Nakajima - 2010/09

September 2010 27
Frank gets a turn at circle burning
The prototype wears two coats of
clear dope under the color dope
base. The scheme is drab-green
upper surfaces and light blue-gray
lower surfaces. All lettering,
striping, and detailing is achieved
with MonoKote.
THE NAKAJIMA Ki-84 Hayate was undoubtedly the best fighter to
be in service for the Japanese in any numbers. When introduced
operationally in China in 1944, the Allied forces in World War II faced
an adversary that was far superior to anything that Japan had previously
fielded.
Code-named “Frank” by the Allies, the Hi-84 possessed superior
performance, respectable firepower, outstanding maneuverability, and
the ability to withstand battle damage to a degree that was previously
unheard of in Japanese fighters. Although it didn’t quite match the
performance of the P-47, P-38, or P-51, it was close.
Frank was superior to the F6F Hellcat, which comprised the bulk of
Allied fighters in the theatre. Its greatest failing was that it suffered at
high altitude and proved to be hopeless at intercepting the Boeing
Superfortress, which started bombing Japan in 1944.
The Hayate was a brilliant design, but because it was introduced so
late in the war, it could rarely be employed in the offensive role for
which it was designed. A total of more than 3,500 Ki-84s were
produced, the majority by Nakajima.
The model I am presenting is simple in construction and
inexpensive. The primary building material is 1/8-inch corrugated
cardboard, which greatly reduces both fabrication time and cost.
This design makes use of cardboard’s unique features. The material can
be used in large sections and folded.
The wing is built from two large pieces, with cardboard ribs and a
single spar. The tail surfaces and fuselage are primarily cardboard, with
little internal bracing required. The result is a quick-to-build aircraft that
has a scalelike appearance and can take plenty of punishment at the
flying field.
Cardboard varies in weight, but any 1/8-inch corrugated type will do
well for this project. Sources of the material include box manufacturers
and shopping centers where you can find stacks of discarded boxes.
Look for cardboard with brown paper on one side and a white
finished Kraft paper on the other. Having the white paper on the
outside of the model results in a smoother finish and neater
appearance.
I’ll describe in the construction hints my method of folding the
cardboard and using gummed paper tape to seal the joints and
exposed corrugations.
The Hi-84 has a wingspan of 60 inches and a length of 54 inches.
The bottom of the airfoil is flat with a curved upper surface, because of
the scoring-and-folding technique I employed.
You can use a .40- to .50-size engine in this airplane. Mine is
powered by a .40 and has a flying weight of 78 ounces. That figure
combined with the 605-square-inch wing area results in a wing loading
of 18.7 ounces per square foot.
The Hayate’s size and stability make it a good sport-flying model.
by Chuck Felton Nakajima
Ki-84 Hayate
09sig1x_00MSTRPG.QXD 7/22/10 9:40 AM Page 27
Take a look at the following tips
for working with cardboard.
Use water-based adhesive,
such as white glue or Titebond. I
don’t recommend that you
employ contact cement, because
parts cannot be shifted when
gluing surfaces.
Score fold lines with a
screening tool, which is available
at most hardware stores. It
consists of a handle with a 11/2-
inch-radius wheel at one end.
Run the wheel along a metal
straightedge on the fold lines.
Cardboard provides a solid
surface with no open areas to
cover, and it is nonporous. The
easiest finishing method is to
apply two coats of clear dope
sanding lightly
between each layer
with 400-grit
sandpaper. Follow that with two coats of color dope.
There is also a
32 MODEL AVIATION
wide variety of finishing materials you can use
on cardboard, such as Solarfilm, MonoKote,
and vinyl paper. If you do use any of those, do
not dope the surface of the cardboard; this will
result in a better bond.
Cover all seams, joints, and exposed edges
with strips of gummed paper tape. Obtain a 1-
inch-wide roll from a stationery store. To use
this material, simply cut a thin strip to length,
dip it in water, and smooth it over the seam.
CONSTRUCTION
Cut out all cardboard and wood parts,
making sure to note the direction of the
corrugations. Score and fold cardboard parts
as the plans indicate.
Empennage: The fin, rudder, stabilizer, and
elevator are each made from two pieces of 1/8-
inch-thick cardboard. They are laminated
together cross-grain, to make 1/4-inch-thick
surfaces.
Add a 1/8 x 1/4 balsa strip to the fin LE, and
round it off. Add 1/8 x 1/4 balsa strips to the
stabilizer LEs and TEs, and round those off.
Glue the elevators to the 1/4-inch-diameter
dowel. Add 1/8 x 1/4 balsa strips to the
remainder of the elevator LE, and round off.
Seal all raw edges with gummed paper
tape. Hinge elevators to the stabilizer with
nylon flex hinges at four places.
Wing:Make the two wing spars from hard 1/4
balsa. Connect the segments with a 1/8
plywood joiner on the forward side.
Glue 1/8 plywood gear mounts into the
bottom of each wing panel. Adhere the rightside
spar into the bottom of the right-hand
wing panel. Install ribs W1 through W7. Add
a cardboard doubler over the plywood gear
mount.
Bond a 1-ounce weight to the right
wingtip. Glue the left wing panel to the left
spar in a similar fashion. Add the ribs to the
left wing and the cardboard doubler over the
plywood gear mount.
Apply glue to the top of the wing spar, the
top of the ribs, and the wing TE. In turn, fold
each top wing surface down and pin it
securely in place until dry. Add the balsa tips
to the wing.
Make a line guide from 1/8 plywood. Cut a
slot in the left-wing balsa tip and glue the line
guide in place. Cover the TE, centerline seam,
and wingtip seams with gummed paper tape.
Fuselage: This section’s edges are outlined on
the drawing with a triangular symbol. Line the
upper and lower edges of each fuselage side
with 1/8 x 1/4 balsa strips, as shown in the
fuselage side view. The strips are recessed 1/8
inch from the edges.
Bevel the strips at the aft end of the
fuselage so that the cardboard sides will come
together. Add cardboard supports to each
fuselage side above the fuel tank and below
the bellcrank.
Make the firewall, C1, from 1/4 plywood.
Locate mounting holes for the Hayes KM-40
Motor Mount on the face of C1. Drill
mounting holes and install blind mounting
nuts on the backside of C1.
Drill a hole in C1 for a fuel line. Drill two
holes in C1 and install blind nuts for the cowl
hold-down bolts. These holes in C1 must align
with the holes in C2.
Glue C1 to the right side of the fuselage.
When dry, adhere the left side of the fuselage
to C1. Attach the fuel tank to the 1/8 plywood
support with rubber bands.
Make a pushrod from 3/32-inch-diameter
wire and 1/4 square spruce, and attach it to the
bellcrank along with the leadout wires. Install
tank and bellcrank assemblies by gluing the
plywood supports to the cardboard supports
on the insides of the fuselage. Be sure to bring
the pushrod end through the cutout in the left
aft fuselage.
Bond the fuselage sides at the tail. Glue F1
and F2 in place, to cover the top fuselage.
Cover the bottom fuselage with F3, F4, F5,
and F6. Make sure to bring out fuel-tubing fill
and overflow lines during all covering
operations.
Add fuselage formers A through D to the
top fuselage, adding a 1/8 x 1/4-inch centerline
stringer. Cover bulkheads A through D with
decking piece D1. Glue the horizontal
stabilizer assembly to the rear fuselage.
Add formers D through G with a centerline
balsa stringer, and cover with decking piece
D2. Formers H and J are glued to the forward
bottom fuselage, with centerline stringer, and
covered with decking piece D3.
Fabricate the cowl from 1/2 balsa sheet and
carve to shape. The bottom half is glued to the
model, while the top half is removable.
The latter has a 1/8 plywood former, C2,
glued to the back. The two holes in C2 must
align with the blind nuts in firewall C1.
Sand, carve, and hollow the cowl to shape.
Test-fit the engine in the cowl, and drill
mounting holes. Use a shaft extension to give
adequate spinner clearance. Cut holes in the
cowl block for the cylinder head, exhaust,
and needle valve. Apply epoxy to the
inside of the cowl and front of the firewall.
Glue the rudder to the fin with the TE
offset 1/2 inch to the outside of the flying
circle. Adhere the fin assembly to the
fuselage/stabilizer. When dry, add balsa to the
root of the fin and sand to fall into the fuselage
shape.
Make the tail wheel gear from 3/32-inchdiameter
wire. Bend as shown, place on the 1/8
plywood support, wrap with nylon thread, and
smear the thread with glue. When dry, glue in
place in the bottom fuselage cutout.
Bond the wing to the fuselage. Make the
main gear from 5/32-inch-diameter wire, as
shown. Make gear fairings from 1/8 plywood,
and attach the gear assemblies to the 1/8
plywood supports in the bottom wing with
nylon gear clips.
Final Assembly: As I instructed you to do,
give the model two coats of clear dope,
sanding lightly after each coat with 400-grit
sandpaper. Follow that with two coats of
color.
The color scheme I used consists of drabgreen
upper surfaces and light blue-gray lower
surfaces. I made lettering, striping, aileron
outlines, and all detailing from MonoKote.
Make the canopy from thin plastic, and use
epoxy to attach it to the fuselage. Outline the
canopy with thin strips of MonoKote.
Pass leadout wires through the wingtip line
guide and tie off. Attach the nylon control
horn to the elevator and hook up the pushrod.
Attach 31/2-inch-diameter wheels to the main
gear and a 1-inch-diameter wheel to the tail
gear.
Add an 11 x 6 propeller and a 3-inch
spinner to the engine, and your fighter will be
complete. Ensure that you balance it at the
point shown on the plans.
If you have comments, suggestions for, or
questions concerning the cardboard Ki-84
Hayate, please contact me. I’d love to see a
photo of your completed cardboard model.
You can visit my Web site to see more
cardboard designs and building
techniques. MA
Chuck Felton
[email protected]
Sources:
Chuck Felton
825 Lake Park Dr.
Lakehills TX 78063
http://home.earthlink.net/~charlesfelton
09sig1x_00MSTRPG.QXD 7/22/10 9:52 AM Page 32

September 2010 27
Frank gets a turn at circle burning
The prototype wears two coats of
clear dope under the color dope
base. The scheme is drab-green
upper surfaces and light blue-gray
lower surfaces. All lettering,
striping, and detailing is achieved
with MonoKote.
THE NAKAJIMA Ki-84 Hayate was undoubtedly the best fighter to
be in service for the Japanese in any numbers. When introduced
operationally in China in 1944, the Allied forces in World War II faced
an adversary that was far superior to anything that Japan had previously
fielded.
Code-named “Frank” by the Allies, the Hi-84 possessed superior
performance, respectable firepower, outstanding maneuverability, and
the ability to withstand battle damage to a degree that was previously
unheard of in Japanese fighters. Although it didn’t quite match the
performance of the P-47, P-38, or P-51, it was close.
Frank was superior to the F6F Hellcat, which comprised the bulk of
Allied fighters in the theatre. Its greatest failing was that it suffered at
high altitude and proved to be hopeless at intercepting the Boeing
Superfortress, which started bombing Japan in 1944.
The Hayate was a brilliant design, but because it was introduced so
late in the war, it could rarely be employed in the offensive role for
which it was designed. A total of more than 3,500 Ki-84s were
produced, the majority by Nakajima.
The model I am presenting is simple in construction and
inexpensive. The primary building material is 1/8-inch corrugated
cardboard, which greatly reduces both fabrication time and cost.
This design makes use of cardboard’s unique features. The material can
be used in large sections and folded.
The wing is built from two large pieces, with cardboard ribs and a
single spar. The tail surfaces and fuselage are primarily cardboard, with
little internal bracing required. The result is a quick-to-build aircraft that
has a scalelike appearance and can take plenty of punishment at the
flying field.
Cardboard varies in weight, but any 1/8-inch corrugated type will do
well for this project. Sources of the material include box manufacturers
and shopping centers where you can find stacks of discarded boxes.
Look for cardboard with brown paper on one side and a white
finished Kraft paper on the other. Having the white paper on the
outside of the model results in a smoother finish and neater
appearance.
I’ll describe in the construction hints my method of folding the
cardboard and using gummed paper tape to seal the joints and
exposed corrugations.
The Hi-84 has a wingspan of 60 inches and a length of 54 inches.
The bottom of the airfoil is flat with a curved upper surface, because of
the scoring-and-folding technique I employed.
You can use a .40- to .50-size engine in this airplane. Mine is
powered by a .40 and has a flying weight of 78 ounces. That figure
combined with the 605-square-inch wing area results in a wing loading
of 18.7 ounces per square foot.
The Hayate’s size and stability make it a good sport-flying model.
by Chuck Felton Nakajima
Ki-84 Hayate
09sig1x_00MSTRPG.QXD 7/22/10 9:40 AM Page 27
Take a look at the following tips
for working with cardboard.
Use water-based adhesive,
such as white glue or Titebond. I
don’t recommend that you
employ contact cement, because
parts cannot be shifted when
gluing surfaces.
Score fold lines with a
screening tool, which is available
at most hardware stores. It
consists of a handle with a 11/2-
inch-radius wheel at one end.
Run the wheel along a metal
straightedge on the fold lines.
Cardboard provides a solid
surface with no open areas to
cover, and it is nonporous. The
easiest finishing method is to
apply two coats of clear dope
sanding lightly
between each layer
with 400-grit
sandpaper. Follow that with two coats of color dope.
There is also a
32 MODEL AVIATION
wide variety of finishing materials you can use
on cardboard, such as Solarfilm, MonoKote,
and vinyl paper. If you do use any of those, do
not dope the surface of the cardboard; this will
result in a better bond.
Cover all seams, joints, and exposed edges
with strips of gummed paper tape. Obtain a 1-
inch-wide roll from a stationery store. To use
this material, simply cut a thin strip to length,
dip it in water, and smooth it over the seam.
CONSTRUCTION
Cut out all cardboard and wood parts,
making sure to note the direction of the
corrugations. Score and fold cardboard parts
as the plans indicate.
Empennage: The fin, rudder, stabilizer, and
elevator are each made from two pieces of 1/8-
inch-thick cardboard. They are laminated
together cross-grain, to make 1/4-inch-thick
surfaces.
Add a 1/8 x 1/4 balsa strip to the fin LE, and
round it off. Add 1/8 x 1/4 balsa strips to the
stabilizer LEs and TEs, and round those off.
Glue the elevators to the 1/4-inch-diameter
dowel. Add 1/8 x 1/4 balsa strips to the
remainder of the elevator LE, and round off.
Seal all raw edges with gummed paper
tape. Hinge elevators to the stabilizer with
nylon flex hinges at four places.
Wing:Make the two wing spars from hard 1/4
balsa. Connect the segments with a 1/8
plywood joiner on the forward side.
Glue 1/8 plywood gear mounts into the
bottom of each wing panel. Adhere the rightside
spar into the bottom of the right-hand
wing panel. Install ribs W1 through W7. Add
a cardboard doubler over the plywood gear
mount.
Bond a 1-ounce weight to the right
wingtip. Glue the left wing panel to the left
spar in a similar fashion. Add the ribs to the
left wing and the cardboard doubler over the
plywood gear mount.
Apply glue to the top of the wing spar, the
top of the ribs, and the wing TE. In turn, fold
each top wing surface down and pin it
securely in place until dry. Add the balsa tips
to the wing.
Make a line guide from 1/8 plywood. Cut a
slot in the left-wing balsa tip and glue the line
guide in place. Cover the TE, centerline seam,
and wingtip seams with gummed paper tape.
Fuselage: This section’s edges are outlined on
the drawing with a triangular symbol. Line the
upper and lower edges of each fuselage side
with 1/8 x 1/4 balsa strips, as shown in the
fuselage side view. The strips are recessed 1/8
inch from the edges.
Bevel the strips at the aft end of the
fuselage so that the cardboard sides will come
together. Add cardboard supports to each
fuselage side above the fuel tank and below
the bellcrank.
Make the firewall, C1, from 1/4 plywood.
Locate mounting holes for the Hayes KM-40
Motor Mount on the face of C1. Drill
mounting holes and install blind mounting
nuts on the backside of C1.
Drill a hole in C1 for a fuel line. Drill two
holes in C1 and install blind nuts for the cowl
hold-down bolts. These holes in C1 must align
with the holes in C2.
Glue C1 to the right side of the fuselage.
When dry, adhere the left side of the fuselage
to C1. Attach the fuel tank to the 1/8 plywood
support with rubber bands.
Make a pushrod from 3/32-inch-diameter
wire and 1/4 square spruce, and attach it to the
bellcrank along with the leadout wires. Install
tank and bellcrank assemblies by gluing the
plywood supports to the cardboard supports
on the insides of the fuselage. Be sure to bring
the pushrod end through the cutout in the left
aft fuselage.
Bond the fuselage sides at the tail. Glue F1
and F2 in place, to cover the top fuselage.
Cover the bottom fuselage with F3, F4, F5,
and F6. Make sure to bring out fuel-tubing fill
and overflow lines during all covering
operations.
Add fuselage formers A through D to the
top fuselage, adding a 1/8 x 1/4-inch centerline
stringer. Cover bulkheads A through D with
decking piece D1. Glue the horizontal
stabilizer assembly to the rear fuselage.
Add formers D through G with a centerline
balsa stringer, and cover with decking piece
D2. Formers H and J are glued to the forward
bottom fuselage, with centerline stringer, and
covered with decking piece D3.
Fabricate the cowl from 1/2 balsa sheet and
carve to shape. The bottom half is glued to the
model, while the top half is removable.
The latter has a 1/8 plywood former, C2,
glued to the back. The two holes in C2 must
align with the blind nuts in firewall C1.
Sand, carve, and hollow the cowl to shape.
Test-fit the engine in the cowl, and drill
mounting holes. Use a shaft extension to give
adequate spinner clearance. Cut holes in the
cowl block for the cylinder head, exhaust,
and needle valve. Apply epoxy to the
inside of the cowl and front of the firewall.
Glue the rudder to the fin with the TE
offset 1/2 inch to the outside of the flying
circle. Adhere the fin assembly to the
fuselage/stabilizer. When dry, add balsa to the
root of the fin and sand to fall into the fuselage
shape.
Make the tail wheel gear from 3/32-inchdiameter
wire. Bend as shown, place on the 1/8
plywood support, wrap with nylon thread, and
smear the thread with glue. When dry, glue in
place in the bottom fuselage cutout.
Bond the wing to the fuselage. Make the
main gear from 5/32-inch-diameter wire, as
shown. Make gear fairings from 1/8 plywood,
and attach the gear assemblies to the 1/8
plywood supports in the bottom wing with
nylon gear clips.
Final Assembly: As I instructed you to do,
give the model two coats of clear dope,
sanding lightly after each coat with 400-grit
sandpaper. Follow that with two coats of
color.
The color scheme I used consists of drabgreen
upper surfaces and light blue-gray lower
surfaces. I made lettering, striping, aileron
outlines, and all detailing from MonoKote.
Make the canopy from thin plastic, and use
epoxy to attach it to the fuselage. Outline the
canopy with thin strips of MonoKote.
Pass leadout wires through the wingtip line
guide and tie off. Attach the nylon control
horn to the elevator and hook up the pushrod.
Attach 31/2-inch-diameter wheels to the main
gear and a 1-inch-diameter wheel to the tail
gear.
Add an 11 x 6 propeller and a 3-inch
spinner to the engine, and your fighter will be
complete. Ensure that you balance it at the
point shown on the plans.
If you have comments, suggestions for, or
questions concerning the cardboard Ki-84
Hayate, please contact me. I’d love to see a
photo of your completed cardboard model.
You can visit my Web site to see more
cardboard designs and building
techniques. MA
Chuck Felton
[email protected]
Sources:
Chuck Felton
825 Lake Park Dr.
Lakehills TX 78063
http://home.earthlink.net/~charlesfelton
09sig1x_00MSTRPG.QXD 7/22/10 9:52 AM Page 32

September 2010 27
Frank gets a turn at circle burning
The prototype wears two coats of
clear dope under the color dope
base. The scheme is drab-green
upper surfaces and light blue-gray
lower surfaces. All lettering,
striping, and detailing is achieved
with MonoKote.
THE NAKAJIMA Ki-84 Hayate was undoubtedly the best fighter to
be in service for the Japanese in any numbers. When introduced
operationally in China in 1944, the Allied forces in World War II faced
an adversary that was far superior to anything that Japan had previously
fielded.
Code-named “Frank” by the Allies, the Hi-84 possessed superior
performance, respectable firepower, outstanding maneuverability, and
the ability to withstand battle damage to a degree that was previously
unheard of in Japanese fighters. Although it didn’t quite match the
performance of the P-47, P-38, or P-51, it was close.
Frank was superior to the F6F Hellcat, which comprised the bulk of
Allied fighters in the theatre. Its greatest failing was that it suffered at
high altitude and proved to be hopeless at intercepting the Boeing
Superfortress, which started bombing Japan in 1944.
The Hayate was a brilliant design, but because it was introduced so
late in the war, it could rarely be employed in the offensive role for
which it was designed. A total of more than 3,500 Ki-84s were
produced, the majority by Nakajima.
The model I am presenting is simple in construction and
inexpensive. The primary building material is 1/8-inch corrugated
cardboard, which greatly reduces both fabrication time and cost.
This design makes use of cardboard’s unique features. The material can
be used in large sections and folded.
The wing is built from two large pieces, with cardboard ribs and a
single spar. The tail surfaces and fuselage are primarily cardboard, with
little internal bracing required. The result is a quick-to-build aircraft that
has a scalelike appearance and can take plenty of punishment at the
flying field.
Cardboard varies in weight, but any 1/8-inch corrugated type will do
well for this project. Sources of the material include box manufacturers
and shopping centers where you can find stacks of discarded boxes.
Look for cardboard with brown paper on one side and a white
finished Kraft paper on the other. Having the white paper on the
outside of the model results in a smoother finish and neater
appearance.
I’ll describe in the construction hints my method of folding the
cardboard and using gummed paper tape to seal the joints and
exposed corrugations.
The Hi-84 has a wingspan of 60 inches and a length of 54 inches.
The bottom of the airfoil is flat with a curved upper surface, because of
the scoring-and-folding technique I employed.
You can use a .40- to .50-size engine in this airplane. Mine is
powered by a .40 and has a flying weight of 78 ounces. That figure
combined with the 605-square-inch wing area results in a wing loading
of 18.7 ounces per square foot.
The Hayate’s size and stability make it a good sport-flying model.
by Chuck Felton Nakajima
Ki-84 Hayate
09sig1x_00MSTRPG.QXD 7/22/10 9:40 AM Page 27
Take a look at the following tips
for working with cardboard.
Use water-based adhesive,
such as white glue or Titebond. I
don’t recommend that you
employ contact cement, because
parts cannot be shifted when
gluing surfaces.
Score fold lines with a
screening tool, which is available
at most hardware stores. It
consists of a handle with a 11/2-
inch-radius wheel at one end.
Run the wheel along a metal
straightedge on the fold lines.
Cardboard provides a solid
surface with no open areas to
cover, and it is nonporous. The
easiest finishing method is to
apply two coats of clear dope
sanding lightly
between each layer
with 400-grit
sandpaper. Follow that with two coats of color dope.
There is also a
32 MODEL AVIATION
wide variety of finishing materials you can use
on cardboard, such as Solarfilm, MonoKote,
and vinyl paper. If you do use any of those, do
not dope the surface of the cardboard; this will
result in a better bond.
Cover all seams, joints, and exposed edges
with strips of gummed paper tape. Obtain a 1-
inch-wide roll from a stationery store. To use
this material, simply cut a thin strip to length,
dip it in water, and smooth it over the seam.
CONSTRUCTION
Cut out all cardboard and wood parts,
making sure to note the direction of the
corrugations. Score and fold cardboard parts
as the plans indicate.
Empennage: The fin, rudder, stabilizer, and
elevator are each made from two pieces of 1/8-
inch-thick cardboard. They are laminated
together cross-grain, to make 1/4-inch-thick
surfaces.
Add a 1/8 x 1/4 balsa strip to the fin LE, and
round it off. Add 1/8 x 1/4 balsa strips to the
stabilizer LEs and TEs, and round those off.
Glue the elevators to the 1/4-inch-diameter
dowel. Add 1/8 x 1/4 balsa strips to the
remainder of the elevator LE, and round off.
Seal all raw edges with gummed paper
tape. Hinge elevators to the stabilizer with
nylon flex hinges at four places.
Wing:Make the two wing spars from hard 1/4
balsa. Connect the segments with a 1/8
plywood joiner on the forward side.
Glue 1/8 plywood gear mounts into the
bottom of each wing panel. Adhere the rightside
spar into the bottom of the right-hand
wing panel. Install ribs W1 through W7. Add
a cardboard doubler over the plywood gear
mount.
Bond a 1-ounce weight to the right
wingtip. Glue the left wing panel to the left
spar in a similar fashion. Add the ribs to the
left wing and the cardboard doubler over the
plywood gear mount.
Apply glue to the top of the wing spar, the
top of the ribs, and the wing TE. In turn, fold
each top wing surface down and pin it
securely in place until dry. Add the balsa tips
to the wing.
Make a line guide from 1/8 plywood. Cut a
slot in the left-wing balsa tip and glue the line
guide in place. Cover the TE, centerline seam,
and wingtip seams with gummed paper tape.
Fuselage: This section’s edges are outlined on
the drawing with a triangular symbol. Line the
upper and lower edges of each fuselage side
with 1/8 x 1/4 balsa strips, as shown in the
fuselage side view. The strips are recessed 1/8
inch from the edges.
Bevel the strips at the aft end of the
fuselage so that the cardboard sides will come
together. Add cardboard supports to each
fuselage side above the fuel tank and below
the bellcrank.
Make the firewall, C1, from 1/4 plywood.
Locate mounting holes for the Hayes KM-40
Motor Mount on the face of C1. Drill
mounting holes and install blind mounting
nuts on the backside of C1.
Drill a hole in C1 for a fuel line. Drill two
holes in C1 and install blind nuts for the cowl
hold-down bolts. These holes in C1 must align
with the holes in C2.
Glue C1 to the right side of the fuselage.
When dry, adhere the left side of the fuselage
to C1. Attach the fuel tank to the 1/8 plywood
support with rubber bands.
Make a pushrod from 3/32-inch-diameter
wire and 1/4 square spruce, and attach it to the
bellcrank along with the leadout wires. Install
tank and bellcrank assemblies by gluing the
plywood supports to the cardboard supports
on the insides of the fuselage. Be sure to bring
the pushrod end through the cutout in the left
aft fuselage.
Bond the fuselage sides at the tail. Glue F1
and F2 in place, to cover the top fuselage.
Cover the bottom fuselage with F3, F4, F5,
and F6. Make sure to bring out fuel-tubing fill
and overflow lines during all covering
operations.
Add fuselage formers A through D to the
top fuselage, adding a 1/8 x 1/4-inch centerline
stringer. Cover bulkheads A through D with
decking piece D1. Glue the horizontal
stabilizer assembly to the rear fuselage.
Add formers D through G with a centerline
balsa stringer, and cover with decking piece
D2. Formers H and J are glued to the forward
bottom fuselage, with centerline stringer, and
covered with decking piece D3.
Fabricate the cowl from 1/2 balsa sheet and
carve to shape. The bottom half is glued to the
model, while the top half is removable.
The latter has a 1/8 plywood former, C2,
glued to the back. The two holes in C2 must
align with the blind nuts in firewall C1.
Sand, carve, and hollow the cowl to shape.
Test-fit the engine in the cowl, and drill
mounting holes. Use a shaft extension to give
adequate spinner clearance. Cut holes in the
cowl block for the cylinder head, exhaust,
and needle valve. Apply epoxy to the
inside of the cowl and front of the firewall.
Glue the rudder to the fin with the TE
offset 1/2 inch to the outside of the flying
circle. Adhere the fin assembly to the
fuselage/stabilizer. When dry, add balsa to the
root of the fin and sand to fall into the fuselage
shape.
Make the tail wheel gear from 3/32-inchdiameter
wire. Bend as shown, place on the 1/8
plywood support, wrap with nylon thread, and
smear the thread with glue. When dry, glue in
place in the bottom fuselage cutout.
Bond the wing to the fuselage. Make the
main gear from 5/32-inch-diameter wire, as
shown. Make gear fairings from 1/8 plywood,
and attach the gear assemblies to the 1/8
plywood supports in the bottom wing with
nylon gear clips.
Final Assembly: As I instructed you to do,
give the model two coats of clear dope,
sanding lightly after each coat with 400-grit
sandpaper. Follow that with two coats of
color.
The color scheme I used consists of drabgreen
upper surfaces and light blue-gray lower
surfaces. I made lettering, striping, aileron
outlines, and all detailing from MonoKote.
Make the canopy from thin plastic, and use
epoxy to attach it to the fuselage. Outline the
canopy with thin strips of MonoKote.
Pass leadout wires through the wingtip line
guide and tie off. Attach the nylon control
horn to the elevator and hook up the pushrod.
Attach 31/2-inch-diameter wheels to the main
gear and a 1-inch-diameter wheel to the tail
gear.
Add an 11 x 6 propeller and a 3-inch
spinner to the engine, and your fighter will be
complete. Ensure that you balance it at the
point shown on the plans.
If you have comments, suggestions for, or
questions concerning the cardboard Ki-84
Hayate, please contact me. I’d love to see a
photo of your completed cardboard model.
You can visit my Web site to see more
cardboard designs and building
techniques. MA
Chuck Felton
[email protected]
Sources:
Chuck Felton
825 Lake Park Dr.
Lakehills TX 78063
http://home.earthlink.net/~charlesfelton
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