18 MODEL AVIATION
IF AN AIRPLANE looks good and flies well, I suspect
that most modelers would have very little interest in its
design history or design inspiration. This lightweight,
all-built-up balsa, electric-powered sport model offers
an interesting appearance and lively, fun aerobatic
performance.
This project is based on a 50-year-old CL aircraft
design by Harold “Red” Reinhart. I was so impressed at
that time by Red’s flying ability and his aircraft that, for
some nostalgic fun, I went back in history to use this design
as the basis for a new electric-powered RC sport aircraft
with today’s technology in equipment and power plants.
At the time, Red’s Roger Dodger (I don’t know where
he got that name) was a design and technology
breakthrough of sorts. It was published in the March 1950
Air Trails magazine.
Roger
Dodger
Top photo shows the original rudder configuration. The photo
above depicts the author holding the model that features the
optional full-depth rudder.
by Dick Sarpolus
Sporty, easy-to-build electric
funster inspired by 1950s
1⁄2A CL Aerobatics design
May 2005 19
In a time when most modelers felt that
only a large Class D (.60-size engine) CL
Aerobatics model on 60- or 70-foot lines
could perform well, Red built this small,
light airframe using a then-new .049 glow
engine and flying on 15-foot-long string
lines. He showed that it could fly great
and do everything the big models could
do. His designing and flying skills were
absolutely top-notch.
I borrowed the Roger Dodger’s overall
appearance, modifying it to accommodate
the electronic equipment and motor and
batteries we use today for RC sport
flying. I like this airplane’s different
appearance, and it offers plenty of sportflying
fun in a small package.
My Roger Dodger is built
traditionally, with balsa ribs, spars, etc. I
used no molded plastic, no foam, and no
shortcuts. The ARFs are nice, but I like
making sawdust in the workshop.
This model worked out to have a 35-
inch wingspan with 280 square inches of
wing area, and it’s 27 inches long. The
weight—ready to go with a brushless
motor and a Li-Poly battery pack—is 17
ounces, for a wing loading of 8.7
ounces/square foot.
From some experience with similarsize
and -weight airplanes, I figured that a
Speed 400 or Speed 480 direct-drive
setup would work and be exceptionally
low in cost. However, the benefits of
brushless motors—so much more power
and longer flight times because of their
higher efficiency—have convinced me to
go brushless.
I’m using a HiMaxx 2015-4100 motor
in a GWS gearbox with its D gearing, a
Phoenix-25 ESC, and a three-cell 1200
mAh Li-Poly battery pack. I’m sure that
many other power setups would also work
well. If you’re a sport-flying scratchbuilder
and like working from plans for
your aircraft projects, take a close look
and consider this design.
I didn’t bother hooking up the
movable rudder on my prototype model,
figuring that it was quite small and that
I’d get along without it for sporty flying.
And Roger does fly fine that way.
If you’re uninterested in the design
heritage and want a full-house aircraft
with an effective rudder, I’ve drawn a
suggested rudder modification on the
plans. Split the elevator and install a large
rudder farther to the rear for even more
aerobatic fun. After flying my Roger
Dodger for a while as originally built, I
did chop into it and make this easy
modification, as shown. I like the
additional fun you can have with the large
rudder.
CONSTRUCTION
As a scratch builder, you’ll have to cut
out all the parts to make a kit before starting
construction. It’s not that much work.
This spirited performer sports looks from another era. It’s fully aerobatic and flies
smoothly with precise response to control. It’s a fun airplane.
er
Photos courtesy the author
Wing: Since the airfoil is fully
symmetrical, the ribs have “feet” by the
TE so that the wing can be assembled flat
on the building surface.
Build the wing upside down so that the
top surface ends up flat with the taper in
the bottom surface. Position the top spar
over the plans, and then add and pin the
ribs in place. Add the bottom spar, along
with the LE, TE sheeting, and centersection
sheeting.
With the wing structure removed from
the building board, trim the “feet” from
the ribs, and add the TE sheeting and the
center sheeting to the top side. The
diagonal spar bracing between the ribs is a
bit of a pain to install, but it adds little
weight and makes the wing much more
rigid.
The ailerons are built up and
conventional aileron linkage is used, with
the aileron servo mounted in the wing
center-section.
Fuselage: Start with the 3⁄32 balsa sides
and the 1⁄32 plywood doublers. I put
lightening holes in the plywood doublers
and in the rear section of the balsa sides.
Assemble the fuselage sides with the
first two plywood bulkheads and the
bulkhead behind the wing TE position, and
then add the top two forward bulkheads.
Pull the rear fuselage sides together, and
add the rear two bulkheads.
Add the fuselage top sheeting, with all
edges well rounded. I add the rear bottom
sheeting after the elevator servo and the
rudder servo, if used, and their pushrods
have been installed.
Final Assembly: Build the tail surfaces on
a flat working area. With the wing fitted to
the fuselage and bolted in place, glue the
horizontal stabilizer and vertical fin to the
fuselage and align with the wing.
I covered the Roger Dodger with
transparent MonoKote because I’m used to
working with that material, but lighter
covering films are available. I used the
cyanoacrylate-type hinges on the ailerons
and hinged the elevator and rudder with
ironed-on strips of MonoKote.
Glue a 3⁄8-inch square piece of hard
balsa or other wood into the first two
bulkheads to accept the GWS gearbox
motor mount. If you use any other type of
motor, you’ll have to fabricate a suitable
mount.
The removable hatch—that is shaped
from a piece of scrap balsa—is retained by
two small screws. The battery pack can be
switched through the hatch opening. I let
the battery lead and the ESC lead extend
through holes in the front bulkhead, and I
plug their connectors together to fly.
Using a three-cell, 1200 mAh Li-Poly
battery, the airplane balanced as it should,
with no added weight or need to shift
components around.
Flying: Since I do almost all of my flying
over grass fields, I don’t bother with a
landing gear; but you could easily add a
removable gear of 1⁄16-inch wire and light
wheels.
The Roger Dodger flies right out of a
hand launch and settles in for slow
landings.
The control-surface throws should be
adjusted to suit the particular pilot; I have
friends who prefer extremely sensitive
setups and others who prefer very soft
Dick uses a HiMaxx 2015-4100 motor in a GWS gearbox with D gearing,
a Phoenix-25 ESC, and a three-cell 1200 mAh Li-Poly battery pack.
Dick likes to leave “feet” on rib bottoms to allow the wing to be built
accurately on a flat board. Feet are removed after assembly.
There is nothing like constructing your own model. You can see Dick’s
craftsmanship and the model’s lightweight design.
20 MODEL AVIATION
Roger
Dodger
Type: RC electric-powered sport
Wingspan: 35 inches
Wing area: 280 square inches
Weight: 17 ounces
Wing loading: 8.7 ounces/square foot
Length: 27 inches
Motor: HiMaxx 2015-4100 in GWS 300-series
gearbox with D gearing (6.6:1).
Author suggests adding Castle Creations
Phoenix-25 ESC.
Propeller: GWS 11 x 8
Motor current: Estimated 10 amps maximum
Motor voltage: Depends on battery pack
used; 11.1 volts with three-cell Li-Poly pack.
Battery: Three-cell Li-Poly, 11.1 volts, 1200 mAh
Radio system: Any four-channel radio.
Prototype used Futaba T6XA transmitter, Berg
receiver, three GWS Naro servos.
Flight duration: Twelve minutes plus,
depending on throttle usage
Construction: Balsa and plywood
Covering/finish: MonoKote
setups. On the Roger Dodger I increased the aileron
movement a bit and reduced the elevator throw to suit me.
I’m pleased with the results for some sporty fun-flying
and enjoyed the built-up balsa construction work. I like the
overall appearance of Red’s 50-year-old design, even
though I did end up changing the rudder arrangement. If
Red were around today, I’m sure he’d be designing and
flying some great aircraft. MA
Dick Sarpolus
32 Alameda Ct.
Shrewsbury NJ 07702
[email protected]
Edition: Model Aviation - 2005/05
Page Numbers: 18,19,20
Edition: Model Aviation - 2005/05
Page Numbers: 18,19,20
18 MODEL AVIATION
IF AN AIRPLANE looks good and flies well, I suspect
that most modelers would have very little interest in its
design history or design inspiration. This lightweight,
all-built-up balsa, electric-powered sport model offers
an interesting appearance and lively, fun aerobatic
performance.
This project is based on a 50-year-old CL aircraft
design by Harold “Red” Reinhart. I was so impressed at
that time by Red’s flying ability and his aircraft that, for
some nostalgic fun, I went back in history to use this design
as the basis for a new electric-powered RC sport aircraft
with today’s technology in equipment and power plants.
At the time, Red’s Roger Dodger (I don’t know where
he got that name) was a design and technology
breakthrough of sorts. It was published in the March 1950
Air Trails magazine.
Roger
Dodger
Top photo shows the original rudder configuration. The photo
above depicts the author holding the model that features the
optional full-depth rudder.
by Dick Sarpolus
Sporty, easy-to-build electric
funster inspired by 1950s
1⁄2A CL Aerobatics design
May 2005 19
In a time when most modelers felt that
only a large Class D (.60-size engine) CL
Aerobatics model on 60- or 70-foot lines
could perform well, Red built this small,
light airframe using a then-new .049 glow
engine and flying on 15-foot-long string
lines. He showed that it could fly great
and do everything the big models could
do. His designing and flying skills were
absolutely top-notch.
I borrowed the Roger Dodger’s overall
appearance, modifying it to accommodate
the electronic equipment and motor and
batteries we use today for RC sport
flying. I like this airplane’s different
appearance, and it offers plenty of sportflying
fun in a small package.
My Roger Dodger is built
traditionally, with balsa ribs, spars, etc. I
used no molded plastic, no foam, and no
shortcuts. The ARFs are nice, but I like
making sawdust in the workshop.
This model worked out to have a 35-
inch wingspan with 280 square inches of
wing area, and it’s 27 inches long. The
weight—ready to go with a brushless
motor and a Li-Poly battery pack—is 17
ounces, for a wing loading of 8.7
ounces/square foot.
From some experience with similarsize
and -weight airplanes, I figured that a
Speed 400 or Speed 480 direct-drive
setup would work and be exceptionally
low in cost. However, the benefits of
brushless motors—so much more power
and longer flight times because of their
higher efficiency—have convinced me to
go brushless.
I’m using a HiMaxx 2015-4100 motor
in a GWS gearbox with its D gearing, a
Phoenix-25 ESC, and a three-cell 1200
mAh Li-Poly battery pack. I’m sure that
many other power setups would also work
well. If you’re a sport-flying scratchbuilder
and like working from plans for
your aircraft projects, take a close look
and consider this design.
I didn’t bother hooking up the
movable rudder on my prototype model,
figuring that it was quite small and that
I’d get along without it for sporty flying.
And Roger does fly fine that way.
If you’re uninterested in the design
heritage and want a full-house aircraft
with an effective rudder, I’ve drawn a
suggested rudder modification on the
plans. Split the elevator and install a large
rudder farther to the rear for even more
aerobatic fun. After flying my Roger
Dodger for a while as originally built, I
did chop into it and make this easy
modification, as shown. I like the
additional fun you can have with the large
rudder.
CONSTRUCTION
As a scratch builder, you’ll have to cut
out all the parts to make a kit before starting
construction. It’s not that much work.
This spirited performer sports looks from another era. It’s fully aerobatic and flies
smoothly with precise response to control. It’s a fun airplane.
er
Photos courtesy the author
Wing: Since the airfoil is fully
symmetrical, the ribs have “feet” by the
TE so that the wing can be assembled flat
on the building surface.
Build the wing upside down so that the
top surface ends up flat with the taper in
the bottom surface. Position the top spar
over the plans, and then add and pin the
ribs in place. Add the bottom spar, along
with the LE, TE sheeting, and centersection
sheeting.
With the wing structure removed from
the building board, trim the “feet” from
the ribs, and add the TE sheeting and the
center sheeting to the top side. The
diagonal spar bracing between the ribs is a
bit of a pain to install, but it adds little
weight and makes the wing much more
rigid.
The ailerons are built up and
conventional aileron linkage is used, with
the aileron servo mounted in the wing
center-section.
Fuselage: Start with the 3⁄32 balsa sides
and the 1⁄32 plywood doublers. I put
lightening holes in the plywood doublers
and in the rear section of the balsa sides.
Assemble the fuselage sides with the
first two plywood bulkheads and the
bulkhead behind the wing TE position, and
then add the top two forward bulkheads.
Pull the rear fuselage sides together, and
add the rear two bulkheads.
Add the fuselage top sheeting, with all
edges well rounded. I add the rear bottom
sheeting after the elevator servo and the
rudder servo, if used, and their pushrods
have been installed.
Final Assembly: Build the tail surfaces on
a flat working area. With the wing fitted to
the fuselage and bolted in place, glue the
horizontal stabilizer and vertical fin to the
fuselage and align with the wing.
I covered the Roger Dodger with
transparent MonoKote because I’m used to
working with that material, but lighter
covering films are available. I used the
cyanoacrylate-type hinges on the ailerons
and hinged the elevator and rudder with
ironed-on strips of MonoKote.
Glue a 3⁄8-inch square piece of hard
balsa or other wood into the first two
bulkheads to accept the GWS gearbox
motor mount. If you use any other type of
motor, you’ll have to fabricate a suitable
mount.
The removable hatch—that is shaped
from a piece of scrap balsa—is retained by
two small screws. The battery pack can be
switched through the hatch opening. I let
the battery lead and the ESC lead extend
through holes in the front bulkhead, and I
plug their connectors together to fly.
Using a three-cell, 1200 mAh Li-Poly
battery, the airplane balanced as it should,
with no added weight or need to shift
components around.
Flying: Since I do almost all of my flying
over grass fields, I don’t bother with a
landing gear; but you could easily add a
removable gear of 1⁄16-inch wire and light
wheels.
The Roger Dodger flies right out of a
hand launch and settles in for slow
landings.
The control-surface throws should be
adjusted to suit the particular pilot; I have
friends who prefer extremely sensitive
setups and others who prefer very soft
Dick uses a HiMaxx 2015-4100 motor in a GWS gearbox with D gearing,
a Phoenix-25 ESC, and a three-cell 1200 mAh Li-Poly battery pack.
Dick likes to leave “feet” on rib bottoms to allow the wing to be built
accurately on a flat board. Feet are removed after assembly.
There is nothing like constructing your own model. You can see Dick’s
craftsmanship and the model’s lightweight design.
20 MODEL AVIATION
Roger
Dodger
Type: RC electric-powered sport
Wingspan: 35 inches
Wing area: 280 square inches
Weight: 17 ounces
Wing loading: 8.7 ounces/square foot
Length: 27 inches
Motor: HiMaxx 2015-4100 in GWS 300-series
gearbox with D gearing (6.6:1).
Author suggests adding Castle Creations
Phoenix-25 ESC.
Propeller: GWS 11 x 8
Motor current: Estimated 10 amps maximum
Motor voltage: Depends on battery pack
used; 11.1 volts with three-cell Li-Poly pack.
Battery: Three-cell Li-Poly, 11.1 volts, 1200 mAh
Radio system: Any four-channel radio.
Prototype used Futaba T6XA transmitter, Berg
receiver, three GWS Naro servos.
Flight duration: Twelve minutes plus,
depending on throttle usage
Construction: Balsa and plywood
Covering/finish: MonoKote
setups. On the Roger Dodger I increased the aileron
movement a bit and reduced the elevator throw to suit me.
I’m pleased with the results for some sporty fun-flying
and enjoyed the built-up balsa construction work. I like the
overall appearance of Red’s 50-year-old design, even
though I did end up changing the rudder arrangement. If
Red were around today, I’m sure he’d be designing and
flying some great aircraft. MA
Dick Sarpolus
32 Alameda Ct.
Shrewsbury NJ 07702
[email protected]
Edition: Model Aviation - 2005/05
Page Numbers: 18,19,20
18 MODEL AVIATION
IF AN AIRPLANE looks good and flies well, I suspect
that most modelers would have very little interest in its
design history or design inspiration. This lightweight,
all-built-up balsa, electric-powered sport model offers
an interesting appearance and lively, fun aerobatic
performance.
This project is based on a 50-year-old CL aircraft
design by Harold “Red” Reinhart. I was so impressed at
that time by Red’s flying ability and his aircraft that, for
some nostalgic fun, I went back in history to use this design
as the basis for a new electric-powered RC sport aircraft
with today’s technology in equipment and power plants.
At the time, Red’s Roger Dodger (I don’t know where
he got that name) was a design and technology
breakthrough of sorts. It was published in the March 1950
Air Trails magazine.
Roger
Dodger
Top photo shows the original rudder configuration. The photo
above depicts the author holding the model that features the
optional full-depth rudder.
by Dick Sarpolus
Sporty, easy-to-build electric
funster inspired by 1950s
1⁄2A CL Aerobatics design
May 2005 19
In a time when most modelers felt that
only a large Class D (.60-size engine) CL
Aerobatics model on 60- or 70-foot lines
could perform well, Red built this small,
light airframe using a then-new .049 glow
engine and flying on 15-foot-long string
lines. He showed that it could fly great
and do everything the big models could
do. His designing and flying skills were
absolutely top-notch.
I borrowed the Roger Dodger’s overall
appearance, modifying it to accommodate
the electronic equipment and motor and
batteries we use today for RC sport
flying. I like this airplane’s different
appearance, and it offers plenty of sportflying
fun in a small package.
My Roger Dodger is built
traditionally, with balsa ribs, spars, etc. I
used no molded plastic, no foam, and no
shortcuts. The ARFs are nice, but I like
making sawdust in the workshop.
This model worked out to have a 35-
inch wingspan with 280 square inches of
wing area, and it’s 27 inches long. The
weight—ready to go with a brushless
motor and a Li-Poly battery pack—is 17
ounces, for a wing loading of 8.7
ounces/square foot.
From some experience with similarsize
and -weight airplanes, I figured that a
Speed 400 or Speed 480 direct-drive
setup would work and be exceptionally
low in cost. However, the benefits of
brushless motors—so much more power
and longer flight times because of their
higher efficiency—have convinced me to
go brushless.
I’m using a HiMaxx 2015-4100 motor
in a GWS gearbox with its D gearing, a
Phoenix-25 ESC, and a three-cell 1200
mAh Li-Poly battery pack. I’m sure that
many other power setups would also work
well. If you’re a sport-flying scratchbuilder
and like working from plans for
your aircraft projects, take a close look
and consider this design.
I didn’t bother hooking up the
movable rudder on my prototype model,
figuring that it was quite small and that
I’d get along without it for sporty flying.
And Roger does fly fine that way.
If you’re uninterested in the design
heritage and want a full-house aircraft
with an effective rudder, I’ve drawn a
suggested rudder modification on the
plans. Split the elevator and install a large
rudder farther to the rear for even more
aerobatic fun. After flying my Roger
Dodger for a while as originally built, I
did chop into it and make this easy
modification, as shown. I like the
additional fun you can have with the large
rudder.
CONSTRUCTION
As a scratch builder, you’ll have to cut
out all the parts to make a kit before starting
construction. It’s not that much work.
This spirited performer sports looks from another era. It’s fully aerobatic and flies
smoothly with precise response to control. It’s a fun airplane.
er
Photos courtesy the author
Wing: Since the airfoil is fully
symmetrical, the ribs have “feet” by the
TE so that the wing can be assembled flat
on the building surface.
Build the wing upside down so that the
top surface ends up flat with the taper in
the bottom surface. Position the top spar
over the plans, and then add and pin the
ribs in place. Add the bottom spar, along
with the LE, TE sheeting, and centersection
sheeting.
With the wing structure removed from
the building board, trim the “feet” from
the ribs, and add the TE sheeting and the
center sheeting to the top side. The
diagonal spar bracing between the ribs is a
bit of a pain to install, but it adds little
weight and makes the wing much more
rigid.
The ailerons are built up and
conventional aileron linkage is used, with
the aileron servo mounted in the wing
center-section.
Fuselage: Start with the 3⁄32 balsa sides
and the 1⁄32 plywood doublers. I put
lightening holes in the plywood doublers
and in the rear section of the balsa sides.
Assemble the fuselage sides with the
first two plywood bulkheads and the
bulkhead behind the wing TE position, and
then add the top two forward bulkheads.
Pull the rear fuselage sides together, and
add the rear two bulkheads.
Add the fuselage top sheeting, with all
edges well rounded. I add the rear bottom
sheeting after the elevator servo and the
rudder servo, if used, and their pushrods
have been installed.
Final Assembly: Build the tail surfaces on
a flat working area. With the wing fitted to
the fuselage and bolted in place, glue the
horizontal stabilizer and vertical fin to the
fuselage and align with the wing.
I covered the Roger Dodger with
transparent MonoKote because I’m used to
working with that material, but lighter
covering films are available. I used the
cyanoacrylate-type hinges on the ailerons
and hinged the elevator and rudder with
ironed-on strips of MonoKote.
Glue a 3⁄8-inch square piece of hard
balsa or other wood into the first two
bulkheads to accept the GWS gearbox
motor mount. If you use any other type of
motor, you’ll have to fabricate a suitable
mount.
The removable hatch—that is shaped
from a piece of scrap balsa—is retained by
two small screws. The battery pack can be
switched through the hatch opening. I let
the battery lead and the ESC lead extend
through holes in the front bulkhead, and I
plug their connectors together to fly.
Using a three-cell, 1200 mAh Li-Poly
battery, the airplane balanced as it should,
with no added weight or need to shift
components around.
Flying: Since I do almost all of my flying
over grass fields, I don’t bother with a
landing gear; but you could easily add a
removable gear of 1⁄16-inch wire and light
wheels.
The Roger Dodger flies right out of a
hand launch and settles in for slow
landings.
The control-surface throws should be
adjusted to suit the particular pilot; I have
friends who prefer extremely sensitive
setups and others who prefer very soft
Dick uses a HiMaxx 2015-4100 motor in a GWS gearbox with D gearing,
a Phoenix-25 ESC, and a three-cell 1200 mAh Li-Poly battery pack.
Dick likes to leave “feet” on rib bottoms to allow the wing to be built
accurately on a flat board. Feet are removed after assembly.
There is nothing like constructing your own model. You can see Dick’s
craftsmanship and the model’s lightweight design.
20 MODEL AVIATION
Roger
Dodger
Type: RC electric-powered sport
Wingspan: 35 inches
Wing area: 280 square inches
Weight: 17 ounces
Wing loading: 8.7 ounces/square foot
Length: 27 inches
Motor: HiMaxx 2015-4100 in GWS 300-series
gearbox with D gearing (6.6:1).
Author suggests adding Castle Creations
Phoenix-25 ESC.
Propeller: GWS 11 x 8
Motor current: Estimated 10 amps maximum
Motor voltage: Depends on battery pack
used; 11.1 volts with three-cell Li-Poly pack.
Battery: Three-cell Li-Poly, 11.1 volts, 1200 mAh
Radio system: Any four-channel radio.
Prototype used Futaba T6XA transmitter, Berg
receiver, three GWS Naro servos.
Flight duration: Twelve minutes plus,
depending on throttle usage
Construction: Balsa and plywood
Covering/finish: MonoKote
setups. On the Roger Dodger I increased the aileron
movement a bit and reduced the elevator throw to suit me.
I’m pleased with the results for some sporty fun-flying
and enjoyed the built-up balsa construction work. I like the
overall appearance of Red’s 50-year-old design, even
though I did end up changing the rudder arrangement. If
Red were around today, I’m sure he’d be designing and
flying some great aircraft. MA
Dick Sarpolus
32 Alameda Ct.
Shrewsbury NJ 07702
[email protected]
Edition: Model Aviation - 2005/05
Page Numbers: 18,19,20
18 MODEL AVIATION
IF AN AIRPLANE looks good and flies well, I suspect
that most modelers would have very little interest in its
design history or design inspiration. This lightweight,
all-built-up balsa, electric-powered sport model offers
an interesting appearance and lively, fun aerobatic
performance.
This project is based on a 50-year-old CL aircraft
design by Harold “Red” Reinhart. I was so impressed at
that time by Red’s flying ability and his aircraft that, for
some nostalgic fun, I went back in history to use this design
as the basis for a new electric-powered RC sport aircraft
with today’s technology in equipment and power plants.
At the time, Red’s Roger Dodger (I don’t know where
he got that name) was a design and technology
breakthrough of sorts. It was published in the March 1950
Air Trails magazine.
Roger
Dodger
Top photo shows the original rudder configuration. The photo
above depicts the author holding the model that features the
optional full-depth rudder.
by Dick Sarpolus
Sporty, easy-to-build electric
funster inspired by 1950s
1⁄2A CL Aerobatics design
May 2005 19
In a time when most modelers felt that
only a large Class D (.60-size engine) CL
Aerobatics model on 60- or 70-foot lines
could perform well, Red built this small,
light airframe using a then-new .049 glow
engine and flying on 15-foot-long string
lines. He showed that it could fly great
and do everything the big models could
do. His designing and flying skills were
absolutely top-notch.
I borrowed the Roger Dodger’s overall
appearance, modifying it to accommodate
the electronic equipment and motor and
batteries we use today for RC sport
flying. I like this airplane’s different
appearance, and it offers plenty of sportflying
fun in a small package.
My Roger Dodger is built
traditionally, with balsa ribs, spars, etc. I
used no molded plastic, no foam, and no
shortcuts. The ARFs are nice, but I like
making sawdust in the workshop.
This model worked out to have a 35-
inch wingspan with 280 square inches of
wing area, and it’s 27 inches long. The
weight—ready to go with a brushless
motor and a Li-Poly battery pack—is 17
ounces, for a wing loading of 8.7
ounces/square foot.
From some experience with similarsize
and -weight airplanes, I figured that a
Speed 400 or Speed 480 direct-drive
setup would work and be exceptionally
low in cost. However, the benefits of
brushless motors—so much more power
and longer flight times because of their
higher efficiency—have convinced me to
go brushless.
I’m using a HiMaxx 2015-4100 motor
in a GWS gearbox with its D gearing, a
Phoenix-25 ESC, and a three-cell 1200
mAh Li-Poly battery pack. I’m sure that
many other power setups would also work
well. If you’re a sport-flying scratchbuilder
and like working from plans for
your aircraft projects, take a close look
and consider this design.
I didn’t bother hooking up the
movable rudder on my prototype model,
figuring that it was quite small and that
I’d get along without it for sporty flying.
And Roger does fly fine that way.
If you’re uninterested in the design
heritage and want a full-house aircraft
with an effective rudder, I’ve drawn a
suggested rudder modification on the
plans. Split the elevator and install a large
rudder farther to the rear for even more
aerobatic fun. After flying my Roger
Dodger for a while as originally built, I
did chop into it and make this easy
modification, as shown. I like the
additional fun you can have with the large
rudder.
CONSTRUCTION
As a scratch builder, you’ll have to cut
out all the parts to make a kit before starting
construction. It’s not that much work.
This spirited performer sports looks from another era. It’s fully aerobatic and flies
smoothly with precise response to control. It’s a fun airplane.
er
Photos courtesy the author
Wing: Since the airfoil is fully
symmetrical, the ribs have “feet” by the
TE so that the wing can be assembled flat
on the building surface.
Build the wing upside down so that the
top surface ends up flat with the taper in
the bottom surface. Position the top spar
over the plans, and then add and pin the
ribs in place. Add the bottom spar, along
with the LE, TE sheeting, and centersection
sheeting.
With the wing structure removed from
the building board, trim the “feet” from
the ribs, and add the TE sheeting and the
center sheeting to the top side. The
diagonal spar bracing between the ribs is a
bit of a pain to install, but it adds little
weight and makes the wing much more
rigid.
The ailerons are built up and
conventional aileron linkage is used, with
the aileron servo mounted in the wing
center-section.
Fuselage: Start with the 3⁄32 balsa sides
and the 1⁄32 plywood doublers. I put
lightening holes in the plywood doublers
and in the rear section of the balsa sides.
Assemble the fuselage sides with the
first two plywood bulkheads and the
bulkhead behind the wing TE position, and
then add the top two forward bulkheads.
Pull the rear fuselage sides together, and
add the rear two bulkheads.
Add the fuselage top sheeting, with all
edges well rounded. I add the rear bottom
sheeting after the elevator servo and the
rudder servo, if used, and their pushrods
have been installed.
Final Assembly: Build the tail surfaces on
a flat working area. With the wing fitted to
the fuselage and bolted in place, glue the
horizontal stabilizer and vertical fin to the
fuselage and align with the wing.
I covered the Roger Dodger with
transparent MonoKote because I’m used to
working with that material, but lighter
covering films are available. I used the
cyanoacrylate-type hinges on the ailerons
and hinged the elevator and rudder with
ironed-on strips of MonoKote.
Glue a 3⁄8-inch square piece of hard
balsa or other wood into the first two
bulkheads to accept the GWS gearbox
motor mount. If you use any other type of
motor, you’ll have to fabricate a suitable
mount.
The removable hatch—that is shaped
from a piece of scrap balsa—is retained by
two small screws. The battery pack can be
switched through the hatch opening. I let
the battery lead and the ESC lead extend
through holes in the front bulkhead, and I
plug their connectors together to fly.
Using a three-cell, 1200 mAh Li-Poly
battery, the airplane balanced as it should,
with no added weight or need to shift
components around.
Flying: Since I do almost all of my flying
over grass fields, I don’t bother with a
landing gear; but you could easily add a
removable gear of 1⁄16-inch wire and light
wheels.
The Roger Dodger flies right out of a
hand launch and settles in for slow
landings.
The control-surface throws should be
adjusted to suit the particular pilot; I have
friends who prefer extremely sensitive
setups and others who prefer very soft
Dick uses a HiMaxx 2015-4100 motor in a GWS gearbox with D gearing,
a Phoenix-25 ESC, and a three-cell 1200 mAh Li-Poly battery pack.
Dick likes to leave “feet” on rib bottoms to allow the wing to be built
accurately on a flat board. Feet are removed after assembly.
There is nothing like constructing your own model. You can see Dick’s
craftsmanship and the model’s lightweight design.
20 MODEL AVIATION
Roger
Dodger
Type: RC electric-powered sport
Wingspan: 35 inches
Wing area: 280 square inches
Weight: 17 ounces
Wing loading: 8.7 ounces/square foot
Length: 27 inches
Motor: HiMaxx 2015-4100 in GWS 300-series
gearbox with D gearing (6.6:1).
Author suggests adding Castle Creations
Phoenix-25 ESC.
Propeller: GWS 11 x 8
Motor current: Estimated 10 amps maximum
Motor voltage: Depends on battery pack
used; 11.1 volts with three-cell Li-Poly pack.
Battery: Three-cell Li-Poly, 11.1 volts, 1200 mAh
Radio system: Any four-channel radio.
Prototype used Futaba T6XA transmitter, Berg
receiver, three GWS Naro servos.
Flight duration: Twelve minutes plus,
depending on throttle usage
Construction: Balsa and plywood
Covering/finish: MonoKote
setups. On the Roger Dodger I increased the aileron
movement a bit and reduced the elevator throw to suit me.
I’m pleased with the results for some sporty fun-flying
and enjoyed the built-up balsa construction work. I like the
overall appearance of Red’s 50-year-old design, even
though I did end up changing the rudder arrangement. If
Red were around today, I’m sure he’d be designing and
flying some great aircraft. MA
Dick Sarpolus
32 Alameda Ct.
Shrewsbury NJ 07702
[email protected]
