge. The larger dowel plate
glues to the front of the top and bottom spars. Use epoxy
and glue both plates in position between ribs 1 and 2 as
shown on the plan.
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14. D ADD ALL THE BOTTOM SHEETING TO THE
WING PANEL
Add the bottom leading edge sheeting, the trailing
edge sheeting and the center section sheeting. Relieve
(cut away) the leading edge sheeting for landing gear block
clearance. (Relieve the center section sheeting for tricycle
gear.) Add the bottom cap strips. After the glue dries,
remove the wing from your building board and turn it over.
15. D ADD THE WING TIPS, WING TIP FILLERS AND
SUPPORT PIECES
Cut off spars and sheeting even with the outboard
edge of the tip rib. DO NOT CUT THE LEADING EDGE! Add
the wing tip. It should be centered on the tip rib and on the
leading edge. For the 40 and 60 size models, prepare and
install the upper and lower forward and rear wing tip supports. Using the wing tip detail drawing as a guide, cut two
rectangles from the 1/4" scrap piece. Cut the rectangles
diagonally and you have two forward and two rear pieces.
Custom fit all four supports and glue them in place. Use
1/4" scrap and make and glue the aileron filler piece. Glue
it to the inboard side of the wing tip. Add filler pieces to the
rear end of the wing tip, top and bottom. Sand these blocks
to the aileron contour later after installing hinging and centering the ailerons.
* The 20 size kit includes the above parts in the 1/8" razor
cut sheets.
16. D BUILD THE LEFT WING PANEL NOW
Build the left panel in the same manner except
build it upside down. Gear cut outs are "up" and landing
gear blocks are installed before any sheeting is added. Install the wing hold down plate and fillers in the 40 or 60
models (or the wing dowel plates in the 20 size) after you
turn the wing panel over and before the top leading edge
sheeting is installed.
17. D SAND THE LEADING EDGES OF THE WING
PANELS TO THE ROUNDED SHAPE SHOWN ON
THE PLANS
18. D FINISH SAND THE WING PANELS
Sand the leading edge to match the wing tip con-
tour. Remove the trailing edge building shim and cut and
sand the wing parts flush with the root rib (inner rib). Finish
sand the rest of the wing panel.
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19. D PREPARE THE CENTER TRAILING EDGE PIECES
With the top of the wing panels up, draw a centerline down the trailing edge of each wing panel. Prepare the
grooved center trailing edge pieces by notching them for
the servo arm torque rod clearance 3/8" or so in from the
wing center. See plans for location. Make right and left
pieces. Glue the aileron torque rods into the groove in the
center trailing edge pieces. Use vaseline at the ends of the
outer tube so only the tube is glued to the block. Notch the
trailing edge of the wing to permit forward movement of
the torque rod arms.
* The center trailing edge pieces for the 60 size model are
balsa. Cut a groove in the block for torque rod clearance.
20. D GLUE THE CENTER TRAILING EDGE PIECES TO
THE WING PANELS
JOINING THE WING PANELS
1. D GLUE THE CENTER RIB TO THE LEFT WING
PANEL
Glue the wedge-shaped balsa center rib to the root
end of the left wing panel. Make sure the wider edge of the
center rib is down and the wing panel is up. Make sure that
the leading edge and trailing edge are centered on the
tapered rib. Use 5 minute epoxy.
2. D SAND THE CENTER RIB TO THE WING PANEL
CONTOUR
Roughcut the center rib to the wing airfoil, leaving
it about 1/8" oversize. Sand the remainder away with a
sanding block so that the center rib edges are flush with
the wing sheeting surfaces.
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3. D JOIN THE WING PANELS
Join the wing panels upside down. Refer to the di-
hedral detail on the plans. Align at the leading and trailing
edges. Use a straight edge to make sure the wing is
straight. Block up the wing 3/4" at the center for the 20
size, 1" for the 40 size and 1-1/4" for the 60 size model. Glue
the wing panels together using epoxy, rechecking the
alignment before the glue sets up. When the glue is dry,
mark the aileron servo well location. The servo well is
located directly behind the spar and in the center of the
top of the wing.
4. D GLASS THE CENTER SECTION OF THE WING
Use 6 ounce glass cloth (or nylon cloth) and glass
the center section glue joint. Use a 4" wide piece of cloth
and polyester resin or epoxy. Sand the center section when
dry. Apply a second coat of resin or epoxy if necessary.
IMPORTANT — Omitting this step will result in a wing fail-
ure during flight and result in a crash.
*Use a 5" wide piece of cloth in the 60 size.
THE AILERONS
1. D PREPARE THE AILERONS
Cut the aileron stock to length and draw a center-
line down the leading edge of the ailerons. Mark and drill
the torque rod holes. Groove the aileron for torque rod
clearance. Make right and left ailerons.
2. D CUT THE HINGE SLOTS; FINAL SAND THE
AILERONS
Mark and cut the hinge slots into the ailerons and
the wing trailing edge. Shape the leading edge of the aile-
rons to a "V". Temporarily install the ailerons with hinges to
check the fit. Final sand the wing tips to match the aileron
contour at neutral. Do not permanently hinge the ailerons
until after they are covered.
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BUILDING THE FUSELAGE
1. D PREPARE THE FUSELAGE SIDES
Mark the inside of the fuselage sides "right" and
"left". Relieve the wing saddle area as necessary to match
the plans.
STOP! If you plan to install a 4-cycle engine read and
follow the instructions on installation of 4-cycle engines at
the end of this instruction book starting on page 26.
2. D PREPARE BULKHEAD #1
Prepare Bulkhead #1, the firewall. Mark the "top" of
the firewall (slanted part is at the bottom) and mark the
position of the motor mount. Drill the holes for the motor
mount and install the blind nuts. Temporarily install the
mount and cut off the bolts that extend into the tank compartment. Drill the hole for the throttle linkage about 1/4"
from the top corner of the bulkhead (left or right depending
on your engine). (For tricycle gear mark and drill the hole
for the steering linkage in the firewall. Also relieve the
firewall for steering arm clearance.
3. D PREPARE BULKHEAD #3
Prepare bulkhead #3 by drilling holes for the push-
rod outer housings. Use your servos and the plan as a guide
to placement.
4. D BUILD THE THREE REAR FORMERS
Make formers #4, 5 and 6 from 1/4" x 1/8" balsa
stock. Use the plans as a guide. Also make pushrod braces
from 1/8" or 3/32" scrap sheeting. The widths of the braces
are the same as that of the formers. They will be installed
later when the pushrods housings are added.
STOP! Did you read the 4-cycle engine instructions if you
plan to install a 4-cycle? See page 26.
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5. D GLUE THE DOUBLERS TO THE FUSELAGE SIDES
Using bulkhead #1 as a spacer, install the 1/8" balsa
doublers (1/16" for the 20 size) cross-grain on the inside of
the fuselage sides. Custom cut pieces from the stock provided. Use slow set epoxy glue or thick Cyanoacrylate. The
doubler should extend 5/8" beyond the position of
bulkhead #3. Trim and sand the doublers to match the
fuselage contour.
6. D MARK BULKHEAD POSITIONS ON THE INSIDE OF
THE FUSELAGE SIDES
Mark the positions of Bulkhead #2 and 3 on the fuse-
lage sides. Also mark the position of the balsa dash be-
tween #2 and #3 on the fuselage sides.
* Bulkhead #2 in the 20 size is located 1/8" forward of the
wing saddle opening to allow for the dowel jig.
7. D DRILL PUSHROD EXIT HOLES
Mark and drill the holes in the fuselage sides for the
pushrod exits for the elevator and rudder. See the plans for
the locations. A piece of brass tubing sharpened on the inside with an X-acto blade and chucked in an electric drill
makes a neat, clean angled hole for tube-style pushrods.
8. D TRIAL FIT THE WING INTO THE WING SADDLE
Pin the fuselage sides together perfectly aligned.
Check the fit to the wing saddle cutout by placing the fuse
sides on the wing. Custom sand if necessary but do not
change the wing incidence.
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9. D SAND FUSELAGE TAIL; GLUE BULKHEADS #2
AND #3 TO THE RIGHT FUSELAGE SIDE
Slightly relieve the inside edges of the fuse sides at
the tail for a better glue joint. Notch a hole for the throttle
linkage in the side of bulkhead #2 first before gluing it to
the fuselage side. Align and glue bulkheads #2 and #3 to
the inside of the right fuse side which you have pinned
down to your work surface. Make sure the bulkheads are
90 degrees to the fuselage side and that the tops of the
bulkheads are toward the straight edge of the fuselage
sides. Bulkhead #2 has an angled cut on the bottom edge
in the 40 and 60 models. (The straight edge of the fuselage
side is called the Fuselage Reference Line and will be used
later to align the wing and stab to the fuselage.)
* Be careful to locate Bulkhead #2 1/8" forward of the wing
saddle opening in the Sportster 20.
10. D GLUE LEFT FUSELAGE SIDE TO BULKHEADS
Align the fuselage side/bulkhead assembly upside
down over the top view of the plans. Make sure the flat side
is resting flat on the building board and that the bulkheads
are aligned to the plans. Pin in place. Glue the other fuse
side to bulkheads #2 and #3 making sure the second side
is also flat on the building board. Clamp or pin the fuse-
lage in place until the glue is dry.
11. D GLUE IN THE HOLD DOWN PLATES
Add the 1/4" plywood front and rear wing hold
down plates and the 1/4" tri stock braces on the bottom of
the plates in the servo compartment as shown on the
plans. Use epoxy to glue in the plates. You may want to
saw or grind away the pushrod clearance area shown on
the rear plate now. Otherwise do this in step 23.
* The 20 size model has a rear hold down plate only and
uses 1/4" x 1/4" bracing.
12. D GLUE IN THE 1/4" BRACING
Turn the fuselage over and add the 1/4" triangle
stock (or 1/4" x 1/4" for the 20) on the front and rear hold
down plates. Add the 1/4" tri stock behind bulkhead #2. (40
and 60 only).
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Page 13
13. D GLUE IN BULKHEAD #1
Realign the fuselage over the plans and glue the
fuse sides to bulkhead #1. Make sure the top of the
bulkhead is flat on the building board and that the front of
the bulkhead is facing forward.
14. D ADD THE 1/4" BRACING BEHIND THE FIREWALL
Add three pieces of 1/4" triangle stock along the
back side of the firewall. Extend the throttle linkage holes
(and nosegear steering if used) through the tri stock.
* The 20 size model has 1/4" x 1/4" stock behind bulkhead
#1 and in front of bulkhead #2. Glue these pieces in now.
15. D GLUE FORMERS TO THE DECK BASE
Notch the deck base at the corners to clear the
doubler as shown on the plans. The deck base should butt
up to bulkhead #3. Mark the location of formers #4, 5 and 6
and pin the deck base to the plans. Check the fit of the
formers and glue them to the deck base making sure they
are 90 degrees to the base.
*The 20 size deck base is razor cut and has precut
notches.
16. D PREPARE FORMER BRACES FOR PUSHROD
HOUSINGS
Temporarily put the fuselage/bulkhead assembly
over the deck base. Use a pushrod housing and mark the
locations of the housing holes in the former braces. Make
sure the housing follows as straight a path as possible
from bulkhead #3 to the exit. Drill the holes in the braces.
Temporarily install the housings to check your work.
Remove the housings. Tube in a tube style pushrods are
shown here but other types may be used.
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17. D GLUE THE FUSELAGE TO THE DECK BASE
Glue the fuselage sides/bulkhead assembly to the
deck base/former assembly. Fuselage sides are glued to
the sides of the deck base and the sides of the formers.
The deck base should glue to the rear of bulkhead #3.
DO NOT GLUE THE FUSELAGE TOGETHER AT THE TAIL
UNTIL YOU READ THE NEXT STEP!
18. D GLUE THE HINGE TO THE FUSELAGE TAIL;
GLUE THE FUSELAGE SIDES TOGETHER AT
THE TAIL
Glue the fuselage sides together at the tail. Con-
ventional gear-glue the rudder hinge just below stab placement. Use the rudder hinge slot as a guide to placement.
Do not glue the area at the tail where the tail wheel strut
mounting tab will glue later. (Tricycle gear-glue the bottom
hinge at the tail at this time. Use the rudder as a guide to
placement.)
late glue, glue both elevator and rudder housings in place
except at bulkhead #3. This will be glued later when the
servos are installed. You may trim the housings at the exits
now.
IMPORTANT NOTE: The pushrods supplied in this kit are steel rod-in-a-tube type We strongly recommend that you use these pushrods,
installing them as straight as possible, as they provide a very rigid
linkage between the servos and the control surfaces We do not
recommend the use of flexible plastic inner pushrods for this
model, as
their elasticity
may result
in
control surface flutter. See page
43 for recommended pushrod hookups.
20. D GLUE IN 1/4" BRACING AT THE TAIL
Glue 1/4" triangle stock (1/4" x 1/4" for the 20 size) at the
bottom sides of the deck base between former #6 and the tail.
Angle cut the ends of the tri stock at the tail for a good glue joint.
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21, D GLUE THE CHIN BLOCK TO THE FUSELAGE
With the fuselage still at 90 degrees to the board
and over the plans, align the chin block to the back of bulk-
head #2 and glue the chin block to the fuselage.
*0n the Sportster 20 make the rear end of the block even
with the wing saddle openings in the fuselage sides.
22. D ADD THE BALSA BOTTOM SHEETING
Remove all pins from the inside of the fuselage.
Cut and glue on the bottom sheeting. For conventional
gear, leave the last section of sheeting off until the tail
wheel is installed later. When the glue is dry, remove the
fuselage from your building board and trim and sand the
bottom sheeting to shape.
23. D CUT OUT AREA ON REAR HOLD DOWN FOR
AILERON TORQUE ROD CLEARANCE
Align the fuselage over the wing and draw refer-
ence lines on the wing along both sides of the fuselage.
Mark the locations to be relieved on the rear hold down
plate for the aileron torque rod clearance. Remove the
fuselage and cut away the area on the hold down. Check
your work by placing the fuselage on the wing and operat-
ing the torque rods. A Dremel tool and router bit or grind-
ing drum or a coarse wood rasp works well for this step.
24. D PREPARE TOP FORMERS 1A THROUGH 6B
Prepare the fuselage top formers by numbering
them to match the plans. Mark the locations of the stringers
on formers 3B and 6B by referring to the plans. Glue former
3B to the back of 3A. Glue former 6B to the front of 6A.
Draw the location lines for the cockpit floor on the back of
the dash and on the front of the 3A/3B assembly.
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Page 16
25. D GLUE ON FORMERS 1A and 2A; SAND THEM SO
HOOD TOP FITS; TRIAL FIT THE FUEL TANK
Glue formers 1A and 2A to the tops of bulkheads
1 and 2. When the glue is dry sand the tops of these
formers to a slight angle so the hood top will mate squarely
when glued. Trial fit the assembled fuel tank. Carve out a
section of former 2A for fuel tank clearance if necessary. If
you leave the tank in permanently, plug all fuel lines so
balsa dust does not enter the lines.
26. D GLUE IN THE DASH; ADD FORMER 3A/3B
Pin the hood top in place to determine the height
of the dash. Put the cockpit floor in position to determine
the placement of the dash on the fuse side. Glue the dash
to the fuse sides. Do not glue on the hood top yet. Glue
former 3A/3B to the fuselage at the rear of the cockpit on
top of bulkhead #3.
27. D GLUE IN THE COCKPIT FLOOR
Prepare and glue the 1/8" cockpit floor between
the dash and former 3A/3B on the lines you drew earlier.
28. D PREPARE THE BALSA HOOD SIDE PIECES
The balsa hood side pieces need to be twisted
slightly to fit the front of the fuse. To make it easy to twist
the balsa as required, "paint" some ammonia on both
pieces of the balsa sheets. Place one end in a vise and
twist the other end somewhat more than is required. Hold
or clamp this end until the wood dries (about 15 minutes).
Note that the twist in the right piece is opposite that of the
left piece.
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Page 17
29. D INSTALL AND GLUE ON THE HOOD SIDE PIECES
Sand the bottom of the side pieces so they will
mate squarely with the fuselage sides. Glue the side
pieces from the front of former 3A/3B to beyond former 1A
in the following manner. To prevent a twisted fuselage,
glue both pieces at the same time, a little at a time starting
at former 3A/3B. The hood side pieces should extend outside former 3A/3B slightly so they can be sanded to con-
tour later.
30. D SAND THE TOPS OF THE HOOD SIDE PIECES
Sand the top of the hood side pieces flush with
the top of the formers so the hood top will mate squarely.
31. D GLUE ON THE HOOD TOP; SAND THE HOOD
SIDES AT THE COCKPIT.
Sand the angle at the rear of the hood top and
trial fit the hood top to the fuselage. Glue on the hood top.
After the glue is dry, sand the side pieces in the area of the
cockpit as shown on the plans.
32. D ADD FORMER 6A/6B
Pin the stabilizer in place so the stab is aligned
with the back of the fuselage. Mark the position of former
6A/6B and glue it in place. Remove the stab before the glue
sets up.
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33. D GLUE ON THE 1/4" x 1/4" BALSA TOP STRINGER
Cut to length and glue the 1/4" x 1/4" balsa stringer
in place between formers 3A/3B and 6A/6B.
34, D ADD FORMERS 4A AND 5A
Locate the positions of formers 4A and 5A by
placing a straight edge along the top stringer. Place and
glue the formers so they mate with the stringer and are
centered from side to side.
35. D ADD THE 1/8" x 1/4" STRINGERS
Add the 1/8" x 1/4" balsa stringers by gluing them
at 6A/6B first, checking with a straight edge and then gluing
to 5A, 4A and 3A/3B.
36. D PREPARE AND GLUE IN THE SIDE NOSE
BLOCKS; FINAL SAND THE FUSE FRONT
Groove the inside of the nose side block (right or
left depending on your engine) for the throttle linkage
clearance. Using 5 minute epoxy, glue the nose side
blocks in place. Remove excess epoxy at the chin block
joint. Carve and rough sand the hood top, hood sides and
chin block to the shape of the nose side pieces.
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Page 19
37. D CUT AWAY AREAS FOR ENGINE CLEARANCE;
DRILL HOLES IN MOUNT FOR ENGINE; TEMPORARILY MOUNT ENGINE TO FUSE
Temporarily install your mount and engine.
Relieve the engine compartment so the engine rests flat
on the engine mount. Check for binding of the throttle
arm. Mark and drill the holes in the mount for engine
mount bolts. Tap the holes for bolts and nuts or use selftapping bolts to hold the engine on the mount. The engine
has no down thrust and no right thrust.
38. D GLUE NOSE FILLER BLOCK IN PLACE; ADD
SPINNER RING
Using your engine as a guide, locate the place-
ment of the front filler block. The engine thrust washer
should extend 1/16" to 1/8" inches forward of the filler
block. Cut away areas on the block for engine clearance.
The placement of these parts depends on what brand
spinner you will use. Inspect your spinner backplate and
locate the block accordingly. When you are sure of the
placement, glue the crossgrain spinner filler block in
place. Sand the front of the nose if necessary. Glue the
ply spinner ring in place on the filler block using your
engine and spinner backplate as a guide for placement.
39. D ADD 3/8 TRI STOCK TO NOSE; SAND NOSE TO
SHAPE
Remove the engine and add the 3/8 triangle
stock along the bottom sides of the engine compartment
and behind the filler block. Custom fit these pieces so
they glue to the firewall and front filler block. Sand and
carve the nose to the shape of the spinner ring.
40. D DRILL FUEL LINE AND DRAIN HOLES; DRILL
NOSEGEAR CLEARANCE HOLES FOR TRIKE
GEAR
Drill the holes in former 1A for the fuel lines. For
conventional gear, drill a drain hole in the bottom of the
engine compartment just in front of the firewall. (For
tricycle
Relieve the chin block for nosegear spring clearance.
Relieve the 3/8 tri stock for steering arm clearance.)
gear,
drill
a hole
in
the chin block for nosegear,
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Page 20
41. D ALIGN THE STABILIZER TO THE FUSELAGE
First align the fuselage to a flat work surface.
The fuselage reference line (the line along the top of the
fuselage side - see step 9 on page 12) should be parallel
to the work surface. Now align the stabilizer to the
fuselage in this manner: A - Draw a centerline down the
stab bed at the end of the fuselage. Line up the stab
centerline to the fuse centerline. B - Measure from each
stab tip to a point at the center of the top of the firewall
area. Each measurement should be the same. C -Measure
from each stab tip to the work surface. Each measure-
ment should be the same. D - To make sure you have 0
degrees incidence, measure from the center of the leading
edge to the work surface. Measure from the center of the
trailing edge to the work surface. These distances should
be the same. When the stabilizer is aligned, do not glue in
place but go on to the next step.
42. D PREPARE THE FIN FILLER BLOCKS; GLUE ON
THE STAB, FIN AND FIN FILLER BLOCKS
Prepare the fin filler blocks by cutting them to
pick up the angle of the top stringer. Then sand them to
the contour of the stringers. Shaping and sanding is easy
if you tack glue scraps of balsa the thickness of the stab
and fin to the fuselage. Trim the scrap even with the fuse
sides and stringer line, then tack glue the blocks in place
and razor plane and sand them to shape. When ready,
break the blocks loose and remove and discard the scrap.
Use epoxy and glue the stabilizer to the fuselage. Glue
the fin to the stab at 90 degrees to the stab and aligned
on the stab centerline. Glue the prepared fin filler blocks
in place with 5 minute epoxy. Remove excess epoxy.
43. D ADD DORSAL FIN AND FILLER PIECES (MAKE
FROM SCRAP)
Use scrap balsa and custom make the dorsal fin
piece and filler pieces. Glue the dorsal fin to the fin and
1/4" top stringer. Glue the filler pieces between the top
stringer and the next stringer on each side of the dorsal
fin. These filler pieces are used to anchor the covering
material later.
44. D ADD THE TAILWHEEL STRUT; FINISH RUDDER
For conventional gear, glue the tailwheel strut in
place as shown on the plans. Use 5 minute epoxy and
clamp the tail until the glue is dry. Add the last piece of
bottom sheeting. Mark and drill the hole for the tailwheel
tiller arm in the rudder. Also groove the rudder leading
edge below the hole for the nylon bearing clearance.
Shape the leading edge of the rudder to a "V".
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Page 21
FINAL ASSEMBLY
1. D ALIGN THE FUSELAGE TO THE WORK SURFACE
AND THE WING TO THE FUSELAGE
Align the fuselage upside down to the work surface
using the line along the top of the fuselage side as the
reference line. This line should be parallel to the flat work
surface. Align the wing to the fuselage by making the
following measurements: A - Center the wing side to side
in the saddle. The distance from the fuselage side to the
wing tip on each side should be the same. B - The wing tip
to stab tip distance should be the same on both sides. C Wing tip to work surface distance should be the same on
both sides. D - The wing has 0 degrees incidence like the
stabilizer. The leading edge to work surface should be the
same as the trailing edge to work surface distance. When
the wing is aligned correctly, mark the position of the wing
on the fuselage so you can realign the wing again. Re-
member these measurements will not work unless you
have aligned the fuselage to the work surface first. The
reference line should be parallel to the work surface.
Measure from this line down to the work surface at several
points on both sides of the fuselage. All the measure-
ments should be the same from one side to the other.
WING MOUNTING (40 AND 60 SIZE ONLY) (GO TO STEP 5
IF YOU ARE BUILDING A 20 SIZE.)
2. D DRILL AND TAP WING BOLT HOLES IN THE WING
AND FUSE
With the wing still aligned to the fuselage, drill two
13/64" pilot holes through the wing hold down plates in the
leading edge of the wing. Drill a pilot hole for the rear hold
down in the center of the trailing edge for the 40 size. Drill
two holes for the 60 size at the rear. Drill this (these) rear
hole (holes) at an angle so the bolt head(s) will rest flat on
the trailing edge. For the 60 size model, glue the 1/16" Ply
plates at the rear of the wing first before you drill holes for
the rear wing bolts. Remove the wing and redrill and
counterbore the wing holes for the 1/4-20 wing bolt clearance so the bolt heads will rest flat on the hold down
plates in front and on the trailing edge or plates at the rear.
Tap the wing hold down plates in the fuselage using a
1/4-20 tap.
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Page 22
3. D SAND THE WING FAIRINGS TO SHAPE
Prepare to install the wing fairings by drawing lines
on the bottom of the wing even with the fuselage sides.
Cut the fairings to width. Sand to shape by placing sand-
paper on the wing and working the fairings back and forth.
*The 60 size has three fairing blocks where the 40 size
has only two. Sand the blocks to the shape of the wing and
also sand them to mate squarely with each other.
4. D GLUE THE FAIRINGS IN PLACE; SAND THEM TO
FUSELAGE CONTOUR
Drill holes through the fairings large enough for the
wing bolt heads to pass through. Install the wing bolts and
glue the fairings in place with 5 minute epoxy. Be careful
not to get any epoxy on the wing bolts and not to glue the
wing to the fuselage! When the glue is dry, sand the fairings to the fuselage contour.
WING MOUNTING (20 SIZE ONLY)
5. D USE DOWEL JIG AND DRILL HOLES IN THE WING
LEADING EDGE FOR DOWELS
(The dowel jig is used to help you drill holes in the
wing leading edge. The jig also gives you the location of
the 1/4" holes in bulkhead #2. You drill the wing holes first,
position the dowels and jig and then drill the holes in the
bulkhead after the wing is in position.) Use the plan
template and mark and drill 1/4" holes in the 1/8" Ply dowel
jig piece. Center the dowel jig over the wing leading edge
making sure the holes in the jig are centered on the wing
leading edge centerline. Drill 1/4" holes into the wing
leading edge and through both 1/8" dowel plates inside the
wing. Be sure that the holes are drilled parallel to the rib
centerlines and at 90 degrees to the wing leading edge.
6. D REALIGN THE WING TO THE FUSELAGE; GLUE
DOWEL JIG TO FUSELAGE
Place 1/4" dowels into the holes in the wing leading
edge. Place the dowel jig on the dowels. Position the
dowels so they are flush with the dowel jig when the jig is
next to the wing. You may want to tack glue the dowels to
the wing so they don't fall inside the wing during this step.
Now place the wing, dowels and dowel Jig into the wing
saddle. Realign the wing. Push the dowel jig forward
against bulkhead #2 and tack glue the dowel jig to the rear
of bulkhead #2. Remove the wing and dowels from the
fuselage.
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Page 23
7. D DRILL 1/4" DOWEL HOLES THROUGH THE
DOWEL JIG HOLES INTO BULKHEAD #2; GLUE
DOWELS INTO THE WING
Use the holes in the dowel jig as a guide and drill
1/4" holes into bulkhead #2. Remove the dowel jig and now
permanently install this jig with epoxy using the drilled
holes to align the jig in the exact position. Glue the dowels
into the wing with epoxy. A little less than 1/2" of the
dowels should extend beyond the leading edge of the
wing. Put the wing on the fuselage and check your work.
The wing should be aligned correctly.
8. D INSTALL THE REAR WING BOLTS
With the wing aligned to the fuselage, drill 5/32 pilot
holes (at a slight angle so the bolt head will rest flat on the
center trailing edge piece) for 10-32 bolts through the
center trailing edge piece and rear hold down in the
fuselage. Remove the wing. Redrill the wing with a 13/64"
drill for 10-32 bolt clearance. Tap the holes in the fuselage
hold down for 10-32 bolts with a 10-32 tap. Bolt the wing to
the fuselage to check your work.
9. D SAND THE WING FAIRINGS TO SHAPE; GLUE
FAIRINGS TO WING
Refer to steps 3 and 4 under 40 and 60 wing mount-
ing instructions on page 21.
10. D FINISH COCKPIT AREA; FUEL PROOF FUSE;
FINAL SAND MODEL
Finish the cockpit area any way you wish. You
may want to add a pilot, paint the cockpit area and/or add
an instrument panel. Fuelproof the engine compartment
by coating all the balsa and ply parts with resin or epoxy.
Now final sand the entire model.
NOTE: You can cover your Sportster now, but waiting until
later after the radio and other equipment is installed will
save dents and damage to your finished model. Plus you
may find that additional carving, gluing or sanding is
necessary before covering.
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Page 24
11. D INSTALL RADIO COMPONENTS IN THE FUSELAGE
Glue servo rails made from scrap plywood or hardwood into
the radio compartment. Install the rudder, elevator and throttle
servo directly to the hardwood rails or install the servo tray that
comes with your radio. Position the battery and receiver (wrapped
in foam rubber for protection) as shown on the plan. Install the
on/off switch. Install the inner pushrod wires into the outer
pushrod tubes for the rudder and elevator. Also install a cable
type pushrod and its outer tube for throttle linkage. If you have
trike gear, install a pushrod for steerable nose gear. Use a cable
type if you need to bend the pushrod.
12. D CUT SERVO WELL IN THE TOP OF THE WING
The well is located directly behind the spars. Cut
out enough of the wing sheeting, center rib and root ribs to
allow the placement of the servo as deeply as possible in-
to the wing. Glue hardwood rails (from scrap) as shown in
the photo or use the tray that came with your radio. Drill
small pilot holes in the rails for the servo screws.
NOTE: Do not cut the main spar.
13. D INSTALL AILERON SERVO AND LINKAGE
prevent interference with the other servos Install the
threaded wire pushrods with "Z" bends at the servo. Install
the nylon swivels onto the the aileron pushrods. Install the
nylon swivel clevises onto the rods and attach them to the
swivels. Adjust as needed so that the ailerons are equally
neutral when the servo is centered.
14. D INSTALL MAIN GEAR
Place the wire main gear into the landing
gear blocks in the bottom of the wing. Hold the wire
gear in the blocks with the metal hold down straps
and sheet metal screws. Use two straps on each gear.
Drill 1/16" holes in the blocks first. Then put the
screws in place.
15. D INSTALL THE NOSE GEAR, STEERING ARM
AND WHEEL COLLAR (TRIKE GEAR ONLY)
Shorten the steering arm to the length shown
on bulkhead #1 front view on the plan.
Mount the servo as deep into the wing as you can to
16. D INSTALL THE ENGINE MOUNT AND
ENGINE/MUFFLER
Attach the muffler to the engine. Install the
mount to the fuselage. Attach the engine/muffler to
the mount.
17. D INSTALL THE FUEL TANK
Install the tank now if you haven't done so
already. Assemble the tank per manufacturer's directions. Feed extra long fuel lines through the front of
former 1A into the tank compartment. Attach the
lines to the tank and pull the tank into position. Cut
the fuel lines to length and attach them to the engine.
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Page 25
18. D COVER THE MODEL
Remove any equipment that will be in the
way while you are covering. Make sure the model is
all final sanded and clean (use a tack cloth or rag to
pick up any dust) Use heat shrink covering material
and cover your Sportster. Follow the instructions
available with the covering. When the model is completely covered, reinstall the equipment you removed.
19. D INSTALL ALL CONTROL SURFACES AND
CONTROL HORNS
Flex the hinges back and forth a few times
and then glue the hinges into the rudder and fin slots,
at the same time gluing the tiller arm of the tail wheel
into the rudder leading edge Lightly sand both surfaces of the hinges, put epoxy (or Slo-ZAP) into each
hinge slot and place the hinge in place Use 2-56
screws and backplate and attach the nylon horn to
the rudder over the tail wheel tiller arm position for
extra support Glue the elevator joiner wire to the
elevators Glue the hinges to the elevators and stabilizer in the same manner as above Attach the nylon
elevator horn and backplate to the bottom of the right
elevator with 2-56 screws Glue the aileron torque
arms into the ailerons as you glue the hinges into the
ailerons and wing trailing edge.
20. D INSTALL THE CANOPY
Cut the canopy on the cut lines scribed in
the plastic You can dye the canopy using Rit dye
Follow the instructions on the box. Remove the
canopy from the dye when the desired tint is achieved. Glue the canopy to the fuselage with Cyanoacrylate glue. Seal the edge with striping tape.
21. D ASSEMBLE THE WHEEL PANTS
Cut and trim the wheel pant halves on their
parting lines that you find on the inside of the pants
You can score this line with an X-Acto knife and break
on the line or simply cut on the line with a knife
Sand the edges of the wheel pants smooth
An easy way to do this is to lay your sandpaper down
on a flat surface and move the pants over the sandpaper. This way you are assured of a straight, flat
edge when you finish
Cut a starter hole in one half of each pant in
the area of the wheel opening to make it easier to cut
out the opening later after the halves are glued
together Cut the starter hole at the join line
Using Cyanoacrylate (instant glue), join the
two halves together Note that there is a right and a
left half to the wheel pant. Make sure you have a good
fit before you glue the two halves together When the
halves are Joined, sand lightly along the Join line on
the outside of the pant to get a smooth appearance
Use your wheel and measure and mark the
area to be cut out of the pant for the wheel opening
Cut out this area
Find the tape locations on the inside of the
pant in Figure 1 Use 60-100 coarse sandpaper and
sand the areas where you will put the tape.
Reinforce the inside of the wheel pants with
fiberglass tape Cut the tape into one inch squares
You should have eight pieces of tape when you finish
cutting Use 5 minute epoxy and a piece of tape at
each of the places you sanded before Let the tape
hang out of the wheel opening. Cut the excess off
when the epoxy is dry.
22. D MOUNT THE WHEEL PANTS AND WHEELS
Mark the position of the axle hole on the inner
side of each wheel pant Drill a clearance hole at this
location for your gear wire or axle bolt See Figure 1
Mark the position of the brass plate on the
gear Do this by temporarily placing the wheel pant on
the gear Position the pant so it does not touch the
ground and is level or in the correct position for your
model Mark the position of the brass plate on the
gear and the outside of the pant Remove the wheel
pant' Solder the brass plate to the gear using StaBnte silver solder Position and solder the other brass
plate in the same manner
Position the 1/8" plywood plate on the inside
of the wheel pant opposite the brass plate on the
gear Temporarily put the wheel pant back on the gear
to find this position The ply plate is used as a back
up plate for the brass plate so do a good job of lining
these two plates up When you have the correct positions for the ply plates, use 5 minute epoxy and glue
them to the inside of the wheel pants. Let the ply
plates dry
Drill the axle hole through the ply plates in
the pants
Using the brass plate as a guide, drill two
pilot holes through the wheel pants and the ply back
up plate for the #2 x 3/8" screws
Trial fit the wheel pant assembly to the gear
by attaching screws provided, wheels and wheel collars
to hold the wheels to the gear If all is in the correct
position, remove the assembly from the gear See
Figure 2.
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Page 26
WIRE
LANDING GEAR
WHEEL PANT
25. D RANGE CHECK YOUR RADIO SYSTEM,
CHECK THE CENTER OF GRAVITY,
RECHECK ALL ALIGNMENTS
WHEEL COLLARS
#2 SCREW
BRASS PLATE
PLYWOOD PLATE
Figure 2
Paint the wheel pants First, sand lightly
with wet/dry 320-400 sandpaper but use it dry Use K&B
primer or automotive primer Sand the primer after it is
dry You need only to sand the primer lightly Put on the
final coat of paint Spraying works the best for the final
coat but brushing the paint will give you good results
also.
23. D EXTEND THE RADIO ANTENNA
Run the antenna out of the radio compartment of the fuselage and attach it to the front of the
fin. Do NOT cut the antenna wire'
24. D CONNECT ALL LINKAGES (PUSHRODS),
CONTROL SURFACES, CHECK RADIO
OPERATION AND SET THE THROWS
Your model should balance at the point
shown on the plan If it doesn't, move the battery
and/or receiver around until the model balances at
the point shown If additional balance weight is
needed, add lead weights to the nose or tail to get
proper balance Range check your radio at your flying
site as per your manufacturer's recommendations
Recheck your wing and stab alignments Make sure
the rudder is 90 degrees to the fuselage Check to see
that all hardware is secure and that all equipment is
in good condition.
26. D TRIM THE MODEL
Make your first flights, with the help of an
experienced modeler/flyer if this is your first model
The model may need some trim changes or adjustments to the control surfaces after the first flight
Adjust the control surfaces at the clevises until the
model flies correctly.
NOTE: See page 42 for balancing instructions.
Screw a nylon clevis onto the threaded end of
each pushrod Note: Screw them on all the way
until the threads protrude inside the clevis. Cut a
short length of 1/8" diameter plastic tube into 1//4"
pieces Slide half of the these onto each of the pushrod
wires and space them out evenly Temporarily insert
the pushrods into the tubes Adjust the spacers so they
will always stay inside the tube If the spacers are not a
tight fit on the pushrod wire, apply a small drop of thin
CA to secure them Attach the clevises to the rudder
and the elevator control surfaces Holding the surfaces
at neutral, mark on the pushrods where they intersect
with the servo horns Remove the pushrods and make
Z-bends at the marks Cut off the excess wire
Remove the servo horns and reinsert the pushrods
Attach the pushrods to the servo horns and reinstall so
that the surfaces are neutral when the servos are
centered
Attach a clevis to the end of the throttle cable
and attach it to the engine throttle arm Attach the other
end of the cable to the throttle servo with a connector of
your choice If your have trike gear, attach a clevis to
the nose gear pushrod and then to the nosegear
steering arm Attach the other end of the pushrod to
the rudder servo on the opposite side of the servo horn
Operation of the rudder servo on the ground will
therefore turn the nose gear and steer the airplane
The servos and linkages should not bind or interfere
with each other Set the control surface throws as
shown on the plan
GOOD LUCK AND GOOD FLYING!
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Page 27
SUPER SPORTSTER FOUR-CYCLE CONVERSION INSTRUCTIONS
Our popular Sportster series is a "natural" for 4-cycle experimentation. The unique looks of a Sportster
just screams "4-Cycle" and the lightweight air-frame and symmetrical airfoil means the Sportster design
will make the most of the 4-cycle fun. Whether you want to just "putter" around the sky, or loop, roll, and
snap, the Sportster/4-cycle combination is unbeatable!
Four cycle engines offer many benefits — their quiet, realistic sound is pleasing to modelers and nonmodelers alike. High torque allows the use of high pitch or large diameter propellers for a new style of flight
characteristics. They are also very fuel efficient for economical operation.
On the other side of the coin, 4-cycles are larger and heavier than equivalent power 2-cyles. That means
some special care must be taken to avoid a nose-heavy airplane, such as moving the firewall and radio farther back than normal. We'll help you with that task with these instructions.
Because of their similarity in design, we are writing these adaptation instructions for all three Sportster
designs (Super Sportster 20, 40 and 60). Where dimensions or measurements differ, read the appropriate
section for your Sportster.
CHOOSING YOUR ENGINE
It's difficult to say exactly what the optimum engine size is for your Sportster. The old rule of thumb was
to choose a 4-cycle engine with 1-1/2 times the 2-cycle displacement for equivalent horsepower. But recent
advancements by engine manufacturers have brought the power of 4-cycles way up, and the weight of the
engines down. One good example is the Enya .46 Four Cycle. This engine weighs just a fraction more than
most 2-Cycle .40's and it produces comparable power and thrust.
SUPER SPORTSTER 20: For this airplane a Saito .30 will give comparable power to a 2-Cycle but weighs
more and is larger than a 2-Cycle. See page 33 for a drawing of the Saito .30 in a Sportster 20.
SUPER SPORTSER 40: For this plane you can choose between .40 and .60 size 4-cycle. A .40 will give
docile flight performance. A .60 provides plenty of thrust, but with a significant increase in weight and size.
The .60 will fit but it's going to be tight. See page 34 for a full size drawing of the Enya .46 mounted in the
Super Sportster 40. The OS FS-61 is shown on page 35.
SUPER SPORTSTER 60: This model is well suited for the .60 to .90 size 4-cycles. Some of the new .60 size
engines are putting out high thrust that will make a light Sportster 60 perform nicely. For maximum thrust
with a small increase in weight, there are several small case .90's on the market that will fit in the Sportster
60. Pages 36 and 37 show the OS-FS 61 and the Enya .90 mounted in Super Sportster 60.
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Page 28
CHOOSING A MOUNT
Low weight and rigidity are important in 4-cycle mounting. Hayes and Tatone both make good mounts for
4-cycle use.
The Hayes mounts will fit 40's, 46's and 60's. The AL-40 is good for the Saito .30, The Enya .46 and Saito
.45. The AL-60 will fit the Enya .60 and the OS FS-61. Currently Hayes does not make a mount for .90 use.
Tatone produces aluminum mounts that are predrilled for individual engines.
Both brands are lightweight. To improve rigidity, we recommend installing a front bulkhead. This essentially gives a beam mount system that is extremely rigid but makes removal of the mount a little more cumbersome.
BUILDING PROCEDURE
Following are steps that refer to 4-cycle installation to replace the steps in the front of this instruction
book. Refer to these steps as you build your model.
BUILDING THE FUSELAGE
Step 2
Prepare the Firewall. Mark the "top" of the Firewall. Mark the centerline of the engine on the Firewall and
center the mount in position. The thrust line of the engine should be in the same position as shown on your
plan. Drill holes and install blind nuts. Temporarily install the mount and trim the mount bolts that extend
into the tank compartment. Drill hole for throttle pushrod to carburetor (make sure throttle pushrod does not
interfere with tank).
Next bolt the engine to its mount. If you use a Hayes mount, position the engine as far back as possible
leaving sufficient room for engine and/or carburetor clearance. Make sure you don't put in any right or left
thrust.
Then measure the distance from the back of the mount to the prop (thrust) washer. To do this, place the
engine and mount on a flat surface and put a straight edge across the thrust washer. Measure back from
this straight edge to the back of the mount. This distance is "B". Refer to the drawings and the chart on the
next page. We are measuring this distance so we can determine how far back to move the firewall so the
engine will fit into the nose of the model.
Figure 1
2-CYCLE ENGINE
GREAT PLANES MOUNT
S55
28
Page 29
Figure 2
AND
HAYES MOUNT
Now let's figure out how far back to move the firewall from the normal 2-cycle position. We have already
figured out for you the "A" distance of the Sportster 20 (3-5/16"), the Sportster 40 (3-3/4") and the Sportster
60 (4-1/8"). The chart also takes the spinner used into account. If you use a different spinner than mentioned,
just measure the backplate depth and add that distance to one of the above measurements, depending on
which model you are building.
Distance B
(length of your
4-cycle engine and
mount
SPORTSTER 20
B
B
B
SPORTSTER 40
B
B
B
SPORTSTER 60
B
B
B
Minus
—
—
,
—
—
—
—
Distance A
(length of 2-Cycle
engine/mount and spinner
back plate)
3-5/16" (CB Spinner)
3-5/32" (Dubro Spinner)
3-7/16" (Goldberg Spinner)
3-3/4" (CB Spinner)
3-29/32" (Dubro Spinner)
3-7/8" (Goldberg Spinner)
4-1/8" (CB Spinner)
4-9/32" (Dubro Spinner)
4-1/4" (Goldberg Spinner)
Chart 1
Equals
=
=
=
=
=
x
?
(Distance to
move firewall
back)
?
?
?
?
?
?
?
?
?
29
Page 30
Basically all we've done here is to measure how long your new mount and engine is, allow for some spinner
back plate space and subtract the distance shown on the plan (A) from the distance you measured (B). The
result gives you the distance you have to move the firewall back. (See Figure 3 and 4 also.)
Let's do an example to show this. Refer to the drawings on page 35 showing the OS FS-61 in the Sportster
40. We are going to use a Goldberg Spinner. Our "B" measurement is 5-1/8" (measure from the front of the
thrust washer to the rear of the mount). By looking at the information in Chart 1 on page 29, we know that we
have to subtract 3-7/8" (distance A) from our distance B. The result is 1-1/4". We move the Firewall back
1-1/4".
Example:
Work Area:
YourB
Your A
Move Firewall
Back
Step 5
Mark the new position of the Firewall on the inside of each Fuselage Side. Make sure your line is perfectly
parallel to the front of the fuse sides. Using the firewall as a spacer, install the balsa doublers cross grain
on the inside of the fuse side. Custom cut these pieces to fit. Do not glue the Firewall in at this time. Use
epoxy glue or thick CA to glue the doublers in place. The doubler should extend past Bulkhead #3. Carefully
trim the doublers to the fuse side shape.
Step 13
Draw the corrected bulkhead #1 position on the top view of the plans. Next still working over the plans,
glue Bulkhead #1, the Firewall, in place. Then add 3/8" (or 1/4" depending on your mount width- see Figures
4 and 5) scrap balsa filler blocks, vertically grained, forward of Bulkhead #1. Sand the blocks flush with the
fuse sides. Add 1/4" balsa filler below the Firewall later when you remove the fuselage from the building
board.
30
Page 31
Step 36
Check for adequate width clearance for your engine. If your 4 cycle and mount is over 2" wide for the
Sportster 20, 2-1/4" for the 40 and over 2-5/8" for the 60 size, you'll need to relieve the 3/8" or 1/2" balsa nose
blocks and the 3/8" or 1/2" filler pieces in the engine mount area. Or you can custom make 3/8" balsa nose
side blocks as shown in Figure 5. Now follow step 36 in the first part of this book about gluing these side
pieces to the fuselage.
Next, if desired, add a front bulkhead to the engine mount as shown on the drawings on pages 33 through
37. Make this Bulkhead from 1/8" plywood. Once the front Bulkhead is epoxied in, drill the front of this
bulkhead mount for 4-40 bolts. Then tap the mount and install 4-40 bolts.
RELIEVE AS SHOWN
Figure 4
IF MOUNT WIDTH EXCEEDS THE SPACE AVAILABLE.
31
Page 32
GENERAL INFORMATION
Center of Gravity: A nose heavy airplane can be a problem! Make sure you check the CG location during
construction with the radio components installed. You may need to put the radio as far back in the compartment as possible. This will avoid having to carry tail weight.
Props: Always start with the manufacturer's instructions (especially for break in) for prop selection. Read
their instructions carefully because 4 cycles use entirely different diameter and pitch propellers because
they operate at a lower RPM and produce greater torgue than equivalent displacement 2-cycles.
You may find that after operating your Sportster with recommended props that you'll want to experiment
with other props. It is amazing how much you can change flight characteristics of a model by changing props.
If you are looking for higher flight speeds from your Sportster than you are getting from the average recommended prop, consider reducing the diameter and/or blade area slightly and increasing the prop pitch to
bring the RPM back to the normal range. For example, with our Enya .46 equipped Sportster 40, the instructions recommend 13x5,12x6,11 x 7,11 x 6,10x6,10 x 7 or 10x8 props. We started with an 11 x 6 propeller
which gave us fair performance. Larger props will provide slower speeds... fine for big biplanes... but not
what we wanted from our racy Sportster. For faster speed, we found that a 10-1/2 x 7-1/2 propeller added approximately 10 mph to the straight and level flight which helped make vertical maneuvers crisper due to a
faster entry speed. There is a trade off, however, as the engine idle was somewhat higher due to the lower
mass of the wood 10-1/2 x 7-1/2 propeller. Four-cycles like flywheel weight from large diameter props. This
made the plane land a little faster than with the 11x6. The prop we used was a prop designed for .60 size
pattern engines, a Max Dailey (Radio South) propeller. A similar prop is also available from DW Products.
Their addresses are:
Radio South DW Products
180 E. Burgess 5634 Crystal Ct.
Pensacola, FL 32503 Santa Rosa, CA 95404
Fuel Tank: For simplicity, we recommend a 2 line tank for your Sportster. If you can't easily reach the fuel
line for fueling purposes, you might consider using one of the new DuBro fueling valves. This will save ex-
tra plumbing that could leak or cause problems. Most 4 cycles have a small enough venturi that muffler
pressure is unnecessary. Don't forget the crankcase drain line. A lot of excess fuel comes out of the
pressure fitting. Make sure this drainage exits your fuselage. Treat it as though it were a separate exhaust.
Flying: Other than the obvious sound difference, you'll notice one other big difference from your first take
off with a four cycle equipped Sportster: You'll need to add more right rudder than normal to counter the increased torque on acceleration during takeoff. Also, you may be surprised how big an effect the larger pro-
peller may have on abrupt change maneuvers such as a square loop. Because there is more mass to the
propeller, it has a larger gyroscopic force. When you change directions in maneuvers like a square loop, you
may find that the plane changes heading. This may be a result of gyroscopic precession and/or P-factor.
These factors become more prevalent with larger diameter 4 cycle props and with slower speeds generally
encountered with these engines.
Also don't forget to have a slight amount of toe-in with your main wheels. Toe out and lot's of torgue can
cause problems with ground handling. Use some toe-in, add some rudder and your takeoffs will be in a
straight line.
GOOD LUCK AND GREAT FLYING!
32
Page 33
33
Page 34
34
Page 35
35
Page 36
36
Page 37
37
Page 38
SUPER SPORTSTER 20 PARTS LIST
PART#
BAL046
BAL047
BAL126
CANPY035
EM2048L
EM2048R
NYLON87
SS20F01
SS20F02
SS20F03
SS20F05
SS20F07
SS20F08
SS20F09
SS20F10
SS20F16
SS20F17
SS20F20
SS20F21
SS20P01
SS20P02
SS20R01
SS20R02
SS20S01
SS20S02
SS20W07
SS20W08
SS20W09
SS40F29
WPNT001
QTY DESCRIPTION
Q
Balsa 1/4 x 1/4 x 36 Fuselage Brace
2
1
Balsa 1/8 x 1/4 x 36 Former Stock
Balsa 1/16 x 1/4 x 36 Cap Strip
5
1
Plastic Canopy
1
Adjustable Engine Mount Left
1
Adjustable Engine Mount Right
1
CA Hinge Strip 2x9
2
Balsa Shaped 1/8 Fuselage Sides
1
Balsa Shaped 5/8 Chin Block
1
Ply Shaped 1/4 x 2-1/2 x 2-1/4 Bulkhead #1
1
Balsa 3/16 x 2-5/8 x 22-3/4 Bulkhead #3
1
Balsa 3/8 x 3 x 9-3/8 Hood Top
1
Balsa 3/16 x 1-1/4 x 14-7/8 Nose Filler Block
2
Balsa 3/16 x 1-1/4 x 14-7/8 Hood Side
Balsa Shaped 3/8 Side Block
2
2
Balsa Shaped 3/4 Stab Filler
1
Balsa 1/8 x 2-5/8 x 4-3/4 Cockpit Floor
Balsa 1/16 x 3 x 36 Fuselage Doubler
1
Balsa 3/32 x 3 x 24 Top Sheeting
1
1
Plan Sheet
1
Instruction Book
Balsa Shaped 3/16 Fin
1
Balsa Shaped 3/16 Rudder
1
1
Balsa Shaped 3/16 Stabilizer
2
Balsa Shaped 3/16 Elevator
1
Balsa Shaped 21/32 Wing Fairing
Balsa 3/8 x 3 x 4-1/2 Wing Fairing
1
1
Balsa Shaped 1/4 Center Rib
1
Balsa 3/8x12 Triangle Stock
1
Plastic ABS Wheel Pant Set
PART# QTY DESCRIPTION
SS20M01 1
GLPT001 1
METAL007 2
NUTS001 4
NYLON03 2
NYLON16 1
NYLON17 2
NYLON20 2
NYLON21 2
NYLON23 2
NYLON36 1
PLY3013 2
PLTB002 3
SCRW002 4
SCRW003 4
SCRW005 1
SCRW020 1
SCRW024 12
WBNT002 1
WBNT009 1
WBNT070 1
WHCL005 1
WIRES16 2
WIRES17 2
SS20M02 1
WBNT103 2
WBNT104 1
SUB PACK - HARDWARE
Fiberglass Tape 1 x 8
Brass Shaped 1/16 Plate
4-40 Blind Nuts
Nylon Small Control Horn
Nylon 5/32 Nosegear Steering Arm
Nylon Clevis
Nylon Swivel
Nylon Swivel Clevis
Nylon 10-24 Wing Bolt
Nylon Gear Hold Down Straps
Plywood 1/8x1/2x1 Plate
Plastic 36 Outer Pushrod Tube
2-56 x 5/8 Screw
4-40 x 1 Round Head Screw
6-32 x 1/8 Screw
6-32 x 1/4 Screw
#2 x 3/8 Screw
Wire 3/32 Aileron Torque Rod Set
Wire Tailgear Assembly
Wire Elevator Tie
5/32" Wheel Collar
Threaded Pushrod Wire - 16"
Threaded Pushrod Wire - 34"
SUB PACK - LANDING GEAR
Wire Main Gear
Wire Nose Gear
SS20A01
DOWEL018
HRDWD005
HRDWD012
HRDWD022
PLY3004
SS20F13
SS20F14
SS20F18
SS20W11
SS20A02
SS20F11
SS20F12
SS20A03
SS20F04
SS20F06
SS20F19
SS20W10
SS20W13
SS20A04
SS20W12
SUB PACK - FUSE & WING
1
Hardwood 1/4 x 2-3/4 Wing Dowel
2
2
Hardwood Shaped 5/8 x 5/8 LG Gusset
2
Hardwood Grooved 5/8 x 5/8 LG Block
2
Hardwood Grooved 5/8 x 4 LG Block
4
Plywood Shaped 1/16 LG Brace
1
Plywood Shaped 1/16 Spinner Ring
1
Plywood 1/4 x 3/4 x 2-5/8 Hold Down
1
Plywood 1/8 x 3/4 x 2-5/8 Dowel Jig
2
Hardwood Shaped 5/16x3 Center TE
1
SUB PACK - FUSE STRINGERS
1
Balsa 1/4 x 1/4 x 14 Stringer
Balsa 1/8 x 1/4 x 14 Stringer
8
SUB PACK - DIE-CUT SHEETS
1
1
Plywood 1/8 x 3-1/4 x 6 Bulkhead #2
1
Balsa 1/8 Fuselage Formers
1
Balsa 3/32 Deck Base
1
Balsa 1/8 Wing Tip
5
Balsa 3/32 Ribs
1
SUB PACK - WING SHEETING
Balsa 1/16 x 2-5/8 x 6-1/2 Center Wing Sheeting
8
SS20W01 1
BAL080 2
BAL091 4
SB40W04 4
SS20W02 2
SS20W03 4
SS20W05 2
SS20W06 1
SUB PACK - WING PARTS
Balsa 3/16 x 1/4 x 24 Trailing Edge
Balsa 1/4X3/8X24 Spar
Balsa 1/16 X 2-1/8 X 24 LE Sheeting
Balsa 1/4X7/8X24 LE
Balsa 1/16 X 3/4 X 24 TE Sheeting
Balsa 5/16 X 19 Aileron
Balsa 1/4 x 5/8 x 24 Building Shim
38
Page 39
SUPER SPORTSTER 40 PARTS LIST
PART# QTY DESCRIPTION
BAL009 5 Balsa 3/32x1 MX 36 Cap Strip SS40F31 1 SUB PACK - FUSE STRINGER
BAL015 8 Balsa 3/32 x 3 x 7 Center Sheet
BAL019 2 Balsa 1/4 Triangle Fuselage Brace
BAL041 1 Balsa Shaped 5/8 Chin Block
BAL047 1 Balsa 1/8 x 1/4x36 Former Stock
BAL072 1 1/8x3x36 Fuselage Doubler
CANPY017 1 Plastic Canopy SS40M01 1 SUB PACK - HARDWARE
EM4070L 1 Adjustable Engine Mount Left GLTP001 1 Fiberglass Tape 1 x 8
EM4070R 1 Adjustable Engine Mount Right METAL007 2 Brass Shaped 1/16 Plate
SS246P02 1 Instructions NUTS003 4 6-32 Blind Nuts
NYLON87 1 CA Hinge Strip 2x9 NYLON03 2 Nylon Control Horns
SS40F01 2 Balsa Shaped 1/8 Fuselage Sides NYLON 13 3 Nylon 1/4 - 20 Wing Bolt
SS40F02 1 Balsa Shaped 1/8 Deck Base
SS40F03 1 Ply Shaped 1 /4 x 3 x 2-9/16 Bulkhead #1
SS40F04 1 Ply Shaped 1/4 Bulkhead #2
SS40F05 1 Balsa 1 /4 x 3 x 3-3/16 Bulkhead #3
SS40F07 1 Balsa 3/8 x 3-1/2x 11 Hood Top NYLON36 1 Nylon Gear Hold Down Straps
SS40F09 2 Balsa 1/4 x 1-3/8 x 17-1/2 Nose Side
SS40F10 2 Balsa Shaped 1/2 Nose Side Block
SS40F29 1 Balsa 3/8 x 12 Triangle Stock
SS40F30 1 Balsa 1/8x3x5-1/2 Cockpit Floor
SS40F32 1 Balsa 3/32 x 3 x 24 Bottom Sheeting SCRW008 4 6-32 x 1 Screw
SS40P01 1 Plan Sheet SCRW020 1 6-32 x 1/4 Screw
SS40R01 1 Balsa Shaped 1/4 Fin Front SCRW024 12 #2 x 3/8 Screw
SS40R02 1 Balsa Shaped 1/4 Fin Rear WBNT002 1 Wire 3/32 Aileron Torque Rod Set
SS40R03 1 Balsa Shaped 1/4 Rudder WBNT009 1 Wire Tailgear Assembly
SS40S01 1 Balsa Shaped 1/4 Stabilizer Front WBNT101 1 Wire Elevator Tie
SS40S02 1 Balsa Shaped 1/4 Stabilizer Rear WHCL005 1 5/32" Wheel Collar
SS40S03 2 Balsa Shaped 1/4 Elevator WIRES16 2 Threaded Pushrod Wire -16"
SS40W07 1 Balsa Shaped 5/8 Wing Fairing
SS40W08 1 Balsa 3/8x3-1/2x5-1/2 Wing Fairing
SS40W09 1 Balsa Shaped Center Rib
SS40W10 2 Balsa Shaped 3/16 Wing Tip SS40M02 1 SUB PACK - LANDING GEAR
SS40W14 1 Balsa 1/4 x3x 10 Wing Filler WBNT014 2 Wire Main Gear
WPNT002 1 Plastic ABS Wheel Pant Set
PART# QTY DESCRIPTION
SS40F11 1 Balsa 1/4x1/4x16 Stringer
SS40F12 8 Balsa 1/8 x 1/4 x 16 Stringer
NYLON 16 1 Nylon 5/32 Nosegear Steering Arm
NYLON17 2 Nylon Clevis
NYLON20 2 Nylon Swivel
NYLON21 2 Nylon Swivel Clevis
PLY3013 2 Plywood 1/8x1/2x1 Plate
PLTB002 3 Plastic 36" Outer Pushrod Tube
SCRW002 4 2-56 x 5/8 Screw
SCRW005 1 6-32 x 1/8 Screw
WIRES17 2 Threaded Pushrod Wire - 34"
WBNT046 1 Wire Nose Gear
SS40A01 1 SUB PACK - FUSE & WING
HRDWD005 2 Hardwood Shaped 5/8 x 5/8 LG Gusset BAL020 4 Balsa 3/8 x 26-1/2 Spar
HRDWD010 2 Hardwood Grooved 5/8 x 4-1/2LG Block BAL060 5 Balsa 3/32 x 7/8 x 30 TE Sheeting
HRDWD013 2 Hardwood Grooved 5/8 x 3/4 LG Block BAL090 2 Balsa 1/4 x 1/4 x 30 TE
PLY3001 1 Plywood 1/16 Spinner Ring SS40W02 2 Balsa 7/16 Aileron
PLY3004 4 Plywood Shaped 1/16 LG Brace SS40W03 4 Balsa 3/32 x 2-1/2 x 26 LE Sheeting
SS40F17 2 Plywood 1/4x7/8 x 3 Hold Down Plate SS40W05 2 Balsa 1/4 x 7/8 x 28 LE Sheeting
SS40W11 2 Hardwood Shaped 3-1/2 Center TE
SS40W12 2 Hardwood 1/2x5/8 x 3-1/16 Hold Down
SS40A02 1 SUB PACK - BALSA PARTS
SS40F16 1 Balsa 2-1/4 x 2-1/4 x 1/2 Nose Filler Block
SS40F18 1 Balsa Shaped 1/4 Former 1 A
SS40F19 1 Balsa Shaped 1/4 Former 2A
SS40F20 1 Balsa Shaped 1/4 Former 3A
SS40F21 1 Balsa Shaped 1/4 Former Dash
SS40F24 1 Balsa Shaped 1/4 Former 6A
SS40F28 2 Balsa Shaped 5/8 Fin Filler Block
SS40W1 ^ 4 Balsa 1/4x5/8x3 Leading Edge Filler
SS40A03 1 PARTS PACKAGE (DIE-CUT)
SS40F33 1 Balsa 1/8 Former 3B, 4A, 5A, 6B
SS40W04 6 Balsa 3/32 Wing Ribs
SS40W01 1 SUB PACK - WING PARTS
39
Page 40
SUPER SPORTSTER 60 PARTS LIST
PART# QTY DESCRIPTION
BAL009
BAL015
BAL019
BAL047
BAL084
BAL116
BAL120
CANPY025
EM4070L
EM4070R
SS246P02
NYLON87
SS60F01
SS60F02
SS60F03
SS60F04
SS60F05
SS60F07
SS60F09
SS60F10
SS40F29
SS40W14
SS60F30
SS60P01
SS60R01
SS60R02
SS60R03
SS60R04
SS60S01
SS60S02
SS60S03
SS60W07
SS60W08
SS60W10
WPNT003
SS60A01
HRDWD005
HRDWD010
HRDWD013
HRDWD017
PLY3004
PLY3016
PLY3017
SS60F17
SS60A02
BAL103
SS60F16
SS60F18
SS60F19
SS60F20
SS60F21
SS60F24
SS60F28
SS60W11
Balsa 3/32 x 1/4 x 36 Cap Strip
5
Balsa 3/32 x 3 x 7 Center Sheet
8
Balsa 1/4 Triangle Fuselage Brace
3
Balsa 1/8 x 1/4 x 36 Former Stock
1
Balsa 3/32 x 3 x 24 Bottom Fuse Sheeting
2
Balsa Shaped 5/8 Chin Block
1
1
Balsa Shaped 1/4 Center rib
Plastic Canopy
1
Adjustable Engine Mount Left
1
Adjustable Engine Mount Right
1
Instructions
1
1
CA Hinge Strip 2x9
Balsa Shaped 3/16 Fuselage Sides
2
1
Balsa Shaped 1/8 Deck Base
Ply 1/4 x 3-1/4 x 2-15/16 Bulkhead #1
1
Ply Shaped 1/4 Bulkhead #2
1
1
Balsa 1/4 x-3-5/16 x 3-9/16 Bulkhead #3
1
Balsa 3/8x4x11 -3/4 Hood Top
Balsa 1/4 x 1-3/8 x 18 Nose Side
2
Balsa Shaped 1/2 Nose Side Block
2
1
Balsa 3/8x12 Triangle Stock
Basia 1/4x3x10 Wing Filler
1
1
Balsa 1/8 x 3-1/4 x 6-1/8 Cockpit Floor
1
Plan Sheet
Balsa Shaped 1/4 Fin Front
1
Balsa Shaped 1/4 Fin Rear
1
1
Balsa Shaped 1/4 Rudder Front
1
Balsa Shaped 1/4 Rudder Rear
1
Balsa Shaped 3/8 Stabilizer Front
Balsa Shaped 3/8 Stabilizer Rear
1
Balsa Shaped 3/8 Elevator
2
1
Balsa Shaped 7/8 Wing Fairing
Balsa 1/2x2x6 Wing Fairing
2
Balsa Shaped 3/16 Wing Tip
2
1
Plastic ABS Wheel Pant Set
SUB PACK - FUSE & WING
1
Hardwood Shaped 5/8 LG Gusset
2
Hardwood Grooved 5/8 x 4-1/2 LG Block
2
Hardwood Grooved 5/8 x 3/4 LG Block
2
Hardwood 1/2x1 x 3 Wing Hold Down
2
Plywood Shaped 1/16 LG Brace
4
Plywood 1/16 Spinner Ring
1
Plywood 1/16 x 2-5/8 x 3-1/2 Wing Plate
1
Plywood 1/2 x 5/8 x 3-5/16 Hold Down
2
SUB PACK - BALSA PARTS
1
Balsa Shaped 7/16 Filler (LE)
4
Balsa 2-1/2x 2-5/8 x 1/2 Filler
1
Balsa Shaped 1/4 Former 1A
1
Balsa Shaped 1/4 Former 2A
1
Balsa Shaped 1/4 Former 3A
1
Balsa Shaped 1/4 Former Dash
1
1
Balsa Shaped 1/4 Former 6A
Balsa Shaped 3/4 Fin Filler Block
2
Balsa Shaped 1/2 Center Trailing Edge
2
PART# QTY DESCRIPTION
1
SS60A04
SS60F33
SS60W12
SS60F35
SS60F31
SS60F11
SS60F12
SS60M01
GLTP001
METAL007
NUTS003
NYLON03
NYLON 13
NYLON16
NYLON17
NYLON20
NYLON21
NYLON36
PLY3013
PLTB002
SCRW002
SCRW005
SCRW008
SCRW020
SCRW024
WBNT002
WBNT009
WBNT101
WHCL005
WIRES16
WIRES17
SS60M02
WBNT085
WBNT086
SS60W01
BAL025
BAL060
BAL063
BAL118
SS60W03
SS60W04
SUB PACK - RIBS AND FORMERS
1
Balsa 1/8 Former 3B, 4A, 5A, 6B (Die-Cut)
Balsa 3/32 Wing Ribs (Die-Cut)
5
2
Ply 1/8 Fuse Doubler (Die-Cut)
SUB PACK - FUSE STRINGER
1
Balsa 1/4 x 1/4 x 17-1/2 Stringer
1
Balsa 1/8 x 1/4 x 17-1/2 Stringer
8
SUB PACK - HARDWARE
1
1
Fiberglass Tape 1 x 8
2
Brass Shaped 1/16 Plate
6-32 Blind Nuts
4
Nylon Control Horns
2
Nylon 1/4 - 20 Wing Bolt
4
1
Nylon 5/32 Nosegear Steering Arm
Nylon Clevis
2
Nylon Swivel
2
Nylon Swivel Clevis
2
Nylon Gear Hold Down Straps
1
Plywood 1/8x1/2x1 Plate
2
2
Plastic 36" Outer Pushrod Tube
4
2-56 x 5/8 Screw
6-32 x 1/8 Screw
1
6-32 x 1 Screw
4
1
6-32 x 1/4 Screw
#2 x 3/8 Screw
12
1
Wire 3/32 Aileron Torque Rod Set
1
Wire Tailgear Assembly
Wire Elevator Tie
1
5/32" Wheel Collar
2
Threaded Pushrod Wire - 16"
2
2
Threaded Pushrod Wire - 34"
SUB PACK - LANDING GEAR
1
Wire Main Gear
2
Wire Nose Gear
1
SUB PACK - WING PARTS
1
Balsa 3/8 x 1/2 x 29-1/2 Spar
4
Balsa 3/32 x 7/8 x 30 TE Sheeting
4
Balsa 1/4x3/4x30 LE
3
2
Balsa Shaped 1/2 x 30 Aileron
4
Balsa 3/32 x 3-1/4 x 30 LE Sheeting
2
Balsa 1/4x5/16x30 TE
40
Page 41
Use trim MonoKote and these
letters to create your trim
scheme on your Sportster.
41
Page 42
MAX ELEV
CG
(367.)
to
LE
[3/8"]
[5/16"]
[1/4"]
3-3/16"
"]
[5/8"]
[5/16"]
4-1/16"
2-1/16".
4-13/16"
3-5/8"
SSADDOl
The best way to balance your Super Sportster is to make a
Balancing Stand from a square of 1/4" plywood and two 3/8" dowels.
Mark the fore and aft limits of the balance range on the top of the wing (on
(337.)
FOR VARIOUS BALANCE POINTS
RECOMMENDED MAXIMUM ELEVATOR THROWS
(29-30%)
[9/32"
MAX ELEV
CG
to
2-15/16"
LE
[5/16"]
MAX ELEV
CG
to
2-11/16"3"3-5/16"
LE
[11/16"]
[13/32"]
[11/32"]
3-3/8"
[3/8"]
[11/32"]
"
1-7/8
3-3/4-
4-3/8"
"]
[3/8"]
[7/16"]
[3/4
1-1/2"
3-15/16"
Take note of where the airplane balances. If it balances near the
SPORTSTER 20
SPORTSTER 40
SPORTSTER 60
both sides of the fuselage), and place the airplane upside down on the
If it balances outside the 29% to 36% range, you must either shift the
airplane forward or aft on the stand until it balances with the stab level.
balancing stand as shown in the sketch (empty fuel tank). Move the
location of radio components or add weight to the nose or tail until it
balances within the range.
front of the recommended range, then adjust the linkages to your elevator
to provide the maximum throw listed in the 29% - 30% column in the table
below If it balances near the middle of the range, set your elevator for the
maximum throw listed in the 33% column. If it balances near the aft limit
of the range, set your elevator for the maximum throw listed in the 36%
column.
MODEL
SPORTSTER 90
SPORTSTER BIPE
•MEASURED BACK FROU LE Of BOTTOM WING
location but fail to reduce the maximum elevator throw, the
WARNING! If you balance your Super Sportster aft of the plan
in unwanted stalls and "snap rolls"!
elevator may over control the pitch of the airplane, and may result
The recommended balance point for the Super Sportsters is
far back as 36%, and found to be completely stable throughout the entire
total wing chord, as shown in the sketch).
leading edge. However, all Sportsters have been thoroughly test flown as
range from 29% to 36% (These numbers represent a percentage of the
shown on the plan, and is located approximately 29% back from the
INSTRUCTIONS FOR BALANCING YOUR SUPER SPORTSTER
Points
Balance
If, when balancing your Super Sportster, you find it necessary to
the plan, it is preferable to balance farther aft, up to 36% (the aft limit),
add several ounces of nose weight to balance it at the location shown on
the airplane will become more responsive to elevator control; therefore,
you should reduce the maximum elevator throw in accordance with the
table of "Recommended Maximum Elevator Throws." The elevator throw
rather than adding a lot of weight As you balance farther aft, however,
is measured at the widest part of the elevator, as shown in the sketch.
Page 43
PUSHROD LINKAGES
43
Page 44
WARNING! THIS IS NOT A TOY!
THIS IS NOT A BEGINNER'S AIRPLANE!
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, using common sense and in
accordance with all safety standards 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 Drive
Muncie, IN 47302-9252
(800) 435-9262
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