I WAS DISCUSSING with a friend my effort to try to come up
with an interesting model that would be fun to build and fly, and the
Japanese Val was mentioned. All I really knew about it was that it
was a low-wing, fixed-landing-gear dive-bomber the Japanese used
during World War II.
Part of what I enjoy about modeling is researching the various
airplanes I build, so I started researching this aircraft. Did you know
that a Val dropped the first bomb during the attack on Pearl Harbor
in Hawaii in 1941?
After looking at a three-view drawing I decided the Val looked
like it might make a good-flying model. It had a generous amount of
wing area; the landing gear was fixed, which would keep modeling
costs down; and I could have the added fun of a droppable bomb.
The elliptical wing was the only thing I could think of that would
make the Val slightly more difficult to design and build than any
other low-winged sport model. However, the wing turned out to be
fairly easy to build.
Since I like my sport-scale models to be easy to construct, the
fuselage is built with flat sides like most other sport models. I also
like to keep the weight down, so I made the fuselage as skinny as I
could but wide enough to hide the radio and engine.
To make the horizontal and vertical stabilizer simple to build I
used 1/4 balsa sheet. The wheel pants were the only things that gave
me any trouble, and that was only when it was time to cover them
with MonoKote.
I put 2° of washout in the wingtips to help during low-speed
flight. With a ready-to-fly weight of approximately 6 pounds and a
wing area of 680 square inches, the wing loading is only
approximately 20 ounces per square foot; that’s close to the wing
loading of most trainers.
The electric bug has bitten me, so I used a MaxCim motor,
gearbox, and controller in my Val. I think any motor that can put out
at least 350 watts will work. If you want to use glow power, I
recommend a .40-.60 two-stroke or a .52-.70 four-stroke engine.
Artist’s composite of bare
wood and finished model.
Gary covered his Val with MonoKote. Although the colors are
not authentic, the markings were used on a Val during the
attack on Midway Island in 1942. This color scheme is easy to
see in the air. Erin Fuller photo.
The left and right fuselage sides are almost ready to join; all that is needed is to taper the
1/2 balsa triangle stock at the rear end.
Before gluing the tail end of the fuselage together, place scrap wood in the horizontal
stabilizer slot and on the wing saddle. Sight down the fuselage and get the two scrap
wood pieces parallel with each other by adjusting the fuselage sides, which are held
together with the clothespin.
The author prefers Sig-Ment or Ambroid to glue the top and
bottom 3/16 balsa sheeting in place. Holes are drilled in the firewall
to cool the batteries and motor.
The center-section of the wing. Use a piece of aluminum angle to
hold the TE of the ribs in alignment.
Type: RC semiscale
Wingspan: 63 inches
Wing area: 680 square inches
Flying weight: 6 pounds
Wing loading: 20.25 ounces
per square foot
Power: .32-.50 two-stroke or
.40-.65 four-stroke engine or
MaxCim MaxN32-13Y
motor geared 2.2:1, using a
15-volt 4000 mAh battery
Construction: Balsa and
plywood
Covering/finish: MonoKote
Photos by the author except as noted
Before the LE is installed, glue the top TE sheeting in place. The
first of the laminations are shown glued to the LE.
The landing-gear mount block in the wing center-section. After the top spar is glued to the ribs the bottom spar is lifted into the
lower spar slots, and then the spar is blocked up and glued to the ribs.
The R1C angle guide is being used to set rib R1C to the correct
angle. Don’t glue the rib to the spars until all the spars are in place.
Many clothespins are used to hold the LE laminations together
while the glue dries.
Glue the top sheeting to the LE only first. After the glue dries, wet
the top sheeting with water and ammonia to make it more flexible.
Before sheeting the top of the wing center-section, drill the holes for
the landing-gear wires through the landing-gear mounting blocks
using the vertical piece of grooved block as a guide.
32 MODEL AVIATION
Clothespins and clamps are used to hold the outboard section of
the wing to the inboard section while the glue dries.
Clothespins and regular T-pins are used to hold the wing sheeting
in place as the glue dries.
It makes it easier to drill the hole for the 1/4–inch-diameter wingmounting
dowel if you delay the sheeting of the bottom of the
forward fuselage.
Aileron servos are mounted on the bottom of the wing. The ailerons
need more up travel than down to reduce adverse yaw at low
airspeeds.
The motor speed control and receiver are mounted with hook-andloop
material. Other pieces of hook-and-loop are used to hold the
wiring.
Only one nylon landing-gear
strap is needed to mount the
wheel pants to the landing gear.
The motor and radio switches
are painted to match the
covering.
Drill a 1/4-inch hole in a large block of wood and insert the 1/4-inch
wing-mounting dowel. This holds the wing in a vertical position,
aiding in construction.
CONSTRUCTION:
I like to cut most of the parts for my
models before I begin building. There are
numerous ways to transfer the shape of
the part to the wood, but my favorite is to
cut the plans for the separate parts and
then use low-tack glue to adhere the
plans part directly to the wood. I have
had good luck using Elmer’s glue sticks.
Use a band saw to cut the wood to
shape. After the part is cut, remove the
paper from the wood. Drill the holes for
the motor mount when you cut the
firewall.
Fuselage: Start with the fuselage by
laying the left and right sides on my
workbench so that they are top to top;
that way you won’t make two left or right
sides as you glue the various pieces to the
sides.
Glue the 1/16 balsa (or plywood if you
plan to use glow power) doublers to the
sides. Make sure you glue the shorter of
the two doublers to the right side; this is
for the 2° right thrust for the engine.
Adhere the 1/2 balsa triangle stock to
the edges of the side as shown on the
plans. Once the glue has dried, taper the
triangle stock at the back end of the
fuselage. Glue the 1/4 square balsa side
stiffeners to the sides as shown on the
plans.
Glue formers F2, F3, and F4 to only
one side of the fuselage at this time.
Former F2 can be positioned to suit your
needs whether you use a glow engine or
an electric motor. Make sure they are 90°
to the side.
Glue the 1/8 square balsa to F4 as
shown on the plans. Glue the other side
to the formers. I did this by rubber
banding the sides to each other, and using
a square and my eyeballs I aligned the
sides to each other. Glue the formers to
the other side. Glue the firewall in place.
Set the fuselage on the workbench so
it is sitting on its top. Place some 1/4 balsa
sheet scraps in the wing saddle and the
horizontal stabilizer slots on the fuselage,
and then bring the aft end of the fuselage
sides together and hold in place with a
clothespin.
Sighting from the front or back end of
the fuselage, the sides are adjusted at the
back end so the 1/4-inch sticks are parallel
with each other and the fuselage is
straight. Once these are aligned, glue the
back end of the fuselage together. Sheet
the top of the fuselage with 3/16 balsa.
If you plan to use electric power,
build the hatch on the top forward part of
the fuselage. Sheet the bottom of the
fuselage aft of the wing with 3/16 balsa.
The sheeting’s grain should be crosswise
on the top and bottom sheeting.
The bottom forward of the wing will
be sheeted after the wing has been
mounted to the fuselage. Glue in the 1/4
plywood wing-mount plate and set the
fuselage aside to allow the glue to dry.
When the glue has dried on the top and
bottom sheeting, sand the fuselage to shape.
I used a large C-clamp to support a sheet of
1/2 plywood on its edge. Then I carefully
secured the fuselage to the plywood with
part of the fuselage hanging over the edge of
my workbench.
On the part of the fuselage that was
hanging over the edge of the bench I draped
the sandpaper across the top and pulled it
down and back and forth in a method similar
to that you would use to shine your shoes.
When you’re satisfied with the shape of
your fuselage, set it aside and start the wing.
Wing: Start with the center-section. Glue
the R1A and R1B ribs to the R1 ribs as
shown on the plans. Pin the forward spar to
the workbench. Place the rear spar on the
plans, but don’t pin it down; it will need to
be raised up into the ribs after they are in
place. Fit but don’t glue the 1/4 plywood
wing dowel support to the ribs that have the
R1Bs glued to them, and glue them on the
forward spar.
I used landing-gear mounts that Sig sells.
They are 6 inches long, and you need to cut
an inch for the end of each mount. After the
landing-gear mounts are glued in place,
these 1-inch blocks will be glued to the top
of the landing-gear mounts at the inboard
end up against the R1A rib, so don’t throw
them away.
Place the landing-gear mounts on the
plans and adhere the remaining R1 and R1A
ribs to the forward spar. Glue the top
forward and rear spars to the ribs. Pull the
lower rear spar up into the ribs and glue the
ribs to it. Pull the landing-gear mounts up
into the ribs and glue these in place, and then
glue the 1-inch blocks on top of the landinggear
mount against the inboard R1A rib.
Glue the 3/8 balsa LE to the centersection
and then glue the 1/8 plywood wing
dowel support to the LE. Glue a 1 x 3/32-inch
strip of balsa to the top of the ribs at the TE.
Mounting the 1/8 plywood dihedral
supports is next. I did this by drilling some
1/8-inch-diameter holes in the outermost R1
ribs between the top and bottom spars. Then
I joined the holes to form a 1/8-inch-wide
slot from the top spar to the bottom spar by
using a small file.
Install the dihedral joiner into the slot
and glue it to the top and bottom spars.
Make sure the dihedral joiner is at a 90°
angle to the R1 rib before you glue it to the
spars. Do this for the forward and aft
dihedral joiners.
For the outboard wing panels I placed
the forward and main spars on the plans and
then pinned ribs R2-R8 in place on the
plans. I placed rib R1C on the spar but did
not pin it down.
I lifted the main spar up into all the ribs
and placed shims under the spar in various
locations along the spar to hold it off the
workbench and into the ribs. Then I pinned
the spar to the workbench.
Keep the spar straight along the
wingspan and make sure the rib building
tabs are still in contact with the workbench.
Glue all the ribs except R1C to the spar. Lift
the forward spar into rib R1C and R2 and
glue to R2.
Place the top spar on all the ribs and glue
it to all the ribs except R1C. Glue the
forward spar to R2.
Cut the R1C angle guide from the plans
and glue to some scrap plywood, and then
cut the plywood to the shape of the R1C
guide. Place the R1C guide on the bottom
main spar between the top and bottom spars
against R1C.
Adjust R1C so that it is against the
guide, and glue it to the top and bottom
spars. Be careful not to glue the guide to the
rib or the spars, and make sure R1C is in the
proper place on the plans. Move the R1C
guide to the forward spar and adjust rib
R1C, and then glue R1C to the top and
bottom spars.
Glue the 1/4 balsa TE to the aileron
cutout. Make sure you have the cutout at
least 3/32 inch wider than the ribs for the 3/32
balsa sheeting. Glue the top 1 x 3/32-inch
balsa sheeting to the TE at the aileron
cutout. Glue the 3/32 balsa sheeting to the
TE, inboard of the aileron.
I decided to use a laminated balsa LE on
my Val, but you could use a solid balsa LE
if you wanted. For a laminated LE, glue the
first lamination to the ribs’ LEs with some
cyanoacrylate-type glue while the wing is
still pinned to the workbench.
Use a Sig-Ment or Ambroid type of
wood glue to adhere each successive
lamination to the LE. You will need a bunch
of clothespins or clamps to do this;
clothespins may not be long enough to
clamp on the laminations properly.
I worked around this by removing the
wing from the workbench and placing it on
a table with a curved end, with the LE
overhanging the edge of the table. I
weighted down the wing so it would not
move and was held flat on the table. Then I
used the clothespins from the top and
bottom of the LE to hold the laminations on
as the glue dried.
Glue the 3/32 balsa LE sheeting to the top
of the outboard wing section. You may need
to spray some water on the sheeting to make
it easier to bend. Once the glue and sheeting
has dried, sand the wing sheeting flush with
rib R1. Cut the slots in R1 for the dihedral
braces.
Once you are satisfied with the fit of the
outboard section to the inboard section, glue
them together. I used numerous clothespins
to hold ribs R1 and R1C together from the
bottom.
To increase the strength of the plywood
dihedral joint to the top and bottom spars I
added 3/32 balsa to fit between the top and
bottom spars, and then I glued these to the
plywood dihedral braces and the top and
bottom spars.
Build the other outer wing panel in the
same manner as you built the first panel.
Round off the top of the center-section’s
LE so the center-section will fit in the wing
saddle on the fuselage. Center the wing on
the fuselage and then drill the hole for the
1/4-inch wing-mounting dowel through F2
and the wing’s LE. Remove the wing from
the fuselage and glue the 1/4-inch-diameter
dowel in place on the wing.
Sheet the bottom of the wing. Glue the
1/4 balsa TEs to the wing and sand them to
match the contour of the airfoil.
The ailerons are fairly simple to build.
They are 3/32 sheet balsa with half ribs glued
to the top and bottom.
Glue the 1/4-inch-wide balsa capstrips to
the ribs. Use 1/8-inch-thick balsa for the
capstrips. Glue the 1/4 balsa TE to the
ailerons. Cut the slots for the hinges in the
ailerons and in the wing, and then
temporarily mount the ailerons to the wing
and sand the ailerons to match the wing.
Install the aileron-servo mount blocks as
shown on the plans. The 3/32 balsa is to form
a lip around the servo mount hole for the
covering to stick to.
Adhere the wingtip blocks in place and
sand them to shape. Glue the 1/8 plywood
wing-bolt reinforcing plate to the bottom of
the wing on the center-section.
Mount the wing to the fuselage and drill
a 13/64-inch hole in the wing and fuselage for
the wing-mounting screw. Tap the hole in
the fuselage with a 1/4-20 tap. Enlarge the
hole in the wing to 1/4 inch.
Glue F4A and F6 to the bottom of the
wing and then sheet over it with 3/16 balsa.
Use a sharpened brass tube to cut the hole
for access to the wing mounting screw.
Sheet the lower forward part of the fuselage
with 3/16 balsa. Glue the 1/4 balsa F5s in
place. Sand the lower wing fuselage fairing
to match the contour of the fuselage shape.
Flip the fuselage over and secure it to the
worktable so you can mount the horizontal
stabilizer. Slide the horizontal stabilizer into
the slot in the rear of the fuselage. Make
sure the stabilizer is centered on the
fuselage. Sight down the length of the
fuselage from the front or rear and make
sure the stabilizer and wing are parallel to
each other horizontally.
Make sure the stabilizer is square to the
wing by measuring from the wing TE to the
stabilizer TE on both sides of the fuselage,
and make sure these measurements are the
same. Check the horizontal stabilizer’s
incidence to the wing; it should be
approximately 1/2° LE down. When you’re
satisfied that the stabilizer is mounted
correctly, glue it to the fuselage.
Mount the vertical stabilizer to the
fuselage with pins. To align the vertical
stabilizer so that it is not offset to one side
or the other, sight down the top of the
fuselage from the front and pin it in place.
Adjust the vertical stabilizer so it is 90° to
the horizontal stabilizer and then glue the
vertical stabilizer to the fuselage.
The tail-wheel bracket is 1/16-inchdiameter
music wire bent to shape and
mounted to the fuselage with 1/16-inch-insidediameter
brass tube. I built mine by bending
the bottom of the bracket for the axle and
slipping on a small washer to keep the tail
wheel from pushing the rudder up. Then I
soldered the washer to the music wire.
I sharpened the end of the 1/16-inch brass
tube and used it to drill the hole in the
fuselage for the bracket. Then I glued the
brass tube in place on the fuselage and cut it
to length. The music-wire bracket was
slipped into the brass tube and the top of the
bracket was then bent over to fit into the
rudder.
The full-scale Val has a rather large
wing-to-fuselage fillet; this has been drawn
on the plans, but I opted not to install the
fillet on my model. If you want to make a
fillet for yours, I will describe how I was
going to build it.
Cut the fillet base from 1/64 plywood.
Loosely mount the wing to the fuselage and
slip the fillet base in place between the wing
and fuselage. When you are satisfied with
the location of the fillet, tighten the wing to
the fuselage and glue the fillet to the
fuselage only.
Cut some soft balsa blocks and glue
them to the fuselage. Carve and sand them
to the shape of the fillet.
Bend the elevator joiner from 1/8-inch
music wire, and then temporarily mount the
elevator using your favorite hinging method.
Temporarily mount the rudder.
Set the model aside and then bend the
main landing gear from 3/16-inch music wire.
The wheel pants are made from various
thicknesses of balsa. The thickness of the
main core of the wheel pants is determined
by the thickness of the wheels you use and
the addition of the wheel collars.
If you fly from a grass strip, cut the
bottom of the pants so that more of the
wheel is exposed than shown on the plans. I
have seen pictures of a full-scale Val’s
wheel without wheel pants, so you may not
want to build them for your model. Once
you have cut all the parts for the wheel
pants, glue them together and sand them to
shape.
Final-sand the fuselage and cover it with
your favorite covering material. I used
MonoKote. Although the colors I used are
not exactly accurate, I loosely based the color
scheme on a Val that was aboard the aircraft
carrier Akagi during the battle of Midway. I
got the red “meatballs” from a set of decals I
had from an old Top Flite Zero kit.
The canopy I used is from the Great
Planes AT-6 Texan ARF that is available
from Tower Hobbies. I decided early that I
would have cooling holes cut in the fuselage
in the cockpit area and I would leave the
rear of the canopy open for the air to escape.
I cut the excess plastic from the canopy
as if I was going to mount it on the model
for which it was designed. Then I placed the
canopy on the top of the fuselage and
pressed it down until the front of the
windscreen touched the top of the fuselage. I
used a dry-erase marker to indicate the side
of the canopy on which I needed to cut it to
make it fit the fuselage.
After I cut the canopy to fit the fuselage I
used a rag to remove the marks left on the
canopy. I taped the canopy in place on the
fuselage and marked the fuselage so I could
remove the green MonoKote from the
cockpit area and replace it with black
MonoKote.
Once I had re-covered the cockpit area
with the black MonoKote, I carefully cut a
small strip away from the black for the
canopy to be glued to bare wood on the
fuselage. I used a sharpened brass tube to
cut the cooling holes in the cockpit area.
Since I wanted to keep my model simple
but still wanted a pilot and gunner in it, I
decided to use a simple, flat version. I found
a picture of a pilot and gunner and scanned
it into my computer. Then I enlarged the
picture to the correct size. I created a mirror
image of the picture, and then I printed the
mirror image and the original image of the
picture.
I glued one side of the pilot and gunner
to a piece of 1/64 plywood. Then I cut the
plywood to the shape of the pilot and gunner
and glued the mirror image to the other side
of the pilot. To make the plywood blend into
the figures, I darkened the edge of the wood
with a black magic marker.
I glued the pilot and gunner figures into
slots cut in the cockpit area. When I was
happy with the cockpit area, I glued the
canopy to the fuselage with some Formula
560 canopy glue.
I mounted an old Vortac bomb release to
the bottom of the wing near the CG. If you
want to mount a bomb release, be careful
not to cut the wing spars as you make the
cutout for the release. I used a T-pin to poke
through the wing sheeting to locate the
spars. I mounted the bomb-release servo
upside down in the wing so that a servo arm
would actuate the release.
The Val’s nose is rather short, so I
mounted the radio gear as far forward in
the fuselage as I could. I still ended up
adding lead to the nose to get the CG
where I wanted it.
The aileron servos are mounted to the
bottom of the wing and are connected to the
receiver by a Y harness. I like my models to
be fairly responsive, so I set my control
throws as follows: rudder, 1 inch left and
right; elevator, 1/2 inch up and down;
ailerons, 1/4 inch down and 1/2 inch up.
The ailerons need more up than down
travel, and this is achieved by mounting the
servo arm on the servo at roughly a 45° angle
toward the front of the airplane. These are
good starting points for the first few flights.
After that you may want to increase or
decrease the throws to suit your flying style.
Flying: If you are like I am, you probably
skipped most of the article and came right to
this point to see how the Val flies. It flies
exactly like an advanced trainer. If the only
models you have ever flown are high-wing
trainers and you want to move on to a lowwing
trainer, this may be the airplane you’re
looking for.
The first flight with my Val took place
early on a cool, windless Saturday morning.
After range checking my radio with the
motor on, I taxied the model to the far end
of the runway. I slowly advanced the throttle
and let the Val roll down the runway. It
wanted to pull to the left, but I had no
problems keeping it headed down the
runway with the rudder.
After roughly 150 feet I started to feed in
up-elevator and the Val became airborne in
a nice, realistic manner. As I gained some
altitude I realized the Val needed some upelevator
trim and a little right aileron trim to
keep it level.
Once I had the Val trimmed out, I made
some low passes so my daughter Erin could
take some pictures of it in flight. I was
exceptionally pleased with how the model
flew. I took it up high to see how the Val
handled in slow flight; I was quite pleased to
see how slow it was able to fly before it
stalled.
The right wing had a tendency to drop
when the model stalled, but it was easy to
control right up to the stall. After a few
more low passes I tried a few touch-and-gos.
The big propeller windmilling created
quite a bit of drag, and I found that I needed
to keep a little power on during the approach
or make steep approaches to keep up the
airspeed. There is no tendency for the Val to
float too much once the power has been
pulled all the way back, but it doesn’t drop
like a brick either.
When I took my airplane home I checked
the wings for warp and found a slight one in
the right wing. Twisting the wing and
reheating the MonoKote removed the warp.
I also redrew the plans to show 1/2°
incidence in the horizontal stabilizer.
On subsequent flights I was able to see
how aerobatic the Val is. It will fly upside
down by my holding a little down-elevator
with no problem. Rolls are nice and crisp.
There is little roll coupling with the rudder.
Landings are a breeze; you can wheelie it
on, and three point it on, or if you’re careful
you can one-point it on the tail wheel!
If you want a model that can do all the
fancy stuff, the Val will probably make you
yawn. But if you’re looking for an advanced
trainer that looks like a full-scale airplane or
if you want to try flying in a Fun Scale
contest or two, this may be a great fit for
you. MA
Gary Fuller
Edition: Model Aviation - 2007/03
Page Numbers: 29,30,31,32,33,34,35,36,38,40
Edition: Model Aviation - 2007/03
Page Numbers: 29,30,31,32,33,34,35,36,38,40
I WAS DISCUSSING with a friend my effort to try to come up
with an interesting model that would be fun to build and fly, and the
Japanese Val was mentioned. All I really knew about it was that it
was a low-wing, fixed-landing-gear dive-bomber the Japanese used
during World War II.
Part of what I enjoy about modeling is researching the various
airplanes I build, so I started researching this aircraft. Did you know
that a Val dropped the first bomb during the attack on Pearl Harbor
in Hawaii in 1941?
After looking at a three-view drawing I decided the Val looked
like it might make a good-flying model. It had a generous amount of
wing area; the landing gear was fixed, which would keep modeling
costs down; and I could have the added fun of a droppable bomb.
The elliptical wing was the only thing I could think of that would
make the Val slightly more difficult to design and build than any
other low-winged sport model. However, the wing turned out to be
fairly easy to build.
Since I like my sport-scale models to be easy to construct, the
fuselage is built with flat sides like most other sport models. I also
like to keep the weight down, so I made the fuselage as skinny as I
could but wide enough to hide the radio and engine.
To make the horizontal and vertical stabilizer simple to build I
used 1/4 balsa sheet. The wheel pants were the only things that gave
me any trouble, and that was only when it was time to cover them
with MonoKote.
I put 2° of washout in the wingtips to help during low-speed
flight. With a ready-to-fly weight of approximately 6 pounds and a
wing area of 680 square inches, the wing loading is only
approximately 20 ounces per square foot; that’s close to the wing
loading of most trainers.
The electric bug has bitten me, so I used a MaxCim motor,
gearbox, and controller in my Val. I think any motor that can put out
at least 350 watts will work. If you want to use glow power, I
recommend a .40-.60 two-stroke or a .52-.70 four-stroke engine.
Artist’s composite of bare
wood and finished model.
Gary covered his Val with MonoKote. Although the colors are
not authentic, the markings were used on a Val during the
attack on Midway Island in 1942. This color scheme is easy to
see in the air. Erin Fuller photo.
The left and right fuselage sides are almost ready to join; all that is needed is to taper the
1/2 balsa triangle stock at the rear end.
Before gluing the tail end of the fuselage together, place scrap wood in the horizontal
stabilizer slot and on the wing saddle. Sight down the fuselage and get the two scrap
wood pieces parallel with each other by adjusting the fuselage sides, which are held
together with the clothespin.
The author prefers Sig-Ment or Ambroid to glue the top and
bottom 3/16 balsa sheeting in place. Holes are drilled in the firewall
to cool the batteries and motor.
The center-section of the wing. Use a piece of aluminum angle to
hold the TE of the ribs in alignment.
Type: RC semiscale
Wingspan: 63 inches
Wing area: 680 square inches
Flying weight: 6 pounds
Wing loading: 20.25 ounces
per square foot
Power: .32-.50 two-stroke or
.40-.65 four-stroke engine or
MaxCim MaxN32-13Y
motor geared 2.2:1, using a
15-volt 4000 mAh battery
Construction: Balsa and
plywood
Covering/finish: MonoKote
Photos by the author except as noted
Before the LE is installed, glue the top TE sheeting in place. The
first of the laminations are shown glued to the LE.
The landing-gear mount block in the wing center-section. After the top spar is glued to the ribs the bottom spar is lifted into the
lower spar slots, and then the spar is blocked up and glued to the ribs.
The R1C angle guide is being used to set rib R1C to the correct
angle. Don’t glue the rib to the spars until all the spars are in place.
Many clothespins are used to hold the LE laminations together
while the glue dries.
Glue the top sheeting to the LE only first. After the glue dries, wet
the top sheeting with water and ammonia to make it more flexible.
Before sheeting the top of the wing center-section, drill the holes for
the landing-gear wires through the landing-gear mounting blocks
using the vertical piece of grooved block as a guide.
32 MODEL AVIATION
Clothespins and clamps are used to hold the outboard section of
the wing to the inboard section while the glue dries.
Clothespins and regular T-pins are used to hold the wing sheeting
in place as the glue dries.
It makes it easier to drill the hole for the 1/4–inch-diameter wingmounting
dowel if you delay the sheeting of the bottom of the
forward fuselage.
Aileron servos are mounted on the bottom of the wing. The ailerons
need more up travel than down to reduce adverse yaw at low
airspeeds.
The motor speed control and receiver are mounted with hook-andloop
material. Other pieces of hook-and-loop are used to hold the
wiring.
Only one nylon landing-gear
strap is needed to mount the
wheel pants to the landing gear.
The motor and radio switches
are painted to match the
covering.
Drill a 1/4-inch hole in a large block of wood and insert the 1/4-inch
wing-mounting dowel. This holds the wing in a vertical position,
aiding in construction.
CONSTRUCTION:
I like to cut most of the parts for my
models before I begin building. There are
numerous ways to transfer the shape of
the part to the wood, but my favorite is to
cut the plans for the separate parts and
then use low-tack glue to adhere the
plans part directly to the wood. I have
had good luck using Elmer’s glue sticks.
Use a band saw to cut the wood to
shape. After the part is cut, remove the
paper from the wood. Drill the holes for
the motor mount when you cut the
firewall.
Fuselage: Start with the fuselage by
laying the left and right sides on my
workbench so that they are top to top;
that way you won’t make two left or right
sides as you glue the various pieces to the
sides.
Glue the 1/16 balsa (or plywood if you
plan to use glow power) doublers to the
sides. Make sure you glue the shorter of
the two doublers to the right side; this is
for the 2° right thrust for the engine.
Adhere the 1/2 balsa triangle stock to
the edges of the side as shown on the
plans. Once the glue has dried, taper the
triangle stock at the back end of the
fuselage. Glue the 1/4 square balsa side
stiffeners to the sides as shown on the
plans.
Glue formers F2, F3, and F4 to only
one side of the fuselage at this time.
Former F2 can be positioned to suit your
needs whether you use a glow engine or
an electric motor. Make sure they are 90°
to the side.
Glue the 1/8 square balsa to F4 as
shown on the plans. Glue the other side
to the formers. I did this by rubber
banding the sides to each other, and using
a square and my eyeballs I aligned the
sides to each other. Glue the formers to
the other side. Glue the firewall in place.
Set the fuselage on the workbench so
it is sitting on its top. Place some 1/4 balsa
sheet scraps in the wing saddle and the
horizontal stabilizer slots on the fuselage,
and then bring the aft end of the fuselage
sides together and hold in place with a
clothespin.
Sighting from the front or back end of
the fuselage, the sides are adjusted at the
back end so the 1/4-inch sticks are parallel
with each other and the fuselage is
straight. Once these are aligned, glue the
back end of the fuselage together. Sheet
the top of the fuselage with 3/16 balsa.
If you plan to use electric power,
build the hatch on the top forward part of
the fuselage. Sheet the bottom of the
fuselage aft of the wing with 3/16 balsa.
The sheeting’s grain should be crosswise
on the top and bottom sheeting.
The bottom forward of the wing will
be sheeted after the wing has been
mounted to the fuselage. Glue in the 1/4
plywood wing-mount plate and set the
fuselage aside to allow the glue to dry.
When the glue has dried on the top and
bottom sheeting, sand the fuselage to shape.
I used a large C-clamp to support a sheet of
1/2 plywood on its edge. Then I carefully
secured the fuselage to the plywood with
part of the fuselage hanging over the edge of
my workbench.
On the part of the fuselage that was
hanging over the edge of the bench I draped
the sandpaper across the top and pulled it
down and back and forth in a method similar
to that you would use to shine your shoes.
When you’re satisfied with the shape of
your fuselage, set it aside and start the wing.
Wing: Start with the center-section. Glue
the R1A and R1B ribs to the R1 ribs as
shown on the plans. Pin the forward spar to
the workbench. Place the rear spar on the
plans, but don’t pin it down; it will need to
be raised up into the ribs after they are in
place. Fit but don’t glue the 1/4 plywood
wing dowel support to the ribs that have the
R1Bs glued to them, and glue them on the
forward spar.
I used landing-gear mounts that Sig sells.
They are 6 inches long, and you need to cut
an inch for the end of each mount. After the
landing-gear mounts are glued in place,
these 1-inch blocks will be glued to the top
of the landing-gear mounts at the inboard
end up against the R1A rib, so don’t throw
them away.
Place the landing-gear mounts on the
plans and adhere the remaining R1 and R1A
ribs to the forward spar. Glue the top
forward and rear spars to the ribs. Pull the
lower rear spar up into the ribs and glue the
ribs to it. Pull the landing-gear mounts up
into the ribs and glue these in place, and then
glue the 1-inch blocks on top of the landinggear
mount against the inboard R1A rib.
Glue the 3/8 balsa LE to the centersection
and then glue the 1/8 plywood wing
dowel support to the LE. Glue a 1 x 3/32-inch
strip of balsa to the top of the ribs at the TE.
Mounting the 1/8 plywood dihedral
supports is next. I did this by drilling some
1/8-inch-diameter holes in the outermost R1
ribs between the top and bottom spars. Then
I joined the holes to form a 1/8-inch-wide
slot from the top spar to the bottom spar by
using a small file.
Install the dihedral joiner into the slot
and glue it to the top and bottom spars.
Make sure the dihedral joiner is at a 90°
angle to the R1 rib before you glue it to the
spars. Do this for the forward and aft
dihedral joiners.
For the outboard wing panels I placed
the forward and main spars on the plans and
then pinned ribs R2-R8 in place on the
plans. I placed rib R1C on the spar but did
not pin it down.
I lifted the main spar up into all the ribs
and placed shims under the spar in various
locations along the spar to hold it off the
workbench and into the ribs. Then I pinned
the spar to the workbench.
Keep the spar straight along the
wingspan and make sure the rib building
tabs are still in contact with the workbench.
Glue all the ribs except R1C to the spar. Lift
the forward spar into rib R1C and R2 and
glue to R2.
Place the top spar on all the ribs and glue
it to all the ribs except R1C. Glue the
forward spar to R2.
Cut the R1C angle guide from the plans
and glue to some scrap plywood, and then
cut the plywood to the shape of the R1C
guide. Place the R1C guide on the bottom
main spar between the top and bottom spars
against R1C.
Adjust R1C so that it is against the
guide, and glue it to the top and bottom
spars. Be careful not to glue the guide to the
rib or the spars, and make sure R1C is in the
proper place on the plans. Move the R1C
guide to the forward spar and adjust rib
R1C, and then glue R1C to the top and
bottom spars.
Glue the 1/4 balsa TE to the aileron
cutout. Make sure you have the cutout at
least 3/32 inch wider than the ribs for the 3/32
balsa sheeting. Glue the top 1 x 3/32-inch
balsa sheeting to the TE at the aileron
cutout. Glue the 3/32 balsa sheeting to the
TE, inboard of the aileron.
I decided to use a laminated balsa LE on
my Val, but you could use a solid balsa LE
if you wanted. For a laminated LE, glue the
first lamination to the ribs’ LEs with some
cyanoacrylate-type glue while the wing is
still pinned to the workbench.
Use a Sig-Ment or Ambroid type of
wood glue to adhere each successive
lamination to the LE. You will need a bunch
of clothespins or clamps to do this;
clothespins may not be long enough to
clamp on the laminations properly.
I worked around this by removing the
wing from the workbench and placing it on
a table with a curved end, with the LE
overhanging the edge of the table. I
weighted down the wing so it would not
move and was held flat on the table. Then I
used the clothespins from the top and
bottom of the LE to hold the laminations on
as the glue dried.
Glue the 3/32 balsa LE sheeting to the top
of the outboard wing section. You may need
to spray some water on the sheeting to make
it easier to bend. Once the glue and sheeting
has dried, sand the wing sheeting flush with
rib R1. Cut the slots in R1 for the dihedral
braces.
Once you are satisfied with the fit of the
outboard section to the inboard section, glue
them together. I used numerous clothespins
to hold ribs R1 and R1C together from the
bottom.
To increase the strength of the plywood
dihedral joint to the top and bottom spars I
added 3/32 balsa to fit between the top and
bottom spars, and then I glued these to the
plywood dihedral braces and the top and
bottom spars.
Build the other outer wing panel in the
same manner as you built the first panel.
Round off the top of the center-section’s
LE so the center-section will fit in the wing
saddle on the fuselage. Center the wing on
the fuselage and then drill the hole for the
1/4-inch wing-mounting dowel through F2
and the wing’s LE. Remove the wing from
the fuselage and glue the 1/4-inch-diameter
dowel in place on the wing.
Sheet the bottom of the wing. Glue the
1/4 balsa TEs to the wing and sand them to
match the contour of the airfoil.
The ailerons are fairly simple to build.
They are 3/32 sheet balsa with half ribs glued
to the top and bottom.
Glue the 1/4-inch-wide balsa capstrips to
the ribs. Use 1/8-inch-thick balsa for the
capstrips. Glue the 1/4 balsa TE to the
ailerons. Cut the slots for the hinges in the
ailerons and in the wing, and then
temporarily mount the ailerons to the wing
and sand the ailerons to match the wing.
Install the aileron-servo mount blocks as
shown on the plans. The 3/32 balsa is to form
a lip around the servo mount hole for the
covering to stick to.
Adhere the wingtip blocks in place and
sand them to shape. Glue the 1/8 plywood
wing-bolt reinforcing plate to the bottom of
the wing on the center-section.
Mount the wing to the fuselage and drill
a 13/64-inch hole in the wing and fuselage for
the wing-mounting screw. Tap the hole in
the fuselage with a 1/4-20 tap. Enlarge the
hole in the wing to 1/4 inch.
Glue F4A and F6 to the bottom of the
wing and then sheet over it with 3/16 balsa.
Use a sharpened brass tube to cut the hole
for access to the wing mounting screw.
Sheet the lower forward part of the fuselage
with 3/16 balsa. Glue the 1/4 balsa F5s in
place. Sand the lower wing fuselage fairing
to match the contour of the fuselage shape.
Flip the fuselage over and secure it to the
worktable so you can mount the horizontal
stabilizer. Slide the horizontal stabilizer into
the slot in the rear of the fuselage. Make
sure the stabilizer is centered on the
fuselage. Sight down the length of the
fuselage from the front or rear and make
sure the stabilizer and wing are parallel to
each other horizontally.
Make sure the stabilizer is square to the
wing by measuring from the wing TE to the
stabilizer TE on both sides of the fuselage,
and make sure these measurements are the
same. Check the horizontal stabilizer’s
incidence to the wing; it should be
approximately 1/2° LE down. When you’re
satisfied that the stabilizer is mounted
correctly, glue it to the fuselage.
Mount the vertical stabilizer to the
fuselage with pins. To align the vertical
stabilizer so that it is not offset to one side
or the other, sight down the top of the
fuselage from the front and pin it in place.
Adjust the vertical stabilizer so it is 90° to
the horizontal stabilizer and then glue the
vertical stabilizer to the fuselage.
The tail-wheel bracket is 1/16-inchdiameter
music wire bent to shape and
mounted to the fuselage with 1/16-inch-insidediameter
brass tube. I built mine by bending
the bottom of the bracket for the axle and
slipping on a small washer to keep the tail
wheel from pushing the rudder up. Then I
soldered the washer to the music wire.
I sharpened the end of the 1/16-inch brass
tube and used it to drill the hole in the
fuselage for the bracket. Then I glued the
brass tube in place on the fuselage and cut it
to length. The music-wire bracket was
slipped into the brass tube and the top of the
bracket was then bent over to fit into the
rudder.
The full-scale Val has a rather large
wing-to-fuselage fillet; this has been drawn
on the plans, but I opted not to install the
fillet on my model. If you want to make a
fillet for yours, I will describe how I was
going to build it.
Cut the fillet base from 1/64 plywood.
Loosely mount the wing to the fuselage and
slip the fillet base in place between the wing
and fuselage. When you are satisfied with
the location of the fillet, tighten the wing to
the fuselage and glue the fillet to the
fuselage only.
Cut some soft balsa blocks and glue
them to the fuselage. Carve and sand them
to the shape of the fillet.
Bend the elevator joiner from 1/8-inch
music wire, and then temporarily mount the
elevator using your favorite hinging method.
Temporarily mount the rudder.
Set the model aside and then bend the
main landing gear from 3/16-inch music wire.
The wheel pants are made from various
thicknesses of balsa. The thickness of the
main core of the wheel pants is determined
by the thickness of the wheels you use and
the addition of the wheel collars.
If you fly from a grass strip, cut the
bottom of the pants so that more of the
wheel is exposed than shown on the plans. I
have seen pictures of a full-scale Val’s
wheel without wheel pants, so you may not
want to build them for your model. Once
you have cut all the parts for the wheel
pants, glue them together and sand them to
shape.
Final-sand the fuselage and cover it with
your favorite covering material. I used
MonoKote. Although the colors I used are
not exactly accurate, I loosely based the color
scheme on a Val that was aboard the aircraft
carrier Akagi during the battle of Midway. I
got the red “meatballs” from a set of decals I
had from an old Top Flite Zero kit.
The canopy I used is from the Great
Planes AT-6 Texan ARF that is available
from Tower Hobbies. I decided early that I
would have cooling holes cut in the fuselage
in the cockpit area and I would leave the
rear of the canopy open for the air to escape.
I cut the excess plastic from the canopy
as if I was going to mount it on the model
for which it was designed. Then I placed the
canopy on the top of the fuselage and
pressed it down until the front of the
windscreen touched the top of the fuselage. I
used a dry-erase marker to indicate the side
of the canopy on which I needed to cut it to
make it fit the fuselage.
After I cut the canopy to fit the fuselage I
used a rag to remove the marks left on the
canopy. I taped the canopy in place on the
fuselage and marked the fuselage so I could
remove the green MonoKote from the
cockpit area and replace it with black
MonoKote.
Once I had re-covered the cockpit area
with the black MonoKote, I carefully cut a
small strip away from the black for the
canopy to be glued to bare wood on the
fuselage. I used a sharpened brass tube to
cut the cooling holes in the cockpit area.
Since I wanted to keep my model simple
but still wanted a pilot and gunner in it, I
decided to use a simple, flat version. I found
a picture of a pilot and gunner and scanned
it into my computer. Then I enlarged the
picture to the correct size. I created a mirror
image of the picture, and then I printed the
mirror image and the original image of the
picture.
I glued one side of the pilot and gunner
to a piece of 1/64 plywood. Then I cut the
plywood to the shape of the pilot and gunner
and glued the mirror image to the other side
of the pilot. To make the plywood blend into
the figures, I darkened the edge of the wood
with a black magic marker.
I glued the pilot and gunner figures into
slots cut in the cockpit area. When I was
happy with the cockpit area, I glued the
canopy to the fuselage with some Formula
560 canopy glue.
I mounted an old Vortac bomb release to
the bottom of the wing near the CG. If you
want to mount a bomb release, be careful
not to cut the wing spars as you make the
cutout for the release. I used a T-pin to poke
through the wing sheeting to locate the
spars. I mounted the bomb-release servo
upside down in the wing so that a servo arm
would actuate the release.
The Val’s nose is rather short, so I
mounted the radio gear as far forward in
the fuselage as I could. I still ended up
adding lead to the nose to get the CG
where I wanted it.
The aileron servos are mounted to the
bottom of the wing and are connected to the
receiver by a Y harness. I like my models to
be fairly responsive, so I set my control
throws as follows: rudder, 1 inch left and
right; elevator, 1/2 inch up and down;
ailerons, 1/4 inch down and 1/2 inch up.
The ailerons need more up than down
travel, and this is achieved by mounting the
servo arm on the servo at roughly a 45° angle
toward the front of the airplane. These are
good starting points for the first few flights.
After that you may want to increase or
decrease the throws to suit your flying style.
Flying: If you are like I am, you probably
skipped most of the article and came right to
this point to see how the Val flies. It flies
exactly like an advanced trainer. If the only
models you have ever flown are high-wing
trainers and you want to move on to a lowwing
trainer, this may be the airplane you’re
looking for.
The first flight with my Val took place
early on a cool, windless Saturday morning.
After range checking my radio with the
motor on, I taxied the model to the far end
of the runway. I slowly advanced the throttle
and let the Val roll down the runway. It
wanted to pull to the left, but I had no
problems keeping it headed down the
runway with the rudder.
After roughly 150 feet I started to feed in
up-elevator and the Val became airborne in
a nice, realistic manner. As I gained some
altitude I realized the Val needed some upelevator
trim and a little right aileron trim to
keep it level.
Once I had the Val trimmed out, I made
some low passes so my daughter Erin could
take some pictures of it in flight. I was
exceptionally pleased with how the model
flew. I took it up high to see how the Val
handled in slow flight; I was quite pleased to
see how slow it was able to fly before it
stalled.
The right wing had a tendency to drop
when the model stalled, but it was easy to
control right up to the stall. After a few
more low passes I tried a few touch-and-gos.
The big propeller windmilling created
quite a bit of drag, and I found that I needed
to keep a little power on during the approach
or make steep approaches to keep up the
airspeed. There is no tendency for the Val to
float too much once the power has been
pulled all the way back, but it doesn’t drop
like a brick either.
When I took my airplane home I checked
the wings for warp and found a slight one in
the right wing. Twisting the wing and
reheating the MonoKote removed the warp.
I also redrew the plans to show 1/2°
incidence in the horizontal stabilizer.
On subsequent flights I was able to see
how aerobatic the Val is. It will fly upside
down by my holding a little down-elevator
with no problem. Rolls are nice and crisp.
There is little roll coupling with the rudder.
Landings are a breeze; you can wheelie it
on, and three point it on, or if you’re careful
you can one-point it on the tail wheel!
If you want a model that can do all the
fancy stuff, the Val will probably make you
yawn. But if you’re looking for an advanced
trainer that looks like a full-scale airplane or
if you want to try flying in a Fun Scale
contest or two, this may be a great fit for
you. MA
Gary Fuller
Edition: Model Aviation - 2007/03
Page Numbers: 29,30,31,32,33,34,35,36,38,40
I WAS DISCUSSING with a friend my effort to try to come up
with an interesting model that would be fun to build and fly, and the
Japanese Val was mentioned. All I really knew about it was that it
was a low-wing, fixed-landing-gear dive-bomber the Japanese used
during World War II.
Part of what I enjoy about modeling is researching the various
airplanes I build, so I started researching this aircraft. Did you know
that a Val dropped the first bomb during the attack on Pearl Harbor
in Hawaii in 1941?
After looking at a three-view drawing I decided the Val looked
like it might make a good-flying model. It had a generous amount of
wing area; the landing gear was fixed, which would keep modeling
costs down; and I could have the added fun of a droppable bomb.
The elliptical wing was the only thing I could think of that would
make the Val slightly more difficult to design and build than any
other low-winged sport model. However, the wing turned out to be
fairly easy to build.
Since I like my sport-scale models to be easy to construct, the
fuselage is built with flat sides like most other sport models. I also
like to keep the weight down, so I made the fuselage as skinny as I
could but wide enough to hide the radio and engine.
To make the horizontal and vertical stabilizer simple to build I
used 1/4 balsa sheet. The wheel pants were the only things that gave
me any trouble, and that was only when it was time to cover them
with MonoKote.
I put 2° of washout in the wingtips to help during low-speed
flight. With a ready-to-fly weight of approximately 6 pounds and a
wing area of 680 square inches, the wing loading is only
approximately 20 ounces per square foot; that’s close to the wing
loading of most trainers.
The electric bug has bitten me, so I used a MaxCim motor,
gearbox, and controller in my Val. I think any motor that can put out
at least 350 watts will work. If you want to use glow power, I
recommend a .40-.60 two-stroke or a .52-.70 four-stroke engine.
Artist’s composite of bare
wood and finished model.
Gary covered his Val with MonoKote. Although the colors are
not authentic, the markings were used on a Val during the
attack on Midway Island in 1942. This color scheme is easy to
see in the air. Erin Fuller photo.
The left and right fuselage sides are almost ready to join; all that is needed is to taper the
1/2 balsa triangle stock at the rear end.
Before gluing the tail end of the fuselage together, place scrap wood in the horizontal
stabilizer slot and on the wing saddle. Sight down the fuselage and get the two scrap
wood pieces parallel with each other by adjusting the fuselage sides, which are held
together with the clothespin.
The author prefers Sig-Ment or Ambroid to glue the top and
bottom 3/16 balsa sheeting in place. Holes are drilled in the firewall
to cool the batteries and motor.
The center-section of the wing. Use a piece of aluminum angle to
hold the TE of the ribs in alignment.
Type: RC semiscale
Wingspan: 63 inches
Wing area: 680 square inches
Flying weight: 6 pounds
Wing loading: 20.25 ounces
per square foot
Power: .32-.50 two-stroke or
.40-.65 four-stroke engine or
MaxCim MaxN32-13Y
motor geared 2.2:1, using a
15-volt 4000 mAh battery
Construction: Balsa and
plywood
Covering/finish: MonoKote
Photos by the author except as noted
Before the LE is installed, glue the top TE sheeting in place. The
first of the laminations are shown glued to the LE.
The landing-gear mount block in the wing center-section. After the top spar is glued to the ribs the bottom spar is lifted into the
lower spar slots, and then the spar is blocked up and glued to the ribs.
The R1C angle guide is being used to set rib R1C to the correct
angle. Don’t glue the rib to the spars until all the spars are in place.
Many clothespins are used to hold the LE laminations together
while the glue dries.
Glue the top sheeting to the LE only first. After the glue dries, wet
the top sheeting with water and ammonia to make it more flexible.
Before sheeting the top of the wing center-section, drill the holes for
the landing-gear wires through the landing-gear mounting blocks
using the vertical piece of grooved block as a guide.
32 MODEL AVIATION
Clothespins and clamps are used to hold the outboard section of
the wing to the inboard section while the glue dries.
Clothespins and regular T-pins are used to hold the wing sheeting
in place as the glue dries.
It makes it easier to drill the hole for the 1/4–inch-diameter wingmounting
dowel if you delay the sheeting of the bottom of the
forward fuselage.
Aileron servos are mounted on the bottom of the wing. The ailerons
need more up travel than down to reduce adverse yaw at low
airspeeds.
The motor speed control and receiver are mounted with hook-andloop
material. Other pieces of hook-and-loop are used to hold the
wiring.
Only one nylon landing-gear
strap is needed to mount the
wheel pants to the landing gear.
The motor and radio switches
are painted to match the
covering.
Drill a 1/4-inch hole in a large block of wood and insert the 1/4-inch
wing-mounting dowel. This holds the wing in a vertical position,
aiding in construction.
CONSTRUCTION:
I like to cut most of the parts for my
models before I begin building. There are
numerous ways to transfer the shape of
the part to the wood, but my favorite is to
cut the plans for the separate parts and
then use low-tack glue to adhere the
plans part directly to the wood. I have
had good luck using Elmer’s glue sticks.
Use a band saw to cut the wood to
shape. After the part is cut, remove the
paper from the wood. Drill the holes for
the motor mount when you cut the
firewall.
Fuselage: Start with the fuselage by
laying the left and right sides on my
workbench so that they are top to top;
that way you won’t make two left or right
sides as you glue the various pieces to the
sides.
Glue the 1/16 balsa (or plywood if you
plan to use glow power) doublers to the
sides. Make sure you glue the shorter of
the two doublers to the right side; this is
for the 2° right thrust for the engine.
Adhere the 1/2 balsa triangle stock to
the edges of the side as shown on the
plans. Once the glue has dried, taper the
triangle stock at the back end of the
fuselage. Glue the 1/4 square balsa side
stiffeners to the sides as shown on the
plans.
Glue formers F2, F3, and F4 to only
one side of the fuselage at this time.
Former F2 can be positioned to suit your
needs whether you use a glow engine or
an electric motor. Make sure they are 90°
to the side.
Glue the 1/8 square balsa to F4 as
shown on the plans. Glue the other side
to the formers. I did this by rubber
banding the sides to each other, and using
a square and my eyeballs I aligned the
sides to each other. Glue the formers to
the other side. Glue the firewall in place.
Set the fuselage on the workbench so
it is sitting on its top. Place some 1/4 balsa
sheet scraps in the wing saddle and the
horizontal stabilizer slots on the fuselage,
and then bring the aft end of the fuselage
sides together and hold in place with a
clothespin.
Sighting from the front or back end of
the fuselage, the sides are adjusted at the
back end so the 1/4-inch sticks are parallel
with each other and the fuselage is
straight. Once these are aligned, glue the
back end of the fuselage together. Sheet
the top of the fuselage with 3/16 balsa.
If you plan to use electric power,
build the hatch on the top forward part of
the fuselage. Sheet the bottom of the
fuselage aft of the wing with 3/16 balsa.
The sheeting’s grain should be crosswise
on the top and bottom sheeting.
The bottom forward of the wing will
be sheeted after the wing has been
mounted to the fuselage. Glue in the 1/4
plywood wing-mount plate and set the
fuselage aside to allow the glue to dry.
When the glue has dried on the top and
bottom sheeting, sand the fuselage to shape.
I used a large C-clamp to support a sheet of
1/2 plywood on its edge. Then I carefully
secured the fuselage to the plywood with
part of the fuselage hanging over the edge of
my workbench.
On the part of the fuselage that was
hanging over the edge of the bench I draped
the sandpaper across the top and pulled it
down and back and forth in a method similar
to that you would use to shine your shoes.
When you’re satisfied with the shape of
your fuselage, set it aside and start the wing.
Wing: Start with the center-section. Glue
the R1A and R1B ribs to the R1 ribs as
shown on the plans. Pin the forward spar to
the workbench. Place the rear spar on the
plans, but don’t pin it down; it will need to
be raised up into the ribs after they are in
place. Fit but don’t glue the 1/4 plywood
wing dowel support to the ribs that have the
R1Bs glued to them, and glue them on the
forward spar.
I used landing-gear mounts that Sig sells.
They are 6 inches long, and you need to cut
an inch for the end of each mount. After the
landing-gear mounts are glued in place,
these 1-inch blocks will be glued to the top
of the landing-gear mounts at the inboard
end up against the R1A rib, so don’t throw
them away.
Place the landing-gear mounts on the
plans and adhere the remaining R1 and R1A
ribs to the forward spar. Glue the top
forward and rear spars to the ribs. Pull the
lower rear spar up into the ribs and glue the
ribs to it. Pull the landing-gear mounts up
into the ribs and glue these in place, and then
glue the 1-inch blocks on top of the landinggear
mount against the inboard R1A rib.
Glue the 3/8 balsa LE to the centersection
and then glue the 1/8 plywood wing
dowel support to the LE. Glue a 1 x 3/32-inch
strip of balsa to the top of the ribs at the TE.
Mounting the 1/8 plywood dihedral
supports is next. I did this by drilling some
1/8-inch-diameter holes in the outermost R1
ribs between the top and bottom spars. Then
I joined the holes to form a 1/8-inch-wide
slot from the top spar to the bottom spar by
using a small file.
Install the dihedral joiner into the slot
and glue it to the top and bottom spars.
Make sure the dihedral joiner is at a 90°
angle to the R1 rib before you glue it to the
spars. Do this for the forward and aft
dihedral joiners.
For the outboard wing panels I placed
the forward and main spars on the plans and
then pinned ribs R2-R8 in place on the
plans. I placed rib R1C on the spar but did
not pin it down.
I lifted the main spar up into all the ribs
and placed shims under the spar in various
locations along the spar to hold it off the
workbench and into the ribs. Then I pinned
the spar to the workbench.
Keep the spar straight along the
wingspan and make sure the rib building
tabs are still in contact with the workbench.
Glue all the ribs except R1C to the spar. Lift
the forward spar into rib R1C and R2 and
glue to R2.
Place the top spar on all the ribs and glue
it to all the ribs except R1C. Glue the
forward spar to R2.
Cut the R1C angle guide from the plans
and glue to some scrap plywood, and then
cut the plywood to the shape of the R1C
guide. Place the R1C guide on the bottom
main spar between the top and bottom spars
against R1C.
Adjust R1C so that it is against the
guide, and glue it to the top and bottom
spars. Be careful not to glue the guide to the
rib or the spars, and make sure R1C is in the
proper place on the plans. Move the R1C
guide to the forward spar and adjust rib
R1C, and then glue R1C to the top and
bottom spars.
Glue the 1/4 balsa TE to the aileron
cutout. Make sure you have the cutout at
least 3/32 inch wider than the ribs for the 3/32
balsa sheeting. Glue the top 1 x 3/32-inch
balsa sheeting to the TE at the aileron
cutout. Glue the 3/32 balsa sheeting to the
TE, inboard of the aileron.
I decided to use a laminated balsa LE on
my Val, but you could use a solid balsa LE
if you wanted. For a laminated LE, glue the
first lamination to the ribs’ LEs with some
cyanoacrylate-type glue while the wing is
still pinned to the workbench.
Use a Sig-Ment or Ambroid type of
wood glue to adhere each successive
lamination to the LE. You will need a bunch
of clothespins or clamps to do this;
clothespins may not be long enough to
clamp on the laminations properly.
I worked around this by removing the
wing from the workbench and placing it on
a table with a curved end, with the LE
overhanging the edge of the table. I
weighted down the wing so it would not
move and was held flat on the table. Then I
used the clothespins from the top and
bottom of the LE to hold the laminations on
as the glue dried.
Glue the 3/32 balsa LE sheeting to the top
of the outboard wing section. You may need
to spray some water on the sheeting to make
it easier to bend. Once the glue and sheeting
has dried, sand the wing sheeting flush with
rib R1. Cut the slots in R1 for the dihedral
braces.
Once you are satisfied with the fit of the
outboard section to the inboard section, glue
them together. I used numerous clothespins
to hold ribs R1 and R1C together from the
bottom.
To increase the strength of the plywood
dihedral joint to the top and bottom spars I
added 3/32 balsa to fit between the top and
bottom spars, and then I glued these to the
plywood dihedral braces and the top and
bottom spars.
Build the other outer wing panel in the
same manner as you built the first panel.
Round off the top of the center-section’s
LE so the center-section will fit in the wing
saddle on the fuselage. Center the wing on
the fuselage and then drill the hole for the
1/4-inch wing-mounting dowel through F2
and the wing’s LE. Remove the wing from
the fuselage and glue the 1/4-inch-diameter
dowel in place on the wing.
Sheet the bottom of the wing. Glue the
1/4 balsa TEs to the wing and sand them to
match the contour of the airfoil.
The ailerons are fairly simple to build.
They are 3/32 sheet balsa with half ribs glued
to the top and bottom.
Glue the 1/4-inch-wide balsa capstrips to
the ribs. Use 1/8-inch-thick balsa for the
capstrips. Glue the 1/4 balsa TE to the
ailerons. Cut the slots for the hinges in the
ailerons and in the wing, and then
temporarily mount the ailerons to the wing
and sand the ailerons to match the wing.
Install the aileron-servo mount blocks as
shown on the plans. The 3/32 balsa is to form
a lip around the servo mount hole for the
covering to stick to.
Adhere the wingtip blocks in place and
sand them to shape. Glue the 1/8 plywood
wing-bolt reinforcing plate to the bottom of
the wing on the center-section.
Mount the wing to the fuselage and drill
a 13/64-inch hole in the wing and fuselage for
the wing-mounting screw. Tap the hole in
the fuselage with a 1/4-20 tap. Enlarge the
hole in the wing to 1/4 inch.
Glue F4A and F6 to the bottom of the
wing and then sheet over it with 3/16 balsa.
Use a sharpened brass tube to cut the hole
for access to the wing mounting screw.
Sheet the lower forward part of the fuselage
with 3/16 balsa. Glue the 1/4 balsa F5s in
place. Sand the lower wing fuselage fairing
to match the contour of the fuselage shape.
Flip the fuselage over and secure it to the
worktable so you can mount the horizontal
stabilizer. Slide the horizontal stabilizer into
the slot in the rear of the fuselage. Make
sure the stabilizer is centered on the
fuselage. Sight down the length of the
fuselage from the front or rear and make
sure the stabilizer and wing are parallel to
each other horizontally.
Make sure the stabilizer is square to the
wing by measuring from the wing TE to the
stabilizer TE on both sides of the fuselage,
and make sure these measurements are the
same. Check the horizontal stabilizer’s
incidence to the wing; it should be
approximately 1/2° LE down. When you’re
satisfied that the stabilizer is mounted
correctly, glue it to the fuselage.
Mount the vertical stabilizer to the
fuselage with pins. To align the vertical
stabilizer so that it is not offset to one side
or the other, sight down the top of the
fuselage from the front and pin it in place.
Adjust the vertical stabilizer so it is 90° to
the horizontal stabilizer and then glue the
vertical stabilizer to the fuselage.
The tail-wheel bracket is 1/16-inchdiameter
music wire bent to shape and
mounted to the fuselage with 1/16-inch-insidediameter
brass tube. I built mine by bending
the bottom of the bracket for the axle and
slipping on a small washer to keep the tail
wheel from pushing the rudder up. Then I
soldered the washer to the music wire.
I sharpened the end of the 1/16-inch brass
tube and used it to drill the hole in the
fuselage for the bracket. Then I glued the
brass tube in place on the fuselage and cut it
to length. The music-wire bracket was
slipped into the brass tube and the top of the
bracket was then bent over to fit into the
rudder.
The full-scale Val has a rather large
wing-to-fuselage fillet; this has been drawn
on the plans, but I opted not to install the
fillet on my model. If you want to make a
fillet for yours, I will describe how I was
going to build it.
Cut the fillet base from 1/64 plywood.
Loosely mount the wing to the fuselage and
slip the fillet base in place between the wing
and fuselage. When you are satisfied with
the location of the fillet, tighten the wing to
the fuselage and glue the fillet to the
fuselage only.
Cut some soft balsa blocks and glue
them to the fuselage. Carve and sand them
to the shape of the fillet.
Bend the elevator joiner from 1/8-inch
music wire, and then temporarily mount the
elevator using your favorite hinging method.
Temporarily mount the rudder.
Set the model aside and then bend the
main landing gear from 3/16-inch music wire.
The wheel pants are made from various
thicknesses of balsa. The thickness of the
main core of the wheel pants is determined
by the thickness of the wheels you use and
the addition of the wheel collars.
If you fly from a grass strip, cut the
bottom of the pants so that more of the
wheel is exposed than shown on the plans. I
have seen pictures of a full-scale Val’s
wheel without wheel pants, so you may not
want to build them for your model. Once
you have cut all the parts for the wheel
pants, glue them together and sand them to
shape.
Final-sand the fuselage and cover it with
your favorite covering material. I used
MonoKote. Although the colors I used are
not exactly accurate, I loosely based the color
scheme on a Val that was aboard the aircraft
carrier Akagi during the battle of Midway. I
got the red “meatballs” from a set of decals I
had from an old Top Flite Zero kit.
The canopy I used is from the Great
Planes AT-6 Texan ARF that is available
from Tower Hobbies. I decided early that I
would have cooling holes cut in the fuselage
in the cockpit area and I would leave the
rear of the canopy open for the air to escape.
I cut the excess plastic from the canopy
as if I was going to mount it on the model
for which it was designed. Then I placed the
canopy on the top of the fuselage and
pressed it down until the front of the
windscreen touched the top of the fuselage. I
used a dry-erase marker to indicate the side
of the canopy on which I needed to cut it to
make it fit the fuselage.
After I cut the canopy to fit the fuselage I
used a rag to remove the marks left on the
canopy. I taped the canopy in place on the
fuselage and marked the fuselage so I could
remove the green MonoKote from the
cockpit area and replace it with black
MonoKote.
Once I had re-covered the cockpit area
with the black MonoKote, I carefully cut a
small strip away from the black for the
canopy to be glued to bare wood on the
fuselage. I used a sharpened brass tube to
cut the cooling holes in the cockpit area.
Since I wanted to keep my model simple
but still wanted a pilot and gunner in it, I
decided to use a simple, flat version. I found
a picture of a pilot and gunner and scanned
it into my computer. Then I enlarged the
picture to the correct size. I created a mirror
image of the picture, and then I printed the
mirror image and the original image of the
picture.
I glued one side of the pilot and gunner
to a piece of 1/64 plywood. Then I cut the
plywood to the shape of the pilot and gunner
and glued the mirror image to the other side
of the pilot. To make the plywood blend into
the figures, I darkened the edge of the wood
with a black magic marker.
I glued the pilot and gunner figures into
slots cut in the cockpit area. When I was
happy with the cockpit area, I glued the
canopy to the fuselage with some Formula
560 canopy glue.
I mounted an old Vortac bomb release to
the bottom of the wing near the CG. If you
want to mount a bomb release, be careful
not to cut the wing spars as you make the
cutout for the release. I used a T-pin to poke
through the wing sheeting to locate the
spars. I mounted the bomb-release servo
upside down in the wing so that a servo arm
would actuate the release.
The Val’s nose is rather short, so I
mounted the radio gear as far forward in
the fuselage as I could. I still ended up
adding lead to the nose to get the CG
where I wanted it.
The aileron servos are mounted to the
bottom of the wing and are connected to the
receiver by a Y harness. I like my models to
be fairly responsive, so I set my control
throws as follows: rudder, 1 inch left and
right; elevator, 1/2 inch up and down;
ailerons, 1/4 inch down and 1/2 inch up.
The ailerons need more up than down
travel, and this is achieved by mounting the
servo arm on the servo at roughly a 45° angle
toward the front of the airplane. These are
good starting points for the first few flights.
After that you may want to increase or
decrease the throws to suit your flying style.
Flying: If you are like I am, you probably
skipped most of the article and came right to
this point to see how the Val flies. It flies
exactly like an advanced trainer. If the only
models you have ever flown are high-wing
trainers and you want to move on to a lowwing
trainer, this may be the airplane you’re
looking for.
The first flight with my Val took place
early on a cool, windless Saturday morning.
After range checking my radio with the
motor on, I taxied the model to the far end
of the runway. I slowly advanced the throttle
and let the Val roll down the runway. It
wanted to pull to the left, but I had no
problems keeping it headed down the
runway with the rudder.
After roughly 150 feet I started to feed in
up-elevator and the Val became airborne in
a nice, realistic manner. As I gained some
altitude I realized the Val needed some upelevator
trim and a little right aileron trim to
keep it level.
Once I had the Val trimmed out, I made
some low passes so my daughter Erin could
take some pictures of it in flight. I was
exceptionally pleased with how the model
flew. I took it up high to see how the Val
handled in slow flight; I was quite pleased to
see how slow it was able to fly before it
stalled.
The right wing had a tendency to drop
when the model stalled, but it was easy to
control right up to the stall. After a few
more low passes I tried a few touch-and-gos.
The big propeller windmilling created
quite a bit of drag, and I found that I needed
to keep a little power on during the approach
or make steep approaches to keep up the
airspeed. There is no tendency for the Val to
float too much once the power has been
pulled all the way back, but it doesn’t drop
like a brick either.
When I took my airplane home I checked
the wings for warp and found a slight one in
the right wing. Twisting the wing and
reheating the MonoKote removed the warp.
I also redrew the plans to show 1/2°
incidence in the horizontal stabilizer.
On subsequent flights I was able to see
how aerobatic the Val is. It will fly upside
down by my holding a little down-elevator
with no problem. Rolls are nice and crisp.
There is little roll coupling with the rudder.
Landings are a breeze; you can wheelie it
on, and three point it on, or if you’re careful
you can one-point it on the tail wheel!
If you want a model that can do all the
fancy stuff, the Val will probably make you
yawn. But if you’re looking for an advanced
trainer that looks like a full-scale airplane or
if you want to try flying in a Fun Scale
contest or two, this may be a great fit for
you. MA
Gary Fuller
Edition: Model Aviation - 2007/03
Page Numbers: 29,30,31,32,33,34,35,36,38,40
I WAS DISCUSSING with a friend my effort to try to come up
with an interesting model that would be fun to build and fly, and the
Japanese Val was mentioned. All I really knew about it was that it
was a low-wing, fixed-landing-gear dive-bomber the Japanese used
during World War II.
Part of what I enjoy about modeling is researching the various
airplanes I build, so I started researching this aircraft. Did you know
that a Val dropped the first bomb during the attack on Pearl Harbor
in Hawaii in 1941?
After looking at a three-view drawing I decided the Val looked
like it might make a good-flying model. It had a generous amount of
wing area; the landing gear was fixed, which would keep modeling
costs down; and I could have the added fun of a droppable bomb.
The elliptical wing was the only thing I could think of that would
make the Val slightly more difficult to design and build than any
other low-winged sport model. However, the wing turned out to be
fairly easy to build.
Since I like my sport-scale models to be easy to construct, the
fuselage is built with flat sides like most other sport models. I also
like to keep the weight down, so I made the fuselage as skinny as I
could but wide enough to hide the radio and engine.
To make the horizontal and vertical stabilizer simple to build I
used 1/4 balsa sheet. The wheel pants were the only things that gave
me any trouble, and that was only when it was time to cover them
with MonoKote.
I put 2° of washout in the wingtips to help during low-speed
flight. With a ready-to-fly weight of approximately 6 pounds and a
wing area of 680 square inches, the wing loading is only
approximately 20 ounces per square foot; that’s close to the wing
loading of most trainers.
The electric bug has bitten me, so I used a MaxCim motor,
gearbox, and controller in my Val. I think any motor that can put out
at least 350 watts will work. If you want to use glow power, I
recommend a .40-.60 two-stroke or a .52-.70 four-stroke engine.
Artist’s composite of bare
wood and finished model.
Gary covered his Val with MonoKote. Although the colors are
not authentic, the markings were used on a Val during the
attack on Midway Island in 1942. This color scheme is easy to
see in the air. Erin Fuller photo.
The left and right fuselage sides are almost ready to join; all that is needed is to taper the
1/2 balsa triangle stock at the rear end.
Before gluing the tail end of the fuselage together, place scrap wood in the horizontal
stabilizer slot and on the wing saddle. Sight down the fuselage and get the two scrap
wood pieces parallel with each other by adjusting the fuselage sides, which are held
together with the clothespin.
The author prefers Sig-Ment or Ambroid to glue the top and
bottom 3/16 balsa sheeting in place. Holes are drilled in the firewall
to cool the batteries and motor.
The center-section of the wing. Use a piece of aluminum angle to
hold the TE of the ribs in alignment.
Type: RC semiscale
Wingspan: 63 inches
Wing area: 680 square inches
Flying weight: 6 pounds
Wing loading: 20.25 ounces
per square foot
Power: .32-.50 two-stroke or
.40-.65 four-stroke engine or
MaxCim MaxN32-13Y
motor geared 2.2:1, using a
15-volt 4000 mAh battery
Construction: Balsa and
plywood
Covering/finish: MonoKote
Photos by the author except as noted
Before the LE is installed, glue the top TE sheeting in place. The
first of the laminations are shown glued to the LE.
The landing-gear mount block in the wing center-section. After the top spar is glued to the ribs the bottom spar is lifted into the
lower spar slots, and then the spar is blocked up and glued to the ribs.
The R1C angle guide is being used to set rib R1C to the correct
angle. Don’t glue the rib to the spars until all the spars are in place.
Many clothespins are used to hold the LE laminations together
while the glue dries.
Glue the top sheeting to the LE only first. After the glue dries, wet
the top sheeting with water and ammonia to make it more flexible.
Before sheeting the top of the wing center-section, drill the holes for
the landing-gear wires through the landing-gear mounting blocks
using the vertical piece of grooved block as a guide.
32 MODEL AVIATION
Clothespins and clamps are used to hold the outboard section of
the wing to the inboard section while the glue dries.
Clothespins and regular T-pins are used to hold the wing sheeting
in place as the glue dries.
It makes it easier to drill the hole for the 1/4–inch-diameter wingmounting
dowel if you delay the sheeting of the bottom of the
forward fuselage.
Aileron servos are mounted on the bottom of the wing. The ailerons
need more up travel than down to reduce adverse yaw at low
airspeeds.
The motor speed control and receiver are mounted with hook-andloop
material. Other pieces of hook-and-loop are used to hold the
wiring.
Only one nylon landing-gear
strap is needed to mount the
wheel pants to the landing gear.
The motor and radio switches
are painted to match the
covering.
Drill a 1/4-inch hole in a large block of wood and insert the 1/4-inch
wing-mounting dowel. This holds the wing in a vertical position,
aiding in construction.
CONSTRUCTION:
I like to cut most of the parts for my
models before I begin building. There are
numerous ways to transfer the shape of
the part to the wood, but my favorite is to
cut the plans for the separate parts and
then use low-tack glue to adhere the
plans part directly to the wood. I have
had good luck using Elmer’s glue sticks.
Use a band saw to cut the wood to
shape. After the part is cut, remove the
paper from the wood. Drill the holes for
the motor mount when you cut the
firewall.
Fuselage: Start with the fuselage by
laying the left and right sides on my
workbench so that they are top to top;
that way you won’t make two left or right
sides as you glue the various pieces to the
sides.
Glue the 1/16 balsa (or plywood if you
plan to use glow power) doublers to the
sides. Make sure you glue the shorter of
the two doublers to the right side; this is
for the 2° right thrust for the engine.
Adhere the 1/2 balsa triangle stock to
the edges of the side as shown on the
plans. Once the glue has dried, taper the
triangle stock at the back end of the
fuselage. Glue the 1/4 square balsa side
stiffeners to the sides as shown on the
plans.
Glue formers F2, F3, and F4 to only
one side of the fuselage at this time.
Former F2 can be positioned to suit your
needs whether you use a glow engine or
an electric motor. Make sure they are 90°
to the side.
Glue the 1/8 square balsa to F4 as
shown on the plans. Glue the other side
to the formers. I did this by rubber
banding the sides to each other, and using
a square and my eyeballs I aligned the
sides to each other. Glue the formers to
the other side. Glue the firewall in place.
Set the fuselage on the workbench so
it is sitting on its top. Place some 1/4 balsa
sheet scraps in the wing saddle and the
horizontal stabilizer slots on the fuselage,
and then bring the aft end of the fuselage
sides together and hold in place with a
clothespin.
Sighting from the front or back end of
the fuselage, the sides are adjusted at the
back end so the 1/4-inch sticks are parallel
with each other and the fuselage is
straight. Once these are aligned, glue the
back end of the fuselage together. Sheet
the top of the fuselage with 3/16 balsa.
If you plan to use electric power,
build the hatch on the top forward part of
the fuselage. Sheet the bottom of the
fuselage aft of the wing with 3/16 balsa.
The sheeting’s grain should be crosswise
on the top and bottom sheeting.
The bottom forward of the wing will
be sheeted after the wing has been
mounted to the fuselage. Glue in the 1/4
plywood wing-mount plate and set the
fuselage aside to allow the glue to dry.
When the glue has dried on the top and
bottom sheeting, sand the fuselage to shape.
I used a large C-clamp to support a sheet of
1/2 plywood on its edge. Then I carefully
secured the fuselage to the plywood with
part of the fuselage hanging over the edge of
my workbench.
On the part of the fuselage that was
hanging over the edge of the bench I draped
the sandpaper across the top and pulled it
down and back and forth in a method similar
to that you would use to shine your shoes.
When you’re satisfied with the shape of
your fuselage, set it aside and start the wing.
Wing: Start with the center-section. Glue
the R1A and R1B ribs to the R1 ribs as
shown on the plans. Pin the forward spar to
the workbench. Place the rear spar on the
plans, but don’t pin it down; it will need to
be raised up into the ribs after they are in
place. Fit but don’t glue the 1/4 plywood
wing dowel support to the ribs that have the
R1Bs glued to them, and glue them on the
forward spar.
I used landing-gear mounts that Sig sells.
They are 6 inches long, and you need to cut
an inch for the end of each mount. After the
landing-gear mounts are glued in place,
these 1-inch blocks will be glued to the top
of the landing-gear mounts at the inboard
end up against the R1A rib, so don’t throw
them away.
Place the landing-gear mounts on the
plans and adhere the remaining R1 and R1A
ribs to the forward spar. Glue the top
forward and rear spars to the ribs. Pull the
lower rear spar up into the ribs and glue the
ribs to it. Pull the landing-gear mounts up
into the ribs and glue these in place, and then
glue the 1-inch blocks on top of the landinggear
mount against the inboard R1A rib.
Glue the 3/8 balsa LE to the centersection
and then glue the 1/8 plywood wing
dowel support to the LE. Glue a 1 x 3/32-inch
strip of balsa to the top of the ribs at the TE.
Mounting the 1/8 plywood dihedral
supports is next. I did this by drilling some
1/8-inch-diameter holes in the outermost R1
ribs between the top and bottom spars. Then
I joined the holes to form a 1/8-inch-wide
slot from the top spar to the bottom spar by
using a small file.
Install the dihedral joiner into the slot
and glue it to the top and bottom spars.
Make sure the dihedral joiner is at a 90°
angle to the R1 rib before you glue it to the
spars. Do this for the forward and aft
dihedral joiners.
For the outboard wing panels I placed
the forward and main spars on the plans and
then pinned ribs R2-R8 in place on the
plans. I placed rib R1C on the spar but did
not pin it down.
I lifted the main spar up into all the ribs
and placed shims under the spar in various
locations along the spar to hold it off the
workbench and into the ribs. Then I pinned
the spar to the workbench.
Keep the spar straight along the
wingspan and make sure the rib building
tabs are still in contact with the workbench.
Glue all the ribs except R1C to the spar. Lift
the forward spar into rib R1C and R2 and
glue to R2.
Place the top spar on all the ribs and glue
it to all the ribs except R1C. Glue the
forward spar to R2.
Cut the R1C angle guide from the plans
and glue to some scrap plywood, and then
cut the plywood to the shape of the R1C
guide. Place the R1C guide on the bottom
main spar between the top and bottom spars
against R1C.
Adjust R1C so that it is against the
guide, and glue it to the top and bottom
spars. Be careful not to glue the guide to the
rib or the spars, and make sure R1C is in the
proper place on the plans. Move the R1C
guide to the forward spar and adjust rib
R1C, and then glue R1C to the top and
bottom spars.
Glue the 1/4 balsa TE to the aileron
cutout. Make sure you have the cutout at
least 3/32 inch wider than the ribs for the 3/32
balsa sheeting. Glue the top 1 x 3/32-inch
balsa sheeting to the TE at the aileron
cutout. Glue the 3/32 balsa sheeting to the
TE, inboard of the aileron.
I decided to use a laminated balsa LE on
my Val, but you could use a solid balsa LE
if you wanted. For a laminated LE, glue the
first lamination to the ribs’ LEs with some
cyanoacrylate-type glue while the wing is
still pinned to the workbench.
Use a Sig-Ment or Ambroid type of
wood glue to adhere each successive
lamination to the LE. You will need a bunch
of clothespins or clamps to do this;
clothespins may not be long enough to
clamp on the laminations properly.
I worked around this by removing the
wing from the workbench and placing it on
a table with a curved end, with the LE
overhanging the edge of the table. I
weighted down the wing so it would not
move and was held flat on the table. Then I
used the clothespins from the top and
bottom of the LE to hold the laminations on
as the glue dried.
Glue the 3/32 balsa LE sheeting to the top
of the outboard wing section. You may need
to spray some water on the sheeting to make
it easier to bend. Once the glue and sheeting
has dried, sand the wing sheeting flush with
rib R1. Cut the slots in R1 for the dihedral
braces.
Once you are satisfied with the fit of the
outboard section to the inboard section, glue
them together. I used numerous clothespins
to hold ribs R1 and R1C together from the
bottom.
To increase the strength of the plywood
dihedral joint to the top and bottom spars I
added 3/32 balsa to fit between the top and
bottom spars, and then I glued these to the
plywood dihedral braces and the top and
bottom spars.
Build the other outer wing panel in the
same manner as you built the first panel.
Round off the top of the center-section’s
LE so the center-section will fit in the wing
saddle on the fuselage. Center the wing on
the fuselage and then drill the hole for the
1/4-inch wing-mounting dowel through F2
and the wing’s LE. Remove the wing from
the fuselage and glue the 1/4-inch-diameter
dowel in place on the wing.
Sheet the bottom of the wing. Glue the
1/4 balsa TEs to the wing and sand them to
match the contour of the airfoil.
The ailerons are fairly simple to build.
They are 3/32 sheet balsa with half ribs glued
to the top and bottom.
Glue the 1/4-inch-wide balsa capstrips to
the ribs. Use 1/8-inch-thick balsa for the
capstrips. Glue the 1/4 balsa TE to the
ailerons. Cut the slots for the hinges in the
ailerons and in the wing, and then
temporarily mount the ailerons to the wing
and sand the ailerons to match the wing.
Install the aileron-servo mount blocks as
shown on the plans. The 3/32 balsa is to form
a lip around the servo mount hole for the
covering to stick to.
Adhere the wingtip blocks in place and
sand them to shape. Glue the 1/8 plywood
wing-bolt reinforcing plate to the bottom of
the wing on the center-section.
Mount the wing to the fuselage and drill
a 13/64-inch hole in the wing and fuselage for
the wing-mounting screw. Tap the hole in
the fuselage with a 1/4-20 tap. Enlarge the
hole in the wing to 1/4 inch.
Glue F4A and F6 to the bottom of the
wing and then sheet over it with 3/16 balsa.
Use a sharpened brass tube to cut the hole
for access to the wing mounting screw.
Sheet the lower forward part of the fuselage
with 3/16 balsa. Glue the 1/4 balsa F5s in
place. Sand the lower wing fuselage fairing
to match the contour of the fuselage shape.
Flip the fuselage over and secure it to the
worktable so you can mount the horizontal
stabilizer. Slide the horizontal stabilizer into
the slot in the rear of the fuselage. Make
sure the stabilizer is centered on the
fuselage. Sight down the length of the
fuselage from the front or rear and make
sure the stabilizer and wing are parallel to
each other horizontally.
Make sure the stabilizer is square to the
wing by measuring from the wing TE to the
stabilizer TE on both sides of the fuselage,
and make sure these measurements are the
same. Check the horizontal stabilizer’s
incidence to the wing; it should be
approximately 1/2° LE down. When you’re
satisfied that the stabilizer is mounted
correctly, glue it to the fuselage.
Mount the vertical stabilizer to the
fuselage with pins. To align the vertical
stabilizer so that it is not offset to one side
or the other, sight down the top of the
fuselage from the front and pin it in place.
Adjust the vertical stabilizer so it is 90° to
the horizontal stabilizer and then glue the
vertical stabilizer to the fuselage.
The tail-wheel bracket is 1/16-inchdiameter
music wire bent to shape and
mounted to the fuselage with 1/16-inch-insidediameter
brass tube. I built mine by bending
the bottom of the bracket for the axle and
slipping on a small washer to keep the tail
wheel from pushing the rudder up. Then I
soldered the washer to the music wire.
I sharpened the end of the 1/16-inch brass
tube and used it to drill the hole in the
fuselage for the bracket. Then I glued the
brass tube in place on the fuselage and cut it
to length. The music-wire bracket was
slipped into the brass tube and the top of the
bracket was then bent over to fit into the
rudder.
The full-scale Val has a rather large
wing-to-fuselage fillet; this has been drawn
on the plans, but I opted not to install the
fillet on my model. If you want to make a
fillet for yours, I will describe how I was
going to build it.
Cut the fillet base from 1/64 plywood.
Loosely mount the wing to the fuselage and
slip the fillet base in place between the wing
and fuselage. When you are satisfied with
the location of the fillet, tighten the wing to
the fuselage and glue the fillet to the
fuselage only.
Cut some soft balsa blocks and glue
them to the fuselage. Carve and sand them
to the shape of the fillet.
Bend the elevator joiner from 1/8-inch
music wire, and then temporarily mount the
elevator using your favorite hinging method.
Temporarily mount the rudder.
Set the model aside and then bend the
main landing gear from 3/16-inch music wire.
The wheel pants are made from various
thicknesses of balsa. The thickness of the
main core of the wheel pants is determined
by the thickness of the wheels you use and
the addition of the wheel collars.
If you fly from a grass strip, cut the
bottom of the pants so that more of the
wheel is exposed than shown on the plans. I
have seen pictures of a full-scale Val’s
wheel without wheel pants, so you may not
want to build them for your model. Once
you have cut all the parts for the wheel
pants, glue them together and sand them to
shape.
Final-sand the fuselage and cover it with
your favorite covering material. I used
MonoKote. Although the colors I used are
not exactly accurate, I loosely based the color
scheme on a Val that was aboard the aircraft
carrier Akagi during the battle of Midway. I
got the red “meatballs” from a set of decals I
had from an old Top Flite Zero kit.
The canopy I used is from the Great
Planes AT-6 Texan ARF that is available
from Tower Hobbies. I decided early that I
would have cooling holes cut in the fuselage
in the cockpit area and I would leave the
rear of the canopy open for the air to escape.
I cut the excess plastic from the canopy
as if I was going to mount it on the model
for which it was designed. Then I placed the
canopy on the top of the fuselage and
pressed it down until the front of the
windscreen touched the top of the fuselage. I
used a dry-erase marker to indicate the side
of the canopy on which I needed to cut it to
make it fit the fuselage.
After I cut the canopy to fit the fuselage I
used a rag to remove the marks left on the
canopy. I taped the canopy in place on the
fuselage and marked the fuselage so I could
remove the green MonoKote from the
cockpit area and replace it with black
MonoKote.
Once I had re-covered the cockpit area
with the black MonoKote, I carefully cut a
small strip away from the black for the
canopy to be glued to bare wood on the
fuselage. I used a sharpened brass tube to
cut the cooling holes in the cockpit area.
Since I wanted to keep my model simple
but still wanted a pilot and gunner in it, I
decided to use a simple, flat version. I found
a picture of a pilot and gunner and scanned
it into my computer. Then I enlarged the
picture to the correct size. I created a mirror
image of the picture, and then I printed the
mirror image and the original image of the
picture.
I glued one side of the pilot and gunner
to a piece of 1/64 plywood. Then I cut the
plywood to the shape of the pilot and gunner
and glued the mirror image to the other side
of the pilot. To make the plywood blend into
the figures, I darkened the edge of the wood
with a black magic marker.
I glued the pilot and gunner figures into
slots cut in the cockpit area. When I was
happy with the cockpit area, I glued the
canopy to the fuselage with some Formula
560 canopy glue.
I mounted an old Vortac bomb release to
the bottom of the wing near the CG. If you
want to mount a bomb release, be careful
not to cut the wing spars as you make the
cutout for the release. I used a T-pin to poke
through the wing sheeting to locate the
spars. I mounted the bomb-release servo
upside down in the wing so that a servo arm
would actuate the release.
The Val’s nose is rather short, so I
mounted the radio gear as far forward in
the fuselage as I could. I still ended up
adding lead to the nose to get the CG
where I wanted it.
The aileron servos are mounted to the
bottom of the wing and are connected to the
receiver by a Y harness. I like my models to
be fairly responsive, so I set my control
throws as follows: rudder, 1 inch left and
right; elevator, 1/2 inch up and down;
ailerons, 1/4 inch down and 1/2 inch up.
The ailerons need more up than down
travel, and this is achieved by mounting the
servo arm on the servo at roughly a 45° angle
toward the front of the airplane. These are
good starting points for the first few flights.
After that you may want to increase or
decrease the throws to suit your flying style.
Flying: If you are like I am, you probably
skipped most of the article and came right to
this point to see how the Val flies. It flies
exactly like an advanced trainer. If the only
models you have ever flown are high-wing
trainers and you want to move on to a lowwing
trainer, this may be the airplane you’re
looking for.
The first flight with my Val took place
early on a cool, windless Saturday morning.
After range checking my radio with the
motor on, I taxied the model to the far end
of the runway. I slowly advanced the throttle
and let the Val roll down the runway. It
wanted to pull to the left, but I had no
problems keeping it headed down the
runway with the rudder.
After roughly 150 feet I started to feed in
up-elevator and the Val became airborne in
a nice, realistic manner. As I gained some
altitude I realized the Val needed some upelevator
trim and a little right aileron trim to
keep it level.
Once I had the Val trimmed out, I made
some low passes so my daughter Erin could
take some pictures of it in flight. I was
exceptionally pleased with how the model
flew. I took it up high to see how the Val
handled in slow flight; I was quite pleased to
see how slow it was able to fly before it
stalled.
The right wing had a tendency to drop
when the model stalled, but it was easy to
control right up to the stall. After a few
more low passes I tried a few touch-and-gos.
The big propeller windmilling created
quite a bit of drag, and I found that I needed
to keep a little power on during the approach
or make steep approaches to keep up the
airspeed. There is no tendency for the Val to
float too much once the power has been
pulled all the way back, but it doesn’t drop
like a brick either.
When I took my airplane home I checked
the wings for warp and found a slight one in
the right wing. Twisting the wing and
reheating the MonoKote removed the warp.
I also redrew the plans to show 1/2°
incidence in the horizontal stabilizer.
On subsequent flights I was able to see
how aerobatic the Val is. It will fly upside
down by my holding a little down-elevator
with no problem. Rolls are nice and crisp.
There is little roll coupling with the rudder.
Landings are a breeze; you can wheelie it
on, and three point it on, or if you’re careful
you can one-point it on the tail wheel!
If you want a model that can do all the
fancy stuff, the Val will probably make you
yawn. But if you’re looking for an advanced
trainer that looks like a full-scale airplane or
if you want to try flying in a Fun Scale
contest or two, this may be a great fit for
you. MA
Gary Fuller
Edition: Model Aviation - 2007/03
Page Numbers: 29,30,31,32,33,34,35,36,38,40
I WAS DISCUSSING with a friend my effort to try to come up
with an interesting model that would be fun to build and fly, and the
Japanese Val was mentioned. All I really knew about it was that it
was a low-wing, fixed-landing-gear dive-bomber the Japanese used
during World War II.
Part of what I enjoy about modeling is researching the various
airplanes I build, so I started researching this aircraft. Did you know
that a Val dropped the first bomb during the attack on Pearl Harbor
in Hawaii in 1941?
After looking at a three-view drawing I decided the Val looked
like it might make a good-flying model. It had a generous amount of
wing area; the landing gear was fixed, which would keep modeling
costs down; and I could have the added fun of a droppable bomb.
The elliptical wing was the only thing I could think of that would
make the Val slightly more difficult to design and build than any
other low-winged sport model. However, the wing turned out to be
fairly easy to build.
Since I like my sport-scale models to be easy to construct, the
fuselage is built with flat sides like most other sport models. I also
like to keep the weight down, so I made the fuselage as skinny as I
could but wide enough to hide the radio and engine.
To make the horizontal and vertical stabilizer simple to build I
used 1/4 balsa sheet. The wheel pants were the only things that gave
me any trouble, and that was only when it was time to cover them
with MonoKote.
I put 2° of washout in the wingtips to help during low-speed
flight. With a ready-to-fly weight of approximately 6 pounds and a
wing area of 680 square inches, the wing loading is only
approximately 20 ounces per square foot; that’s close to the wing
loading of most trainers.
The electric bug has bitten me, so I used a MaxCim motor,
gearbox, and controller in my Val. I think any motor that can put out
at least 350 watts will work. If you want to use glow power, I
recommend a .40-.60 two-stroke or a .52-.70 four-stroke engine.
Artist’s composite of bare
wood and finished model.
Gary covered his Val with MonoKote. Although the colors are
not authentic, the markings were used on a Val during the
attack on Midway Island in 1942. This color scheme is easy to
see in the air. Erin Fuller photo.
The left and right fuselage sides are almost ready to join; all that is needed is to taper the
1/2 balsa triangle stock at the rear end.
Before gluing the tail end of the fuselage together, place scrap wood in the horizontal
stabilizer slot and on the wing saddle. Sight down the fuselage and get the two scrap
wood pieces parallel with each other by adjusting the fuselage sides, which are held
together with the clothespin.
The author prefers Sig-Ment or Ambroid to glue the top and
bottom 3/16 balsa sheeting in place. Holes are drilled in the firewall
to cool the batteries and motor.
The center-section of the wing. Use a piece of aluminum angle to
hold the TE of the ribs in alignment.
Type: RC semiscale
Wingspan: 63 inches
Wing area: 680 square inches
Flying weight: 6 pounds
Wing loading: 20.25 ounces
per square foot
Power: .32-.50 two-stroke or
.40-.65 four-stroke engine or
MaxCim MaxN32-13Y
motor geared 2.2:1, using a
15-volt 4000 mAh battery
Construction: Balsa and
plywood
Covering/finish: MonoKote
Photos by the author except as noted
Before the LE is installed, glue the top TE sheeting in place. The
first of the laminations are shown glued to the LE.
The landing-gear mount block in the wing center-section. After the top spar is glued to the ribs the bottom spar is lifted into the
lower spar slots, and then the spar is blocked up and glued to the ribs.
The R1C angle guide is being used to set rib R1C to the correct
angle. Don’t glue the rib to the spars until all the spars are in place.
Many clothespins are used to hold the LE laminations together
while the glue dries.
Glue the top sheeting to the LE only first. After the glue dries, wet
the top sheeting with water and ammonia to make it more flexible.
Before sheeting the top of the wing center-section, drill the holes for
the landing-gear wires through the landing-gear mounting blocks
using the vertical piece of grooved block as a guide.
32 MODEL AVIATION
Clothespins and clamps are used to hold the outboard section of
the wing to the inboard section while the glue dries.
Clothespins and regular T-pins are used to hold the wing sheeting
in place as the glue dries.
It makes it easier to drill the hole for the 1/4–inch-diameter wingmounting
dowel if you delay the sheeting of the bottom of the
forward fuselage.
Aileron servos are mounted on the bottom of the wing. The ailerons
need more up travel than down to reduce adverse yaw at low
airspeeds.
The motor speed control and receiver are mounted with hook-andloop
material. Other pieces of hook-and-loop are used to hold the
wiring.
Only one nylon landing-gear
strap is needed to mount the
wheel pants to the landing gear.
The motor and radio switches
are painted to match the
covering.
Drill a 1/4-inch hole in a large block of wood and insert the 1/4-inch
wing-mounting dowel. This holds the wing in a vertical position,
aiding in construction.
CONSTRUCTION:
I like to cut most of the parts for my
models before I begin building. There are
numerous ways to transfer the shape of
the part to the wood, but my favorite is to
cut the plans for the separate parts and
then use low-tack glue to adhere the
plans part directly to the wood. I have
had good luck using Elmer’s glue sticks.
Use a band saw to cut the wood to
shape. After the part is cut, remove the
paper from the wood. Drill the holes for
the motor mount when you cut the
firewall.
Fuselage: Start with the fuselage by
laying the left and right sides on my
workbench so that they are top to top;
that way you won’t make two left or right
sides as you glue the various pieces to the
sides.
Glue the 1/16 balsa (or plywood if you
plan to use glow power) doublers to the
sides. Make sure you glue the shorter of
the two doublers to the right side; this is
for the 2° right thrust for the engine.
Adhere the 1/2 balsa triangle stock to
the edges of the side as shown on the
plans. Once the glue has dried, taper the
triangle stock at the back end of the
fuselage. Glue the 1/4 square balsa side
stiffeners to the sides as shown on the
plans.
Glue formers F2, F3, and F4 to only
one side of the fuselage at this time.
Former F2 can be positioned to suit your
needs whether you use a glow engine or
an electric motor. Make sure they are 90°
to the side.
Glue the 1/8 square balsa to F4 as
shown on the plans. Glue the other side
to the formers. I did this by rubber
banding the sides to each other, and using
a square and my eyeballs I aligned the
sides to each other. Glue the formers to
the other side. Glue the firewall in place.
Set the fuselage on the workbench so
it is sitting on its top. Place some 1/4 balsa
sheet scraps in the wing saddle and the
horizontal stabilizer slots on the fuselage,
and then bring the aft end of the fuselage
sides together and hold in place with a
clothespin.
Sighting from the front or back end of
the fuselage, the sides are adjusted at the
back end so the 1/4-inch sticks are parallel
with each other and the fuselage is
straight. Once these are aligned, glue the
back end of the fuselage together. Sheet
the top of the fuselage with 3/16 balsa.
If you plan to use electric power,
build the hatch on the top forward part of
the fuselage. Sheet the bottom of the
fuselage aft of the wing with 3/16 balsa.
The sheeting’s grain should be crosswise
on the top and bottom sheeting.
The bottom forward of the wing will
be sheeted after the wing has been
mounted to the fuselage. Glue in the 1/4
plywood wing-mount plate and set the
fuselage aside to allow the glue to dry.
When the glue has dried on the top and
bottom sheeting, sand the fuselage to shape.
I used a large C-clamp to support a sheet of
1/2 plywood on its edge. Then I carefully
secured the fuselage to the plywood with
part of the fuselage hanging over the edge of
my workbench.
On the part of the fuselage that was
hanging over the edge of the bench I draped
the sandpaper across the top and pulled it
down and back and forth in a method similar
to that you would use to shine your shoes.
When you’re satisfied with the shape of
your fuselage, set it aside and start the wing.
Wing: Start with the center-section. Glue
the R1A and R1B ribs to the R1 ribs as
shown on the plans. Pin the forward spar to
the workbench. Place the rear spar on the
plans, but don’t pin it down; it will need to
be raised up into the ribs after they are in
place. Fit but don’t glue the 1/4 plywood
wing dowel support to the ribs that have the
R1Bs glued to them, and glue them on the
forward spar.
I used landing-gear mounts that Sig sells.
They are 6 inches long, and you need to cut
an inch for the end of each mount. After the
landing-gear mounts are glued in place,
these 1-inch blocks will be glued to the top
of the landing-gear mounts at the inboard
end up against the R1A rib, so don’t throw
them away.
Place the landing-gear mounts on the
plans and adhere the remaining R1 and R1A
ribs to the forward spar. Glue the top
forward and rear spars to the ribs. Pull the
lower rear spar up into the ribs and glue the
ribs to it. Pull the landing-gear mounts up
into the ribs and glue these in place, and then
glue the 1-inch blocks on top of the landinggear
mount against the inboard R1A rib.
Glue the 3/8 balsa LE to the centersection
and then glue the 1/8 plywood wing
dowel support to the LE. Glue a 1 x 3/32-inch
strip of balsa to the top of the ribs at the TE.
Mounting the 1/8 plywood dihedral
supports is next. I did this by drilling some
1/8-inch-diameter holes in the outermost R1
ribs between the top and bottom spars. Then
I joined the holes to form a 1/8-inch-wide
slot from the top spar to the bottom spar by
using a small file.
Install the dihedral joiner into the slot
and glue it to the top and bottom spars.
Make sure the dihedral joiner is at a 90°
angle to the R1 rib before you glue it to the
spars. Do this for the forward and aft
dihedral joiners.
For the outboard wing panels I placed
the forward and main spars on the plans and
then pinned ribs R2-R8 in place on the
plans. I placed rib R1C on the spar but did
not pin it down.
I lifted the main spar up into all the ribs
and placed shims under the spar in various
locations along the spar to hold it off the
workbench and into the ribs. Then I pinned
the spar to the workbench.
Keep the spar straight along the
wingspan and make sure the rib building
tabs are still in contact with the workbench.
Glue all the ribs except R1C to the spar. Lift
the forward spar into rib R1C and R2 and
glue to R2.
Place the top spar on all the ribs and glue
it to all the ribs except R1C. Glue the
forward spar to R2.
Cut the R1C angle guide from the plans
and glue to some scrap plywood, and then
cut the plywood to the shape of the R1C
guide. Place the R1C guide on the bottom
main spar between the top and bottom spars
against R1C.
Adjust R1C so that it is against the
guide, and glue it to the top and bottom
spars. Be careful not to glue the guide to the
rib or the spars, and make sure R1C is in the
proper place on the plans. Move the R1C
guide to the forward spar and adjust rib
R1C, and then glue R1C to the top and
bottom spars.
Glue the 1/4 balsa TE to the aileron
cutout. Make sure you have the cutout at
least 3/32 inch wider than the ribs for the 3/32
balsa sheeting. Glue the top 1 x 3/32-inch
balsa sheeting to the TE at the aileron
cutout. Glue the 3/32 balsa sheeting to the
TE, inboard of the aileron.
I decided to use a laminated balsa LE on
my Val, but you could use a solid balsa LE
if you wanted. For a laminated LE, glue the
first lamination to the ribs’ LEs with some
cyanoacrylate-type glue while the wing is
still pinned to the workbench.
Use a Sig-Ment or Ambroid type of
wood glue to adhere each successive
lamination to the LE. You will need a bunch
of clothespins or clamps to do this;
clothespins may not be long enough to
clamp on the laminations properly.
I worked around this by removing the
wing from the workbench and placing it on
a table with a curved end, with the LE
overhanging the edge of the table. I
weighted down the wing so it would not
move and was held flat on the table. Then I
used the clothespins from the top and
bottom of the LE to hold the laminations on
as the glue dried.
Glue the 3/32 balsa LE sheeting to the top
of the outboard wing section. You may need
to spray some water on the sheeting to make
it easier to bend. Once the glue and sheeting
has dried, sand the wing sheeting flush with
rib R1. Cut the slots in R1 for the dihedral
braces.
Once you are satisfied with the fit of the
outboard section to the inboard section, glue
them together. I used numerous clothespins
to hold ribs R1 and R1C together from the
bottom.
To increase the strength of the plywood
dihedral joint to the top and bottom spars I
added 3/32 balsa to fit between the top and
bottom spars, and then I glued these to the
plywood dihedral braces and the top and
bottom spars.
Build the other outer wing panel in the
same manner as you built the first panel.
Round off the top of the center-section’s
LE so the center-section will fit in the wing
saddle on the fuselage. Center the wing on
the fuselage and then drill the hole for the
1/4-inch wing-mounting dowel through F2
and the wing’s LE. Remove the wing from
the fuselage and glue the 1/4-inch-diameter
dowel in place on the wing.
Sheet the bottom of the wing. Glue the
1/4 balsa TEs to the wing and sand them to
match the contour of the airfoil.
The ailerons are fairly simple to build.
They are 3/32 sheet balsa with half ribs glued
to the top and bottom.
Glue the 1/4-inch-wide balsa capstrips to
the ribs. Use 1/8-inch-thick balsa for the
capstrips. Glue the 1/4 balsa TE to the
ailerons. Cut the slots for the hinges in the
ailerons and in the wing, and then
temporarily mount the ailerons to the wing
and sand the ailerons to match the wing.
Install the aileron-servo mount blocks as
shown on the plans. The 3/32 balsa is to form
a lip around the servo mount hole for the
covering to stick to.
Adhere the wingtip blocks in place and
sand them to shape. Glue the 1/8 plywood
wing-bolt reinforcing plate to the bottom of
the wing on the center-section.
Mount the wing to the fuselage and drill
a 13/64-inch hole in the wing and fuselage for
the wing-mounting screw. Tap the hole in
the fuselage with a 1/4-20 tap. Enlarge the
hole in the wing to 1/4 inch.
Glue F4A and F6 to the bottom of the
wing and then sheet over it with 3/16 balsa.
Use a sharpened brass tube to cut the hole
for access to the wing mounting screw.
Sheet the lower forward part of the fuselage
with 3/16 balsa. Glue the 1/4 balsa F5s in
place. Sand the lower wing fuselage fairing
to match the contour of the fuselage shape.
Flip the fuselage over and secure it to the
worktable so you can mount the horizontal
stabilizer. Slide the horizontal stabilizer into
the slot in the rear of the fuselage. Make
sure the stabilizer is centered on the
fuselage. Sight down the length of the
fuselage from the front or rear and make
sure the stabilizer and wing are parallel to
each other horizontally.
Make sure the stabilizer is square to the
wing by measuring from the wing TE to the
stabilizer TE on both sides of the fuselage,
and make sure these measurements are the
same. Check the horizontal stabilizer’s
incidence to the wing; it should be
approximately 1/2° LE down. When you’re
satisfied that the stabilizer is mounted
correctly, glue it to the fuselage.
Mount the vertical stabilizer to the
fuselage with pins. To align the vertical
stabilizer so that it is not offset to one side
or the other, sight down the top of the
fuselage from the front and pin it in place.
Adjust the vertical stabilizer so it is 90° to
the horizontal stabilizer and then glue the
vertical stabilizer to the fuselage.
The tail-wheel bracket is 1/16-inchdiameter
music wire bent to shape and
mounted to the fuselage with 1/16-inch-insidediameter
brass tube. I built mine by bending
the bottom of the bracket for the axle and
slipping on a small washer to keep the tail
wheel from pushing the rudder up. Then I
soldered the washer to the music wire.
I sharpened the end of the 1/16-inch brass
tube and used it to drill the hole in the
fuselage for the bracket. Then I glued the
brass tube in place on the fuselage and cut it
to length. The music-wire bracket was
slipped into the brass tube and the top of the
bracket was then bent over to fit into the
rudder.
The full-scale Val has a rather large
wing-to-fuselage fillet; this has been drawn
on the plans, but I opted not to install the
fillet on my model. If you want to make a
fillet for yours, I will describe how I was
going to build it.
Cut the fillet base from 1/64 plywood.
Loosely mount the wing to the fuselage and
slip the fillet base in place between the wing
and fuselage. When you are satisfied with
the location of the fillet, tighten the wing to
the fuselage and glue the fillet to the
fuselage only.
Cut some soft balsa blocks and glue
them to the fuselage. Carve and sand them
to the shape of the fillet.
Bend the elevator joiner from 1/8-inch
music wire, and then temporarily mount the
elevator using your favorite hinging method.
Temporarily mount the rudder.
Set the model aside and then bend the
main landing gear from 3/16-inch music wire.
The wheel pants are made from various
thicknesses of balsa. The thickness of the
main core of the wheel pants is determined
by the thickness of the wheels you use and
the addition of the wheel collars.
If you fly from a grass strip, cut the
bottom of the pants so that more of the
wheel is exposed than shown on the plans. I
have seen pictures of a full-scale Val’s
wheel without wheel pants, so you may not
want to build them for your model. Once
you have cut all the parts for the wheel
pants, glue them together and sand them to
shape.
Final-sand the fuselage and cover it with
your favorite covering material. I used
MonoKote. Although the colors I used are
not exactly accurate, I loosely based the color
scheme on a Val that was aboard the aircraft
carrier Akagi during the battle of Midway. I
got the red “meatballs” from a set of decals I
had from an old Top Flite Zero kit.
The canopy I used is from the Great
Planes AT-6 Texan ARF that is available
from Tower Hobbies. I decided early that I
would have cooling holes cut in the fuselage
in the cockpit area and I would leave the
rear of the canopy open for the air to escape.
I cut the excess plastic from the canopy
as if I was going to mount it on the model
for which it was designed. Then I placed the
canopy on the top of the fuselage and
pressed it down until the front of the
windscreen touched the top of the fuselage. I
used a dry-erase marker to indicate the side
of the canopy on which I needed to cut it to
make it fit the fuselage.
After I cut the canopy to fit the fuselage I
used a rag to remove the marks left on the
canopy. I taped the canopy in place on the
fuselage and marked the fuselage so I could
remove the green MonoKote from the
cockpit area and replace it with black
MonoKote.
Once I had re-covered the cockpit area
with the black MonoKote, I carefully cut a
small strip away from the black for the
canopy to be glued to bare wood on the
fuselage. I used a sharpened brass tube to
cut the cooling holes in the cockpit area.
Since I wanted to keep my model simple
but still wanted a pilot and gunner in it, I
decided to use a simple, flat version. I found
a picture of a pilot and gunner and scanned
it into my computer. Then I enlarged the
picture to the correct size. I created a mirror
image of the picture, and then I printed the
mirror image and the original image of the
picture.
I glued one side of the pilot and gunner
to a piece of 1/64 plywood. Then I cut the
plywood to the shape of the pilot and gunner
and glued the mirror image to the other side
of the pilot. To make the plywood blend into
the figures, I darkened the edge of the wood
with a black magic marker.
I glued the pilot and gunner figures into
slots cut in the cockpit area. When I was
happy with the cockpit area, I glued the
canopy to the fuselage with some Formula
560 canopy glue.
I mounted an old Vortac bomb release to
the bottom of the wing near the CG. If you
want to mount a bomb release, be careful
not to cut the wing spars as you make the
cutout for the release. I used a T-pin to poke
through the wing sheeting to locate the
spars. I mounted the bomb-release servo
upside down in the wing so that a servo arm
would actuate the release.
The Val’s nose is rather short, so I
mounted the radio gear as far forward in
the fuselage as I could. I still ended up
adding lead to the nose to get the CG
where I wanted it.
The aileron servos are mounted to the
bottom of the wing and are connected to the
receiver by a Y harness. I like my models to
be fairly responsive, so I set my control
throws as follows: rudder, 1 inch left and
right; elevator, 1/2 inch up and down;
ailerons, 1/4 inch down and 1/2 inch up.
The ailerons need more up than down
travel, and this is achieved by mounting the
servo arm on the servo at roughly a 45° angle
toward the front of the airplane. These are
good starting points for the first few flights.
After that you may want to increase or
decrease the throws to suit your flying style.
Flying: If you are like I am, you probably
skipped most of the article and came right to
this point to see how the Val flies. It flies
exactly like an advanced trainer. If the only
models you have ever flown are high-wing
trainers and you want to move on to a lowwing
trainer, this may be the airplane you’re
looking for.
The first flight with my Val took place
early on a cool, windless Saturday morning.
After range checking my radio with the
motor on, I taxied the model to the far end
of the runway. I slowly advanced the throttle
and let the Val roll down the runway. It
wanted to pull to the left, but I had no
problems keeping it headed down the
runway with the rudder.
After roughly 150 feet I started to feed in
up-elevator and the Val became airborne in
a nice, realistic manner. As I gained some
altitude I realized the Val needed some upelevator
trim and a little right aileron trim to
keep it level.
Once I had the Val trimmed out, I made
some low passes so my daughter Erin could
take some pictures of it in flight. I was
exceptionally pleased with how the model
flew. I took it up high to see how the Val
handled in slow flight; I was quite pleased to
see how slow it was able to fly before it
stalled.
The right wing had a tendency to drop
when the model stalled, but it was easy to
control right up to the stall. After a few
more low passes I tried a few touch-and-gos.
The big propeller windmilling created
quite a bit of drag, and I found that I needed
to keep a little power on during the approach
or make steep approaches to keep up the
airspeed. There is no tendency for the Val to
float too much once the power has been
pulled all the way back, but it doesn’t drop
like a brick either.
When I took my airplane home I checked
the wings for warp and found a slight one in
the right wing. Twisting the wing and
reheating the MonoKote removed the warp.
I also redrew the plans to show 1/2°
incidence in the horizontal stabilizer.
On subsequent flights I was able to see
how aerobatic the Val is. It will fly upside
down by my holding a little down-elevator
with no problem. Rolls are nice and crisp.
There is little roll coupling with the rudder.
Landings are a breeze; you can wheelie it
on, and three point it on, or if you’re careful
you can one-point it on the tail wheel!
If you want a model that can do all the
fancy stuff, the Val will probably make you
yawn. But if you’re looking for an advanced
trainer that looks like a full-scale airplane or
if you want to try flying in a Fun Scale
contest or two, this may be a great fit for
you. MA
Gary Fuller
Edition: Model Aviation - 2007/03
Page Numbers: 29,30,31,32,33,34,35,36,38,40
I WAS DISCUSSING with a friend my effort to try to come up
with an interesting model that would be fun to build and fly, and the
Japanese Val was mentioned. All I really knew about it was that it
was a low-wing, fixed-landing-gear dive-bomber the Japanese used
during World War II.
Part of what I enjoy about modeling is researching the various
airplanes I build, so I started researching this aircraft. Did you know
that a Val dropped the first bomb during the attack on Pearl Harbor
in Hawaii in 1941?
After looking at a three-view drawing I decided the Val looked
like it might make a good-flying model. It had a generous amount of
wing area; the landing gear was fixed, which would keep modeling
costs down; and I could have the added fun of a droppable bomb.
The elliptical wing was the only thing I could think of that would
make the Val slightly more difficult to design and build than any
other low-winged sport model. However, the wing turned out to be
fairly easy to build.
Since I like my sport-scale models to be easy to construct, the
fuselage is built with flat sides like most other sport models. I also
like to keep the weight down, so I made the fuselage as skinny as I
could but wide enough to hide the radio and engine.
To make the horizontal and vertical stabilizer simple to build I
used 1/4 balsa sheet. The wheel pants were the only things that gave
me any trouble, and that was only when it was time to cover them
with MonoKote.
I put 2° of washout in the wingtips to help during low-speed
flight. With a ready-to-fly weight of approximately 6 pounds and a
wing area of 680 square inches, the wing loading is only
approximately 20 ounces per square foot; that’s close to the wing
loading of most trainers.
The electric bug has bitten me, so I used a MaxCim motor,
gearbox, and controller in my Val. I think any motor that can put out
at least 350 watts will work. If you want to use glow power, I
recommend a .40-.60 two-stroke or a .52-.70 four-stroke engine.
Artist’s composite of bare
wood and finished model.
Gary covered his Val with MonoKote. Although the colors are
not authentic, the markings were used on a Val during the
attack on Midway Island in 1942. This color scheme is easy to
see in the air. Erin Fuller photo.
The left and right fuselage sides are almost ready to join; all that is needed is to taper the
1/2 balsa triangle stock at the rear end.
Before gluing the tail end of the fuselage together, place scrap wood in the horizontal
stabilizer slot and on the wing saddle. Sight down the fuselage and get the two scrap
wood pieces parallel with each other by adjusting the fuselage sides, which are held
together with the clothespin.
The author prefers Sig-Ment or Ambroid to glue the top and
bottom 3/16 balsa sheeting in place. Holes are drilled in the firewall
to cool the batteries and motor.
The center-section of the wing. Use a piece of aluminum angle to
hold the TE of the ribs in alignment.
Type: RC semiscale
Wingspan: 63 inches
Wing area: 680 square inches
Flying weight: 6 pounds
Wing loading: 20.25 ounces
per square foot
Power: .32-.50 two-stroke or
.40-.65 four-stroke engine or
MaxCim MaxN32-13Y
motor geared 2.2:1, using a
15-volt 4000 mAh battery
Construction: Balsa and
plywood
Covering/finish: MonoKote
Photos by the author except as noted
Before the LE is installed, glue the top TE sheeting in place. The
first of the laminations are shown glued to the LE.
The landing-gear mount block in the wing center-section. After the top spar is glued to the ribs the bottom spar is lifted into the
lower spar slots, and then the spar is blocked up and glued to the ribs.
The R1C angle guide is being used to set rib R1C to the correct
angle. Don’t glue the rib to the spars until all the spars are in place.
Many clothespins are used to hold the LE laminations together
while the glue dries.
Glue the top sheeting to the LE only first. After the glue dries, wet
the top sheeting with water and ammonia to make it more flexible.
Before sheeting the top of the wing center-section, drill the holes for
the landing-gear wires through the landing-gear mounting blocks
using the vertical piece of grooved block as a guide.
32 MODEL AVIATION
Clothespins and clamps are used to hold the outboard section of
the wing to the inboard section while the glue dries.
Clothespins and regular T-pins are used to hold the wing sheeting
in place as the glue dries.
It makes it easier to drill the hole for the 1/4–inch-diameter wingmounting
dowel if you delay the sheeting of the bottom of the
forward fuselage.
Aileron servos are mounted on the bottom of the wing. The ailerons
need more up travel than down to reduce adverse yaw at low
airspeeds.
The motor speed control and receiver are mounted with hook-andloop
material. Other pieces of hook-and-loop are used to hold the
wiring.
Only one nylon landing-gear
strap is needed to mount the
wheel pants to the landing gear.
The motor and radio switches
are painted to match the
covering.
Drill a 1/4-inch hole in a large block of wood and insert the 1/4-inch
wing-mounting dowel. This holds the wing in a vertical position,
aiding in construction.
CONSTRUCTION:
I like to cut most of the parts for my
models before I begin building. There are
numerous ways to transfer the shape of
the part to the wood, but my favorite is to
cut the plans for the separate parts and
then use low-tack glue to adhere the
plans part directly to the wood. I have
had good luck using Elmer’s glue sticks.
Use a band saw to cut the wood to
shape. After the part is cut, remove the
paper from the wood. Drill the holes for
the motor mount when you cut the
firewall.
Fuselage: Start with the fuselage by
laying the left and right sides on my
workbench so that they are top to top;
that way you won’t make two left or right
sides as you glue the various pieces to the
sides.
Glue the 1/16 balsa (or plywood if you
plan to use glow power) doublers to the
sides. Make sure you glue the shorter of
the two doublers to the right side; this is
for the 2° right thrust for the engine.
Adhere the 1/2 balsa triangle stock to
the edges of the side as shown on the
plans. Once the glue has dried, taper the
triangle stock at the back end of the
fuselage. Glue the 1/4 square balsa side
stiffeners to the sides as shown on the
plans.
Glue formers F2, F3, and F4 to only
one side of the fuselage at this time.
Former F2 can be positioned to suit your
needs whether you use a glow engine or
an electric motor. Make sure they are 90°
to the side.
Glue the 1/8 square balsa to F4 as
shown on the plans. Glue the other side
to the formers. I did this by rubber
banding the sides to each other, and using
a square and my eyeballs I aligned the
sides to each other. Glue the formers to
the other side. Glue the firewall in place.
Set the fuselage on the workbench so
it is sitting on its top. Place some 1/4 balsa
sheet scraps in the wing saddle and the
horizontal stabilizer slots on the fuselage,
and then bring the aft end of the fuselage
sides together and hold in place with a
clothespin.
Sighting from the front or back end of
the fuselage, the sides are adjusted at the
back end so the 1/4-inch sticks are parallel
with each other and the fuselage is
straight. Once these are aligned, glue the
back end of the fuselage together. Sheet
the top of the fuselage with 3/16 balsa.
If you plan to use electric power,
build the hatch on the top forward part of
the fuselage. Sheet the bottom of the
fuselage aft of the wing with 3/16 balsa.
The sheeting’s grain should be crosswise
on the top and bottom sheeting.
The bottom forward of the wing will
be sheeted after the wing has been
mounted to the fuselage. Glue in the 1/4
plywood wing-mount plate and set the
fuselage aside to allow the glue to dry.
When the glue has dried on the top and
bottom sheeting, sand the fuselage to shape.
I used a large C-clamp to support a sheet of
1/2 plywood on its edge. Then I carefully
secured the fuselage to the plywood with
part of the fuselage hanging over the edge of
my workbench.
On the part of the fuselage that was
hanging over the edge of the bench I draped
the sandpaper across the top and pulled it
down and back and forth in a method similar
to that you would use to shine your shoes.
When you’re satisfied with the shape of
your fuselage, set it aside and start the wing.
Wing: Start with the center-section. Glue
the R1A and R1B ribs to the R1 ribs as
shown on the plans. Pin the forward spar to
the workbench. Place the rear spar on the
plans, but don’t pin it down; it will need to
be raised up into the ribs after they are in
place. Fit but don’t glue the 1/4 plywood
wing dowel support to the ribs that have the
R1Bs glued to them, and glue them on the
forward spar.
I used landing-gear mounts that Sig sells.
They are 6 inches long, and you need to cut
an inch for the end of each mount. After the
landing-gear mounts are glued in place,
these 1-inch blocks will be glued to the top
of the landing-gear mounts at the inboard
end up against the R1A rib, so don’t throw
them away.
Place the landing-gear mounts on the
plans and adhere the remaining R1 and R1A
ribs to the forward spar. Glue the top
forward and rear spars to the ribs. Pull the
lower rear spar up into the ribs and glue the
ribs to it. Pull the landing-gear mounts up
into the ribs and glue these in place, and then
glue the 1-inch blocks on top of the landinggear
mount against the inboard R1A rib.
Glue the 3/8 balsa LE to the centersection
and then glue the 1/8 plywood wing
dowel support to the LE. Glue a 1 x 3/32-inch
strip of balsa to the top of the ribs at the TE.
Mounting the 1/8 plywood dihedral
supports is next. I did this by drilling some
1/8-inch-diameter holes in the outermost R1
ribs between the top and bottom spars. Then
I joined the holes to form a 1/8-inch-wide
slot from the top spar to the bottom spar by
using a small file.
Install the dihedral joiner into the slot
and glue it to the top and bottom spars.
Make sure the dihedral joiner is at a 90°
angle to the R1 rib before you glue it to the
spars. Do this for the forward and aft
dihedral joiners.
For the outboard wing panels I placed
the forward and main spars on the plans and
then pinned ribs R2-R8 in place on the
plans. I placed rib R1C on the spar but did
not pin it down.
I lifted the main spar up into all the ribs
and placed shims under the spar in various
locations along the spar to hold it off the
workbench and into the ribs. Then I pinned
the spar to the workbench.
Keep the spar straight along the
wingspan and make sure the rib building
tabs are still in contact with the workbench.
Glue all the ribs except R1C to the spar. Lift
the forward spar into rib R1C and R2 and
glue to R2.
Place the top spar on all the ribs and glue
it to all the ribs except R1C. Glue the
forward spar to R2.
Cut the R1C angle guide from the plans
and glue to some scrap plywood, and then
cut the plywood to the shape of the R1C
guide. Place the R1C guide on the bottom
main spar between the top and bottom spars
against R1C.
Adjust R1C so that it is against the
guide, and glue it to the top and bottom
spars. Be careful not to glue the guide to the
rib or the spars, and make sure R1C is in the
proper place on the plans. Move the R1C
guide to the forward spar and adjust rib
R1C, and then glue R1C to the top and
bottom spars.
Glue the 1/4 balsa TE to the aileron
cutout. Make sure you have the cutout at
least 3/32 inch wider than the ribs for the 3/32
balsa sheeting. Glue the top 1 x 3/32-inch
balsa sheeting to the TE at the aileron
cutout. Glue the 3/32 balsa sheeting to the
TE, inboard of the aileron.
I decided to use a laminated balsa LE on
my Val, but you could use a solid balsa LE
if you wanted. For a laminated LE, glue the
first lamination to the ribs’ LEs with some
cyanoacrylate-type glue while the wing is
still pinned to the workbench.
Use a Sig-Ment or Ambroid type of
wood glue to adhere each successive
lamination to the LE. You will need a bunch
of clothespins or clamps to do this;
clothespins may not be long enough to
clamp on the laminations properly.
I worked around this by removing the
wing from the workbench and placing it on
a table with a curved end, with the LE
overhanging the edge of the table. I
weighted down the wing so it would not
move and was held flat on the table. Then I
used the clothespins from the top and
bottom of the LE to hold the laminations on
as the glue dried.
Glue the 3/32 balsa LE sheeting to the top
of the outboard wing section. You may need
to spray some water on the sheeting to make
it easier to bend. Once the glue and sheeting
has dried, sand the wing sheeting flush with
rib R1. Cut the slots in R1 for the dihedral
braces.
Once you are satisfied with the fit of the
outboard section to the inboard section, glue
them together. I used numerous clothespins
to hold ribs R1 and R1C together from the
bottom.
To increase the strength of the plywood
dihedral joint to the top and bottom spars I
added 3/32 balsa to fit between the top and
bottom spars, and then I glued these to the
plywood dihedral braces and the top and
bottom spars.
Build the other outer wing panel in the
same manner as you built the first panel.
Round off the top of the center-section’s
LE so the center-section will fit in the wing
saddle on the fuselage. Center the wing on
the fuselage and then drill the hole for the
1/4-inch wing-mounting dowel through F2
and the wing’s LE. Remove the wing from
the fuselage and glue the 1/4-inch-diameter
dowel in place on the wing.
Sheet the bottom of the wing. Glue the
1/4 balsa TEs to the wing and sand them to
match the contour of the airfoil.
The ailerons are fairly simple to build.
They are 3/32 sheet balsa with half ribs glued
to the top and bottom.
Glue the 1/4-inch-wide balsa capstrips to
the ribs. Use 1/8-inch-thick balsa for the
capstrips. Glue the 1/4 balsa TE to the
ailerons. Cut the slots for the hinges in the
ailerons and in the wing, and then
temporarily mount the ailerons to the wing
and sand the ailerons to match the wing.
Install the aileron-servo mount blocks as
shown on the plans. The 3/32 balsa is to form
a lip around the servo mount hole for the
covering to stick to.
Adhere the wingtip blocks in place and
sand them to shape. Glue the 1/8 plywood
wing-bolt reinforcing plate to the bottom of
the wing on the center-section.
Mount the wing to the fuselage and drill
a 13/64-inch hole in the wing and fuselage for
the wing-mounting screw. Tap the hole in
the fuselage with a 1/4-20 tap. Enlarge the
hole in the wing to 1/4 inch.
Glue F4A and F6 to the bottom of the
wing and then sheet over it with 3/16 balsa.
Use a sharpened brass tube to cut the hole
for access to the wing mounting screw.
Sheet the lower forward part of the fuselage
with 3/16 balsa. Glue the 1/4 balsa F5s in
place. Sand the lower wing fuselage fairing
to match the contour of the fuselage shape.
Flip the fuselage over and secure it to the
worktable so you can mount the horizontal
stabilizer. Slide the horizontal stabilizer into
the slot in the rear of the fuselage. Make
sure the stabilizer is centered on the
fuselage. Sight down the length of the
fuselage from the front or rear and make
sure the stabilizer and wing are parallel to
each other horizontally.
Make sure the stabilizer is square to the
wing by measuring from the wing TE to the
stabilizer TE on both sides of the fuselage,
and make sure these measurements are the
same. Check the horizontal stabilizer’s
incidence to the wing; it should be
approximately 1/2° LE down. When you’re
satisfied that the stabilizer is mounted
correctly, glue it to the fuselage.
Mount the vertical stabilizer to the
fuselage with pins. To align the vertical
stabilizer so that it is not offset to one side
or the other, sight down the top of the
fuselage from the front and pin it in place.
Adjust the vertical stabilizer so it is 90° to
the horizontal stabilizer and then glue the
vertical stabilizer to the fuselage.
The tail-wheel bracket is 1/16-inchdiameter
music wire bent to shape and
mounted to the fuselage with 1/16-inch-insidediameter
brass tube. I built mine by bending
the bottom of the bracket for the axle and
slipping on a small washer to keep the tail
wheel from pushing the rudder up. Then I
soldered the washer to the music wire.
I sharpened the end of the 1/16-inch brass
tube and used it to drill the hole in the
fuselage for the bracket. Then I glued the
brass tube in place on the fuselage and cut it
to length. The music-wire bracket was
slipped into the brass tube and the top of the
bracket was then bent over to fit into the
rudder.
The full-scale Val has a rather large
wing-to-fuselage fillet; this has been drawn
on the plans, but I opted not to install the
fillet on my model. If you want to make a
fillet for yours, I will describe how I was
going to build it.
Cut the fillet base from 1/64 plywood.
Loosely mount the wing to the fuselage and
slip the fillet base in place between the wing
and fuselage. When you are satisfied with
the location of the fillet, tighten the wing to
the fuselage and glue the fillet to the
fuselage only.
Cut some soft balsa blocks and glue
them to the fuselage. Carve and sand them
to the shape of the fillet.
Bend the elevator joiner from 1/8-inch
music wire, and then temporarily mount the
elevator using your favorite hinging method.
Temporarily mount the rudder.
Set the model aside and then bend the
main landing gear from 3/16-inch music wire.
The wheel pants are made from various
thicknesses of balsa. The thickness of the
main core of the wheel pants is determined
by the thickness of the wheels you use and
the addition of the wheel collars.
If you fly from a grass strip, cut the
bottom of the pants so that more of the
wheel is exposed than shown on the plans. I
have seen pictures of a full-scale Val’s
wheel without wheel pants, so you may not
want to build them for your model. Once
you have cut all the parts for the wheel
pants, glue them together and sand them to
shape.
Final-sand the fuselage and cover it with
your favorite covering material. I used
MonoKote. Although the colors I used are
not exactly accurate, I loosely based the color
scheme on a Val that was aboard the aircraft
carrier Akagi during the battle of Midway. I
got the red “meatballs” from a set of decals I
had from an old Top Flite Zero kit.
The canopy I used is from the Great
Planes AT-6 Texan ARF that is available
from Tower Hobbies. I decided early that I
would have cooling holes cut in the fuselage
in the cockpit area and I would leave the
rear of the canopy open for the air to escape.
I cut the excess plastic from the canopy
as if I was going to mount it on the model
for which it was designed. Then I placed the
canopy on the top of the fuselage and
pressed it down until the front of the
windscreen touched the top of the fuselage. I
used a dry-erase marker to indicate the side
of the canopy on which I needed to cut it to
make it fit the fuselage.
After I cut the canopy to fit the fuselage I
used a rag to remove the marks left on the
canopy. I taped the canopy in place on the
fuselage and marked the fuselage so I could
remove the green MonoKote from the
cockpit area and replace it with black
MonoKote.
Once I had re-covered the cockpit area
with the black MonoKote, I carefully cut a
small strip away from the black for the
canopy to be glued to bare wood on the
fuselage. I used a sharpened brass tube to
cut the cooling holes in the cockpit area.
Since I wanted to keep my model simple
but still wanted a pilot and gunner in it, I
decided to use a simple, flat version. I found
a picture of a pilot and gunner and scanned
it into my computer. Then I enlarged the
picture to the correct size. I created a mirror
image of the picture, and then I printed the
mirror image and the original image of the
picture.
I glued one side of the pilot and gunner
to a piece of 1/64 plywood. Then I cut the
plywood to the shape of the pilot and gunner
and glued the mirror image to the other side
of the pilot. To make the plywood blend into
the figures, I darkened the edge of the wood
with a black magic marker.
I glued the pilot and gunner figures into
slots cut in the cockpit area. When I was
happy with the cockpit area, I glued the
canopy to the fuselage with some Formula
560 canopy glue.
I mounted an old Vortac bomb release to
the bottom of the wing near the CG. If you
want to mount a bomb release, be careful
not to cut the wing spars as you make the
cutout for the release. I used a T-pin to poke
through the wing sheeting to locate the
spars. I mounted the bomb-release servo
upside down in the wing so that a servo arm
would actuate the release.
The Val’s nose is rather short, so I
mounted the radio gear as far forward in
the fuselage as I could. I still ended up
adding lead to the nose to get the CG
where I wanted it.
The aileron servos are mounted to the
bottom of the wing and are connected to the
receiver by a Y harness. I like my models to
be fairly responsive, so I set my control
throws as follows: rudder, 1 inch left and
right; elevator, 1/2 inch up and down;
ailerons, 1/4 inch down and 1/2 inch up.
The ailerons need more up than down
travel, and this is achieved by mounting the
servo arm on the servo at roughly a 45° angle
toward the front of the airplane. These are
good starting points for the first few flights.
After that you may want to increase or
decrease the throws to suit your flying style.
Flying: If you are like I am, you probably
skipped most of the article and came right to
this point to see how the Val flies. It flies
exactly like an advanced trainer. If the only
models you have ever flown are high-wing
trainers and you want to move on to a lowwing
trainer, this may be the airplane you’re
looking for.
The first flight with my Val took place
early on a cool, windless Saturday morning.
After range checking my radio with the
motor on, I taxied the model to the far end
of the runway. I slowly advanced the throttle
and let the Val roll down the runway. It
wanted to pull to the left, but I had no
problems keeping it headed down the
runway with the rudder.
After roughly 150 feet I started to feed in
up-elevator and the Val became airborne in
a nice, realistic manner. As I gained some
altitude I realized the Val needed some upelevator
trim and a little right aileron trim to
keep it level.
Once I had the Val trimmed out, I made
some low passes so my daughter Erin could
take some pictures of it in flight. I was
exceptionally pleased with how the model
flew. I took it up high to see how the Val
handled in slow flight; I was quite pleased to
see how slow it was able to fly before it
stalled.
The right wing had a tendency to drop
when the model stalled, but it was easy to
control right up to the stall. After a few
more low passes I tried a few touch-and-gos.
The big propeller windmilling created
quite a bit of drag, and I found that I needed
to keep a little power on during the approach
or make steep approaches to keep up the
airspeed. There is no tendency for the Val to
float too much once the power has been
pulled all the way back, but it doesn’t drop
like a brick either.
When I took my airplane home I checked
the wings for warp and found a slight one in
the right wing. Twisting the wing and
reheating the MonoKote removed the warp.
I also redrew the plans to show 1/2°
incidence in the horizontal stabilizer.
On subsequent flights I was able to see
how aerobatic the Val is. It will fly upside
down by my holding a little down-elevator
with no problem. Rolls are nice and crisp.
There is little roll coupling with the rudder.
Landings are a breeze; you can wheelie it
on, and three point it on, or if you’re careful
you can one-point it on the tail wheel!
If you want a model that can do all the
fancy stuff, the Val will probably make you
yawn. But if you’re looking for an advanced
trainer that looks like a full-scale airplane or
if you want to try flying in a Fun Scale
contest or two, this may be a great fit for
you. MA
Gary Fuller
Edition: Model Aviation - 2007/03
Page Numbers: 29,30,31,32,33,34,35,36,38,40
I WAS DISCUSSING with a friend my effort to try to come up
with an interesting model that would be fun to build and fly, and the
Japanese Val was mentioned. All I really knew about it was that it
was a low-wing, fixed-landing-gear dive-bomber the Japanese used
during World War II.
Part of what I enjoy about modeling is researching the various
airplanes I build, so I started researching this aircraft. Did you know
that a Val dropped the first bomb during the attack on Pearl Harbor
in Hawaii in 1941?
After looking at a three-view drawing I decided the Val looked
like it might make a good-flying model. It had a generous amount of
wing area; the landing gear was fixed, which would keep modeling
costs down; and I could have the added fun of a droppable bomb.
The elliptical wing was the only thing I could think of that would
make the Val slightly more difficult to design and build than any
other low-winged sport model. However, the wing turned out to be
fairly easy to build.
Since I like my sport-scale models to be easy to construct, the
fuselage is built with flat sides like most other sport models. I also
like to keep the weight down, so I made the fuselage as skinny as I
could but wide enough to hide the radio and engine.
To make the horizontal and vertical stabilizer simple to build I
used 1/4 balsa sheet. The wheel pants were the only things that gave
me any trouble, and that was only when it was time to cover them
with MonoKote.
I put 2° of washout in the wingtips to help during low-speed
flight. With a ready-to-fly weight of approximately 6 pounds and a
wing area of 680 square inches, the wing loading is only
approximately 20 ounces per square foot; that’s close to the wing
loading of most trainers.
The electric bug has bitten me, so I used a MaxCim motor,
gearbox, and controller in my Val. I think any motor that can put out
at least 350 watts will work. If you want to use glow power, I
recommend a .40-.60 two-stroke or a .52-.70 four-stroke engine.
Artist’s composite of bare
wood and finished model.
Gary covered his Val with MonoKote. Although the colors are
not authentic, the markings were used on a Val during the
attack on Midway Island in 1942. This color scheme is easy to
see in the air. Erin Fuller photo.
The left and right fuselage sides are almost ready to join; all that is needed is to taper the
1/2 balsa triangle stock at the rear end.
Before gluing the tail end of the fuselage together, place scrap wood in the horizontal
stabilizer slot and on the wing saddle. Sight down the fuselage and get the two scrap
wood pieces parallel with each other by adjusting the fuselage sides, which are held
together with the clothespin.
The author prefers Sig-Ment or Ambroid to glue the top and
bottom 3/16 balsa sheeting in place. Holes are drilled in the firewall
to cool the batteries and motor.
The center-section of the wing. Use a piece of aluminum angle to
hold the TE of the ribs in alignment.
Type: RC semiscale
Wingspan: 63 inches
Wing area: 680 square inches
Flying weight: 6 pounds
Wing loading: 20.25 ounces
per square foot
Power: .32-.50 two-stroke or
.40-.65 four-stroke engine or
MaxCim MaxN32-13Y
motor geared 2.2:1, using a
15-volt 4000 mAh battery
Construction: Balsa and
plywood
Covering/finish: MonoKote
Photos by the author except as noted
Before the LE is installed, glue the top TE sheeting in place. The
first of the laminations are shown glued to the LE.
The landing-gear mount block in the wing center-section. After the top spar is glued to the ribs the bottom spar is lifted into the
lower spar slots, and then the spar is blocked up and glued to the ribs.
The R1C angle guide is being used to set rib R1C to the correct
angle. Don’t glue the rib to the spars until all the spars are in place.
Many clothespins are used to hold the LE laminations together
while the glue dries.
Glue the top sheeting to the LE only first. After the glue dries, wet
the top sheeting with water and ammonia to make it more flexible.
Before sheeting the top of the wing center-section, drill the holes for
the landing-gear wires through the landing-gear mounting blocks
using the vertical piece of grooved block as a guide.
32 MODEL AVIATION
Clothespins and clamps are used to hold the outboard section of
the wing to the inboard section while the glue dries.
Clothespins and regular T-pins are used to hold the wing sheeting
in place as the glue dries.
It makes it easier to drill the hole for the 1/4–inch-diameter wingmounting
dowel if you delay the sheeting of the bottom of the
forward fuselage.
Aileron servos are mounted on the bottom of the wing. The ailerons
need more up travel than down to reduce adverse yaw at low
airspeeds.
The motor speed control and receiver are mounted with hook-andloop
material. Other pieces of hook-and-loop are used to hold the
wiring.
Only one nylon landing-gear
strap is needed to mount the
wheel pants to the landing gear.
The motor and radio switches
are painted to match the
covering.
Drill a 1/4-inch hole in a large block of wood and insert the 1/4-inch
wing-mounting dowel. This holds the wing in a vertical position,
aiding in construction.
CONSTRUCTION:
I like to cut most of the parts for my
models before I begin building. There are
numerous ways to transfer the shape of
the part to the wood, but my favorite is to
cut the plans for the separate parts and
then use low-tack glue to adhere the
plans part directly to the wood. I have
had good luck using Elmer’s glue sticks.
Use a band saw to cut the wood to
shape. After the part is cut, remove the
paper from the wood. Drill the holes for
the motor mount when you cut the
firewall.
Fuselage: Start with the fuselage by
laying the left and right sides on my
workbench so that they are top to top;
that way you won’t make two left or right
sides as you glue the various pieces to the
sides.
Glue the 1/16 balsa (or plywood if you
plan to use glow power) doublers to the
sides. Make sure you glue the shorter of
the two doublers to the right side; this is
for the 2° right thrust for the engine.
Adhere the 1/2 balsa triangle stock to
the edges of the side as shown on the
plans. Once the glue has dried, taper the
triangle stock at the back end of the
fuselage. Glue the 1/4 square balsa side
stiffeners to the sides as shown on the
plans.
Glue formers F2, F3, and F4 to only
one side of the fuselage at this time.
Former F2 can be positioned to suit your
needs whether you use a glow engine or
an electric motor. Make sure they are 90°
to the side.
Glue the 1/8 square balsa to F4 as
shown on the plans. Glue the other side
to the formers. I did this by rubber
banding the sides to each other, and using
a square and my eyeballs I aligned the
sides to each other. Glue the formers to
the other side. Glue the firewall in place.
Set the fuselage on the workbench so
it is sitting on its top. Place some 1/4 balsa
sheet scraps in the wing saddle and the
horizontal stabilizer slots on the fuselage,
and then bring the aft end of the fuselage
sides together and hold in place with a
clothespin.
Sighting from the front or back end of
the fuselage, the sides are adjusted at the
back end so the 1/4-inch sticks are parallel
with each other and the fuselage is
straight. Once these are aligned, glue the
back end of the fuselage together. Sheet
the top of the fuselage with 3/16 balsa.
If you plan to use electric power,
build the hatch on the top forward part of
the fuselage. Sheet the bottom of the
fuselage aft of the wing with 3/16 balsa.
The sheeting’s grain should be crosswise
on the top and bottom sheeting.
The bottom forward of the wing will
be sheeted after the wing has been
mounted to the fuselage. Glue in the 1/4
plywood wing-mount plate and set the
fuselage aside to allow the glue to dry.
When the glue has dried on the top and
bottom sheeting, sand the fuselage to shape.
I used a large C-clamp to support a sheet of
1/2 plywood on its edge. Then I carefully
secured the fuselage to the plywood with
part of the fuselage hanging over the edge of
my workbench.
On the part of the fuselage that was
hanging over the edge of the bench I draped
the sandpaper across the top and pulled it
down and back and forth in a method similar
to that you would use to shine your shoes.
When you’re satisfied with the shape of
your fuselage, set it aside and start the wing.
Wing: Start with the center-section. Glue
the R1A and R1B ribs to the R1 ribs as
shown on the plans. Pin the forward spar to
the workbench. Place the rear spar on the
plans, but don’t pin it down; it will need to
be raised up into the ribs after they are in
place. Fit but don’t glue the 1/4 plywood
wing dowel support to the ribs that have the
R1Bs glued to them, and glue them on the
forward spar.
I used landing-gear mounts that Sig sells.
They are 6 inches long, and you need to cut
an inch for the end of each mount. After the
landing-gear mounts are glued in place,
these 1-inch blocks will be glued to the top
of the landing-gear mounts at the inboard
end up against the R1A rib, so don’t throw
them away.
Place the landing-gear mounts on the
plans and adhere the remaining R1 and R1A
ribs to the forward spar. Glue the top
forward and rear spars to the ribs. Pull the
lower rear spar up into the ribs and glue the
ribs to it. Pull the landing-gear mounts up
into the ribs and glue these in place, and then
glue the 1-inch blocks on top of the landinggear
mount against the inboard R1A rib.
Glue the 3/8 balsa LE to the centersection
and then glue the 1/8 plywood wing
dowel support to the LE. Glue a 1 x 3/32-inch
strip of balsa to the top of the ribs at the TE.
Mounting the 1/8 plywood dihedral
supports is next. I did this by drilling some
1/8-inch-diameter holes in the outermost R1
ribs between the top and bottom spars. Then
I joined the holes to form a 1/8-inch-wide
slot from the top spar to the bottom spar by
using a small file.
Install the dihedral joiner into the slot
and glue it to the top and bottom spars.
Make sure the dihedral joiner is at a 90°
angle to the R1 rib before you glue it to the
spars. Do this for the forward and aft
dihedral joiners.
For the outboard wing panels I placed
the forward and main spars on the plans and
then pinned ribs R2-R8 in place on the
plans. I placed rib R1C on the spar but did
not pin it down.
I lifted the main spar up into all the ribs
and placed shims under the spar in various
locations along the spar to hold it off the
workbench and into the ribs. Then I pinned
the spar to the workbench.
Keep the spar straight along the
wingspan and make sure the rib building
tabs are still in contact with the workbench.
Glue all the ribs except R1C to the spar. Lift
the forward spar into rib R1C and R2 and
glue to R2.
Place the top spar on all the ribs and glue
it to all the ribs except R1C. Glue the
forward spar to R2.
Cut the R1C angle guide from the plans
and glue to some scrap plywood, and then
cut the plywood to the shape of the R1C
guide. Place the R1C guide on the bottom
main spar between the top and bottom spars
against R1C.
Adjust R1C so that it is against the
guide, and glue it to the top and bottom
spars. Be careful not to glue the guide to the
rib or the spars, and make sure R1C is in the
proper place on the plans. Move the R1C
guide to the forward spar and adjust rib
R1C, and then glue R1C to the top and
bottom spars.
Glue the 1/4 balsa TE to the aileron
cutout. Make sure you have the cutout at
least 3/32 inch wider than the ribs for the 3/32
balsa sheeting. Glue the top 1 x 3/32-inch
balsa sheeting to the TE at the aileron
cutout. Glue the 3/32 balsa sheeting to the
TE, inboard of the aileron.
I decided to use a laminated balsa LE on
my Val, but you could use a solid balsa LE
if you wanted. For a laminated LE, glue the
first lamination to the ribs’ LEs with some
cyanoacrylate-type glue while the wing is
still pinned to the workbench.
Use a Sig-Ment or Ambroid type of
wood glue to adhere each successive
lamination to the LE. You will need a bunch
of clothespins or clamps to do this;
clothespins may not be long enough to
clamp on the laminations properly.
I worked around this by removing the
wing from the workbench and placing it on
a table with a curved end, with the LE
overhanging the edge of the table. I
weighted down the wing so it would not
move and was held flat on the table. Then I
used the clothespins from the top and
bottom of the LE to hold the laminations on
as the glue dried.
Glue the 3/32 balsa LE sheeting to the top
of the outboard wing section. You may need
to spray some water on the sheeting to make
it easier to bend. Once the glue and sheeting
has dried, sand the wing sheeting flush with
rib R1. Cut the slots in R1 for the dihedral
braces.
Once you are satisfied with the fit of the
outboard section to the inboard section, glue
them together. I used numerous clothespins
to hold ribs R1 and R1C together from the
bottom.
To increase the strength of the plywood
dihedral joint to the top and bottom spars I
added 3/32 balsa to fit between the top and
bottom spars, and then I glued these to the
plywood dihedral braces and the top and
bottom spars.
Build the other outer wing panel in the
same manner as you built the first panel.
Round off the top of the center-section’s
LE so the center-section will fit in the wing
saddle on the fuselage. Center the wing on
the fuselage and then drill the hole for the
1/4-inch wing-mounting dowel through F2
and the wing’s LE. Remove the wing from
the fuselage and glue the 1/4-inch-diameter
dowel in place on the wing.
Sheet the bottom of the wing. Glue the
1/4 balsa TEs to the wing and sand them to
match the contour of the airfoil.
The ailerons are fairly simple to build.
They are 3/32 sheet balsa with half ribs glued
to the top and bottom.
Glue the 1/4-inch-wide balsa capstrips to
the ribs. Use 1/8-inch-thick balsa for the
capstrips. Glue the 1/4 balsa TE to the
ailerons. Cut the slots for the hinges in the
ailerons and in the wing, and then
temporarily mount the ailerons to the wing
and sand the ailerons to match the wing.
Install the aileron-servo mount blocks as
shown on the plans. The 3/32 balsa is to form
a lip around the servo mount hole for the
covering to stick to.
Adhere the wingtip blocks in place and
sand them to shape. Glue the 1/8 plywood
wing-bolt reinforcing plate to the bottom of
the wing on the center-section.
Mount the wing to the fuselage and drill
a 13/64-inch hole in the wing and fuselage for
the wing-mounting screw. Tap the hole in
the fuselage with a 1/4-20 tap. Enlarge the
hole in the wing to 1/4 inch.
Glue F4A and F6 to the bottom of the
wing and then sheet over it with 3/16 balsa.
Use a sharpened brass tube to cut the hole
for access to the wing mounting screw.
Sheet the lower forward part of the fuselage
with 3/16 balsa. Glue the 1/4 balsa F5s in
place. Sand the lower wing fuselage fairing
to match the contour of the fuselage shape.
Flip the fuselage over and secure it to the
worktable so you can mount the horizontal
stabilizer. Slide the horizontal stabilizer into
the slot in the rear of the fuselage. Make
sure the stabilizer is centered on the
fuselage. Sight down the length of the
fuselage from the front or rear and make
sure the stabilizer and wing are parallel to
each other horizontally.
Make sure the stabilizer is square to the
wing by measuring from the wing TE to the
stabilizer TE on both sides of the fuselage,
and make sure these measurements are the
same. Check the horizontal stabilizer’s
incidence to the wing; it should be
approximately 1/2° LE down. When you’re
satisfied that the stabilizer is mounted
correctly, glue it to the fuselage.
Mount the vertical stabilizer to the
fuselage with pins. To align the vertical
stabilizer so that it is not offset to one side
or the other, sight down the top of the
fuselage from the front and pin it in place.
Adjust the vertical stabilizer so it is 90° to
the horizontal stabilizer and then glue the
vertical stabilizer to the fuselage.
The tail-wheel bracket is 1/16-inchdiameter
music wire bent to shape and
mounted to the fuselage with 1/16-inch-insidediameter
brass tube. I built mine by bending
the bottom of the bracket for the axle and
slipping on a small washer to keep the tail
wheel from pushing the rudder up. Then I
soldered the washer to the music wire.
I sharpened the end of the 1/16-inch brass
tube and used it to drill the hole in the
fuselage for the bracket. Then I glued the
brass tube in place on the fuselage and cut it
to length. The music-wire bracket was
slipped into the brass tube and the top of the
bracket was then bent over to fit into the
rudder.
The full-scale Val has a rather large
wing-to-fuselage fillet; this has been drawn
on the plans, but I opted not to install the
fillet on my model. If you want to make a
fillet for yours, I will describe how I was
going to build it.
Cut the fillet base from 1/64 plywood.
Loosely mount the wing to the fuselage and
slip the fillet base in place between the wing
and fuselage. When you are satisfied with
the location of the fillet, tighten the wing to
the fuselage and glue the fillet to the
fuselage only.
Cut some soft balsa blocks and glue
them to the fuselage. Carve and sand them
to the shape of the fillet.
Bend the elevator joiner from 1/8-inch
music wire, and then temporarily mount the
elevator using your favorite hinging method.
Temporarily mount the rudder.
Set the model aside and then bend the
main landing gear from 3/16-inch music wire.
The wheel pants are made from various
thicknesses of balsa. The thickness of the
main core of the wheel pants is determined
by the thickness of the wheels you use and
the addition of the wheel collars.
If you fly from a grass strip, cut the
bottom of the pants so that more of the
wheel is exposed than shown on the plans. I
have seen pictures of a full-scale Val’s
wheel without wheel pants, so you may not
want to build them for your model. Once
you have cut all the parts for the wheel
pants, glue them together and sand them to
shape.
Final-sand the fuselage and cover it with
your favorite covering material. I used
MonoKote. Although the colors I used are
not exactly accurate, I loosely based the color
scheme on a Val that was aboard the aircraft
carrier Akagi during the battle of Midway. I
got the red “meatballs” from a set of decals I
had from an old Top Flite Zero kit.
The canopy I used is from the Great
Planes AT-6 Texan ARF that is available
from Tower Hobbies. I decided early that I
would have cooling holes cut in the fuselage
in the cockpit area and I would leave the
rear of the canopy open for the air to escape.
I cut the excess plastic from the canopy
as if I was going to mount it on the model
for which it was designed. Then I placed the
canopy on the top of the fuselage and
pressed it down until the front of the
windscreen touched the top of the fuselage. I
used a dry-erase marker to indicate the side
of the canopy on which I needed to cut it to
make it fit the fuselage.
After I cut the canopy to fit the fuselage I
used a rag to remove the marks left on the
canopy. I taped the canopy in place on the
fuselage and marked the fuselage so I could
remove the green MonoKote from the
cockpit area and replace it with black
MonoKote.
Once I had re-covered the cockpit area
with the black MonoKote, I carefully cut a
small strip away from the black for the
canopy to be glued to bare wood on the
fuselage. I used a sharpened brass tube to
cut the cooling holes in the cockpit area.
Since I wanted to keep my model simple
but still wanted a pilot and gunner in it, I
decided to use a simple, flat version. I found
a picture of a pilot and gunner and scanned
it into my computer. Then I enlarged the
picture to the correct size. I created a mirror
image of the picture, and then I printed the
mirror image and the original image of the
picture.
I glued one side of the pilot and gunner
to a piece of 1/64 plywood. Then I cut the
plywood to the shape of the pilot and gunner
and glued the mirror image to the other side
of the pilot. To make the plywood blend into
the figures, I darkened the edge of the wood
with a black magic marker.
I glued the pilot and gunner figures into
slots cut in the cockpit area. When I was
happy with the cockpit area, I glued the
canopy to the fuselage with some Formula
560 canopy glue.
I mounted an old Vortac bomb release to
the bottom of the wing near the CG. If you
want to mount a bomb release, be careful
not to cut the wing spars as you make the
cutout for the release. I used a T-pin to poke
through the wing sheeting to locate the
spars. I mounted the bomb-release servo
upside down in the wing so that a servo arm
would actuate the release.
The Val’s nose is rather short, so I
mounted the radio gear as far forward in
the fuselage as I could. I still ended up
adding lead to the nose to get the CG
where I wanted it.
The aileron servos are mounted to the
bottom of the wing and are connected to the
receiver by a Y harness. I like my models to
be fairly responsive, so I set my control
throws as follows: rudder, 1 inch left and
right; elevator, 1/2 inch up and down;
ailerons, 1/4 inch down and 1/2 inch up.
The ailerons need more up than down
travel, and this is achieved by mounting the
servo arm on the servo at roughly a 45° angle
toward the front of the airplane. These are
good starting points for the first few flights.
After that you may want to increase or
decrease the throws to suit your flying style.
Flying: If you are like I am, you probably
skipped most of the article and came right to
this point to see how the Val flies. It flies
exactly like an advanced trainer. If the only
models you have ever flown are high-wing
trainers and you want to move on to a lowwing
trainer, this may be the airplane you’re
looking for.
The first flight with my Val took place
early on a cool, windless Saturday morning.
After range checking my radio with the
motor on, I taxied the model to the far end
of the runway. I slowly advanced the throttle
and let the Val roll down the runway. It
wanted to pull to the left, but I had no
problems keeping it headed down the
runway with the rudder.
After roughly 150 feet I started to feed in
up-elevator and the Val became airborne in
a nice, realistic manner. As I gained some
altitude I realized the Val needed some upelevator
trim and a little right aileron trim to
keep it level.
Once I had the Val trimmed out, I made
some low passes so my daughter Erin could
take some pictures of it in flight. I was
exceptionally pleased with how the model
flew. I took it up high to see how the Val
handled in slow flight; I was quite pleased to
see how slow it was able to fly before it
stalled.
The right wing had a tendency to drop
when the model stalled, but it was easy to
control right up to the stall. After a few
more low passes I tried a few touch-and-gos.
The big propeller windmilling created
quite a bit of drag, and I found that I needed
to keep a little power on during the approach
or make steep approaches to keep up the
airspeed. There is no tendency for the Val to
float too much once the power has been
pulled all the way back, but it doesn’t drop
like a brick either.
When I took my airplane home I checked
the wings for warp and found a slight one in
the right wing. Twisting the wing and
reheating the MonoKote removed the warp.
I also redrew the plans to show 1/2°
incidence in the horizontal stabilizer.
On subsequent flights I was able to see
how aerobatic the Val is. It will fly upside
down by my holding a little down-elevator
with no problem. Rolls are nice and crisp.
There is little roll coupling with the rudder.
Landings are a breeze; you can wheelie it
on, and three point it on, or if you’re careful
you can one-point it on the tail wheel!
If you want a model that can do all the
fancy stuff, the Val will probably make you
yawn. But if you’re looking for an advanced
trainer that looks like a full-scale airplane or
if you want to try flying in a Fun Scale
contest or two, this may be a great fit for
you. MA
Gary Fuller
Edition: Model Aviation - 2007/03
Page Numbers: 29,30,31,32,33,34,35,36,38,40
I WAS DISCUSSING with a friend my effort to try to come up
with an interesting model that would be fun to build and fly, and the
Japanese Val was mentioned. All I really knew about it was that it
was a low-wing, fixed-landing-gear dive-bomber the Japanese used
during World War II.
Part of what I enjoy about modeling is researching the various
airplanes I build, so I started researching this aircraft. Did you know
that a Val dropped the first bomb during the attack on Pearl Harbor
in Hawaii in 1941?
After looking at a three-view drawing I decided the Val looked
like it might make a good-flying model. It had a generous amount of
wing area; the landing gear was fixed, which would keep modeling
costs down; and I could have the added fun of a droppable bomb.
The elliptical wing was the only thing I could think of that would
make the Val slightly more difficult to design and build than any
other low-winged sport model. However, the wing turned out to be
fairly easy to build.
Since I like my sport-scale models to be easy to construct, the
fuselage is built with flat sides like most other sport models. I also
like to keep the weight down, so I made the fuselage as skinny as I
could but wide enough to hide the radio and engine.
To make the horizontal and vertical stabilizer simple to build I
used 1/4 balsa sheet. The wheel pants were the only things that gave
me any trouble, and that was only when it was time to cover them
with MonoKote.
I put 2° of washout in the wingtips to help during low-speed
flight. With a ready-to-fly weight of approximately 6 pounds and a
wing area of 680 square inches, the wing loading is only
approximately 20 ounces per square foot; that’s close to the wing
loading of most trainers.
The electric bug has bitten me, so I used a MaxCim motor,
gearbox, and controller in my Val. I think any motor that can put out
at least 350 watts will work. If you want to use glow power, I
recommend a .40-.60 two-stroke or a .52-.70 four-stroke engine.
Artist’s composite of bare
wood and finished model.
Gary covered his Val with MonoKote. Although the colors are
not authentic, the markings were used on a Val during the
attack on Midway Island in 1942. This color scheme is easy to
see in the air. Erin Fuller photo.
The left and right fuselage sides are almost ready to join; all that is needed is to taper the
1/2 balsa triangle stock at the rear end.
Before gluing the tail end of the fuselage together, place scrap wood in the horizontal
stabilizer slot and on the wing saddle. Sight down the fuselage and get the two scrap
wood pieces parallel with each other by adjusting the fuselage sides, which are held
together with the clothespin.
The author prefers Sig-Ment or Ambroid to glue the top and
bottom 3/16 balsa sheeting in place. Holes are drilled in the firewall
to cool the batteries and motor.
The center-section of the wing. Use a piece of aluminum angle to
hold the TE of the ribs in alignment.
Type: RC semiscale
Wingspan: 63 inches
Wing area: 680 square inches
Flying weight: 6 pounds
Wing loading: 20.25 ounces
per square foot
Power: .32-.50 two-stroke or
.40-.65 four-stroke engine or
MaxCim MaxN32-13Y
motor geared 2.2:1, using a
15-volt 4000 mAh battery
Construction: Balsa and
plywood
Covering/finish: MonoKote
Photos by the author except as noted
Before the LE is installed, glue the top TE sheeting in place. The
first of the laminations are shown glued to the LE.
The landing-gear mount block in the wing center-section. After the top spar is glued to the ribs the bottom spar is lifted into the
lower spar slots, and then the spar is blocked up and glued to the ribs.
The R1C angle guide is being used to set rib R1C to the correct
angle. Don’t glue the rib to the spars until all the spars are in place.
Many clothespins are used to hold the LE laminations together
while the glue dries.
Glue the top sheeting to the LE only first. After the glue dries, wet
the top sheeting with water and ammonia to make it more flexible.
Before sheeting the top of the wing center-section, drill the holes for
the landing-gear wires through the landing-gear mounting blocks
using the vertical piece of grooved block as a guide.
32 MODEL AVIATION
Clothespins and clamps are used to hold the outboard section of
the wing to the inboard section while the glue dries.
Clothespins and regular T-pins are used to hold the wing sheeting
in place as the glue dries.
It makes it easier to drill the hole for the 1/4–inch-diameter wingmounting
dowel if you delay the sheeting of the bottom of the
forward fuselage.
Aileron servos are mounted on the bottom of the wing. The ailerons
need more up travel than down to reduce adverse yaw at low
airspeeds.
The motor speed control and receiver are mounted with hook-andloop
material. Other pieces of hook-and-loop are used to hold the
wiring.
Only one nylon landing-gear
strap is needed to mount the
wheel pants to the landing gear.
The motor and radio switches
are painted to match the
covering.
Drill a 1/4-inch hole in a large block of wood and insert the 1/4-inch
wing-mounting dowel. This holds the wing in a vertical position,
aiding in construction.
CONSTRUCTION:
I like to cut most of the parts for my
models before I begin building. There are
numerous ways to transfer the shape of
the part to the wood, but my favorite is to
cut the plans for the separate parts and
then use low-tack glue to adhere the
plans part directly to the wood. I have
had good luck using Elmer’s glue sticks.
Use a band saw to cut the wood to
shape. After the part is cut, remove the
paper from the wood. Drill the holes for
the motor mount when you cut the
firewall.
Fuselage: Start with the fuselage by
laying the left and right sides on my
workbench so that they are top to top;
that way you won’t make two left or right
sides as you glue the various pieces to the
sides.
Glue the 1/16 balsa (or plywood if you
plan to use glow power) doublers to the
sides. Make sure you glue the shorter of
the two doublers to the right side; this is
for the 2° right thrust for the engine.
Adhere the 1/2 balsa triangle stock to
the edges of the side as shown on the
plans. Once the glue has dried, taper the
triangle stock at the back end of the
fuselage. Glue the 1/4 square balsa side
stiffeners to the sides as shown on the
plans.
Glue formers F2, F3, and F4 to only
one side of the fuselage at this time.
Former F2 can be positioned to suit your
needs whether you use a glow engine or
an electric motor. Make sure they are 90°
to the side.
Glue the 1/8 square balsa to F4 as
shown on the plans. Glue the other side
to the formers. I did this by rubber
banding the sides to each other, and using
a square and my eyeballs I aligned the
sides to each other. Glue the formers to
the other side. Glue the firewall in place.
Set the fuselage on the workbench so
it is sitting on its top. Place some 1/4 balsa
sheet scraps in the wing saddle and the
horizontal stabilizer slots on the fuselage,
and then bring the aft end of the fuselage
sides together and hold in place with a
clothespin.
Sighting from the front or back end of
the fuselage, the sides are adjusted at the
back end so the 1/4-inch sticks are parallel
with each other and the fuselage is
straight. Once these are aligned, glue the
back end of the fuselage together. Sheet
the top of the fuselage with 3/16 balsa.
If you plan to use electric power,
build the hatch on the top forward part of
the fuselage. Sheet the bottom of the
fuselage aft of the wing with 3/16 balsa.
The sheeting’s grain should be crosswise
on the top and bottom sheeting.
The bottom forward of the wing will
be sheeted after the wing has been
mounted to the fuselage. Glue in the 1/4
plywood wing-mount plate and set the
fuselage aside to allow the glue to dry.
When the glue has dried on the top and
bottom sheeting, sand the fuselage to shape.
I used a large C-clamp to support a sheet of
1/2 plywood on its edge. Then I carefully
secured the fuselage to the plywood with
part of the fuselage hanging over the edge of
my workbench.
On the part of the fuselage that was
hanging over the edge of the bench I draped
the sandpaper across the top and pulled it
down and back and forth in a method similar
to that you would use to shine your shoes.
When you’re satisfied with the shape of
your fuselage, set it aside and start the wing.
Wing: Start with the center-section. Glue
the R1A and R1B ribs to the R1 ribs as
shown on the plans. Pin the forward spar to
the workbench. Place the rear spar on the
plans, but don’t pin it down; it will need to
be raised up into the ribs after they are in
place. Fit but don’t glue the 1/4 plywood
wing dowel support to the ribs that have the
R1Bs glued to them, and glue them on the
forward spar.
I used landing-gear mounts that Sig sells.
They are 6 inches long, and you need to cut
an inch for the end of each mount. After the
landing-gear mounts are glued in place,
these 1-inch blocks will be glued to the top
of the landing-gear mounts at the inboard
end up against the R1A rib, so don’t throw
them away.
Place the landing-gear mounts on the
plans and adhere the remaining R1 and R1A
ribs to the forward spar. Glue the top
forward and rear spars to the ribs. Pull the
lower rear spar up into the ribs and glue the
ribs to it. Pull the landing-gear mounts up
into the ribs and glue these in place, and then
glue the 1-inch blocks on top of the landinggear
mount against the inboard R1A rib.
Glue the 3/8 balsa LE to the centersection
and then glue the 1/8 plywood wing
dowel support to the LE. Glue a 1 x 3/32-inch
strip of balsa to the top of the ribs at the TE.
Mounting the 1/8 plywood dihedral
supports is next. I did this by drilling some
1/8-inch-diameter holes in the outermost R1
ribs between the top and bottom spars. Then
I joined the holes to form a 1/8-inch-wide
slot from the top spar to the bottom spar by
using a small file.
Install the dihedral joiner into the slot
and glue it to the top and bottom spars.
Make sure the dihedral joiner is at a 90°
angle to the R1 rib before you glue it to the
spars. Do this for the forward and aft
dihedral joiners.
For the outboard wing panels I placed
the forward and main spars on the plans and
then pinned ribs R2-R8 in place on the
plans. I placed rib R1C on the spar but did
not pin it down.
I lifted the main spar up into all the ribs
and placed shims under the spar in various
locations along the spar to hold it off the
workbench and into the ribs. Then I pinned
the spar to the workbench.
Keep the spar straight along the
wingspan and make sure the rib building
tabs are still in contact with the workbench.
Glue all the ribs except R1C to the spar. Lift
the forward spar into rib R1C and R2 and
glue to R2.
Place the top spar on all the ribs and glue
it to all the ribs except R1C. Glue the
forward spar to R2.
Cut the R1C angle guide from the plans
and glue to some scrap plywood, and then
cut the plywood to the shape of the R1C
guide. Place the R1C guide on the bottom
main spar between the top and bottom spars
against R1C.
Adjust R1C so that it is against the
guide, and glue it to the top and bottom
spars. Be careful not to glue the guide to the
rib or the spars, and make sure R1C is in the
proper place on the plans. Move the R1C
guide to the forward spar and adjust rib
R1C, and then glue R1C to the top and
bottom spars.
Glue the 1/4 balsa TE to the aileron
cutout. Make sure you have the cutout at
least 3/32 inch wider than the ribs for the 3/32
balsa sheeting. Glue the top 1 x 3/32-inch
balsa sheeting to the TE at the aileron
cutout. Glue the 3/32 balsa sheeting to the
TE, inboard of the aileron.
I decided to use a laminated balsa LE on
my Val, but you could use a solid balsa LE
if you wanted. For a laminated LE, glue the
first lamination to the ribs’ LEs with some
cyanoacrylate-type glue while the wing is
still pinned to the workbench.
Use a Sig-Ment or Ambroid type of
wood glue to adhere each successive
lamination to the LE. You will need a bunch
of clothespins or clamps to do this;
clothespins may not be long enough to
clamp on the laminations properly.
I worked around this by removing the
wing from the workbench and placing it on
a table with a curved end, with the LE
overhanging the edge of the table. I
weighted down the wing so it would not
move and was held flat on the table. Then I
used the clothespins from the top and
bottom of the LE to hold the laminations on
as the glue dried.
Glue the 3/32 balsa LE sheeting to the top
of the outboard wing section. You may need
to spray some water on the sheeting to make
it easier to bend. Once the glue and sheeting
has dried, sand the wing sheeting flush with
rib R1. Cut the slots in R1 for the dihedral
braces.
Once you are satisfied with the fit of the
outboard section to the inboard section, glue
them together. I used numerous clothespins
to hold ribs R1 and R1C together from the
bottom.
To increase the strength of the plywood
dihedral joint to the top and bottom spars I
added 3/32 balsa to fit between the top and
bottom spars, and then I glued these to the
plywood dihedral braces and the top and
bottom spars.
Build the other outer wing panel in the
same manner as you built the first panel.
Round off the top of the center-section’s
LE so the center-section will fit in the wing
saddle on the fuselage. Center the wing on
the fuselage and then drill the hole for the
1/4-inch wing-mounting dowel through F2
and the wing’s LE. Remove the wing from
the fuselage and glue the 1/4-inch-diameter
dowel in place on the wing.
Sheet the bottom of the wing. Glue the
1/4 balsa TEs to the wing and sand them to
match the contour of the airfoil.
The ailerons are fairly simple to build.
They are 3/32 sheet balsa with half ribs glued
to the top and bottom.
Glue the 1/4-inch-wide balsa capstrips to
the ribs. Use 1/8-inch-thick balsa for the
capstrips. Glue the 1/4 balsa TE to the
ailerons. Cut the slots for the hinges in the
ailerons and in the wing, and then
temporarily mount the ailerons to the wing
and sand the ailerons to match the wing.
Install the aileron-servo mount blocks as
shown on the plans. The 3/32 balsa is to form
a lip around the servo mount hole for the
covering to stick to.
Adhere the wingtip blocks in place and
sand them to shape. Glue the 1/8 plywood
wing-bolt reinforcing plate to the bottom of
the wing on the center-section.
Mount the wing to the fuselage and drill
a 13/64-inch hole in the wing and fuselage for
the wing-mounting screw. Tap the hole in
the fuselage with a 1/4-20 tap. Enlarge the
hole in the wing to 1/4 inch.
Glue F4A and F6 to the bottom of the
wing and then sheet over it with 3/16 balsa.
Use a sharpened brass tube to cut the hole
for access to the wing mounting screw.
Sheet the lower forward part of the fuselage
with 3/16 balsa. Glue the 1/4 balsa F5s in
place. Sand the lower wing fuselage fairing
to match the contour of the fuselage shape.
Flip the fuselage over and secure it to the
worktable so you can mount the horizontal
stabilizer. Slide the horizontal stabilizer into
the slot in the rear of the fuselage. Make
sure the stabilizer is centered on the
fuselage. Sight down the length of the
fuselage from the front or rear and make
sure the stabilizer and wing are parallel to
each other horizontally.
Make sure the stabilizer is square to the
wing by measuring from the wing TE to the
stabilizer TE on both sides of the fuselage,
and make sure these measurements are the
same. Check the horizontal stabilizer’s
incidence to the wing; it should be
approximately 1/2° LE down. When you’re
satisfied that the stabilizer is mounted
correctly, glue it to the fuselage.
Mount the vertical stabilizer to the
fuselage with pins. To align the vertical
stabilizer so that it is not offset to one side
or the other, sight down the top of the
fuselage from the front and pin it in place.
Adjust the vertical stabilizer so it is 90° to
the horizontal stabilizer and then glue the
vertical stabilizer to the fuselage.
The tail-wheel bracket is 1/16-inchdiameter
music wire bent to shape and
mounted to the fuselage with 1/16-inch-insidediameter
brass tube. I built mine by bending
the bottom of the bracket for the axle and
slipping on a small washer to keep the tail
wheel from pushing the rudder up. Then I
soldered the washer to the music wire.
I sharpened the end of the 1/16-inch brass
tube and used it to drill the hole in the
fuselage for the bracket. Then I glued the
brass tube in place on the fuselage and cut it
to length. The music-wire bracket was
slipped into the brass tube and the top of the
bracket was then bent over to fit into the
rudder.
The full-scale Val has a rather large
wing-to-fuselage fillet; this has been drawn
on the plans, but I opted not to install the
fillet on my model. If you want to make a
fillet for yours, I will describe how I was
going to build it.
Cut the fillet base from 1/64 plywood.
Loosely mount the wing to the fuselage and
slip the fillet base in place between the wing
and fuselage. When you are satisfied with
the location of the fillet, tighten the wing to
the fuselage and glue the fillet to the
fuselage only.
Cut some soft balsa blocks and glue
them to the fuselage. Carve and sand them
to the shape of the fillet.
Bend the elevator joiner from 1/8-inch
music wire, and then temporarily mount the
elevator using your favorite hinging method.
Temporarily mount the rudder.
Set the model aside and then bend the
main landing gear from 3/16-inch music wire.
The wheel pants are made from various
thicknesses of balsa. The thickness of the
main core of the wheel pants is determined
by the thickness of the wheels you use and
the addition of the wheel collars.
If you fly from a grass strip, cut the
bottom of the pants so that more of the
wheel is exposed than shown on the plans. I
have seen pictures of a full-scale Val’s
wheel without wheel pants, so you may not
want to build them for your model. Once
you have cut all the parts for the wheel
pants, glue them together and sand them to
shape.
Final-sand the fuselage and cover it with
your favorite covering material. I used
MonoKote. Although the colors I used are
not exactly accurate, I loosely based the color
scheme on a Val that was aboard the aircraft
carrier Akagi during the battle of Midway. I
got the red “meatballs” from a set of decals I
had from an old Top Flite Zero kit.
The canopy I used is from the Great
Planes AT-6 Texan ARF that is available
from Tower Hobbies. I decided early that I
would have cooling holes cut in the fuselage
in the cockpit area and I would leave the
rear of the canopy open for the air to escape.
I cut the excess plastic from the canopy
as if I was going to mount it on the model
for which it was designed. Then I placed the
canopy on the top of the fuselage and
pressed it down until the front of the
windscreen touched the top of the fuselage. I
used a dry-erase marker to indicate the side
of the canopy on which I needed to cut it to
make it fit the fuselage.
After I cut the canopy to fit the fuselage I
used a rag to remove the marks left on the
canopy. I taped the canopy in place on the
fuselage and marked the fuselage so I could
remove the green MonoKote from the
cockpit area and replace it with black
MonoKote.
Once I had re-covered the cockpit area
with the black MonoKote, I carefully cut a
small strip away from the black for the
canopy to be glued to bare wood on the
fuselage. I used a sharpened brass tube to
cut the cooling holes in the cockpit area.
Since I wanted to keep my model simple
but still wanted a pilot and gunner in it, I
decided to use a simple, flat version. I found
a picture of a pilot and gunner and scanned
it into my computer. Then I enlarged the
picture to the correct size. I created a mirror
image of the picture, and then I printed the
mirror image and the original image of the
picture.
I glued one side of the pilot and gunner
to a piece of 1/64 plywood. Then I cut the
plywood to the shape of the pilot and gunner
and glued the mirror image to the other side
of the pilot. To make the plywood blend into
the figures, I darkened the edge of the wood
with a black magic marker.
I glued the pilot and gunner figures into
slots cut in the cockpit area. When I was
happy with the cockpit area, I glued the
canopy to the fuselage with some Formula
560 canopy glue.
I mounted an old Vortac bomb release to
the bottom of the wing near the CG. If you
want to mount a bomb release, be careful
not to cut the wing spars as you make the
cutout for the release. I used a T-pin to poke
through the wing sheeting to locate the
spars. I mounted the bomb-release servo
upside down in the wing so that a servo arm
would actuate the release.
The Val’s nose is rather short, so I
mounted the radio gear as far forward in
the fuselage as I could. I still ended up
adding lead to the nose to get the CG
where I wanted it.
The aileron servos are mounted to the
bottom of the wing and are connected to the
receiver by a Y harness. I like my models to
be fairly responsive, so I set my control
throws as follows: rudder, 1 inch left and
right; elevator, 1/2 inch up and down;
ailerons, 1/4 inch down and 1/2 inch up.
The ailerons need more up than down
travel, and this is achieved by mounting the
servo arm on the servo at roughly a 45° angle
toward the front of the airplane. These are
good starting points for the first few flights.
After that you may want to increase or
decrease the throws to suit your flying style.
Flying: If you are like I am, you probably
skipped most of the article and came right to
this point to see how the Val flies. It flies
exactly like an advanced trainer. If the only
models you have ever flown are high-wing
trainers and you want to move on to a lowwing
trainer, this may be the airplane you’re
looking for.
The first flight with my Val took place
early on a cool, windless Saturday morning.
After range checking my radio with the
motor on, I taxied the model to the far end
of the runway. I slowly advanced the throttle
and let the Val roll down the runway. It
wanted to pull to the left, but I had no
problems keeping it headed down the
runway with the rudder.
After roughly 150 feet I started to feed in
up-elevator and the Val became airborne in
a nice, realistic manner. As I gained some
altitude I realized the Val needed some upelevator
trim and a little right aileron trim to
keep it level.
Once I had the Val trimmed out, I made
some low passes so my daughter Erin could
take some pictures of it in flight. I was
exceptionally pleased with how the model
flew. I took it up high to see how the Val
handled in slow flight; I was quite pleased to
see how slow it was able to fly before it
stalled.
The right wing had a tendency to drop
when the model stalled, but it was easy to
control right up to the stall. After a few
more low passes I tried a few touch-and-gos.
The big propeller windmilling created
quite a bit of drag, and I found that I needed
to keep a little power on during the approach
or make steep approaches to keep up the
airspeed. There is no tendency for the Val to
float too much once the power has been
pulled all the way back, but it doesn’t drop
like a brick either.
When I took my airplane home I checked
the wings for warp and found a slight one in
the right wing. Twisting the wing and
reheating the MonoKote removed the warp.
I also redrew the plans to show 1/2°
incidence in the horizontal stabilizer.
On subsequent flights I was able to see
how aerobatic the Val is. It will fly upside
down by my holding a little down-elevator
with no problem. Rolls are nice and crisp.
There is little roll coupling with the rudder.
Landings are a breeze; you can wheelie it
on, and three point it on, or if you’re careful
you can one-point it on the tail wheel!
If you want a model that can do all the
fancy stuff, the Val will probably make you
yawn. But if you’re looking for an advanced
trainer that looks like a full-scale airplane or
if you want to try flying in a Fun Scale
contest or two, this may be a great fit for
you. MA
Gary Fuller
Edition: Model Aviation - 2007/03
Page Numbers: 29,30,31,32,33,34,35,36,38,40
I WAS DISCUSSING with a friend my effort to try to come up
with an interesting model that would be fun to build and fly, and the
Japanese Val was mentioned. All I really knew about it was that it
was a low-wing, fixed-landing-gear dive-bomber the Japanese used
during World War II.
Part of what I enjoy about modeling is researching the various
airplanes I build, so I started researching this aircraft. Did you know
that a Val dropped the first bomb during the attack on Pearl Harbor
in Hawaii in 1941?
After looking at a three-view drawing I decided the Val looked
like it might make a good-flying model. It had a generous amount of
wing area; the landing gear was fixed, which would keep modeling
costs down; and I could have the added fun of a droppable bomb.
The elliptical wing was the only thing I could think of that would
make the Val slightly more difficult to design and build than any
other low-winged sport model. However, the wing turned out to be
fairly easy to build.
Since I like my sport-scale models to be easy to construct, the
fuselage is built with flat sides like most other sport models. I also
like to keep the weight down, so I made the fuselage as skinny as I
could but wide enough to hide the radio and engine.
To make the horizontal and vertical stabilizer simple to build I
used 1/4 balsa sheet. The wheel pants were the only things that gave
me any trouble, and that was only when it was time to cover them
with MonoKote.
I put 2° of washout in the wingtips to help during low-speed
flight. With a ready-to-fly weight of approximately 6 pounds and a
wing area of 680 square inches, the wing loading is only
approximately 20 ounces per square foot; that’s close to the wing
loading of most trainers.
The electric bug has bitten me, so I used a MaxCim motor,
gearbox, and controller in my Val. I think any motor that can put out
at least 350 watts will work. If you want to use glow power, I
recommend a .40-.60 two-stroke or a .52-.70 four-stroke engine.
Artist’s composite of bare
wood and finished model.
Gary covered his Val with MonoKote. Although the colors are
not authentic, the markings were used on a Val during the
attack on Midway Island in 1942. This color scheme is easy to
see in the air. Erin Fuller photo.
The left and right fuselage sides are almost ready to join; all that is needed is to taper the
1/2 balsa triangle stock at the rear end.
Before gluing the tail end of the fuselage together, place scrap wood in the horizontal
stabilizer slot and on the wing saddle. Sight down the fuselage and get the two scrap
wood pieces parallel with each other by adjusting the fuselage sides, which are held
together with the clothespin.
The author prefers Sig-Ment or Ambroid to glue the top and
bottom 3/16 balsa sheeting in place. Holes are drilled in the firewall
to cool the batteries and motor.
The center-section of the wing. Use a piece of aluminum angle to
hold the TE of the ribs in alignment.
Type: RC semiscale
Wingspan: 63 inches
Wing area: 680 square inches
Flying weight: 6 pounds
Wing loading: 20.25 ounces
per square foot
Power: .32-.50 two-stroke or
.40-.65 four-stroke engine or
MaxCim MaxN32-13Y
motor geared 2.2:1, using a
15-volt 4000 mAh battery
Construction: Balsa and
plywood
Covering/finish: MonoKote
Photos by the author except as noted
Before the LE is installed, glue the top TE sheeting in place. The
first of the laminations are shown glued to the LE.
The landing-gear mount block in the wing center-section. After the top spar is glued to the ribs the bottom spar is lifted into the
lower spar slots, and then the spar is blocked up and glued to the ribs.
The R1C angle guide is being used to set rib R1C to the correct
angle. Don’t glue the rib to the spars until all the spars are in place.
Many clothespins are used to hold the LE laminations together
while the glue dries.
Glue the top sheeting to the LE only first. After the glue dries, wet
the top sheeting with water and ammonia to make it more flexible.
Before sheeting the top of the wing center-section, drill the holes for
the landing-gear wires through the landing-gear mounting blocks
using the vertical piece of grooved block as a guide.
32 MODEL AVIATION
Clothespins and clamps are used to hold the outboard section of
the wing to the inboard section while the glue dries.
Clothespins and regular T-pins are used to hold the wing sheeting
in place as the glue dries.
It makes it easier to drill the hole for the 1/4–inch-diameter wingmounting
dowel if you delay the sheeting of the bottom of the
forward fuselage.
Aileron servos are mounted on the bottom of the wing. The ailerons
need more up travel than down to reduce adverse yaw at low
airspeeds.
The motor speed control and receiver are mounted with hook-andloop
material. Other pieces of hook-and-loop are used to hold the
wiring.
Only one nylon landing-gear
strap is needed to mount the
wheel pants to the landing gear.
The motor and radio switches
are painted to match the
covering.
Drill a 1/4-inch hole in a large block of wood and insert the 1/4-inch
wing-mounting dowel. This holds the wing in a vertical position,
aiding in construction.
CONSTRUCTION:
I like to cut most of the parts for my
models before I begin building. There are
numerous ways to transfer the shape of
the part to the wood, but my favorite is to
cut the plans for the separate parts and
then use low-tack glue to adhere the
plans part directly to the wood. I have
had good luck using Elmer’s glue sticks.
Use a band saw to cut the wood to
shape. After the part is cut, remove the
paper from the wood. Drill the holes for
the motor mount when you cut the
firewall.
Fuselage: Start with the fuselage by
laying the left and right sides on my
workbench so that they are top to top;
that way you won’t make two left or right
sides as you glue the various pieces to the
sides.
Glue the 1/16 balsa (or plywood if you
plan to use glow power) doublers to the
sides. Make sure you glue the shorter of
the two doublers to the right side; this is
for the 2° right thrust for the engine.
Adhere the 1/2 balsa triangle stock to
the edges of the side as shown on the
plans. Once the glue has dried, taper the
triangle stock at the back end of the
fuselage. Glue the 1/4 square balsa side
stiffeners to the sides as shown on the
plans.
Glue formers F2, F3, and F4 to only
one side of the fuselage at this time.
Former F2 can be positioned to suit your
needs whether you use a glow engine or
an electric motor. Make sure they are 90°
to the side.
Glue the 1/8 square balsa to F4 as
shown on the plans. Glue the other side
to the formers. I did this by rubber
banding the sides to each other, and using
a square and my eyeballs I aligned the
sides to each other. Glue the formers to
the other side. Glue the firewall in place.
Set the fuselage on the workbench so
it is sitting on its top. Place some 1/4 balsa
sheet scraps in the wing saddle and the
horizontal stabilizer slots on the fuselage,
and then bring the aft end of the fuselage
sides together and hold in place with a
clothespin.
Sighting from the front or back end of
the fuselage, the sides are adjusted at the
back end so the 1/4-inch sticks are parallel
with each other and the fuselage is
straight. Once these are aligned, glue the
back end of the fuselage together. Sheet
the top of the fuselage with 3/16 balsa.
If you plan to use electric power,
build the hatch on the top forward part of
the fuselage. Sheet the bottom of the
fuselage aft of the wing with 3/16 balsa.
The sheeting’s grain should be crosswise
on the top and bottom sheeting.
The bottom forward of the wing will
be sheeted after the wing has been
mounted to the fuselage. Glue in the 1/4
plywood wing-mount plate and set the
fuselage aside to allow the glue to dry.
When the glue has dried on the top and
bottom sheeting, sand the fuselage to shape.
I used a large C-clamp to support a sheet of
1/2 plywood on its edge. Then I carefully
secured the fuselage to the plywood with
part of the fuselage hanging over the edge of
my workbench.
On the part of the fuselage that was
hanging over the edge of the bench I draped
the sandpaper across the top and pulled it
down and back and forth in a method similar
to that you would use to shine your shoes.
When you’re satisfied with the shape of
your fuselage, set it aside and start the wing.
Wing: Start with the center-section. Glue
the R1A and R1B ribs to the R1 ribs as
shown on the plans. Pin the forward spar to
the workbench. Place the rear spar on the
plans, but don’t pin it down; it will need to
be raised up into the ribs after they are in
place. Fit but don’t glue the 1/4 plywood
wing dowel support to the ribs that have the
R1Bs glued to them, and glue them on the
forward spar.
I used landing-gear mounts that Sig sells.
They are 6 inches long, and you need to cut
an inch for the end of each mount. After the
landing-gear mounts are glued in place,
these 1-inch blocks will be glued to the top
of the landing-gear mounts at the inboard
end up against the R1A rib, so don’t throw
them away.
Place the landing-gear mounts on the
plans and adhere the remaining R1 and R1A
ribs to the forward spar. Glue the top
forward and rear spars to the ribs. Pull the
lower rear spar up into the ribs and glue the
ribs to it. Pull the landing-gear mounts up
into the ribs and glue these in place, and then
glue the 1-inch blocks on top of the landinggear
mount against the inboard R1A rib.
Glue the 3/8 balsa LE to the centersection
and then glue the 1/8 plywood wing
dowel support to the LE. Glue a 1 x 3/32-inch
strip of balsa to the top of the ribs at the TE.
Mounting the 1/8 plywood dihedral
supports is next. I did this by drilling some
1/8-inch-diameter holes in the outermost R1
ribs between the top and bottom spars. Then
I joined the holes to form a 1/8-inch-wide
slot from the top spar to the bottom spar by
using a small file.
Install the dihedral joiner into the slot
and glue it to the top and bottom spars.
Make sure the dihedral joiner is at a 90°
angle to the R1 rib before you glue it to the
spars. Do this for the forward and aft
dihedral joiners.
For the outboard wing panels I placed
the forward and main spars on the plans and
then pinned ribs R2-R8 in place on the
plans. I placed rib R1C on the spar but did
not pin it down.
I lifted the main spar up into all the ribs
and placed shims under the spar in various
locations along the spar to hold it off the
workbench and into the ribs. Then I pinned
the spar to the workbench.
Keep the spar straight along the
wingspan and make sure the rib building
tabs are still in contact with the workbench.
Glue all the ribs except R1C to the spar. Lift
the forward spar into rib R1C and R2 and
glue to R2.
Place the top spar on all the ribs and glue
it to all the ribs except R1C. Glue the
forward spar to R2.
Cut the R1C angle guide from the plans
and glue to some scrap plywood, and then
cut the plywood to the shape of the R1C
guide. Place the R1C guide on the bottom
main spar between the top and bottom spars
against R1C.
Adjust R1C so that it is against the
guide, and glue it to the top and bottom
spars. Be careful not to glue the guide to the
rib or the spars, and make sure R1C is in the
proper place on the plans. Move the R1C
guide to the forward spar and adjust rib
R1C, and then glue R1C to the top and
bottom spars.
Glue the 1/4 balsa TE to the aileron
cutout. Make sure you have the cutout at
least 3/32 inch wider than the ribs for the 3/32
balsa sheeting. Glue the top 1 x 3/32-inch
balsa sheeting to the TE at the aileron
cutout. Glue the 3/32 balsa sheeting to the
TE, inboard of the aileron.
I decided to use a laminated balsa LE on
my Val, but you could use a solid balsa LE
if you wanted. For a laminated LE, glue the
first lamination to the ribs’ LEs with some
cyanoacrylate-type glue while the wing is
still pinned to the workbench.
Use a Sig-Ment or Ambroid type of
wood glue to adhere each successive
lamination to the LE. You will need a bunch
of clothespins or clamps to do this;
clothespins may not be long enough to
clamp on the laminations properly.
I worked around this by removing the
wing from the workbench and placing it on
a table with a curved end, with the LE
overhanging the edge of the table. I
weighted down the wing so it would not
move and was held flat on the table. Then I
used the clothespins from the top and
bottom of the LE to hold the laminations on
as the glue dried.
Glue the 3/32 balsa LE sheeting to the top
of the outboard wing section. You may need
to spray some water on the sheeting to make
it easier to bend. Once the glue and sheeting
has dried, sand the wing sheeting flush with
rib R1. Cut the slots in R1 for the dihedral
braces.
Once you are satisfied with the fit of the
outboard section to the inboard section, glue
them together. I used numerous clothespins
to hold ribs R1 and R1C together from the
bottom.
To increase the strength of the plywood
dihedral joint to the top and bottom spars I
added 3/32 balsa to fit between the top and
bottom spars, and then I glued these to the
plywood dihedral braces and the top and
bottom spars.
Build the other outer wing panel in the
same manner as you built the first panel.
Round off the top of the center-section’s
LE so the center-section will fit in the wing
saddle on the fuselage. Center the wing on
the fuselage and then drill the hole for the
1/4-inch wing-mounting dowel through F2
and the wing’s LE. Remove the wing from
the fuselage and glue the 1/4-inch-diameter
dowel in place on the wing.
Sheet the bottom of the wing. Glue the
1/4 balsa TEs to the wing and sand them to
match the contour of the airfoil.
The ailerons are fairly simple to build.
They are 3/32 sheet balsa with half ribs glued
to the top and bottom.
Glue the 1/4-inch-wide balsa capstrips to
the ribs. Use 1/8-inch-thick balsa for the
capstrips. Glue the 1/4 balsa TE to the
ailerons. Cut the slots for the hinges in the
ailerons and in the wing, and then
temporarily mount the ailerons to the wing
and sand the ailerons to match the wing.
Install the aileron-servo mount blocks as
shown on the plans. The 3/32 balsa is to form
a lip around the servo mount hole for the
covering to stick to.
Adhere the wingtip blocks in place and
sand them to shape. Glue the 1/8 plywood
wing-bolt reinforcing plate to the bottom of
the wing on the center-section.
Mount the wing to the fuselage and drill
a 13/64-inch hole in the wing and fuselage for
the wing-mounting screw. Tap the hole in
the fuselage with a 1/4-20 tap. Enlarge the
hole in the wing to 1/4 inch.
Glue F4A and F6 to the bottom of the
wing and then sheet over it with 3/16 balsa.
Use a sharpened brass tube to cut the hole
for access to the wing mounting screw.
Sheet the lower forward part of the fuselage
with 3/16 balsa. Glue the 1/4 balsa F5s in
place. Sand the lower wing fuselage fairing
to match the contour of the fuselage shape.
Flip the fuselage over and secure it to the
worktable so you can mount the horizontal
stabilizer. Slide the horizontal stabilizer into
the slot in the rear of the fuselage. Make
sure the stabilizer is centered on the
fuselage. Sight down the length of the
fuselage from the front or rear and make
sure the stabilizer and wing are parallel to
each other horizontally.
Make sure the stabilizer is square to the
wing by measuring from the wing TE to the
stabilizer TE on both sides of the fuselage,
and make sure these measurements are the
same. Check the horizontal stabilizer’s
incidence to the wing; it should be
approximately 1/2° LE down. When you’re
satisfied that the stabilizer is mounted
correctly, glue it to the fuselage.
Mount the vertical stabilizer to the
fuselage with pins. To align the vertical
stabilizer so that it is not offset to one side
or the other, sight down the top of the
fuselage from the front and pin it in place.
Adjust the vertical stabilizer so it is 90° to
the horizontal stabilizer and then glue the
vertical stabilizer to the fuselage.
The tail-wheel bracket is 1/16-inchdiameter
music wire bent to shape and
mounted to the fuselage with 1/16-inch-insidediameter
brass tube. I built mine by bending
the bottom of the bracket for the axle and
slipping on a small washer to keep the tail
wheel from pushing the rudder up. Then I
soldered the washer to the music wire.
I sharpened the end of the 1/16-inch brass
tube and used it to drill the hole in the
fuselage for the bracket. Then I glued the
brass tube in place on the fuselage and cut it
to length. The music-wire bracket was
slipped into the brass tube and the top of the
bracket was then bent over to fit into the
rudder.
The full-scale Val has a rather large
wing-to-fuselage fillet; this has been drawn
on the plans, but I opted not to install the
fillet on my model. If you want to make a
fillet for yours, I will describe how I was
going to build it.
Cut the fillet base from 1/64 plywood.
Loosely mount the wing to the fuselage and
slip the fillet base in place between the wing
and fuselage. When you are satisfied with
the location of the fillet, tighten the wing to
the fuselage and glue the fillet to the
fuselage only.
Cut some soft balsa blocks and glue
them to the fuselage. Carve and sand them
to the shape of the fillet.
Bend the elevator joiner from 1/8-inch
music wire, and then temporarily mount the
elevator using your favorite hinging method.
Temporarily mount the rudder.
Set the model aside and then bend the
main landing gear from 3/16-inch music wire.
The wheel pants are made from various
thicknesses of balsa. The thickness of the
main core of the wheel pants is determined
by the thickness of the wheels you use and
the addition of the wheel collars.
If you fly from a grass strip, cut the
bottom of the pants so that more of the
wheel is exposed than shown on the plans. I
have seen pictures of a full-scale Val’s
wheel without wheel pants, so you may not
want to build them for your model. Once
you have cut all the parts for the wheel
pants, glue them together and sand them to
shape.
Final-sand the fuselage and cover it with
your favorite covering material. I used
MonoKote. Although the colors I used are
not exactly accurate, I loosely based the color
scheme on a Val that was aboard the aircraft
carrier Akagi during the battle of Midway. I
got the red “meatballs” from a set of decals I
had from an old Top Flite Zero kit.
The canopy I used is from the Great
Planes AT-6 Texan ARF that is available
from Tower Hobbies. I decided early that I
would have cooling holes cut in the fuselage
in the cockpit area and I would leave the
rear of the canopy open for the air to escape.
I cut the excess plastic from the canopy
as if I was going to mount it on the model
for which it was designed. Then I placed the
canopy on the top of the fuselage and
pressed it down until the front of the
windscreen touched the top of the fuselage. I
used a dry-erase marker to indicate the side
of the canopy on which I needed to cut it to
make it fit the fuselage.
After I cut the canopy to fit the fuselage I
used a rag to remove the marks left on the
canopy. I taped the canopy in place on the
fuselage and marked the fuselage so I could
remove the green MonoKote from the
cockpit area and replace it with black
MonoKote.
Once I had re-covered the cockpit area
with the black MonoKote, I carefully cut a
small strip away from the black for the
canopy to be glued to bare wood on the
fuselage. I used a sharpened brass tube to
cut the cooling holes in the cockpit area.
Since I wanted to keep my model simple
but still wanted a pilot and gunner in it, I
decided to use a simple, flat version. I found
a picture of a pilot and gunner and scanned
it into my computer. Then I enlarged the
picture to the correct size. I created a mirror
image of the picture, and then I printed the
mirror image and the original image of the
picture.
I glued one side of the pilot and gunner
to a piece of 1/64 plywood. Then I cut the
plywood to the shape of the pilot and gunner
and glued the mirror image to the other side
of the pilot. To make the plywood blend into
the figures, I darkened the edge of the wood
with a black magic marker.
I glued the pilot and gunner figures into
slots cut in the cockpit area. When I was
happy with the cockpit area, I glued the
canopy to the fuselage with some Formula
560 canopy glue.
I mounted an old Vortac bomb release to
the bottom of the wing near the CG. If you
want to mount a bomb release, be careful
not to cut the wing spars as you make the
cutout for the release. I used a T-pin to poke
through the wing sheeting to locate the
spars. I mounted the bomb-release servo
upside down in the wing so that a servo arm
would actuate the release.
The Val’s nose is rather short, so I
mounted the radio gear as far forward in
the fuselage as I could. I still ended up
adding lead to the nose to get the CG
where I wanted it.
The aileron servos are mounted to the
bottom of the wing and are connected to the
receiver by a Y harness. I like my models to
be fairly responsive, so I set my control
throws as follows: rudder, 1 inch left and
right; elevator, 1/2 inch up and down;
ailerons, 1/4 inch down and 1/2 inch up.
The ailerons need more up than down
travel, and this is achieved by mounting the
servo arm on the servo at roughly a 45° angle
toward the front of the airplane. These are
good starting points for the first few flights.
After that you may want to increase or
decrease the throws to suit your flying style.
Flying: If you are like I am, you probably
skipped most of the article and came right to
this point to see how the Val flies. It flies
exactly like an advanced trainer. If the only
models you have ever flown are high-wing
trainers and you want to move on to a lowwing
trainer, this may be the airplane you’re
looking for.
The first flight with my Val took place
early on a cool, windless Saturday morning.
After range checking my radio with the
motor on, I taxied the model to the far end
of the runway. I slowly advanced the throttle
and let the Val roll down the runway. It
wanted to pull to the left, but I had no
problems keeping it headed down the
runway with the rudder.
After roughly 150 feet I started to feed in
up-elevator and the Val became airborne in
a nice, realistic manner. As I gained some
altitude I realized the Val needed some upelevator
trim and a little right aileron trim to
keep it level.
Once I had the Val trimmed out, I made
some low passes so my daughter Erin could
take some pictures of it in flight. I was
exceptionally pleased with how the model
flew. I took it up high to see how the Val
handled in slow flight; I was quite pleased to
see how slow it was able to fly before it
stalled.
The right wing had a tendency to drop
when the model stalled, but it was easy to
control right up to the stall. After a few
more low passes I tried a few touch-and-gos.
The big propeller windmilling created
quite a bit of drag, and I found that I needed
to keep a little power on during the approach
or make steep approaches to keep up the
airspeed. There is no tendency for the Val to
float too much once the power has been
pulled all the way back, but it doesn’t drop
like a brick either.
When I took my airplane home I checked
the wings for warp and found a slight one in
the right wing. Twisting the wing and
reheating the MonoKote removed the warp.
I also redrew the plans to show 1/2°
incidence in the horizontal stabilizer.
On subsequent flights I was able to see
how aerobatic the Val is. It will fly upside
down by my holding a little down-elevator
with no problem. Rolls are nice and crisp.
There is little roll coupling with the rudder.
Landings are a breeze; you can wheelie it
on, and three point it on, or if you’re careful
you can one-point it on the tail wheel!
If you want a model that can do all the
fancy stuff, the Val will probably make you
yawn. But if you’re looking for an advanced
trainer that looks like a full-scale airplane or
if you want to try flying in a Fun Scale
contest or two, this may be a great fit for
you. MA
Gary Fuller
Edition: Model Aviation - 2007/03
Page Numbers: 29,30,31,32,33,34,35,36,38,40
I WAS DISCUSSING with a friend my effort to try to come up
with an interesting model that would be fun to build and fly, and the
Japanese Val was mentioned. All I really knew about it was that it
was a low-wing, fixed-landing-gear dive-bomber the Japanese used
during World War II.
Part of what I enjoy about modeling is researching the various
airplanes I build, so I started researching this aircraft. Did you know
that a Val dropped the first bomb during the attack on Pearl Harbor
in Hawaii in 1941?
After looking at a three-view drawing I decided the Val looked
like it might make a good-flying model. It had a generous amount of
wing area; the landing gear was fixed, which would keep modeling
costs down; and I could have the added fun of a droppable bomb.
The elliptical wing was the only thing I could think of that would
make the Val slightly more difficult to design and build than any
other low-winged sport model. However, the wing turned out to be
fairly easy to build.
Since I like my sport-scale models to be easy to construct, the
fuselage is built with flat sides like most other sport models. I also
like to keep the weight down, so I made the fuselage as skinny as I
could but wide enough to hide the radio and engine.
To make the horizontal and vertical stabilizer simple to build I
used 1/4 balsa sheet. The wheel pants were the only things that gave
me any trouble, and that was only when it was time to cover them
with MonoKote.
I put 2° of washout in the wingtips to help during low-speed
flight. With a ready-to-fly weight of approximately 6 pounds and a
wing area of 680 square inches, the wing loading is only
approximately 20 ounces per square foot; that’s close to the wing
loading of most trainers.
The electric bug has bitten me, so I used a MaxCim motor,
gearbox, and controller in my Val. I think any motor that can put out
at least 350 watts will work. If you want to use glow power, I
recommend a .40-.60 two-stroke or a .52-.70 four-stroke engine.
Artist’s composite of bare
wood and finished model.
Gary covered his Val with MonoKote. Although the colors are
not authentic, the markings were used on a Val during the
attack on Midway Island in 1942. This color scheme is easy to
see in the air. Erin Fuller photo.
The left and right fuselage sides are almost ready to join; all that is needed is to taper the
1/2 balsa triangle stock at the rear end.
Before gluing the tail end of the fuselage together, place scrap wood in the horizontal
stabilizer slot and on the wing saddle. Sight down the fuselage and get the two scrap
wood pieces parallel with each other by adjusting the fuselage sides, which are held
together with the clothespin.
The author prefers Sig-Ment or Ambroid to glue the top and
bottom 3/16 balsa sheeting in place. Holes are drilled in the firewall
to cool the batteries and motor.
The center-section of the wing. Use a piece of aluminum angle to
hold the TE of the ribs in alignment.
Type: RC semiscale
Wingspan: 63 inches
Wing area: 680 square inches
Flying weight: 6 pounds
Wing loading: 20.25 ounces
per square foot
Power: .32-.50 two-stroke or
.40-.65 four-stroke engine or
MaxCim MaxN32-13Y
motor geared 2.2:1, using a
15-volt 4000 mAh battery
Construction: Balsa and
plywood
Covering/finish: MonoKote
Photos by the author except as noted
Before the LE is installed, glue the top TE sheeting in place. The
first of the laminations are shown glued to the LE.
The landing-gear mount block in the wing center-section. After the top spar is glued to the ribs the bottom spar is lifted into the
lower spar slots, and then the spar is blocked up and glued to the ribs.
The R1C angle guide is being used to set rib R1C to the correct
angle. Don’t glue the rib to the spars until all the spars are in place.
Many clothespins are used to hold the LE laminations together
while the glue dries.
Glue the top sheeting to the LE only first. After the glue dries, wet
the top sheeting with water and ammonia to make it more flexible.
Before sheeting the top of the wing center-section, drill the holes for
the landing-gear wires through the landing-gear mounting blocks
using the vertical piece of grooved block as a guide.
32 MODEL AVIATION
Clothespins and clamps are used to hold the outboard section of
the wing to the inboard section while the glue dries.
Clothespins and regular T-pins are used to hold the wing sheeting
in place as the glue dries.
It makes it easier to drill the hole for the 1/4–inch-diameter wingmounting
dowel if you delay the sheeting of the bottom of the
forward fuselage.
Aileron servos are mounted on the bottom of the wing. The ailerons
need more up travel than down to reduce adverse yaw at low
airspeeds.
The motor speed control and receiver are mounted with hook-andloop
material. Other pieces of hook-and-loop are used to hold the
wiring.
Only one nylon landing-gear
strap is needed to mount the
wheel pants to the landing gear.
The motor and radio switches
are painted to match the
covering.
Drill a 1/4-inch hole in a large block of wood and insert the 1/4-inch
wing-mounting dowel. This holds the wing in a vertical position,
aiding in construction.
CONSTRUCTION:
I like to cut most of the parts for my
models before I begin building. There are
numerous ways to transfer the shape of
the part to the wood, but my favorite is to
cut the plans for the separate parts and
then use low-tack glue to adhere the
plans part directly to the wood. I have
had good luck using Elmer’s glue sticks.
Use a band saw to cut the wood to
shape. After the part is cut, remove the
paper from the wood. Drill the holes for
the motor mount when you cut the
firewall.
Fuselage: Start with the fuselage by
laying the left and right sides on my
workbench so that they are top to top;
that way you won’t make two left or right
sides as you glue the various pieces to the
sides.
Glue the 1/16 balsa (or plywood if you
plan to use glow power) doublers to the
sides. Make sure you glue the shorter of
the two doublers to the right side; this is
for the 2° right thrust for the engine.
Adhere the 1/2 balsa triangle stock to
the edges of the side as shown on the
plans. Once the glue has dried, taper the
triangle stock at the back end of the
fuselage. Glue the 1/4 square balsa side
stiffeners to the sides as shown on the
plans.
Glue formers F2, F3, and F4 to only
one side of the fuselage at this time.
Former F2 can be positioned to suit your
needs whether you use a glow engine or
an electric motor. Make sure they are 90°
to the side.
Glue the 1/8 square balsa to F4 as
shown on the plans. Glue the other side
to the formers. I did this by rubber
banding the sides to each other, and using
a square and my eyeballs I aligned the
sides to each other. Glue the formers to
the other side. Glue the firewall in place.
Set the fuselage on the workbench so
it is sitting on its top. Place some 1/4 balsa
sheet scraps in the wing saddle and the
horizontal stabilizer slots on the fuselage,
and then bring the aft end of the fuselage
sides together and hold in place with a
clothespin.
Sighting from the front or back end of
the fuselage, the sides are adjusted at the
back end so the 1/4-inch sticks are parallel
with each other and the fuselage is
straight. Once these are aligned, glue the
back end of the fuselage together. Sheet
the top of the fuselage with 3/16 balsa.
If you plan to use electric power,
build the hatch on the top forward part of
the fuselage. Sheet the bottom of the
fuselage aft of the wing with 3/16 balsa.
The sheeting’s grain should be crosswise
on the top and bottom sheeting.
The bottom forward of the wing will
be sheeted after the wing has been
mounted to the fuselage. Glue in the 1/4
plywood wing-mount plate and set the
fuselage aside to allow the glue to dry.
When the glue has dried on the top and
bottom sheeting, sand the fuselage to shape.
I used a large C-clamp to support a sheet of
1/2 plywood on its edge. Then I carefully
secured the fuselage to the plywood with
part of the fuselage hanging over the edge of
my workbench.
On the part of the fuselage that was
hanging over the edge of the bench I draped
the sandpaper across the top and pulled it
down and back and forth in a method similar
to that you would use to shine your shoes.
When you’re satisfied with the shape of
your fuselage, set it aside and start the wing.
Wing: Start with the center-section. Glue
the R1A and R1B ribs to the R1 ribs as
shown on the plans. Pin the forward spar to
the workbench. Place the rear spar on the
plans, but don’t pin it down; it will need to
be raised up into the ribs after they are in
place. Fit but don’t glue the 1/4 plywood
wing dowel support to the ribs that have the
R1Bs glued to them, and glue them on the
forward spar.
I used landing-gear mounts that Sig sells.
They are 6 inches long, and you need to cut
an inch for the end of each mount. After the
landing-gear mounts are glued in place,
these 1-inch blocks will be glued to the top
of the landing-gear mounts at the inboard
end up against the R1A rib, so don’t throw
them away.
Place the landing-gear mounts on the
plans and adhere the remaining R1 and R1A
ribs to the forward spar. Glue the top
forward and rear spars to the ribs. Pull the
lower rear spar up into the ribs and glue the
ribs to it. Pull the landing-gear mounts up
into the ribs and glue these in place, and then
glue the 1-inch blocks on top of the landinggear
mount against the inboard R1A rib.
Glue the 3/8 balsa LE to the centersection
and then glue the 1/8 plywood wing
dowel support to the LE. Glue a 1 x 3/32-inch
strip of balsa to the top of the ribs at the TE.
Mounting the 1/8 plywood dihedral
supports is next. I did this by drilling some
1/8-inch-diameter holes in the outermost R1
ribs between the top and bottom spars. Then
I joined the holes to form a 1/8-inch-wide
slot from the top spar to the bottom spar by
using a small file.
Install the dihedral joiner into the slot
and glue it to the top and bottom spars.
Make sure the dihedral joiner is at a 90°
angle to the R1 rib before you glue it to the
spars. Do this for the forward and aft
dihedral joiners.
For the outboard wing panels I placed
the forward and main spars on the plans and
then pinned ribs R2-R8 in place on the
plans. I placed rib R1C on the spar but did
not pin it down.
I lifted the main spar up into all the ribs
and placed shims under the spar in various
locations along the spar to hold it off the
workbench and into the ribs. Then I pinned
the spar to the workbench.
Keep the spar straight along the
wingspan and make sure the rib building
tabs are still in contact with the workbench.
Glue all the ribs except R1C to the spar. Lift
the forward spar into rib R1C and R2 and
glue to R2.
Place the top spar on all the ribs and glue
it to all the ribs except R1C. Glue the
forward spar to R2.
Cut the R1C angle guide from the plans
and glue to some scrap plywood, and then
cut the plywood to the shape of the R1C
guide. Place the R1C guide on the bottom
main spar between the top and bottom spars
against R1C.
Adjust R1C so that it is against the
guide, and glue it to the top and bottom
spars. Be careful not to glue the guide to the
rib or the spars, and make sure R1C is in the
proper place on the plans. Move the R1C
guide to the forward spar and adjust rib
R1C, and then glue R1C to the top and
bottom spars.
Glue the 1/4 balsa TE to the aileron
cutout. Make sure you have the cutout at
least 3/32 inch wider than the ribs for the 3/32
balsa sheeting. Glue the top 1 x 3/32-inch
balsa sheeting to the TE at the aileron
cutout. Glue the 3/32 balsa sheeting to the
TE, inboard of the aileron.
I decided to use a laminated balsa LE on
my Val, but you could use a solid balsa LE
if you wanted. For a laminated LE, glue the
first lamination to the ribs’ LEs with some
cyanoacrylate-type glue while the wing is
still pinned to the workbench.
Use a Sig-Ment or Ambroid type of
wood glue to adhere each successive
lamination to the LE. You will need a bunch
of clothespins or clamps to do this;
clothespins may not be long enough to
clamp on the laminations properly.
I worked around this by removing the
wing from the workbench and placing it on
a table with a curved end, with the LE
overhanging the edge of the table. I
weighted down the wing so it would not
move and was held flat on the table. Then I
used the clothespins from the top and
bottom of the LE to hold the laminations on
as the glue dried.
Glue the 3/32 balsa LE sheeting to the top
of the outboard wing section. You may need
to spray some water on the sheeting to make
it easier to bend. Once the glue and sheeting
has dried, sand the wing sheeting flush with
rib R1. Cut the slots in R1 for the dihedral
braces.
Once you are satisfied with the fit of the
outboard section to the inboard section, glue
them together. I used numerous clothespins
to hold ribs R1 and R1C together from the
bottom.
To increase the strength of the plywood
dihedral joint to the top and bottom spars I
added 3/32 balsa to fit between the top and
bottom spars, and then I glued these to the
plywood dihedral braces and the top and
bottom spars.
Build the other outer wing panel in the
same manner as you built the first panel.
Round off the top of the center-section’s
LE so the center-section will fit in the wing
saddle on the fuselage. Center the wing on
the fuselage and then drill the hole for the
1/4-inch wing-mounting dowel through F2
and the wing’s LE. Remove the wing from
the fuselage and glue the 1/4-inch-diameter
dowel in place on the wing.
Sheet the bottom of the wing. Glue the
1/4 balsa TEs to the wing and sand them to
match the contour of the airfoil.
The ailerons are fairly simple to build.
They are 3/32 sheet balsa with half ribs glued
to the top and bottom.
Glue the 1/4-inch-wide balsa capstrips to
the ribs. Use 1/8-inch-thick balsa for the
capstrips. Glue the 1/4 balsa TE to the
ailerons. Cut the slots for the hinges in the
ailerons and in the wing, and then
temporarily mount the ailerons to the wing
and sand the ailerons to match the wing.
Install the aileron-servo mount blocks as
shown on the plans. The 3/32 balsa is to form
a lip around the servo mount hole for the
covering to stick to.
Adhere the wingtip blocks in place and
sand them to shape. Glue the 1/8 plywood
wing-bolt reinforcing plate to the bottom of
the wing on the center-section.
Mount the wing to the fuselage and drill
a 13/64-inch hole in the wing and fuselage for
the wing-mounting screw. Tap the hole in
the fuselage with a 1/4-20 tap. Enlarge the
hole in the wing to 1/4 inch.
Glue F4A and F6 to the bottom of the
wing and then sheet over it with 3/16 balsa.
Use a sharpened brass tube to cut the hole
for access to the wing mounting screw.
Sheet the lower forward part of the fuselage
with 3/16 balsa. Glue the 1/4 balsa F5s in
place. Sand the lower wing fuselage fairing
to match the contour of the fuselage shape.
Flip the fuselage over and secure it to the
worktable so you can mount the horizontal
stabilizer. Slide the horizontal stabilizer into
the slot in the rear of the fuselage. Make
sure the stabilizer is centered on the
fuselage. Sight down the length of the
fuselage from the front or rear and make
sure the stabilizer and wing are parallel to
each other horizontally.
Make sure the stabilizer is square to the
wing by measuring from the wing TE to the
stabilizer TE on both sides of the fuselage,
and make sure these measurements are the
same. Check the horizontal stabilizer’s
incidence to the wing; it should be
approximately 1/2° LE down. When you’re
satisfied that the stabilizer is mounted
correctly, glue it to the fuselage.
Mount the vertical stabilizer to the
fuselage with pins. To align the vertical
stabilizer so that it is not offset to one side
or the other, sight down the top of the
fuselage from the front and pin it in place.
Adjust the vertical stabilizer so it is 90° to
the horizontal stabilizer and then glue the
vertical stabilizer to the fuselage.
The tail-wheel bracket is 1/16-inchdiameter
music wire bent to shape and
mounted to the fuselage with 1/16-inch-insidediameter
brass tube. I built mine by bending
the bottom of the bracket for the axle and
slipping on a small washer to keep the tail
wheel from pushing the rudder up. Then I
soldered the washer to the music wire.
I sharpened the end of the 1/16-inch brass
tube and used it to drill the hole in the
fuselage for the bracket. Then I glued the
brass tube in place on the fuselage and cut it
to length. The music-wire bracket was
slipped into the brass tube and the top of the
bracket was then bent over to fit into the
rudder.
The full-scale Val has a rather large
wing-to-fuselage fillet; this has been drawn
on the plans, but I opted not to install the
fillet on my model. If you want to make a
fillet for yours, I will describe how I was
going to build it.
Cut the fillet base from 1/64 plywood.
Loosely mount the wing to the fuselage and
slip the fillet base in place between the wing
and fuselage. When you are satisfied with
the location of the fillet, tighten the wing to
the fuselage and glue the fillet to the
fuselage only.
Cut some soft balsa blocks and glue
them to the fuselage. Carve and sand them
to the shape of the fillet.
Bend the elevator joiner from 1/8-inch
music wire, and then temporarily mount the
elevator using your favorite hinging method.
Temporarily mount the rudder.
Set the model aside and then bend the
main landing gear from 3/16-inch music wire.
The wheel pants are made from various
thicknesses of balsa. The thickness of the
main core of the wheel pants is determined
by the thickness of the wheels you use and
the addition of the wheel collars.
If you fly from a grass strip, cut the
bottom of the pants so that more of the
wheel is exposed than shown on the plans. I
have seen pictures of a full-scale Val’s
wheel without wheel pants, so you may not
want to build them for your model. Once
you have cut all the parts for the wheel
pants, glue them together and sand them to
shape.
Final-sand the fuselage and cover it with
your favorite covering material. I used
MonoKote. Although the colors I used are
not exactly accurate, I loosely based the color
scheme on a Val that was aboard the aircraft
carrier Akagi during the battle of Midway. I
got the red “meatballs” from a set of decals I
had from an old Top Flite Zero kit.
The canopy I used is from the Great
Planes AT-6 Texan ARF that is available
from Tower Hobbies. I decided early that I
would have cooling holes cut in the fuselage
in the cockpit area and I would leave the
rear of the canopy open for the air to escape.
I cut the excess plastic from the canopy
as if I was going to mount it on the model
for which it was designed. Then I placed the
canopy on the top of the fuselage and
pressed it down until the front of the
windscreen touched the top of the fuselage. I
used a dry-erase marker to indicate the side
of the canopy on which I needed to cut it to
make it fit the fuselage.
After I cut the canopy to fit the fuselage I
used a rag to remove the marks left on the
canopy. I taped the canopy in place on the
fuselage and marked the fuselage so I could
remove the green MonoKote from the
cockpit area and replace it with black
MonoKote.
Once I had re-covered the cockpit area
with the black MonoKote, I carefully cut a
small strip away from the black for the
canopy to be glued to bare wood on the
fuselage. I used a sharpened brass tube to
cut the cooling holes in the cockpit area.
Since I wanted to keep my model simple
but still wanted a pilot and gunner in it, I
decided to use a simple, flat version. I found
a picture of a pilot and gunner and scanned
it into my computer. Then I enlarged the
picture to the correct size. I created a mirror
image of the picture, and then I printed the
mirror image and the original image of the
picture.
I glued one side of the pilot and gunner
to a piece of 1/64 plywood. Then I cut the
plywood to the shape of the pilot and gunner
and glued the mirror image to the other side
of the pilot. To make the plywood blend into
the figures, I darkened the edge of the wood
with a black magic marker.
I glued the pilot and gunner figures into
slots cut in the cockpit area. When I was
happy with the cockpit area, I glued the
canopy to the fuselage with some Formula
560 canopy glue.
I mounted an old Vortac bomb release to
the bottom of the wing near the CG. If you
want to mount a bomb release, be careful
not to cut the wing spars as you make the
cutout for the release. I used a T-pin to poke
through the wing sheeting to locate the
spars. I mounted the bomb-release servo
upside down in the wing so that a servo arm
would actuate the release.
The Val’s nose is rather short, so I
mounted the radio gear as far forward in
the fuselage as I could. I still ended up
adding lead to the nose to get the CG
where I wanted it.
The aileron servos are mounted to the
bottom of the wing and are connected to the
receiver by a Y harness. I like my models to
be fairly responsive, so I set my control
throws as follows: rudder, 1 inch left and
right; elevator, 1/2 inch up and down;
ailerons, 1/4 inch down and 1/2 inch up.
The ailerons need more up than down
travel, and this is achieved by mounting the
servo arm on the servo at roughly a 45° angle
toward the front of the airplane. These are
good starting points for the first few flights.
After that you may want to increase or
decrease the throws to suit your flying style.
Flying: If you are like I am, you probably
skipped most of the article and came right to
this point to see how the Val flies. It flies
exactly like an advanced trainer. If the only
models you have ever flown are high-wing
trainers and you want to move on to a lowwing
trainer, this may be the airplane you’re
looking for.
The first flight with my Val took place
early on a cool, windless Saturday morning.
After range checking my radio with the
motor on, I taxied the model to the far end
of the runway. I slowly advanced the throttle
and let the Val roll down the runway. It
wanted to pull to the left, but I had no
problems keeping it headed down the
runway with the rudder.
After roughly 150 feet I started to feed in
up-elevator and the Val became airborne in
a nice, realistic manner. As I gained some
altitude I realized the Val needed some upelevator
trim and a little right aileron trim to
keep it level.
Once I had the Val trimmed out, I made
some low passes so my daughter Erin could
take some pictures of it in flight. I was
exceptionally pleased with how the model
flew. I took it up high to see how the Val
handled in slow flight; I was quite pleased to
see how slow it was able to fly before it
stalled.
The right wing had a tendency to drop
when the model stalled, but it was easy to
control right up to the stall. After a few
more low passes I tried a few touch-and-gos.
The big propeller windmilling created
quite a bit of drag, and I found that I needed
to keep a little power on during the approach
or make steep approaches to keep up the
airspeed. There is no tendency for the Val to
float too much once the power has been
pulled all the way back, but it doesn’t drop
like a brick either.
When I took my airplane home I checked
the wings for warp and found a slight one in
the right wing. Twisting the wing and
reheating the MonoKote removed the warp.
I also redrew the plans to show 1/2°
incidence in the horizontal stabilizer.
On subsequent flights I was able to see
how aerobatic the Val is. It will fly upside
down by my holding a little down-elevator
with no problem. Rolls are nice and crisp.
There is little roll coupling with the rudder.
Landings are a breeze; you can wheelie it
on, and three point it on, or if you’re careful
you can one-point it on the tail wheel!
If you want a model that can do all the
fancy stuff, the Val will probably make you
yawn. But if you’re looking for an advanced
trainer that looks like a full-scale airplane or
if you want to try flying in a Fun Scale
contest or two, this may be a great fit for
you. MA
Gary Fuller