STARTING IN SLOPE Soaring with an
EPP-foam glider is the most commonly taken
path these days, but there may come a time
when a pilot wants a better-looking
sailplane—one that is smoother, rounder, and
sleeker.
Perhaps he or she needs a lighter glider for
small air or small hills. It’s possible that a
person needs a heavier slope rocket for big air
and big hills. Maybe he or she has taken up
Slope Racing, and a stronger, stiffer airframe
would improve lap times.
“Moldies,” or sailplanes with molded
composite parts, can be designed and built
lighter than EPP-foam sailplanes or heavier
when ballast is added. If any of the preceding
capabilities are a siren song to you, a moldie
may be in your future.
“Moldies” is a nickname for moldedfuselage
airframes. “Composite” means that a
combination of dissimilar materials are mixed
during construction, such as epoxy resin and
fiberglass cloth.
Additional materials are often introduced,
to take advantage of special properties, such as
carbon fiber for tensile strength and stiffness
and Kevlar for strength and toughness. Some
sailplane designs even have hollow molded
wings. Aircraft designers go to this time and
trouble to achieve more accurate wing-airfoil
sections, lighter wings, or both.
Some slope fliers advocate the advantages
of foamies over moldies, and they might miss
out on some top-end speed. Other slope pilots
won’t fly anything but molded composite
super sailplanes, and they may have fewer
flying sites to choose from, leaving out
especially those with rock-strewn or
manzanita-bush-infested landing areas.
I like both foamies and moldies. I prefer to
build a fiberglass-fuselage airframe. I prefer
flying a bounceable foam airplane when I
have to land between bushes or even in
bushes. But for pure flying ability, I prefer
composite construction. For appearance
points, moldies win again.
I remember flying my first fiberglass model—a Sig Samurai—a
huge step up from the Sig Ninja balsa-and-plywood glider. Although
it was nearly 20 years ago, I can remember the adrenaline rush that the
Samurai’s speed and precision delivered.
In a review of the kit in the April 1993 Model Airplane News,
I wrote:
“The semi-symmetrical airfoil [1/64 inch plywood sheeted wings]
and the slippery fuselage let this airplane pour on the speed, and it’s
really at ease when traveling fast. Of the 24 sailplanes I’ve built and
flown, only one is faster, and none are as relaxed at speed.”
At the World Soaring Jamboree in 1994, I saw my first highperformance
WW II warbird: a Slope Scale Mitsubishi A6M6
Zero fighter. The molded-fiberglass-fuselage model was not only
tearing up the slope at Eagle Butte, Washington, with speed and
maneuverability, but it looked like an airplane while doing it. I had to
have one of those, too. Then another, and another.
The Slope Scale warbirds can be ordered to be molded with light,
medium, or heavy fiberglass-and-epoxy layup, and it’s awesome to be
able to have one of each to match different lift conditions. Right now I
have four Slope Scale warbirds with receivers installed, ready to fly.
Also at this point, molded Slope Racers were starting to fill my
quiver of slope aircraft—notably a Charlie Richardson Fun-1 One
Design Racer (ODR) and a full-on screamer: a CR carbon Renegade.
Man, I had arrived, stylin’ and flyin’ real fast. Oh happy day.
Stage three for me began when I learned to use an airbrush. My
first Slope Scale models were finished with Krylon and a paintbrush,
but three flying buddies urged me to learn airbrushing, and I am glad I
did.
Then came more molded scale airplanes: a Doug Buchanan BAe
Hawk in a British camouflage scheme and another Hawk in air-showteam
colors. There’s no shame in wearing out an airframe. Then I built
and finished a Jeff Fukushima Focke-Wulf Fw 190 Dora, which was a
great-flying large-scale warbird.
My airbrush high-water mark so far is a Carl Maas Sukhoi Su-25
Frogfoot, which you might remember from the cover of the April
2008 MA. There’s an article about airbrushing in that issue.
Stage four for me (I hope) will be making a mold and pulling
composite fuselage parts from that mold. I know enough about this
process to respect and admire the high level of engineering,
craftsmanship, and attention to detail that is needed to produce quality
molded parts, but I have not done it myself. In the meantime, “support
your local molder.”
Moldie Advantages: Following are the advantages of composite
molded construction over wood or EPP-foam construction.
• Shape: Who doesn’t appreciate the attractive appearance of rounded
and curved parts? If it’s a curved shape you need and you want a
smooth finish on it, molding is the way to get it.
It’s far less work than building the form from sticks and a far
smoother final finish than any reasonable EPP construction effort.
Shape is important in scale models, and rounded shapes are strong and
make efficient use of interior space on nonscale airplanes. Look at
airliners.
• Stiffness: The composite materials’ stiffness allows lightness in
airframe production. EPP foam is soft and floppy, and foam aircraft
need spars and fuselages stiffeners—often wood (heavy) or carbonfiber
tubes (expensive).
Molded-fiberglass models can be made both lighter and heavier
than foam or balsa-and-plywood airplanes. Lighter because the
strength and stiffness allow materials weighing less to be used.
Heavier because a design can have room inside for removable ballast.
• Easier construction: Let’s start with the fact that a hollow fuselage
makes radio installation easy. There’s no cutting pockets in foam that
let the servo wiggle under load; just install servo rails and mount with
screws—the way servo designers intend for them to be installed.
Do you need a hard point, say, for mounting a wing? Epoxy a bit of
plywood in place and tap some threads to receive a bolt. How do you
attach a fin or a horizontal stabilizer? Glue it on with epoxy.
• Takes paint well: Sometimes you need more subtle colors than are
available in iron-on covering. Sometimes you need a matte finish or a
feather edge for camouflage markings. Paint is the answer, and
fiberglass seems like it was made to be painted. Even the simplest and
cheapest rattle-can spray finish will be more durable than almost any
iron-on finish.
Are you ready to dive into airbrushing for decorating your models?
You’ll like the way airbrushed paint lays down on fiberglass.
• Repairability: I’ve smashed plenty of sailplanes in my time—wood,
foam, and fiberglass—but I’d rather repair a fiberglass model than a
foam or wood model. Sure, there are several tricks to learn about
adhesives and reinforcing broken areas, but you can get a moldie back
to its original shape and strength.
For me, balsa models come out of the repair slightly crooked and
much heavier, and foamies gain weight from repeated applications of
Goop and tape, and they still tend to develop soft and weak spots.
• Fly better: Molded sailplanes penetrate into headwinds better.
Molded sailplanes accelerate quicker, have higher top speeds, and fly
better in off-direction lift. The successful racing sailplanes and
dynamic soaring (DS) models are molded composite.
Yes, there are trainer racers and DS airplanes, but the real-deal, gofast
models are moldies. Toss out a fiberglass slope airplane after
flying a foamie and you’re in for a pleasant surprise.
Moldie Disadvantages: No sailplane design
or material is all good or bad, and I can think
of three areas in which balsa and EPP-foam
airplanes can excel.
• Higher cost: The cost of building a
composite model is generally higher than an
equivalent-size wood or foam design.
Building time will probably be longer with
composites, which adds to the cost as well.
• Learning curve: The methods and
techniques used to build and finish moldies
can be new for some modelers, depending on
previous experience. You may have to do
some reading or get advice from experienced
builders.
• Fear of breaking: This is likely the single
largest fear that keeps pilots from trying
moldies.
Although they can be broken, they can be
repaired back to 100%. Hey! No guts, no
glory. If you let the fear of crashing and
repairing hold you back, you might miss the
experience of higher speed and the superior
ability to penetrate.
When I began this piece about molded slope
sailplanes, I was hoping that after the EPP
revolution and well into the period of rising
demand for prebuilt sailplanes, there were
enough composite molding houses in
operation to supply the need. I knew that Dan
Sampson had taken over production of the
Slope Scale line. I knew that Jeff Fukushima
at Vortech Models was still molding
fuselages and making new designs.
While researching for this column, I
learned that there were at least 28 companies
in the US and Canada that supplied moldedfuselage
kits and composite-built sailplanes
that were suitable for slope flying. Many
thanks to correspondents on RCGroups for
helping to complete the list of sources. MA
Sources:
Ventus 3.8-meter scale glider:
AMD Hobby
(+852) 2858 6698 (Hong Kong)
www.amdhobby.com
Composite gliders:
Art Hobby
(406) 545-4118
www.arthobby.com
Molded scale gliders:
ICARE Sailplanes
(450) 449-9094
www.icare-rc.com
F-104 Starfighter:
California Sailplanes
(951) 656-5454
www.californiasailplanes.com
Bird of Time ARF:
Dynaflite
(217) 398-8970
www.dynaflite.com
Bad Voodoo slope ODR:
(785) 625-7660
Eaton Air RC
www.eatonairrc.com
High-performance gliders and racers:
Esprit Model
(321) 729-4287
www.espritmodel.com
Racers and high performance sailplanes:
F3X.com
(949) 645-7032
www.f3x.com
Spirit 100 ARF, Spirit Elite ARF:
Great Planes Manufacturing
(800) 637-7660
www.greatplanes.com
DaVinci floater/sloper:
Jarel Aircraft Design
(541) 772-4207
www.jareldesign.com
The legendary JART, kit:
JARTworld
www.jartworld.com
Caldera S:
Kennedy Composites
(972) 602-3144
www.kennedycomposites.com
A-6 Intruder, P-38 Lightning, V-2 Buzz
114 MODEL AVIATION
Bomb:
K&A Models Unlimited
(505) 994-8083
www.kamodels.com/pss.htm
Molded ODR:
Leading Edge Gliders
(785) 525-6263
www.leadingedgegliders.com
Bad Voodoo slope ODR:
Magnum Models/Eaton Air RC
(865) 583-9241
www.magnumrcmodels.com
Composite gliders:
Northeast Sailplane Products
(802) 655-7700
www.nesail.com
Zipper 48- and 60-inch-span kits:
Off The Edge Sailplanes
www.offtheedge.com.au
Harley Michaelis LT/S fuselage:
Pacific Sailplanes
www.pacificsailplanes.com
High-performance gliders and racers:
Skip Miller Models
(303) 442-6454
www.skipmillermodels.com
Harris Nelson and other retro designs:
SkyKing RC Products
(612) 709-0790
www.skykingrcproducts.com
Airacobra, A6M6 Zero, F-20, F-86, Tucano,
U-2, BD-5:
Slope Scale Models
flybyudan.blogspot.com/2009_02_01_archive
.html
High-performance gliders and racers:
Soaring USA
(626) 967-6660
www.soaringusa.com
Schweizer SGS 2-32 (the vista cruiser of
sailplanes):
Tom Martin Radio Control
(816) 392-8640
www.tmrcsailplanes.com
A6M Zero, F9F Panther, Fw 190D:
Vortech Models (Jeff Fukushima)
jeff@[email protected]
Viking Models USA fuselages:
Laser Flight Models
(530) 878-0728
www.laserflight.com
Composite slope sailplanes:
Wyoming Wind Works
(605) 431-4773
wyowindworks.com
Tangent, Multiplex, Roke Modelle imports:
XL Sailplanes
(863) 206-4962
www.xl-sailplanes.com/index.htm
Edition: Model Aviation - 2009/08
Page Numbers: 112,113,114
Edition: Model Aviation - 2009/08
Page Numbers: 112,113,114
STARTING IN SLOPE Soaring with an
EPP-foam glider is the most commonly taken
path these days, but there may come a time
when a pilot wants a better-looking
sailplane—one that is smoother, rounder, and
sleeker.
Perhaps he or she needs a lighter glider for
small air or small hills. It’s possible that a
person needs a heavier slope rocket for big air
and big hills. Maybe he or she has taken up
Slope Racing, and a stronger, stiffer airframe
would improve lap times.
“Moldies,” or sailplanes with molded
composite parts, can be designed and built
lighter than EPP-foam sailplanes or heavier
when ballast is added. If any of the preceding
capabilities are a siren song to you, a moldie
may be in your future.
“Moldies” is a nickname for moldedfuselage
airframes. “Composite” means that a
combination of dissimilar materials are mixed
during construction, such as epoxy resin and
fiberglass cloth.
Additional materials are often introduced,
to take advantage of special properties, such as
carbon fiber for tensile strength and stiffness
and Kevlar for strength and toughness. Some
sailplane designs even have hollow molded
wings. Aircraft designers go to this time and
trouble to achieve more accurate wing-airfoil
sections, lighter wings, or both.
Some slope fliers advocate the advantages
of foamies over moldies, and they might miss
out on some top-end speed. Other slope pilots
won’t fly anything but molded composite
super sailplanes, and they may have fewer
flying sites to choose from, leaving out
especially those with rock-strewn or
manzanita-bush-infested landing areas.
I like both foamies and moldies. I prefer to
build a fiberglass-fuselage airframe. I prefer
flying a bounceable foam airplane when I
have to land between bushes or even in
bushes. But for pure flying ability, I prefer
composite construction. For appearance
points, moldies win again.
I remember flying my first fiberglass model—a Sig Samurai—a
huge step up from the Sig Ninja balsa-and-plywood glider. Although
it was nearly 20 years ago, I can remember the adrenaline rush that the
Samurai’s speed and precision delivered.
In a review of the kit in the April 1993 Model Airplane News,
I wrote:
“The semi-symmetrical airfoil [1/64 inch plywood sheeted wings]
and the slippery fuselage let this airplane pour on the speed, and it’s
really at ease when traveling fast. Of the 24 sailplanes I’ve built and
flown, only one is faster, and none are as relaxed at speed.”
At the World Soaring Jamboree in 1994, I saw my first highperformance
WW II warbird: a Slope Scale Mitsubishi A6M6
Zero fighter. The molded-fiberglass-fuselage model was not only
tearing up the slope at Eagle Butte, Washington, with speed and
maneuverability, but it looked like an airplane while doing it. I had to
have one of those, too. Then another, and another.
The Slope Scale warbirds can be ordered to be molded with light,
medium, or heavy fiberglass-and-epoxy layup, and it’s awesome to be
able to have one of each to match different lift conditions. Right now I
have four Slope Scale warbirds with receivers installed, ready to fly.
Also at this point, molded Slope Racers were starting to fill my
quiver of slope aircraft—notably a Charlie Richardson Fun-1 One
Design Racer (ODR) and a full-on screamer: a CR carbon Renegade.
Man, I had arrived, stylin’ and flyin’ real fast. Oh happy day.
Stage three for me began when I learned to use an airbrush. My
first Slope Scale models were finished with Krylon and a paintbrush,
but three flying buddies urged me to learn airbrushing, and I am glad I
did.
Then came more molded scale airplanes: a Doug Buchanan BAe
Hawk in a British camouflage scheme and another Hawk in air-showteam
colors. There’s no shame in wearing out an airframe. Then I built
and finished a Jeff Fukushima Focke-Wulf Fw 190 Dora, which was a
great-flying large-scale warbird.
My airbrush high-water mark so far is a Carl Maas Sukhoi Su-25
Frogfoot, which you might remember from the cover of the April
2008 MA. There’s an article about airbrushing in that issue.
Stage four for me (I hope) will be making a mold and pulling
composite fuselage parts from that mold. I know enough about this
process to respect and admire the high level of engineering,
craftsmanship, and attention to detail that is needed to produce quality
molded parts, but I have not done it myself. In the meantime, “support
your local molder.”
Moldie Advantages: Following are the advantages of composite
molded construction over wood or EPP-foam construction.
• Shape: Who doesn’t appreciate the attractive appearance of rounded
and curved parts? If it’s a curved shape you need and you want a
smooth finish on it, molding is the way to get it.
It’s far less work than building the form from sticks and a far
smoother final finish than any reasonable EPP construction effort.
Shape is important in scale models, and rounded shapes are strong and
make efficient use of interior space on nonscale airplanes. Look at
airliners.
• Stiffness: The composite materials’ stiffness allows lightness in
airframe production. EPP foam is soft and floppy, and foam aircraft
need spars and fuselages stiffeners—often wood (heavy) or carbonfiber
tubes (expensive).
Molded-fiberglass models can be made both lighter and heavier
than foam or balsa-and-plywood airplanes. Lighter because the
strength and stiffness allow materials weighing less to be used.
Heavier because a design can have room inside for removable ballast.
• Easier construction: Let’s start with the fact that a hollow fuselage
makes radio installation easy. There’s no cutting pockets in foam that
let the servo wiggle under load; just install servo rails and mount with
screws—the way servo designers intend for them to be installed.
Do you need a hard point, say, for mounting a wing? Epoxy a bit of
plywood in place and tap some threads to receive a bolt. How do you
attach a fin or a horizontal stabilizer? Glue it on with epoxy.
• Takes paint well: Sometimes you need more subtle colors than are
available in iron-on covering. Sometimes you need a matte finish or a
feather edge for camouflage markings. Paint is the answer, and
fiberglass seems like it was made to be painted. Even the simplest and
cheapest rattle-can spray finish will be more durable than almost any
iron-on finish.
Are you ready to dive into airbrushing for decorating your models?
You’ll like the way airbrushed paint lays down on fiberglass.
• Repairability: I’ve smashed plenty of sailplanes in my time—wood,
foam, and fiberglass—but I’d rather repair a fiberglass model than a
foam or wood model. Sure, there are several tricks to learn about
adhesives and reinforcing broken areas, but you can get a moldie back
to its original shape and strength.
For me, balsa models come out of the repair slightly crooked and
much heavier, and foamies gain weight from repeated applications of
Goop and tape, and they still tend to develop soft and weak spots.
• Fly better: Molded sailplanes penetrate into headwinds better.
Molded sailplanes accelerate quicker, have higher top speeds, and fly
better in off-direction lift. The successful racing sailplanes and
dynamic soaring (DS) models are molded composite.
Yes, there are trainer racers and DS airplanes, but the real-deal, gofast
models are moldies. Toss out a fiberglass slope airplane after
flying a foamie and you’re in for a pleasant surprise.
Moldie Disadvantages: No sailplane design
or material is all good or bad, and I can think
of three areas in which balsa and EPP-foam
airplanes can excel.
• Higher cost: The cost of building a
composite model is generally higher than an
equivalent-size wood or foam design.
Building time will probably be longer with
composites, which adds to the cost as well.
• Learning curve: The methods and
techniques used to build and finish moldies
can be new for some modelers, depending on
previous experience. You may have to do
some reading or get advice from experienced
builders.
• Fear of breaking: This is likely the single
largest fear that keeps pilots from trying
moldies.
Although they can be broken, they can be
repaired back to 100%. Hey! No guts, no
glory. If you let the fear of crashing and
repairing hold you back, you might miss the
experience of higher speed and the superior
ability to penetrate.
When I began this piece about molded slope
sailplanes, I was hoping that after the EPP
revolution and well into the period of rising
demand for prebuilt sailplanes, there were
enough composite molding houses in
operation to supply the need. I knew that Dan
Sampson had taken over production of the
Slope Scale line. I knew that Jeff Fukushima
at Vortech Models was still molding
fuselages and making new designs.
While researching for this column, I
learned that there were at least 28 companies
in the US and Canada that supplied moldedfuselage
kits and composite-built sailplanes
that were suitable for slope flying. Many
thanks to correspondents on RCGroups for
helping to complete the list of sources. MA
Sources:
Ventus 3.8-meter scale glider:
AMD Hobby
(+852) 2858 6698 (Hong Kong)
www.amdhobby.com
Composite gliders:
Art Hobby
(406) 545-4118
www.arthobby.com
Molded scale gliders:
ICARE Sailplanes
(450) 449-9094
www.icare-rc.com
F-104 Starfighter:
California Sailplanes
(951) 656-5454
www.californiasailplanes.com
Bird of Time ARF:
Dynaflite
(217) 398-8970
www.dynaflite.com
Bad Voodoo slope ODR:
(785) 625-7660
Eaton Air RC
www.eatonairrc.com
High-performance gliders and racers:
Esprit Model
(321) 729-4287
www.espritmodel.com
Racers and high performance sailplanes:
F3X.com
(949) 645-7032
www.f3x.com
Spirit 100 ARF, Spirit Elite ARF:
Great Planes Manufacturing
(800) 637-7660
www.greatplanes.com
DaVinci floater/sloper:
Jarel Aircraft Design
(541) 772-4207
www.jareldesign.com
The legendary JART, kit:
JARTworld
www.jartworld.com
Caldera S:
Kennedy Composites
(972) 602-3144
www.kennedycomposites.com
A-6 Intruder, P-38 Lightning, V-2 Buzz
114 MODEL AVIATION
Bomb:
K&A Models Unlimited
(505) 994-8083
www.kamodels.com/pss.htm
Molded ODR:
Leading Edge Gliders
(785) 525-6263
www.leadingedgegliders.com
Bad Voodoo slope ODR:
Magnum Models/Eaton Air RC
(865) 583-9241
www.magnumrcmodels.com
Composite gliders:
Northeast Sailplane Products
(802) 655-7700
www.nesail.com
Zipper 48- and 60-inch-span kits:
Off The Edge Sailplanes
www.offtheedge.com.au
Harley Michaelis LT/S fuselage:
Pacific Sailplanes
www.pacificsailplanes.com
High-performance gliders and racers:
Skip Miller Models
(303) 442-6454
www.skipmillermodels.com
Harris Nelson and other retro designs:
SkyKing RC Products
(612) 709-0790
www.skykingrcproducts.com
Airacobra, A6M6 Zero, F-20, F-86, Tucano,
U-2, BD-5:
Slope Scale Models
flybyudan.blogspot.com/2009_02_01_archive
.html
High-performance gliders and racers:
Soaring USA
(626) 967-6660
www.soaringusa.com
Schweizer SGS 2-32 (the vista cruiser of
sailplanes):
Tom Martin Radio Control
(816) 392-8640
www.tmrcsailplanes.com
A6M Zero, F9F Panther, Fw 190D:
Vortech Models (Jeff Fukushima)
jeff@[email protected]
Viking Models USA fuselages:
Laser Flight Models
(530) 878-0728
www.laserflight.com
Composite slope sailplanes:
Wyoming Wind Works
(605) 431-4773
wyowindworks.com
Tangent, Multiplex, Roke Modelle imports:
XL Sailplanes
(863) 206-4962
www.xl-sailplanes.com/index.htm
Edition: Model Aviation - 2009/08
Page Numbers: 112,113,114
STARTING IN SLOPE Soaring with an
EPP-foam glider is the most commonly taken
path these days, but there may come a time
when a pilot wants a better-looking
sailplane—one that is smoother, rounder, and
sleeker.
Perhaps he or she needs a lighter glider for
small air or small hills. It’s possible that a
person needs a heavier slope rocket for big air
and big hills. Maybe he or she has taken up
Slope Racing, and a stronger, stiffer airframe
would improve lap times.
“Moldies,” or sailplanes with molded
composite parts, can be designed and built
lighter than EPP-foam sailplanes or heavier
when ballast is added. If any of the preceding
capabilities are a siren song to you, a moldie
may be in your future.
“Moldies” is a nickname for moldedfuselage
airframes. “Composite” means that a
combination of dissimilar materials are mixed
during construction, such as epoxy resin and
fiberglass cloth.
Additional materials are often introduced,
to take advantage of special properties, such as
carbon fiber for tensile strength and stiffness
and Kevlar for strength and toughness. Some
sailplane designs even have hollow molded
wings. Aircraft designers go to this time and
trouble to achieve more accurate wing-airfoil
sections, lighter wings, or both.
Some slope fliers advocate the advantages
of foamies over moldies, and they might miss
out on some top-end speed. Other slope pilots
won’t fly anything but molded composite
super sailplanes, and they may have fewer
flying sites to choose from, leaving out
especially those with rock-strewn or
manzanita-bush-infested landing areas.
I like both foamies and moldies. I prefer to
build a fiberglass-fuselage airframe. I prefer
flying a bounceable foam airplane when I
have to land between bushes or even in
bushes. But for pure flying ability, I prefer
composite construction. For appearance
points, moldies win again.
I remember flying my first fiberglass model—a Sig Samurai—a
huge step up from the Sig Ninja balsa-and-plywood glider. Although
it was nearly 20 years ago, I can remember the adrenaline rush that the
Samurai’s speed and precision delivered.
In a review of the kit in the April 1993 Model Airplane News,
I wrote:
“The semi-symmetrical airfoil [1/64 inch plywood sheeted wings]
and the slippery fuselage let this airplane pour on the speed, and it’s
really at ease when traveling fast. Of the 24 sailplanes I’ve built and
flown, only one is faster, and none are as relaxed at speed.”
At the World Soaring Jamboree in 1994, I saw my first highperformance
WW II warbird: a Slope Scale Mitsubishi A6M6
Zero fighter. The molded-fiberglass-fuselage model was not only
tearing up the slope at Eagle Butte, Washington, with speed and
maneuverability, but it looked like an airplane while doing it. I had to
have one of those, too. Then another, and another.
The Slope Scale warbirds can be ordered to be molded with light,
medium, or heavy fiberglass-and-epoxy layup, and it’s awesome to be
able to have one of each to match different lift conditions. Right now I
have four Slope Scale warbirds with receivers installed, ready to fly.
Also at this point, molded Slope Racers were starting to fill my
quiver of slope aircraft—notably a Charlie Richardson Fun-1 One
Design Racer (ODR) and a full-on screamer: a CR carbon Renegade.
Man, I had arrived, stylin’ and flyin’ real fast. Oh happy day.
Stage three for me began when I learned to use an airbrush. My
first Slope Scale models were finished with Krylon and a paintbrush,
but three flying buddies urged me to learn airbrushing, and I am glad I
did.
Then came more molded scale airplanes: a Doug Buchanan BAe
Hawk in a British camouflage scheme and another Hawk in air-showteam
colors. There’s no shame in wearing out an airframe. Then I built
and finished a Jeff Fukushima Focke-Wulf Fw 190 Dora, which was a
great-flying large-scale warbird.
My airbrush high-water mark so far is a Carl Maas Sukhoi Su-25
Frogfoot, which you might remember from the cover of the April
2008 MA. There’s an article about airbrushing in that issue.
Stage four for me (I hope) will be making a mold and pulling
composite fuselage parts from that mold. I know enough about this
process to respect and admire the high level of engineering,
craftsmanship, and attention to detail that is needed to produce quality
molded parts, but I have not done it myself. In the meantime, “support
your local molder.”
Moldie Advantages: Following are the advantages of composite
molded construction over wood or EPP-foam construction.
• Shape: Who doesn’t appreciate the attractive appearance of rounded
and curved parts? If it’s a curved shape you need and you want a
smooth finish on it, molding is the way to get it.
It’s far less work than building the form from sticks and a far
smoother final finish than any reasonable EPP construction effort.
Shape is important in scale models, and rounded shapes are strong and
make efficient use of interior space on nonscale airplanes. Look at
airliners.
• Stiffness: The composite materials’ stiffness allows lightness in
airframe production. EPP foam is soft and floppy, and foam aircraft
need spars and fuselages stiffeners—often wood (heavy) or carbonfiber
tubes (expensive).
Molded-fiberglass models can be made both lighter and heavier
than foam or balsa-and-plywood airplanes. Lighter because the
strength and stiffness allow materials weighing less to be used.
Heavier because a design can have room inside for removable ballast.
• Easier construction: Let’s start with the fact that a hollow fuselage
makes radio installation easy. There’s no cutting pockets in foam that
let the servo wiggle under load; just install servo rails and mount with
screws—the way servo designers intend for them to be installed.
Do you need a hard point, say, for mounting a wing? Epoxy a bit of
plywood in place and tap some threads to receive a bolt. How do you
attach a fin or a horizontal stabilizer? Glue it on with epoxy.
• Takes paint well: Sometimes you need more subtle colors than are
available in iron-on covering. Sometimes you need a matte finish or a
feather edge for camouflage markings. Paint is the answer, and
fiberglass seems like it was made to be painted. Even the simplest and
cheapest rattle-can spray finish will be more durable than almost any
iron-on finish.
Are you ready to dive into airbrushing for decorating your models?
You’ll like the way airbrushed paint lays down on fiberglass.
• Repairability: I’ve smashed plenty of sailplanes in my time—wood,
foam, and fiberglass—but I’d rather repair a fiberglass model than a
foam or wood model. Sure, there are several tricks to learn about
adhesives and reinforcing broken areas, but you can get a moldie back
to its original shape and strength.
For me, balsa models come out of the repair slightly crooked and
much heavier, and foamies gain weight from repeated applications of
Goop and tape, and they still tend to develop soft and weak spots.
• Fly better: Molded sailplanes penetrate into headwinds better.
Molded sailplanes accelerate quicker, have higher top speeds, and fly
better in off-direction lift. The successful racing sailplanes and
dynamic soaring (DS) models are molded composite.
Yes, there are trainer racers and DS airplanes, but the real-deal, gofast
models are moldies. Toss out a fiberglass slope airplane after
flying a foamie and you’re in for a pleasant surprise.
Moldie Disadvantages: No sailplane design
or material is all good or bad, and I can think
of three areas in which balsa and EPP-foam
airplanes can excel.
• Higher cost: The cost of building a
composite model is generally higher than an
equivalent-size wood or foam design.
Building time will probably be longer with
composites, which adds to the cost as well.
• Learning curve: The methods and
techniques used to build and finish moldies
can be new for some modelers, depending on
previous experience. You may have to do
some reading or get advice from experienced
builders.
• Fear of breaking: This is likely the single
largest fear that keeps pilots from trying
moldies.
Although they can be broken, they can be
repaired back to 100%. Hey! No guts, no
glory. If you let the fear of crashing and
repairing hold you back, you might miss the
experience of higher speed and the superior
ability to penetrate.
When I began this piece about molded slope
sailplanes, I was hoping that after the EPP
revolution and well into the period of rising
demand for prebuilt sailplanes, there were
enough composite molding houses in
operation to supply the need. I knew that Dan
Sampson had taken over production of the
Slope Scale line. I knew that Jeff Fukushima
at Vortech Models was still molding
fuselages and making new designs.
While researching for this column, I
learned that there were at least 28 companies
in the US and Canada that supplied moldedfuselage
kits and composite-built sailplanes
that were suitable for slope flying. Many
thanks to correspondents on RCGroups for
helping to complete the list of sources. MA
Sources:
Ventus 3.8-meter scale glider:
AMD Hobby
(+852) 2858 6698 (Hong Kong)
www.amdhobby.com
Composite gliders:
Art Hobby
(406) 545-4118
www.arthobby.com
Molded scale gliders:
ICARE Sailplanes
(450) 449-9094
www.icare-rc.com
F-104 Starfighter:
California Sailplanes
(951) 656-5454
www.californiasailplanes.com
Bird of Time ARF:
Dynaflite
(217) 398-8970
www.dynaflite.com
Bad Voodoo slope ODR:
(785) 625-7660
Eaton Air RC
www.eatonairrc.com
High-performance gliders and racers:
Esprit Model
(321) 729-4287
www.espritmodel.com
Racers and high performance sailplanes:
F3X.com
(949) 645-7032
www.f3x.com
Spirit 100 ARF, Spirit Elite ARF:
Great Planes Manufacturing
(800) 637-7660
www.greatplanes.com
DaVinci floater/sloper:
Jarel Aircraft Design
(541) 772-4207
www.jareldesign.com
The legendary JART, kit:
JARTworld
www.jartworld.com
Caldera S:
Kennedy Composites
(972) 602-3144
www.kennedycomposites.com
A-6 Intruder, P-38 Lightning, V-2 Buzz
114 MODEL AVIATION
Bomb:
K&A Models Unlimited
(505) 994-8083
www.kamodels.com/pss.htm
Molded ODR:
Leading Edge Gliders
(785) 525-6263
www.leadingedgegliders.com
Bad Voodoo slope ODR:
Magnum Models/Eaton Air RC
(865) 583-9241
www.magnumrcmodels.com
Composite gliders:
Northeast Sailplane Products
(802) 655-7700
www.nesail.com
Zipper 48- and 60-inch-span kits:
Off The Edge Sailplanes
www.offtheedge.com.au
Harley Michaelis LT/S fuselage:
Pacific Sailplanes
www.pacificsailplanes.com
High-performance gliders and racers:
Skip Miller Models
(303) 442-6454
www.skipmillermodels.com
Harris Nelson and other retro designs:
SkyKing RC Products
(612) 709-0790
www.skykingrcproducts.com
Airacobra, A6M6 Zero, F-20, F-86, Tucano,
U-2, BD-5:
Slope Scale Models
flybyudan.blogspot.com/2009_02_01_archive
.html
High-performance gliders and racers:
Soaring USA
(626) 967-6660
www.soaringusa.com
Schweizer SGS 2-32 (the vista cruiser of
sailplanes):
Tom Martin Radio Control
(816) 392-8640
www.tmrcsailplanes.com
A6M Zero, F9F Panther, Fw 190D:
Vortech Models (Jeff Fukushima)
jeff@[email protected]
Viking Models USA fuselages:
Laser Flight Models
(530) 878-0728
www.laserflight.com
Composite slope sailplanes:
Wyoming Wind Works
(605) 431-4773
wyowindworks.com
Tangent, Multiplex, Roke Modelle imports:
XL Sailplanes
(863) 206-4962
www.xl-sailplanes.com/index.htm
