LaGG-3
Lavochkin by Chuck Felton
An obscure WW II Russian
fighter and an unusual
construction technique add up
to modeling adventure!
02sig3.QXD 11/25/03 11:00 am Page 68
February 2004 69
THE LAGG-3 was one of a trio of modern aircraft that
the Soviets produced before and during World War II to
replace their obsolete fighters. S.A. Lavochkin, V.P.
Gorbunov, and M.I. Gudkov designed the aircraft, hence
the name LaGG—from their initials.
Although outwardly conventional, the LaGG-3 was
the only one of the world’s new crop of streamlined
monoplane fighters not to have metal stressed-skin
construction. Since the Soviet Union faced difficulties at
that time obtaining aluminum and other light alloys, the
fighter was built mostly from birch plywood and pine.
A new technology called “delta wood” was
developed, which consisted of layers of birch strips that
were glued cross-grained, impregnated, and used in
conjunction with a Bakelite plywood. The result was a
neat, clean, maneuverable fighter that showed
outstanding robustness and resistance to battle damage.
On the other hand, it was inferior to other Russian
fighters in all-around performance.
The first of these fighters reached the aviation
regiments just a few months before the German
invasion. More than 6,500 aircraft had been produced
when production ended in September 1943.
My model of the LaGG-3 is inexpensive and simple in
construction; I use 1⁄8-inch corrugated cardboard as the
primary building material, which greatly reduces
building time and cost.
The design makes use of cardboard’s unique
features: it can be used in large sections and folded. The
wing is built from two big pieces of cardboard, with
cardboard ribs and a single spar. The tail surfaces and
fuselage are primarily cardboard, with little internal
bracing required. The result is a model with a good
scalelike appearance that can take plenty of punishment
at the flying field.
Cardboard varies in weight, but any 1⁄8-inch
corrugated will do. Sources for this material include box
manufacturers and local shopping centers where you can
find stacks of discarded boxes. Look for cardboard with
brown paper on one side and a white finished paper
on the other side. Having the white paper on
the outside of the model results in a
smoother finish and a neater
appearance. The method of
folding the cardboard and
using gummed paper tape
to seal the joints and
exposed corrugations is
explained in the
construction tips.
The model has a wingspan
of 65 inches and a length of 58
inches. The bottom of the airfoil is flat with a curved
upper surface because of the scoring and folding
technique employed. Engines of .40 to .50 displacement
can be used. The LaGG-3’s size and stability make it a
good sport-flying model.
CONSTRUCTION
Cut out all cardboard and wood parts, making sure to
note the direction of the corrugations. Score and fold
cardboard parts as indicated on the plans.
Empennage: The fin, rudder, stabilizer, and elevator are
each made from two pieces of 1⁄8-inch cardboard
laminated together cross-grain to give 1⁄4-inch-thick
Special Tips
for Working
With Cardboard
Before we begin, I have some special tips for
working with cardboard.
Gluing: Use water-based glue such as white glue
or Titebond. Don’t use contact cement since parts
cannot be shifted when you are gluing surfaces.
Folding: Score the fold lines with a screening
tool, which is available at any hardware store. It
has a handle with a 11⁄2-inch-radius wheel at one
end that you run along a metal straightedge on the
fold line.
Waterproofing: Making cardboard waterproof is
simple, and you can do it to the raw material
before you cut out the model’s parts. Mix 25%
clear polyurethane with 75% paint thinner; the
latter can be the most inexpensive hardware-store
variety. Brush the mixture liberally onto the
cardboard sheet and allow it to dry for 48 hours.
This adds no appreciable weight to the
material and renders the cardboard completely
waterproof. In addition, when you cut the treated
cardboard you will find that it is as crisp as wood
and cuts sharply and cleanly.
Finishing: Cardboard provides a solid surface
with no open areas to cover and is nonporous. The
easiest finishing method is to apply two coats of
clear dope, sand lightly between coats with 400-
grit paper, and follow with three coats of colored
dope.
However, a wide variety of finishing materials
such as Solarfilm, MonoKote, and vinyl paper can
be used on the cardboard. With any of these
coverings I recommended that you not dope the
cardboard’s surface; it will result in a better bond.
Covering the Edges: Cover all of the model’s
seams, joints, and exposed edges with strips of
gummed paper tape. You can obtain a 1-inch-wide
roll from a stationery store. To use it, cut a thin
strip to length, dip it in water, and smooth it over
the seam(s). MA
—Chuck Felton
3
n
02sig3.QXD 11/25/03 11:01 am Page 69
70 MODEL AVIATION
The fuselage sides are lined with balsa strips and have
cardboard supports for the bellcrank and fuel-tank mounts.
Carved-balsa cowl halves have 1⁄8 plywood inserts with blind
nuts to serve as cowl-attachment points. Clean work!
The fuselage sides have been joined to the firewall, and the tank
and bellcrank mounts have been installed.
Edges of the tail components are capped with 1⁄8 x 1⁄4 balsa strips
and rounded. Elevator joiner is 1⁄4-inch dowel.
A cardboard fuselage top piece, cardboard bulkheads, and the
single balsa centerline stringer have been added.
Wing has single spar, cardboard ribs, and leading edge folds to
obtain curved upper surface. Note 1⁄8 plywood gear mount.
1 2
3 4
5 6
02sig3.QXD 11/25/03 11:01 am Page 70
1
2
3
4
5
surfaces. Add a 1⁄8 x 1⁄4 balsa strip to the fin
leading edge (LE) and round it off. Add 1⁄8 x
1⁄4 balsa strips to the stabilizer LEs and
trailing edges (TEs) and round them off.
Glue the elevators to the 1⁄4-inch dowel.
Add 1⁄8 x 1⁄4 balsa strips to the remainder of
the elevator LE and round them off. Seal all
raw edges with gummed paper tape. Hinge
the elevators to the stabilizer with cloth
hinges at four places.
Wing: Make the wing spar by capping
each 1⁄4 balsa spar with a 1⁄4 x 1⁄4 spruce
strip top and bottom. Join the spar halves
with 1⁄8 plywood joiners front and rear at
the centerline.
Glue the 1⁄8 plywood gear mount into
the bottom of each wing panel. Glue the
right side of the wing spar onto the righthand
wing panel. Glue all cardboard ribs
into the right wing. Add a cardboard
doubler over the plywood gear mount
between ribs W3 and W4. Glue a 1-ounce
weight to the right wingtip.
Glue the left wing panel to the left spar
in a similar fashion. Add the ribs and gear
doubler to the left wing. Apply glue to the
top of the wing spar, the top of the ribs, and
the wing TE. Fold the 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 balsa wingtip, and glue the line guide
in place. Cover the TE and all seams with
gummed paper tape.
Fuselage: The fuselage edges are outlined
with a triangular symbol on the drawing.
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 fuselage
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 the mounting holes for a
KM-40 motor mount on the face of C1.
Drill the mounting holes and install blind
mounting nuts on the back side of C1. Drill
a hole in C1 for a fuel-tubing exit. Line all
four back edges of C1 with 1⁄2-inch
triangular balsa for bracing.
Glue C1 to the right side of the
fuselage. When dry, glue the left side of the
fuselage to C1. Attach the fuel tank to the
1⁄8 plywood support. You can attach the
fuel tank to the support with rubber bands.
Make a pushrod from 3⁄32-inch wire and
1⁄4 square spruce, and attach it to the
bellcrank along with the leadout wires.
Install the tank and bellcrank assemblies by
gluing the plywood supports to the
cardboard supports on the insides of the
fuselage.
Glue the fuselage sides together at the
tail. Glue F1 and F2 in place to cover the
top fuselage. Be sure to bring fuel tubing
fill and overflow lines out during all
covering operations. Cover the bottom
fuselage with F3, F4, and F5.
Add bulkheads A through K to the top
fuselage, adding 1⁄8 x 1⁄4-inch stringers.
Cover bulkheads A through D with D1,
bulkheads E through G with D2, and
bulkheads G through K with D3. Add
bulkheads L, M, and N, with stringer, to
forward bottom fuselage, and cover with
D4.
The cowl is built up from 1⁄2 balsa sheet
and hollowed out. The top half has the 1⁄4
plywood C2 glued to the front. The
removable bottom half of the cowl has C3
glued to the front. Sand, carve, and hollow
the cowl to shape. Add 1⁄8-inch rectangular
plywood pieces to the inside of the top and
bottom halves at the cowl sides, as shown
in the cowl top and side views.
Install a blind nut on the inside of the
top cowl plywood and run a 4-40 bolt
through the bottom cowl to form the cowl
attach. Permanently glue the top half of the
cowl to the model’s nose.
Test-fit the engine in the cowl and drill
mounting holes in the KM-40 engine
February 2004 71
The finished nose section. Notice the tank fill line and the spinner fit. The camo paint
job is extremely effective.
The leadouts are external and go through a line guide that is attached where the wing
meets the wingtip.
Photos courtesy the author
02sig3.QXD 11/25/03 11:03 am Page 71
6
mount. 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 the front
of the firewall.
Glue the stabilizer to the fuselage. Add balsa block fairings at
the stabilizer/fin intersection. Add the rudder to the fin with the TE
offset 1⁄2 inch to the outside of the flying circle.
Make the tail-wheel gear from 3⁄32-inch-diameter wire. Bend it
as shown, place it on the 1⁄8 plywood support, wrap it with nylon
thread, and smear the thread with glue. When it’s dry, glue it in
place in the bottom fuselage cutout.
Make the main gear from 5⁄32-inch-diameter wire, as shown.
Make gear fairings from 1⁄8 plywood and attach them to the gear
with nylon gear clips. Attach the gear assemblies to the 1⁄8 plywood
supports in the bottom wing with nylon gear clips.
Finish: Now is the time to paint and trim the model before final
assembly. The color scheme is medium- and dark-green uppersurface
camouflage and light-blue undersurface. Cut the red
lettering and insignia from MonoKote. Make the canopy from thin
plastic, and epoxy it to the fuselage. Outline the canopy with thin
strips of MonoKote. Make the aileron outlines from Black
MonoKote.
Final Assembly: Glue the wing to the fuselage. Make the air
scoop from 1⁄2 balsa and glue it to the bottom of the wing/fuselage.
Add balsa exhaust stacks to both sides of the forward fuselage.
Pass the leadout wires through the wingtip line guide and tie them
off. Attach the nylon control horn to the elevator and hook up the
pushrod.
Attach 33⁄4-inch-diameter wheels to the main gear and a 11⁄2-
inch-diameter wheel to the tail gear. Add an 11 x 6 propeller and a
31⁄2-inch spinner to the engine, and your model will be completed.
Be sure to balance the model at the point shown on the plans.
If you have any comments, suggestions, or questions concerning
the LaGG-3, please write to me at the following address or E-mail
me, maybe with a photo of your completed cardboard model. MA
Chuck Felton
825 Lake Park Dr.
Lakehills TX 78063
[email protected]
72 MODEL AVIATION
The landing-gear struts mount to the plywood plates in the wing.
Notice the simulated wheel wells.
It’s hard to believe that this model is mostly cardboard. The tail
section is neat and clean, with great paint detail.
A pilot adds to the model’s realism. The canopy is simple to
construct, and tape frame lines add to the effect.
Lavochkin
LaGG-3
Type: CL Sport Scale
Wingspan: 65 inches
Engine: .40-.50 glow
Flying weight: 60 ounces
Construction: Cardboard, balsa, plywood
Covering/finish: Modeling paints,
MonoKote trim and insignia
02sig3.QXD 11/25/03 11:04 am Page 72
74 MODEL AVIATION
Full-Size Plans Available—see page 199
02sig3.QXD 11/25/03 11:05 am Page 74
76 MODEL AVIATION
Full-Size Plans Available—see page 199
02sig3.QXD 11/25/03 11:06 am Page 76
Edition: Model Aviation - 2004/02
Page Numbers: 68,69,70,71,72,74,76
Edition: Model Aviation - 2004/02
Page Numbers: 68,69,70,71,72,74,76
LaGG-3
Lavochkin by Chuck Felton
An obscure WW II Russian
fighter and an unusual
construction technique add up
to modeling adventure!
02sig3.QXD 11/25/03 11:00 am Page 68
February 2004 69
THE LAGG-3 was one of a trio of modern aircraft that
the Soviets produced before and during World War II to
replace their obsolete fighters. S.A. Lavochkin, V.P.
Gorbunov, and M.I. Gudkov designed the aircraft, hence
the name LaGG—from their initials.
Although outwardly conventional, the LaGG-3 was
the only one of the world’s new crop of streamlined
monoplane fighters not to have metal stressed-skin
construction. Since the Soviet Union faced difficulties at
that time obtaining aluminum and other light alloys, the
fighter was built mostly from birch plywood and pine.
A new technology called “delta wood” was
developed, which consisted of layers of birch strips that
were glued cross-grained, impregnated, and used in
conjunction with a Bakelite plywood. The result was a
neat, clean, maneuverable fighter that showed
outstanding robustness and resistance to battle damage.
On the other hand, it was inferior to other Russian
fighters in all-around performance.
The first of these fighters reached the aviation
regiments just a few months before the German
invasion. More than 6,500 aircraft had been produced
when production ended in September 1943.
My model of the LaGG-3 is inexpensive and simple in
construction; I use 1⁄8-inch corrugated cardboard as the
primary building material, which greatly reduces
building time and cost.
The design makes use of cardboard’s unique
features: it can be used in large sections and folded. The
wing is built from two big pieces of cardboard, with
cardboard ribs and a single spar. The tail surfaces and
fuselage are primarily cardboard, with little internal
bracing required. The result is a model with a good
scalelike appearance that can take plenty of punishment
at the flying field.
Cardboard varies in weight, but any 1⁄8-inch
corrugated will do. Sources for this material include box
manufacturers and local shopping centers where you can
find stacks of discarded boxes. Look for cardboard with
brown paper on one side and a white finished paper
on the other side. Having the white paper on
the outside of the model results in a
smoother finish and a neater
appearance. The method of
folding the cardboard and
using gummed paper tape
to seal the joints and
exposed corrugations is
explained in the
construction tips.
The model has a wingspan
of 65 inches and a length of 58
inches. The bottom of the airfoil is flat with a curved
upper surface because of the scoring and folding
technique employed. Engines of .40 to .50 displacement
can be used. The LaGG-3’s size and stability make it a
good sport-flying model.
CONSTRUCTION
Cut out all cardboard and wood parts, making sure to
note the direction of the corrugations. Score and fold
cardboard parts as indicated on the plans.
Empennage: The fin, rudder, stabilizer, and elevator are
each made from two pieces of 1⁄8-inch cardboard
laminated together cross-grain to give 1⁄4-inch-thick
Special Tips
for Working
With Cardboard
Before we begin, I have some special tips for
working with cardboard.
Gluing: Use water-based glue such as white glue
or Titebond. Don’t use contact cement since parts
cannot be shifted when you are gluing surfaces.
Folding: Score the fold lines with a screening
tool, which is available at any hardware store. It
has a handle with a 11⁄2-inch-radius wheel at one
end that you run along a metal straightedge on the
fold line.
Waterproofing: Making cardboard waterproof is
simple, and you can do it to the raw material
before you cut out the model’s parts. Mix 25%
clear polyurethane with 75% paint thinner; the
latter can be the most inexpensive hardware-store
variety. Brush the mixture liberally onto the
cardboard sheet and allow it to dry for 48 hours.
This adds no appreciable weight to the
material and renders the cardboard completely
waterproof. In addition, when you cut the treated
cardboard you will find that it is as crisp as wood
and cuts sharply and cleanly.
Finishing: Cardboard provides a solid surface
with no open areas to cover and is nonporous. The
easiest finishing method is to apply two coats of
clear dope, sand lightly between coats with 400-
grit paper, and follow with three coats of colored
dope.
However, a wide variety of finishing materials
such as Solarfilm, MonoKote, and vinyl paper can
be used on the cardboard. With any of these
coverings I recommended that you not dope the
cardboard’s surface; it will result in a better bond.
Covering the Edges: Cover all of the model’s
seams, joints, and exposed edges with strips of
gummed paper tape. You can obtain a 1-inch-wide
roll from a stationery store. To use it, cut a thin
strip to length, dip it in water, and smooth it over
the seam(s). MA
—Chuck Felton
3
n
02sig3.QXD 11/25/03 11:01 am Page 69
70 MODEL AVIATION
The fuselage sides are lined with balsa strips and have
cardboard supports for the bellcrank and fuel-tank mounts.
Carved-balsa cowl halves have 1⁄8 plywood inserts with blind
nuts to serve as cowl-attachment points. Clean work!
The fuselage sides have been joined to the firewall, and the tank
and bellcrank mounts have been installed.
Edges of the tail components are capped with 1⁄8 x 1⁄4 balsa strips
and rounded. Elevator joiner is 1⁄4-inch dowel.
A cardboard fuselage top piece, cardboard bulkheads, and the
single balsa centerline stringer have been added.
Wing has single spar, cardboard ribs, and leading edge folds to
obtain curved upper surface. Note 1⁄8 plywood gear mount.
1 2
3 4
5 6
02sig3.QXD 11/25/03 11:01 am Page 70
1
2
3
4
5
surfaces. Add a 1⁄8 x 1⁄4 balsa strip to the fin
leading edge (LE) and round it off. Add 1⁄8 x
1⁄4 balsa strips to the stabilizer LEs and
trailing edges (TEs) and round them off.
Glue the elevators to the 1⁄4-inch dowel.
Add 1⁄8 x 1⁄4 balsa strips to the remainder of
the elevator LE and round them off. Seal all
raw edges with gummed paper tape. Hinge
the elevators to the stabilizer with cloth
hinges at four places.
Wing: Make the wing spar by capping
each 1⁄4 balsa spar with a 1⁄4 x 1⁄4 spruce
strip top and bottom. Join the spar halves
with 1⁄8 plywood joiners front and rear at
the centerline.
Glue the 1⁄8 plywood gear mount into
the bottom of each wing panel. Glue the
right side of the wing spar onto the righthand
wing panel. Glue all cardboard ribs
into the right wing. Add a cardboard
doubler over the plywood gear mount
between ribs W3 and W4. Glue a 1-ounce
weight to the right wingtip.
Glue the left wing panel to the left spar
in a similar fashion. Add the ribs and gear
doubler to the left wing. Apply glue to the
top of the wing spar, the top of the ribs, and
the wing TE. Fold the 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 balsa wingtip, and glue the line guide
in place. Cover the TE and all seams with
gummed paper tape.
Fuselage: The fuselage edges are outlined
with a triangular symbol on the drawing.
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 fuselage
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 the mounting holes for a
KM-40 motor mount on the face of C1.
Drill the mounting holes and install blind
mounting nuts on the back side of C1. Drill
a hole in C1 for a fuel-tubing exit. Line all
four back edges of C1 with 1⁄2-inch
triangular balsa for bracing.
Glue C1 to the right side of the
fuselage. When dry, glue the left side of the
fuselage to C1. Attach the fuel tank to the
1⁄8 plywood support. You can attach the
fuel tank to the support with rubber bands.
Make a pushrod from 3⁄32-inch wire and
1⁄4 square spruce, and attach it to the
bellcrank along with the leadout wires.
Install the tank and bellcrank assemblies by
gluing the plywood supports to the
cardboard supports on the insides of the
fuselage.
Glue the fuselage sides together at the
tail. Glue F1 and F2 in place to cover the
top fuselage. Be sure to bring fuel tubing
fill and overflow lines out during all
covering operations. Cover the bottom
fuselage with F3, F4, and F5.
Add bulkheads A through K to the top
fuselage, adding 1⁄8 x 1⁄4-inch stringers.
Cover bulkheads A through D with D1,
bulkheads E through G with D2, and
bulkheads G through K with D3. Add
bulkheads L, M, and N, with stringer, to
forward bottom fuselage, and cover with
D4.
The cowl is built up from 1⁄2 balsa sheet
and hollowed out. The top half has the 1⁄4
plywood C2 glued to the front. The
removable bottom half of the cowl has C3
glued to the front. Sand, carve, and hollow
the cowl to shape. Add 1⁄8-inch rectangular
plywood pieces to the inside of the top and
bottom halves at the cowl sides, as shown
in the cowl top and side views.
Install a blind nut on the inside of the
top cowl plywood and run a 4-40 bolt
through the bottom cowl to form the cowl
attach. Permanently glue the top half of the
cowl to the model’s nose.
Test-fit the engine in the cowl and drill
mounting holes in the KM-40 engine
February 2004 71
The finished nose section. Notice the tank fill line and the spinner fit. The camo paint
job is extremely effective.
The leadouts are external and go through a line guide that is attached where the wing
meets the wingtip.
Photos courtesy the author
02sig3.QXD 11/25/03 11:03 am Page 71
6
mount. 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 the front
of the firewall.
Glue the stabilizer to the fuselage. Add balsa block fairings at
the stabilizer/fin intersection. Add the rudder to the fin with the TE
offset 1⁄2 inch to the outside of the flying circle.
Make the tail-wheel gear from 3⁄32-inch-diameter wire. Bend it
as shown, place it on the 1⁄8 plywood support, wrap it with nylon
thread, and smear the thread with glue. When it’s dry, glue it in
place in the bottom fuselage cutout.
Make the main gear from 5⁄32-inch-diameter wire, as shown.
Make gear fairings from 1⁄8 plywood and attach them to the gear
with nylon gear clips. Attach the gear assemblies to the 1⁄8 plywood
supports in the bottom wing with nylon gear clips.
Finish: Now is the time to paint and trim the model before final
assembly. The color scheme is medium- and dark-green uppersurface
camouflage and light-blue undersurface. Cut the red
lettering and insignia from MonoKote. Make the canopy from thin
plastic, and epoxy it to the fuselage. Outline the canopy with thin
strips of MonoKote. Make the aileron outlines from Black
MonoKote.
Final Assembly: Glue the wing to the fuselage. Make the air
scoop from 1⁄2 balsa and glue it to the bottom of the wing/fuselage.
Add balsa exhaust stacks to both sides of the forward fuselage.
Pass the leadout wires through the wingtip line guide and tie them
off. Attach the nylon control horn to the elevator and hook up the
pushrod.
Attach 33⁄4-inch-diameter wheels to the main gear and a 11⁄2-
inch-diameter wheel to the tail gear. Add an 11 x 6 propeller and a
31⁄2-inch spinner to the engine, and your model will be completed.
Be sure to balance the model at the point shown on the plans.
If you have any comments, suggestions, or questions concerning
the LaGG-3, please write to me at the following address or E-mail
me, maybe with a photo of your completed cardboard model. MA
Chuck Felton
825 Lake Park Dr.
Lakehills TX 78063
[email protected]
72 MODEL AVIATION
The landing-gear struts mount to the plywood plates in the wing.
Notice the simulated wheel wells.
It’s hard to believe that this model is mostly cardboard. The tail
section is neat and clean, with great paint detail.
A pilot adds to the model’s realism. The canopy is simple to
construct, and tape frame lines add to the effect.
Lavochkin
LaGG-3
Type: CL Sport Scale
Wingspan: 65 inches
Engine: .40-.50 glow
Flying weight: 60 ounces
Construction: Cardboard, balsa, plywood
Covering/finish: Modeling paints,
MonoKote trim and insignia
02sig3.QXD 11/25/03 11:04 am Page 72
74 MODEL AVIATION
Full-Size Plans Available—see page 199
02sig3.QXD 11/25/03 11:05 am Page 74
76 MODEL AVIATION
Full-Size Plans Available—see page 199
02sig3.QXD 11/25/03 11:06 am Page 76
Edition: Model Aviation - 2004/02
Page Numbers: 68,69,70,71,72,74,76
LaGG-3
Lavochkin by Chuck Felton
An obscure WW II Russian
fighter and an unusual
construction technique add up
to modeling adventure!
02sig3.QXD 11/25/03 11:00 am Page 68
February 2004 69
THE LAGG-3 was one of a trio of modern aircraft that
the Soviets produced before and during World War II to
replace their obsolete fighters. S.A. Lavochkin, V.P.
Gorbunov, and M.I. Gudkov designed the aircraft, hence
the name LaGG—from their initials.
Although outwardly conventional, the LaGG-3 was
the only one of the world’s new crop of streamlined
monoplane fighters not to have metal stressed-skin
construction. Since the Soviet Union faced difficulties at
that time obtaining aluminum and other light alloys, the
fighter was built mostly from birch plywood and pine.
A new technology called “delta wood” was
developed, which consisted of layers of birch strips that
were glued cross-grained, impregnated, and used in
conjunction with a Bakelite plywood. The result was a
neat, clean, maneuverable fighter that showed
outstanding robustness and resistance to battle damage.
On the other hand, it was inferior to other Russian
fighters in all-around performance.
The first of these fighters reached the aviation
regiments just a few months before the German
invasion. More than 6,500 aircraft had been produced
when production ended in September 1943.
My model of the LaGG-3 is inexpensive and simple in
construction; I use 1⁄8-inch corrugated cardboard as the
primary building material, which greatly reduces
building time and cost.
The design makes use of cardboard’s unique
features: it can be used in large sections and folded. The
wing is built from two big pieces of cardboard, with
cardboard ribs and a single spar. The tail surfaces and
fuselage are primarily cardboard, with little internal
bracing required. The result is a model with a good
scalelike appearance that can take plenty of punishment
at the flying field.
Cardboard varies in weight, but any 1⁄8-inch
corrugated will do. Sources for this material include box
manufacturers and local shopping centers where you can
find stacks of discarded boxes. Look for cardboard with
brown paper on one side and a white finished paper
on the other side. Having the white paper on
the outside of the model results in a
smoother finish and a neater
appearance. The method of
folding the cardboard and
using gummed paper tape
to seal the joints and
exposed corrugations is
explained in the
construction tips.
The model has a wingspan
of 65 inches and a length of 58
inches. The bottom of the airfoil is flat with a curved
upper surface because of the scoring and folding
technique employed. Engines of .40 to .50 displacement
can be used. The LaGG-3’s size and stability make it a
good sport-flying model.
CONSTRUCTION
Cut out all cardboard and wood parts, making sure to
note the direction of the corrugations. Score and fold
cardboard parts as indicated on the plans.
Empennage: The fin, rudder, stabilizer, and elevator are
each made from two pieces of 1⁄8-inch cardboard
laminated together cross-grain to give 1⁄4-inch-thick
Special Tips
for Working
With Cardboard
Before we begin, I have some special tips for
working with cardboard.
Gluing: Use water-based glue such as white glue
or Titebond. Don’t use contact cement since parts
cannot be shifted when you are gluing surfaces.
Folding: Score the fold lines with a screening
tool, which is available at any hardware store. It
has a handle with a 11⁄2-inch-radius wheel at one
end that you run along a metal straightedge on the
fold line.
Waterproofing: Making cardboard waterproof is
simple, and you can do it to the raw material
before you cut out the model’s parts. Mix 25%
clear polyurethane with 75% paint thinner; the
latter can be the most inexpensive hardware-store
variety. Brush the mixture liberally onto the
cardboard sheet and allow it to dry for 48 hours.
This adds no appreciable weight to the
material and renders the cardboard completely
waterproof. In addition, when you cut the treated
cardboard you will find that it is as crisp as wood
and cuts sharply and cleanly.
Finishing: Cardboard provides a solid surface
with no open areas to cover and is nonporous. The
easiest finishing method is to apply two coats of
clear dope, sand lightly between coats with 400-
grit paper, and follow with three coats of colored
dope.
However, a wide variety of finishing materials
such as Solarfilm, MonoKote, and vinyl paper can
be used on the cardboard. With any of these
coverings I recommended that you not dope the
cardboard’s surface; it will result in a better bond.
Covering the Edges: Cover all of the model’s
seams, joints, and exposed edges with strips of
gummed paper tape. You can obtain a 1-inch-wide
roll from a stationery store. To use it, cut a thin
strip to length, dip it in water, and smooth it over
the seam(s). MA
—Chuck Felton
3
n
02sig3.QXD 11/25/03 11:01 am Page 69
70 MODEL AVIATION
The fuselage sides are lined with balsa strips and have
cardboard supports for the bellcrank and fuel-tank mounts.
Carved-balsa cowl halves have 1⁄8 plywood inserts with blind
nuts to serve as cowl-attachment points. Clean work!
The fuselage sides have been joined to the firewall, and the tank
and bellcrank mounts have been installed.
Edges of the tail components are capped with 1⁄8 x 1⁄4 balsa strips
and rounded. Elevator joiner is 1⁄4-inch dowel.
A cardboard fuselage top piece, cardboard bulkheads, and the
single balsa centerline stringer have been added.
Wing has single spar, cardboard ribs, and leading edge folds to
obtain curved upper surface. Note 1⁄8 plywood gear mount.
1 2
3 4
5 6
02sig3.QXD 11/25/03 11:01 am Page 70
1
2
3
4
5
surfaces. Add a 1⁄8 x 1⁄4 balsa strip to the fin
leading edge (LE) and round it off. Add 1⁄8 x
1⁄4 balsa strips to the stabilizer LEs and
trailing edges (TEs) and round them off.
Glue the elevators to the 1⁄4-inch dowel.
Add 1⁄8 x 1⁄4 balsa strips to the remainder of
the elevator LE and round them off. Seal all
raw edges with gummed paper tape. Hinge
the elevators to the stabilizer with cloth
hinges at four places.
Wing: Make the wing spar by capping
each 1⁄4 balsa spar with a 1⁄4 x 1⁄4 spruce
strip top and bottom. Join the spar halves
with 1⁄8 plywood joiners front and rear at
the centerline.
Glue the 1⁄8 plywood gear mount into
the bottom of each wing panel. Glue the
right side of the wing spar onto the righthand
wing panel. Glue all cardboard ribs
into the right wing. Add a cardboard
doubler over the plywood gear mount
between ribs W3 and W4. Glue a 1-ounce
weight to the right wingtip.
Glue the left wing panel to the left spar
in a similar fashion. Add the ribs and gear
doubler to the left wing. Apply glue to the
top of the wing spar, the top of the ribs, and
the wing TE. Fold the 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 balsa wingtip, and glue the line guide
in place. Cover the TE and all seams with
gummed paper tape.
Fuselage: The fuselage edges are outlined
with a triangular symbol on the drawing.
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 fuselage
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 the mounting holes for a
KM-40 motor mount on the face of C1.
Drill the mounting holes and install blind
mounting nuts on the back side of C1. Drill
a hole in C1 for a fuel-tubing exit. Line all
four back edges of C1 with 1⁄2-inch
triangular balsa for bracing.
Glue C1 to the right side of the
fuselage. When dry, glue the left side of the
fuselage to C1. Attach the fuel tank to the
1⁄8 plywood support. You can attach the
fuel tank to the support with rubber bands.
Make a pushrod from 3⁄32-inch wire and
1⁄4 square spruce, and attach it to the
bellcrank along with the leadout wires.
Install the tank and bellcrank assemblies by
gluing the plywood supports to the
cardboard supports on the insides of the
fuselage.
Glue the fuselage sides together at the
tail. Glue F1 and F2 in place to cover the
top fuselage. Be sure to bring fuel tubing
fill and overflow lines out during all
covering operations. Cover the bottom
fuselage with F3, F4, and F5.
Add bulkheads A through K to the top
fuselage, adding 1⁄8 x 1⁄4-inch stringers.
Cover bulkheads A through D with D1,
bulkheads E through G with D2, and
bulkheads G through K with D3. Add
bulkheads L, M, and N, with stringer, to
forward bottom fuselage, and cover with
D4.
The cowl is built up from 1⁄2 balsa sheet
and hollowed out. The top half has the 1⁄4
plywood C2 glued to the front. The
removable bottom half of the cowl has C3
glued to the front. Sand, carve, and hollow
the cowl to shape. Add 1⁄8-inch rectangular
plywood pieces to the inside of the top and
bottom halves at the cowl sides, as shown
in the cowl top and side views.
Install a blind nut on the inside of the
top cowl plywood and run a 4-40 bolt
through the bottom cowl to form the cowl
attach. Permanently glue the top half of the
cowl to the model’s nose.
Test-fit the engine in the cowl and drill
mounting holes in the KM-40 engine
February 2004 71
The finished nose section. Notice the tank fill line and the spinner fit. The camo paint
job is extremely effective.
The leadouts are external and go through a line guide that is attached where the wing
meets the wingtip.
Photos courtesy the author
02sig3.QXD 11/25/03 11:03 am Page 71
6
mount. 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 the front
of the firewall.
Glue the stabilizer to the fuselage. Add balsa block fairings at
the stabilizer/fin intersection. Add the rudder to the fin with the TE
offset 1⁄2 inch to the outside of the flying circle.
Make the tail-wheel gear from 3⁄32-inch-diameter wire. Bend it
as shown, place it on the 1⁄8 plywood support, wrap it with nylon
thread, and smear the thread with glue. When it’s dry, glue it in
place in the bottom fuselage cutout.
Make the main gear from 5⁄32-inch-diameter wire, as shown.
Make gear fairings from 1⁄8 plywood and attach them to the gear
with nylon gear clips. Attach the gear assemblies to the 1⁄8 plywood
supports in the bottom wing with nylon gear clips.
Finish: Now is the time to paint and trim the model before final
assembly. The color scheme is medium- and dark-green uppersurface
camouflage and light-blue undersurface. Cut the red
lettering and insignia from MonoKote. Make the canopy from thin
plastic, and epoxy it to the fuselage. Outline the canopy with thin
strips of MonoKote. Make the aileron outlines from Black
MonoKote.
Final Assembly: Glue the wing to the fuselage. Make the air
scoop from 1⁄2 balsa and glue it to the bottom of the wing/fuselage.
Add balsa exhaust stacks to both sides of the forward fuselage.
Pass the leadout wires through the wingtip line guide and tie them
off. Attach the nylon control horn to the elevator and hook up the
pushrod.
Attach 33⁄4-inch-diameter wheels to the main gear and a 11⁄2-
inch-diameter wheel to the tail gear. Add an 11 x 6 propeller and a
31⁄2-inch spinner to the engine, and your model will be completed.
Be sure to balance the model at the point shown on the plans.
If you have any comments, suggestions, or questions concerning
the LaGG-3, please write to me at the following address or E-mail
me, maybe with a photo of your completed cardboard model. MA
Chuck Felton
825 Lake Park Dr.
Lakehills TX 78063
[email protected]
72 MODEL AVIATION
The landing-gear struts mount to the plywood plates in the wing.
Notice the simulated wheel wells.
It’s hard to believe that this model is mostly cardboard. The tail
section is neat and clean, with great paint detail.
A pilot adds to the model’s realism. The canopy is simple to
construct, and tape frame lines add to the effect.
Lavochkin
LaGG-3
Type: CL Sport Scale
Wingspan: 65 inches
Engine: .40-.50 glow
Flying weight: 60 ounces
Construction: Cardboard, balsa, plywood
Covering/finish: Modeling paints,
MonoKote trim and insignia
02sig3.QXD 11/25/03 11:04 am Page 72
74 MODEL AVIATION
Full-Size Plans Available—see page 199
02sig3.QXD 11/25/03 11:05 am Page 74
76 MODEL AVIATION
Full-Size Plans Available—see page 199
02sig3.QXD 11/25/03 11:06 am Page 76
Edition: Model Aviation - 2004/02
Page Numbers: 68,69,70,71,72,74,76
LaGG-3
Lavochkin by Chuck Felton
An obscure WW II Russian
fighter and an unusual
construction technique add up
to modeling adventure!
02sig3.QXD 11/25/03 11:00 am Page 68
February 2004 69
THE LAGG-3 was one of a trio of modern aircraft that
the Soviets produced before and during World War II to
replace their obsolete fighters. S.A. Lavochkin, V.P.
Gorbunov, and M.I. Gudkov designed the aircraft, hence
the name LaGG—from their initials.
Although outwardly conventional, the LaGG-3 was
the only one of the world’s new crop of streamlined
monoplane fighters not to have metal stressed-skin
construction. Since the Soviet Union faced difficulties at
that time obtaining aluminum and other light alloys, the
fighter was built mostly from birch plywood and pine.
A new technology called “delta wood” was
developed, which consisted of layers of birch strips that
were glued cross-grained, impregnated, and used in
conjunction with a Bakelite plywood. The result was a
neat, clean, maneuverable fighter that showed
outstanding robustness and resistance to battle damage.
On the other hand, it was inferior to other Russian
fighters in all-around performance.
The first of these fighters reached the aviation
regiments just a few months before the German
invasion. More than 6,500 aircraft had been produced
when production ended in September 1943.
My model of the LaGG-3 is inexpensive and simple in
construction; I use 1⁄8-inch corrugated cardboard as the
primary building material, which greatly reduces
building time and cost.
The design makes use of cardboard’s unique
features: it can be used in large sections and folded. The
wing is built from two big pieces of cardboard, with
cardboard ribs and a single spar. The tail surfaces and
fuselage are primarily cardboard, with little internal
bracing required. The result is a model with a good
scalelike appearance that can take plenty of punishment
at the flying field.
Cardboard varies in weight, but any 1⁄8-inch
corrugated will do. Sources for this material include box
manufacturers and local shopping centers where you can
find stacks of discarded boxes. Look for cardboard with
brown paper on one side and a white finished paper
on the other side. Having the white paper on
the outside of the model results in a
smoother finish and a neater
appearance. The method of
folding the cardboard and
using gummed paper tape
to seal the joints and
exposed corrugations is
explained in the
construction tips.
The model has a wingspan
of 65 inches and a length of 58
inches. The bottom of the airfoil is flat with a curved
upper surface because of the scoring and folding
technique employed. Engines of .40 to .50 displacement
can be used. The LaGG-3’s size and stability make it a
good sport-flying model.
CONSTRUCTION
Cut out all cardboard and wood parts, making sure to
note the direction of the corrugations. Score and fold
cardboard parts as indicated on the plans.
Empennage: The fin, rudder, stabilizer, and elevator are
each made from two pieces of 1⁄8-inch cardboard
laminated together cross-grain to give 1⁄4-inch-thick
Special Tips
for Working
With Cardboard
Before we begin, I have some special tips for
working with cardboard.
Gluing: Use water-based glue such as white glue
or Titebond. Don’t use contact cement since parts
cannot be shifted when you are gluing surfaces.
Folding: Score the fold lines with a screening
tool, which is available at any hardware store. It
has a handle with a 11⁄2-inch-radius wheel at one
end that you run along a metal straightedge on the
fold line.
Waterproofing: Making cardboard waterproof is
simple, and you can do it to the raw material
before you cut out the model’s parts. Mix 25%
clear polyurethane with 75% paint thinner; the
latter can be the most inexpensive hardware-store
variety. Brush the mixture liberally onto the
cardboard sheet and allow it to dry for 48 hours.
This adds no appreciable weight to the
material and renders the cardboard completely
waterproof. In addition, when you cut the treated
cardboard you will find that it is as crisp as wood
and cuts sharply and cleanly.
Finishing: Cardboard provides a solid surface
with no open areas to cover and is nonporous. The
easiest finishing method is to apply two coats of
clear dope, sand lightly between coats with 400-
grit paper, and follow with three coats of colored
dope.
However, a wide variety of finishing materials
such as Solarfilm, MonoKote, and vinyl paper can
be used on the cardboard. With any of these
coverings I recommended that you not dope the
cardboard’s surface; it will result in a better bond.
Covering the Edges: Cover all of the model’s
seams, joints, and exposed edges with strips of
gummed paper tape. You can obtain a 1-inch-wide
roll from a stationery store. To use it, cut a thin
strip to length, dip it in water, and smooth it over
the seam(s). MA
—Chuck Felton
3
n
02sig3.QXD 11/25/03 11:01 am Page 69
70 MODEL AVIATION
The fuselage sides are lined with balsa strips and have
cardboard supports for the bellcrank and fuel-tank mounts.
Carved-balsa cowl halves have 1⁄8 plywood inserts with blind
nuts to serve as cowl-attachment points. Clean work!
The fuselage sides have been joined to the firewall, and the tank
and bellcrank mounts have been installed.
Edges of the tail components are capped with 1⁄8 x 1⁄4 balsa strips
and rounded. Elevator joiner is 1⁄4-inch dowel.
A cardboard fuselage top piece, cardboard bulkheads, and the
single balsa centerline stringer have been added.
Wing has single spar, cardboard ribs, and leading edge folds to
obtain curved upper surface. Note 1⁄8 plywood gear mount.
1 2
3 4
5 6
02sig3.QXD 11/25/03 11:01 am Page 70
1
2
3
4
5
surfaces. Add a 1⁄8 x 1⁄4 balsa strip to the fin
leading edge (LE) and round it off. Add 1⁄8 x
1⁄4 balsa strips to the stabilizer LEs and
trailing edges (TEs) and round them off.
Glue the elevators to the 1⁄4-inch dowel.
Add 1⁄8 x 1⁄4 balsa strips to the remainder of
the elevator LE and round them off. Seal all
raw edges with gummed paper tape. Hinge
the elevators to the stabilizer with cloth
hinges at four places.
Wing: Make the wing spar by capping
each 1⁄4 balsa spar with a 1⁄4 x 1⁄4 spruce
strip top and bottom. Join the spar halves
with 1⁄8 plywood joiners front and rear at
the centerline.
Glue the 1⁄8 plywood gear mount into
the bottom of each wing panel. Glue the
right side of the wing spar onto the righthand
wing panel. Glue all cardboard ribs
into the right wing. Add a cardboard
doubler over the plywood gear mount
between ribs W3 and W4. Glue a 1-ounce
weight to the right wingtip.
Glue the left wing panel to the left spar
in a similar fashion. Add the ribs and gear
doubler to the left wing. Apply glue to the
top of the wing spar, the top of the ribs, and
the wing TE. Fold the 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 balsa wingtip, and glue the line guide
in place. Cover the TE and all seams with
gummed paper tape.
Fuselage: The fuselage edges are outlined
with a triangular symbol on the drawing.
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 fuselage
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 the mounting holes for a
KM-40 motor mount on the face of C1.
Drill the mounting holes and install blind
mounting nuts on the back side of C1. Drill
a hole in C1 for a fuel-tubing exit. Line all
four back edges of C1 with 1⁄2-inch
triangular balsa for bracing.
Glue C1 to the right side of the
fuselage. When dry, glue the left side of the
fuselage to C1. Attach the fuel tank to the
1⁄8 plywood support. You can attach the
fuel tank to the support with rubber bands.
Make a pushrod from 3⁄32-inch wire and
1⁄4 square spruce, and attach it to the
bellcrank along with the leadout wires.
Install the tank and bellcrank assemblies by
gluing the plywood supports to the
cardboard supports on the insides of the
fuselage.
Glue the fuselage sides together at the
tail. Glue F1 and F2 in place to cover the
top fuselage. Be sure to bring fuel tubing
fill and overflow lines out during all
covering operations. Cover the bottom
fuselage with F3, F4, and F5.
Add bulkheads A through K to the top
fuselage, adding 1⁄8 x 1⁄4-inch stringers.
Cover bulkheads A through D with D1,
bulkheads E through G with D2, and
bulkheads G through K with D3. Add
bulkheads L, M, and N, with stringer, to
forward bottom fuselage, and cover with
D4.
The cowl is built up from 1⁄2 balsa sheet
and hollowed out. The top half has the 1⁄4
plywood C2 glued to the front. The
removable bottom half of the cowl has C3
glued to the front. Sand, carve, and hollow
the cowl to shape. Add 1⁄8-inch rectangular
plywood pieces to the inside of the top and
bottom halves at the cowl sides, as shown
in the cowl top and side views.
Install a blind nut on the inside of the
top cowl plywood and run a 4-40 bolt
through the bottom cowl to form the cowl
attach. Permanently glue the top half of the
cowl to the model’s nose.
Test-fit the engine in the cowl and drill
mounting holes in the KM-40 engine
February 2004 71
The finished nose section. Notice the tank fill line and the spinner fit. The camo paint
job is extremely effective.
The leadouts are external and go through a line guide that is attached where the wing
meets the wingtip.
Photos courtesy the author
02sig3.QXD 11/25/03 11:03 am Page 71
6
mount. 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 the front
of the firewall.
Glue the stabilizer to the fuselage. Add balsa block fairings at
the stabilizer/fin intersection. Add the rudder to the fin with the TE
offset 1⁄2 inch to the outside of the flying circle.
Make the tail-wheel gear from 3⁄32-inch-diameter wire. Bend it
as shown, place it on the 1⁄8 plywood support, wrap it with nylon
thread, and smear the thread with glue. When it’s dry, glue it in
place in the bottom fuselage cutout.
Make the main gear from 5⁄32-inch-diameter wire, as shown.
Make gear fairings from 1⁄8 plywood and attach them to the gear
with nylon gear clips. Attach the gear assemblies to the 1⁄8 plywood
supports in the bottom wing with nylon gear clips.
Finish: Now is the time to paint and trim the model before final
assembly. The color scheme is medium- and dark-green uppersurface
camouflage and light-blue undersurface. Cut the red
lettering and insignia from MonoKote. Make the canopy from thin
plastic, and epoxy it to the fuselage. Outline the canopy with thin
strips of MonoKote. Make the aileron outlines from Black
MonoKote.
Final Assembly: Glue the wing to the fuselage. Make the air
scoop from 1⁄2 balsa and glue it to the bottom of the wing/fuselage.
Add balsa exhaust stacks to both sides of the forward fuselage.
Pass the leadout wires through the wingtip line guide and tie them
off. Attach the nylon control horn to the elevator and hook up the
pushrod.
Attach 33⁄4-inch-diameter wheels to the main gear and a 11⁄2-
inch-diameter wheel to the tail gear. Add an 11 x 6 propeller and a
31⁄2-inch spinner to the engine, and your model will be completed.
Be sure to balance the model at the point shown on the plans.
If you have any comments, suggestions, or questions concerning
the LaGG-3, please write to me at the following address or E-mail
me, maybe with a photo of your completed cardboard model. MA
Chuck Felton
825 Lake Park Dr.
Lakehills TX 78063
[email protected]
72 MODEL AVIATION
The landing-gear struts mount to the plywood plates in the wing.
Notice the simulated wheel wells.
It’s hard to believe that this model is mostly cardboard. The tail
section is neat and clean, with great paint detail.
A pilot adds to the model’s realism. The canopy is simple to
construct, and tape frame lines add to the effect.
Lavochkin
LaGG-3
Type: CL Sport Scale
Wingspan: 65 inches
Engine: .40-.50 glow
Flying weight: 60 ounces
Construction: Cardboard, balsa, plywood
Covering/finish: Modeling paints,
MonoKote trim and insignia
02sig3.QXD 11/25/03 11:04 am Page 72
74 MODEL AVIATION
Full-Size Plans Available—see page 199
02sig3.QXD 11/25/03 11:05 am Page 74
76 MODEL AVIATION
Full-Size Plans Available—see page 199
02sig3.QXD 11/25/03 11:06 am Page 76
Edition: Model Aviation - 2004/02
Page Numbers: 68,69,70,71,72,74,76
LaGG-3
Lavochkin by Chuck Felton
An obscure WW II Russian
fighter and an unusual
construction technique add up
to modeling adventure!
02sig3.QXD 11/25/03 11:00 am Page 68
February 2004 69
THE LAGG-3 was one of a trio of modern aircraft that
the Soviets produced before and during World War II to
replace their obsolete fighters. S.A. Lavochkin, V.P.
Gorbunov, and M.I. Gudkov designed the aircraft, hence
the name LaGG—from their initials.
Although outwardly conventional, the LaGG-3 was
the only one of the world’s new crop of streamlined
monoplane fighters not to have metal stressed-skin
construction. Since the Soviet Union faced difficulties at
that time obtaining aluminum and other light alloys, the
fighter was built mostly from birch plywood and pine.
A new technology called “delta wood” was
developed, which consisted of layers of birch strips that
were glued cross-grained, impregnated, and used in
conjunction with a Bakelite plywood. The result was a
neat, clean, maneuverable fighter that showed
outstanding robustness and resistance to battle damage.
On the other hand, it was inferior to other Russian
fighters in all-around performance.
The first of these fighters reached the aviation
regiments just a few months before the German
invasion. More than 6,500 aircraft had been produced
when production ended in September 1943.
My model of the LaGG-3 is inexpensive and simple in
construction; I use 1⁄8-inch corrugated cardboard as the
primary building material, which greatly reduces
building time and cost.
The design makes use of cardboard’s unique
features: it can be used in large sections and folded. The
wing is built from two big pieces of cardboard, with
cardboard ribs and a single spar. The tail surfaces and
fuselage are primarily cardboard, with little internal
bracing required. The result is a model with a good
scalelike appearance that can take plenty of punishment
at the flying field.
Cardboard varies in weight, but any 1⁄8-inch
corrugated will do. Sources for this material include box
manufacturers and local shopping centers where you can
find stacks of discarded boxes. Look for cardboard with
brown paper on one side and a white finished paper
on the other side. Having the white paper on
the outside of the model results in a
smoother finish and a neater
appearance. The method of
folding the cardboard and
using gummed paper tape
to seal the joints and
exposed corrugations is
explained in the
construction tips.
The model has a wingspan
of 65 inches and a length of 58
inches. The bottom of the airfoil is flat with a curved
upper surface because of the scoring and folding
technique employed. Engines of .40 to .50 displacement
can be used. The LaGG-3’s size and stability make it a
good sport-flying model.
CONSTRUCTION
Cut out all cardboard and wood parts, making sure to
note the direction of the corrugations. Score and fold
cardboard parts as indicated on the plans.
Empennage: The fin, rudder, stabilizer, and elevator are
each made from two pieces of 1⁄8-inch cardboard
laminated together cross-grain to give 1⁄4-inch-thick
Special Tips
for Working
With Cardboard
Before we begin, I have some special tips for
working with cardboard.
Gluing: Use water-based glue such as white glue
or Titebond. Don’t use contact cement since parts
cannot be shifted when you are gluing surfaces.
Folding: Score the fold lines with a screening
tool, which is available at any hardware store. It
has a handle with a 11⁄2-inch-radius wheel at one
end that you run along a metal straightedge on the
fold line.
Waterproofing: Making cardboard waterproof is
simple, and you can do it to the raw material
before you cut out the model’s parts. Mix 25%
clear polyurethane with 75% paint thinner; the
latter can be the most inexpensive hardware-store
variety. Brush the mixture liberally onto the
cardboard sheet and allow it to dry for 48 hours.
This adds no appreciable weight to the
material and renders the cardboard completely
waterproof. In addition, when you cut the treated
cardboard you will find that it is as crisp as wood
and cuts sharply and cleanly.
Finishing: Cardboard provides a solid surface
with no open areas to cover and is nonporous. The
easiest finishing method is to apply two coats of
clear dope, sand lightly between coats with 400-
grit paper, and follow with three coats of colored
dope.
However, a wide variety of finishing materials
such as Solarfilm, MonoKote, and vinyl paper can
be used on the cardboard. With any of these
coverings I recommended that you not dope the
cardboard’s surface; it will result in a better bond.
Covering the Edges: Cover all of the model’s
seams, joints, and exposed edges with strips of
gummed paper tape. You can obtain a 1-inch-wide
roll from a stationery store. To use it, cut a thin
strip to length, dip it in water, and smooth it over
the seam(s). MA
—Chuck Felton
3
n
02sig3.QXD 11/25/03 11:01 am Page 69
70 MODEL AVIATION
The fuselage sides are lined with balsa strips and have
cardboard supports for the bellcrank and fuel-tank mounts.
Carved-balsa cowl halves have 1⁄8 plywood inserts with blind
nuts to serve as cowl-attachment points. Clean work!
The fuselage sides have been joined to the firewall, and the tank
and bellcrank mounts have been installed.
Edges of the tail components are capped with 1⁄8 x 1⁄4 balsa strips
and rounded. Elevator joiner is 1⁄4-inch dowel.
A cardboard fuselage top piece, cardboard bulkheads, and the
single balsa centerline stringer have been added.
Wing has single spar, cardboard ribs, and leading edge folds to
obtain curved upper surface. Note 1⁄8 plywood gear mount.
1 2
3 4
5 6
02sig3.QXD 11/25/03 11:01 am Page 70
1
2
3
4
5
surfaces. Add a 1⁄8 x 1⁄4 balsa strip to the fin
leading edge (LE) and round it off. Add 1⁄8 x
1⁄4 balsa strips to the stabilizer LEs and
trailing edges (TEs) and round them off.
Glue the elevators to the 1⁄4-inch dowel.
Add 1⁄8 x 1⁄4 balsa strips to the remainder of
the elevator LE and round them off. Seal all
raw edges with gummed paper tape. Hinge
the elevators to the stabilizer with cloth
hinges at four places.
Wing: Make the wing spar by capping
each 1⁄4 balsa spar with a 1⁄4 x 1⁄4 spruce
strip top and bottom. Join the spar halves
with 1⁄8 plywood joiners front and rear at
the centerline.
Glue the 1⁄8 plywood gear mount into
the bottom of each wing panel. Glue the
right side of the wing spar onto the righthand
wing panel. Glue all cardboard ribs
into the right wing. Add a cardboard
doubler over the plywood gear mount
between ribs W3 and W4. Glue a 1-ounce
weight to the right wingtip.
Glue the left wing panel to the left spar
in a similar fashion. Add the ribs and gear
doubler to the left wing. Apply glue to the
top of the wing spar, the top of the ribs, and
the wing TE. Fold the 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 balsa wingtip, and glue the line guide
in place. Cover the TE and all seams with
gummed paper tape.
Fuselage: The fuselage edges are outlined
with a triangular symbol on the drawing.
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 fuselage
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 the mounting holes for a
KM-40 motor mount on the face of C1.
Drill the mounting holes and install blind
mounting nuts on the back side of C1. Drill
a hole in C1 for a fuel-tubing exit. Line all
four back edges of C1 with 1⁄2-inch
triangular balsa for bracing.
Glue C1 to the right side of the
fuselage. When dry, glue the left side of the
fuselage to C1. Attach the fuel tank to the
1⁄8 plywood support. You can attach the
fuel tank to the support with rubber bands.
Make a pushrod from 3⁄32-inch wire and
1⁄4 square spruce, and attach it to the
bellcrank along with the leadout wires.
Install the tank and bellcrank assemblies by
gluing the plywood supports to the
cardboard supports on the insides of the
fuselage.
Glue the fuselage sides together at the
tail. Glue F1 and F2 in place to cover the
top fuselage. Be sure to bring fuel tubing
fill and overflow lines out during all
covering operations. Cover the bottom
fuselage with F3, F4, and F5.
Add bulkheads A through K to the top
fuselage, adding 1⁄8 x 1⁄4-inch stringers.
Cover bulkheads A through D with D1,
bulkheads E through G with D2, and
bulkheads G through K with D3. Add
bulkheads L, M, and N, with stringer, to
forward bottom fuselage, and cover with
D4.
The cowl is built up from 1⁄2 balsa sheet
and hollowed out. The top half has the 1⁄4
plywood C2 glued to the front. The
removable bottom half of the cowl has C3
glued to the front. Sand, carve, and hollow
the cowl to shape. Add 1⁄8-inch rectangular
plywood pieces to the inside of the top and
bottom halves at the cowl sides, as shown
in the cowl top and side views.
Install a blind nut on the inside of the
top cowl plywood and run a 4-40 bolt
through the bottom cowl to form the cowl
attach. Permanently glue the top half of the
cowl to the model’s nose.
Test-fit the engine in the cowl and drill
mounting holes in the KM-40 engine
February 2004 71
The finished nose section. Notice the tank fill line and the spinner fit. The camo paint
job is extremely effective.
The leadouts are external and go through a line guide that is attached where the wing
meets the wingtip.
Photos courtesy the author
02sig3.QXD 11/25/03 11:03 am Page 71
6
mount. 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 the front
of the firewall.
Glue the stabilizer to the fuselage. Add balsa block fairings at
the stabilizer/fin intersection. Add the rudder to the fin with the TE
offset 1⁄2 inch to the outside of the flying circle.
Make the tail-wheel gear from 3⁄32-inch-diameter wire. Bend it
as shown, place it on the 1⁄8 plywood support, wrap it with nylon
thread, and smear the thread with glue. When it’s dry, glue it in
place in the bottom fuselage cutout.
Make the main gear from 5⁄32-inch-diameter wire, as shown.
Make gear fairings from 1⁄8 plywood and attach them to the gear
with nylon gear clips. Attach the gear assemblies to the 1⁄8 plywood
supports in the bottom wing with nylon gear clips.
Finish: Now is the time to paint and trim the model before final
assembly. The color scheme is medium- and dark-green uppersurface
camouflage and light-blue undersurface. Cut the red
lettering and insignia from MonoKote. Make the canopy from thin
plastic, and epoxy it to the fuselage. Outline the canopy with thin
strips of MonoKote. Make the aileron outlines from Black
MonoKote.
Final Assembly: Glue the wing to the fuselage. Make the air
scoop from 1⁄2 balsa and glue it to the bottom of the wing/fuselage.
Add balsa exhaust stacks to both sides of the forward fuselage.
Pass the leadout wires through the wingtip line guide and tie them
off. Attach the nylon control horn to the elevator and hook up the
pushrod.
Attach 33⁄4-inch-diameter wheels to the main gear and a 11⁄2-
inch-diameter wheel to the tail gear. Add an 11 x 6 propeller and a
31⁄2-inch spinner to the engine, and your model will be completed.
Be sure to balance the model at the point shown on the plans.
If you have any comments, suggestions, or questions concerning
the LaGG-3, please write to me at the following address or E-mail
me, maybe with a photo of your completed cardboard model. MA
Chuck Felton
825 Lake Park Dr.
Lakehills TX 78063
[email protected]
72 MODEL AVIATION
The landing-gear struts mount to the plywood plates in the wing.
Notice the simulated wheel wells.
It’s hard to believe that this model is mostly cardboard. The tail
section is neat and clean, with great paint detail.
A pilot adds to the model’s realism. The canopy is simple to
construct, and tape frame lines add to the effect.
Lavochkin
LaGG-3
Type: CL Sport Scale
Wingspan: 65 inches
Engine: .40-.50 glow
Flying weight: 60 ounces
Construction: Cardboard, balsa, plywood
Covering/finish: Modeling paints,
MonoKote trim and insignia
02sig3.QXD 11/25/03 11:04 am Page 72
74 MODEL AVIATION
Full-Size Plans Available—see page 199
02sig3.QXD 11/25/03 11:05 am Page 74
76 MODEL AVIATION
Full-Size Plans Available—see page 199
02sig3.QXD 11/25/03 11:06 am Page 76
Edition: Model Aviation - 2004/02
Page Numbers: 68,69,70,71,72,74,76
LaGG-3
Lavochkin by Chuck Felton
An obscure WW II Russian
fighter and an unusual
construction technique add up
to modeling adventure!
02sig3.QXD 11/25/03 11:00 am Page 68
February 2004 69
THE LAGG-3 was one of a trio of modern aircraft that
the Soviets produced before and during World War II to
replace their obsolete fighters. S.A. Lavochkin, V.P.
Gorbunov, and M.I. Gudkov designed the aircraft, hence
the name LaGG—from their initials.
Although outwardly conventional, the LaGG-3 was
the only one of the world’s new crop of streamlined
monoplane fighters not to have metal stressed-skin
construction. Since the Soviet Union faced difficulties at
that time obtaining aluminum and other light alloys, the
fighter was built mostly from birch plywood and pine.
A new technology called “delta wood” was
developed, which consisted of layers of birch strips that
were glued cross-grained, impregnated, and used in
conjunction with a Bakelite plywood. The result was a
neat, clean, maneuverable fighter that showed
outstanding robustness and resistance to battle damage.
On the other hand, it was inferior to other Russian
fighters in all-around performance.
The first of these fighters reached the aviation
regiments just a few months before the German
invasion. More than 6,500 aircraft had been produced
when production ended in September 1943.
My model of the LaGG-3 is inexpensive and simple in
construction; I use 1⁄8-inch corrugated cardboard as the
primary building material, which greatly reduces
building time and cost.
The design makes use of cardboard’s unique
features: it can be used in large sections and folded. The
wing is built from two big pieces of cardboard, with
cardboard ribs and a single spar. The tail surfaces and
fuselage are primarily cardboard, with little internal
bracing required. The result is a model with a good
scalelike appearance that can take plenty of punishment
at the flying field.
Cardboard varies in weight, but any 1⁄8-inch
corrugated will do. Sources for this material include box
manufacturers and local shopping centers where you can
find stacks of discarded boxes. Look for cardboard with
brown paper on one side and a white finished paper
on the other side. Having the white paper on
the outside of the model results in a
smoother finish and a neater
appearance. The method of
folding the cardboard and
using gummed paper tape
to seal the joints and
exposed corrugations is
explained in the
construction tips.
The model has a wingspan
of 65 inches and a length of 58
inches. The bottom of the airfoil is flat with a curved
upper surface because of the scoring and folding
technique employed. Engines of .40 to .50 displacement
can be used. The LaGG-3’s size and stability make it a
good sport-flying model.
CONSTRUCTION
Cut out all cardboard and wood parts, making sure to
note the direction of the corrugations. Score and fold
cardboard parts as indicated on the plans.
Empennage: The fin, rudder, stabilizer, and elevator are
each made from two pieces of 1⁄8-inch cardboard
laminated together cross-grain to give 1⁄4-inch-thick
Special Tips
for Working
With Cardboard
Before we begin, I have some special tips for
working with cardboard.
Gluing: Use water-based glue such as white glue
or Titebond. Don’t use contact cement since parts
cannot be shifted when you are gluing surfaces.
Folding: Score the fold lines with a screening
tool, which is available at any hardware store. It
has a handle with a 11⁄2-inch-radius wheel at one
end that you run along a metal straightedge on the
fold line.
Waterproofing: Making cardboard waterproof is
simple, and you can do it to the raw material
before you cut out the model’s parts. Mix 25%
clear polyurethane with 75% paint thinner; the
latter can be the most inexpensive hardware-store
variety. Brush the mixture liberally onto the
cardboard sheet and allow it to dry for 48 hours.
This adds no appreciable weight to the
material and renders the cardboard completely
waterproof. In addition, when you cut the treated
cardboard you will find that it is as crisp as wood
and cuts sharply and cleanly.
Finishing: Cardboard provides a solid surface
with no open areas to cover and is nonporous. The
easiest finishing method is to apply two coats of
clear dope, sand lightly between coats with 400-
grit paper, and follow with three coats of colored
dope.
However, a wide variety of finishing materials
such as Solarfilm, MonoKote, and vinyl paper can
be used on the cardboard. With any of these
coverings I recommended that you not dope the
cardboard’s surface; it will result in a better bond.
Covering the Edges: Cover all of the model’s
seams, joints, and exposed edges with strips of
gummed paper tape. You can obtain a 1-inch-wide
roll from a stationery store. To use it, cut a thin
strip to length, dip it in water, and smooth it over
the seam(s). MA
—Chuck Felton
3
n
02sig3.QXD 11/25/03 11:01 am Page 69
70 MODEL AVIATION
The fuselage sides are lined with balsa strips and have
cardboard supports for the bellcrank and fuel-tank mounts.
Carved-balsa cowl halves have 1⁄8 plywood inserts with blind
nuts to serve as cowl-attachment points. Clean work!
The fuselage sides have been joined to the firewall, and the tank
and bellcrank mounts have been installed.
Edges of the tail components are capped with 1⁄8 x 1⁄4 balsa strips
and rounded. Elevator joiner is 1⁄4-inch dowel.
A cardboard fuselage top piece, cardboard bulkheads, and the
single balsa centerline stringer have been added.
Wing has single spar, cardboard ribs, and leading edge folds to
obtain curved upper surface. Note 1⁄8 plywood gear mount.
1 2
3 4
5 6
02sig3.QXD 11/25/03 11:01 am Page 70
1
2
3
4
5
surfaces. Add a 1⁄8 x 1⁄4 balsa strip to the fin
leading edge (LE) and round it off. Add 1⁄8 x
1⁄4 balsa strips to the stabilizer LEs and
trailing edges (TEs) and round them off.
Glue the elevators to the 1⁄4-inch dowel.
Add 1⁄8 x 1⁄4 balsa strips to the remainder of
the elevator LE and round them off. Seal all
raw edges with gummed paper tape. Hinge
the elevators to the stabilizer with cloth
hinges at four places.
Wing: Make the wing spar by capping
each 1⁄4 balsa spar with a 1⁄4 x 1⁄4 spruce
strip top and bottom. Join the spar halves
with 1⁄8 plywood joiners front and rear at
the centerline.
Glue the 1⁄8 plywood gear mount into
the bottom of each wing panel. Glue the
right side of the wing spar onto the righthand
wing panel. Glue all cardboard ribs
into the right wing. Add a cardboard
doubler over the plywood gear mount
between ribs W3 and W4. Glue a 1-ounce
weight to the right wingtip.
Glue the left wing panel to the left spar
in a similar fashion. Add the ribs and gear
doubler to the left wing. Apply glue to the
top of the wing spar, the top of the ribs, and
the wing TE. Fold the 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 balsa wingtip, and glue the line guide
in place. Cover the TE and all seams with
gummed paper tape.
Fuselage: The fuselage edges are outlined
with a triangular symbol on the drawing.
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 fuselage
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 the mounting holes for a
KM-40 motor mount on the face of C1.
Drill the mounting holes and install blind
mounting nuts on the back side of C1. Drill
a hole in C1 for a fuel-tubing exit. Line all
four back edges of C1 with 1⁄2-inch
triangular balsa for bracing.
Glue C1 to the right side of the
fuselage. When dry, glue the left side of the
fuselage to C1. Attach the fuel tank to the
1⁄8 plywood support. You can attach the
fuel tank to the support with rubber bands.
Make a pushrod from 3⁄32-inch wire and
1⁄4 square spruce, and attach it to the
bellcrank along with the leadout wires.
Install the tank and bellcrank assemblies by
gluing the plywood supports to the
cardboard supports on the insides of the
fuselage.
Glue the fuselage sides together at the
tail. Glue F1 and F2 in place to cover the
top fuselage. Be sure to bring fuel tubing
fill and overflow lines out during all
covering operations. Cover the bottom
fuselage with F3, F4, and F5.
Add bulkheads A through K to the top
fuselage, adding 1⁄8 x 1⁄4-inch stringers.
Cover bulkheads A through D with D1,
bulkheads E through G with D2, and
bulkheads G through K with D3. Add
bulkheads L, M, and N, with stringer, to
forward bottom fuselage, and cover with
D4.
The cowl is built up from 1⁄2 balsa sheet
and hollowed out. The top half has the 1⁄4
plywood C2 glued to the front. The
removable bottom half of the cowl has C3
glued to the front. Sand, carve, and hollow
the cowl to shape. Add 1⁄8-inch rectangular
plywood pieces to the inside of the top and
bottom halves at the cowl sides, as shown
in the cowl top and side views.
Install a blind nut on the inside of the
top cowl plywood and run a 4-40 bolt
through the bottom cowl to form the cowl
attach. Permanently glue the top half of the
cowl to the model’s nose.
Test-fit the engine in the cowl and drill
mounting holes in the KM-40 engine
February 2004 71
The finished nose section. Notice the tank fill line and the spinner fit. The camo paint
job is extremely effective.
The leadouts are external and go through a line guide that is attached where the wing
meets the wingtip.
Photos courtesy the author
02sig3.QXD 11/25/03 11:03 am Page 71
6
mount. 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 the front
of the firewall.
Glue the stabilizer to the fuselage. Add balsa block fairings at
the stabilizer/fin intersection. Add the rudder to the fin with the TE
offset 1⁄2 inch to the outside of the flying circle.
Make the tail-wheel gear from 3⁄32-inch-diameter wire. Bend it
as shown, place it on the 1⁄8 plywood support, wrap it with nylon
thread, and smear the thread with glue. When it’s dry, glue it in
place in the bottom fuselage cutout.
Make the main gear from 5⁄32-inch-diameter wire, as shown.
Make gear fairings from 1⁄8 plywood and attach them to the gear
with nylon gear clips. Attach the gear assemblies to the 1⁄8 plywood
supports in the bottom wing with nylon gear clips.
Finish: Now is the time to paint and trim the model before final
assembly. The color scheme is medium- and dark-green uppersurface
camouflage and light-blue undersurface. Cut the red
lettering and insignia from MonoKote. Make the canopy from thin
plastic, and epoxy it to the fuselage. Outline the canopy with thin
strips of MonoKote. Make the aileron outlines from Black
MonoKote.
Final Assembly: Glue the wing to the fuselage. Make the air
scoop from 1⁄2 balsa and glue it to the bottom of the wing/fuselage.
Add balsa exhaust stacks to both sides of the forward fuselage.
Pass the leadout wires through the wingtip line guide and tie them
off. Attach the nylon control horn to the elevator and hook up the
pushrod.
Attach 33⁄4-inch-diameter wheels to the main gear and a 11⁄2-
inch-diameter wheel to the tail gear. Add an 11 x 6 propeller and a
31⁄2-inch spinner to the engine, and your model will be completed.
Be sure to balance the model at the point shown on the plans.
If you have any comments, suggestions, or questions concerning
the LaGG-3, please write to me at the following address or E-mail
me, maybe with a photo of your completed cardboard model. MA
Chuck Felton
825 Lake Park Dr.
Lakehills TX 78063
[email protected]
72 MODEL AVIATION
The landing-gear struts mount to the plywood plates in the wing.
Notice the simulated wheel wells.
It’s hard to believe that this model is mostly cardboard. The tail
section is neat and clean, with great paint detail.
A pilot adds to the model’s realism. The canopy is simple to
construct, and tape frame lines add to the effect.
Lavochkin
LaGG-3
Type: CL Sport Scale
Wingspan: 65 inches
Engine: .40-.50 glow
Flying weight: 60 ounces
Construction: Cardboard, balsa, plywood
Covering/finish: Modeling paints,
MonoKote trim and insignia
02sig3.QXD 11/25/03 11:04 am Page 72
74 MODEL AVIATION
Full-Size Plans Available—see page 199
02sig3.QXD 11/25/03 11:05 am Page 74
76 MODEL AVIATION
Full-Size Plans Available—see page 199
02sig3.QXD 11/25/03 11:06 am Page 76
Edition: Model Aviation - 2004/02
Page Numbers: 68,69,70,71,72,74,76
LaGG-3
Lavochkin by Chuck Felton
An obscure WW II Russian
fighter and an unusual
construction technique add up
to modeling adventure!
02sig3.QXD 11/25/03 11:00 am Page 68
February 2004 69
THE LAGG-3 was one of a trio of modern aircraft that
the Soviets produced before and during World War II to
replace their obsolete fighters. S.A. Lavochkin, V.P.
Gorbunov, and M.I. Gudkov designed the aircraft, hence
the name LaGG—from their initials.
Although outwardly conventional, the LaGG-3 was
the only one of the world’s new crop of streamlined
monoplane fighters not to have metal stressed-skin
construction. Since the Soviet Union faced difficulties at
that time obtaining aluminum and other light alloys, the
fighter was built mostly from birch plywood and pine.
A new technology called “delta wood” was
developed, which consisted of layers of birch strips that
were glued cross-grained, impregnated, and used in
conjunction with a Bakelite plywood. The result was a
neat, clean, maneuverable fighter that showed
outstanding robustness and resistance to battle damage.
On the other hand, it was inferior to other Russian
fighters in all-around performance.
The first of these fighters reached the aviation
regiments just a few months before the German
invasion. More than 6,500 aircraft had been produced
when production ended in September 1943.
My model of the LaGG-3 is inexpensive and simple in
construction; I use 1⁄8-inch corrugated cardboard as the
primary building material, which greatly reduces
building time and cost.
The design makes use of cardboard’s unique
features: it can be used in large sections and folded. The
wing is built from two big pieces of cardboard, with
cardboard ribs and a single spar. The tail surfaces and
fuselage are primarily cardboard, with little internal
bracing required. The result is a model with a good
scalelike appearance that can take plenty of punishment
at the flying field.
Cardboard varies in weight, but any 1⁄8-inch
corrugated will do. Sources for this material include box
manufacturers and local shopping centers where you can
find stacks of discarded boxes. Look for cardboard with
brown paper on one side and a white finished paper
on the other side. Having the white paper on
the outside of the model results in a
smoother finish and a neater
appearance. The method of
folding the cardboard and
using gummed paper tape
to seal the joints and
exposed corrugations is
explained in the
construction tips.
The model has a wingspan
of 65 inches and a length of 58
inches. The bottom of the airfoil is flat with a curved
upper surface because of the scoring and folding
technique employed. Engines of .40 to .50 displacement
can be used. The LaGG-3’s size and stability make it a
good sport-flying model.
CONSTRUCTION
Cut out all cardboard and wood parts, making sure to
note the direction of the corrugations. Score and fold
cardboard parts as indicated on the plans.
Empennage: The fin, rudder, stabilizer, and elevator are
each made from two pieces of 1⁄8-inch cardboard
laminated together cross-grain to give 1⁄4-inch-thick
Special Tips
for Working
With Cardboard
Before we begin, I have some special tips for
working with cardboard.
Gluing: Use water-based glue such as white glue
or Titebond. Don’t use contact cement since parts
cannot be shifted when you are gluing surfaces.
Folding: Score the fold lines with a screening
tool, which is available at any hardware store. It
has a handle with a 11⁄2-inch-radius wheel at one
end that you run along a metal straightedge on the
fold line.
Waterproofing: Making cardboard waterproof is
simple, and you can do it to the raw material
before you cut out the model’s parts. Mix 25%
clear polyurethane with 75% paint thinner; the
latter can be the most inexpensive hardware-store
variety. Brush the mixture liberally onto the
cardboard sheet and allow it to dry for 48 hours.
This adds no appreciable weight to the
material and renders the cardboard completely
waterproof. In addition, when you cut the treated
cardboard you will find that it is as crisp as wood
and cuts sharply and cleanly.
Finishing: Cardboard provides a solid surface
with no open areas to cover and is nonporous. The
easiest finishing method is to apply two coats of
clear dope, sand lightly between coats with 400-
grit paper, and follow with three coats of colored
dope.
However, a wide variety of finishing materials
such as Solarfilm, MonoKote, and vinyl paper can
be used on the cardboard. With any of these
coverings I recommended that you not dope the
cardboard’s surface; it will result in a better bond.
Covering the Edges: Cover all of the model’s
seams, joints, and exposed edges with strips of
gummed paper tape. You can obtain a 1-inch-wide
roll from a stationery store. To use it, cut a thin
strip to length, dip it in water, and smooth it over
the seam(s). MA
—Chuck Felton
3
n
02sig3.QXD 11/25/03 11:01 am Page 69
70 MODEL AVIATION
The fuselage sides are lined with balsa strips and have
cardboard supports for the bellcrank and fuel-tank mounts.
Carved-balsa cowl halves have 1⁄8 plywood inserts with blind
nuts to serve as cowl-attachment points. Clean work!
The fuselage sides have been joined to the firewall, and the tank
and bellcrank mounts have been installed.
Edges of the tail components are capped with 1⁄8 x 1⁄4 balsa strips
and rounded. Elevator joiner is 1⁄4-inch dowel.
A cardboard fuselage top piece, cardboard bulkheads, and the
single balsa centerline stringer have been added.
Wing has single spar, cardboard ribs, and leading edge folds to
obtain curved upper surface. Note 1⁄8 plywood gear mount.
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surfaces. Add a 1⁄8 x 1⁄4 balsa strip to the fin
leading edge (LE) and round it off. Add 1⁄8 x
1⁄4 balsa strips to the stabilizer LEs and
trailing edges (TEs) and round them off.
Glue the elevators to the 1⁄4-inch dowel.
Add 1⁄8 x 1⁄4 balsa strips to the remainder of
the elevator LE and round them off. Seal all
raw edges with gummed paper tape. Hinge
the elevators to the stabilizer with cloth
hinges at four places.
Wing: Make the wing spar by capping
each 1⁄4 balsa spar with a 1⁄4 x 1⁄4 spruce
strip top and bottom. Join the spar halves
with 1⁄8 plywood joiners front and rear at
the centerline.
Glue the 1⁄8 plywood gear mount into
the bottom of each wing panel. Glue the
right side of the wing spar onto the righthand
wing panel. Glue all cardboard ribs
into the right wing. Add a cardboard
doubler over the plywood gear mount
between ribs W3 and W4. Glue a 1-ounce
weight to the right wingtip.
Glue the left wing panel to the left spar
in a similar fashion. Add the ribs and gear
doubler to the left wing. Apply glue to the
top of the wing spar, the top of the ribs, and
the wing TE. Fold the 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 balsa wingtip, and glue the line guide
in place. Cover the TE and all seams with
gummed paper tape.
Fuselage: The fuselage edges are outlined
with a triangular symbol on the drawing.
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 fuselage
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 the mounting holes for a
KM-40 motor mount on the face of C1.
Drill the mounting holes and install blind
mounting nuts on the back side of C1. Drill
a hole in C1 for a fuel-tubing exit. Line all
four back edges of C1 with 1⁄2-inch
triangular balsa for bracing.
Glue C1 to the right side of the
fuselage. When dry, glue the left side of the
fuselage to C1. Attach the fuel tank to the
1⁄8 plywood support. You can attach the
fuel tank to the support with rubber bands.
Make a pushrod from 3⁄32-inch wire and
1⁄4 square spruce, and attach it to the
bellcrank along with the leadout wires.
Install the tank and bellcrank assemblies by
gluing the plywood supports to the
cardboard supports on the insides of the
fuselage.
Glue the fuselage sides together at the
tail. Glue F1 and F2 in place to cover the
top fuselage. Be sure to bring fuel tubing
fill and overflow lines out during all
covering operations. Cover the bottom
fuselage with F3, F4, and F5.
Add bulkheads A through K to the top
fuselage, adding 1⁄8 x 1⁄4-inch stringers.
Cover bulkheads A through D with D1,
bulkheads E through G with D2, and
bulkheads G through K with D3. Add
bulkheads L, M, and N, with stringer, to
forward bottom fuselage, and cover with
D4.
The cowl is built up from 1⁄2 balsa sheet
and hollowed out. The top half has the 1⁄4
plywood C2 glued to the front. The
removable bottom half of the cowl has C3
glued to the front. Sand, carve, and hollow
the cowl to shape. Add 1⁄8-inch rectangular
plywood pieces to the inside of the top and
bottom halves at the cowl sides, as shown
in the cowl top and side views.
Install a blind nut on the inside of the
top cowl plywood and run a 4-40 bolt
through the bottom cowl to form the cowl
attach. Permanently glue the top half of the
cowl to the model’s nose.
Test-fit the engine in the cowl and drill
mounting holes in the KM-40 engine
February 2004 71
The finished nose section. Notice the tank fill line and the spinner fit. The camo paint
job is extremely effective.
The leadouts are external and go through a line guide that is attached where the wing
meets the wingtip.
Photos courtesy the author
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mount. 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 the front
of the firewall.
Glue the stabilizer to the fuselage. Add balsa block fairings at
the stabilizer/fin intersection. Add the rudder to the fin with the TE
offset 1⁄2 inch to the outside of the flying circle.
Make the tail-wheel gear from 3⁄32-inch-diameter wire. Bend it
as shown, place it on the 1⁄8 plywood support, wrap it with nylon
thread, and smear the thread with glue. When it’s dry, glue it in
place in the bottom fuselage cutout.
Make the main gear from 5⁄32-inch-diameter wire, as shown.
Make gear fairings from 1⁄8 plywood and attach them to the gear
with nylon gear clips. Attach the gear assemblies to the 1⁄8 plywood
supports in the bottom wing with nylon gear clips.
Finish: Now is the time to paint and trim the model before final
assembly. The color scheme is medium- and dark-green uppersurface
camouflage and light-blue undersurface. Cut the red
lettering and insignia from MonoKote. Make the canopy from thin
plastic, and epoxy it to the fuselage. Outline the canopy with thin
strips of MonoKote. Make the aileron outlines from Black
MonoKote.
Final Assembly: Glue the wing to the fuselage. Make the air
scoop from 1⁄2 balsa and glue it to the bottom of the wing/fuselage.
Add balsa exhaust stacks to both sides of the forward fuselage.
Pass the leadout wires through the wingtip line guide and tie them
off. Attach the nylon control horn to the elevator and hook up the
pushrod.
Attach 33⁄4-inch-diameter wheels to the main gear and a 11⁄2-
inch-diameter wheel to the tail gear. Add an 11 x 6 propeller and a
31⁄2-inch spinner to the engine, and your model will be completed.
Be sure to balance the model at the point shown on the plans.
If you have any comments, suggestions, or questions concerning
the LaGG-3, please write to me at the following address or E-mail
me, maybe with a photo of your completed cardboard model. MA
Chuck Felton
825 Lake Park Dr.
Lakehills TX 78063
[email protected]
72 MODEL AVIATION
The landing-gear struts mount to the plywood plates in the wing.
Notice the simulated wheel wells.
It’s hard to believe that this model is mostly cardboard. The tail
section is neat and clean, with great paint detail.
A pilot adds to the model’s realism. The canopy is simple to
construct, and tape frame lines add to the effect.
Lavochkin
LaGG-3
Type: CL Sport Scale
Wingspan: 65 inches
Engine: .40-.50 glow
Flying weight: 60 ounces
Construction: Cardboard, balsa, plywood
Covering/finish: Modeling paints,
MonoKote trim and insignia
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Full-Size Plans Available—see page 199
02sig3.QXD 11/25/03 11:05 am Page 74
76 MODEL AVIATION
Full-Size Plans Available—see page 199
02sig3.QXD 11/25/03 11:06 am Page 76
