Generic Building Instruction Sheet
This is a generic instruction sheet for assembling any of our 1/20th or 1/12th scale war birds.
On this page, in the instructions, you will find the procedures to build our planes:
Wing and ailerons
Preparing the ailerons
Setting up for the Slickmount
Tail group installation
Trimming and flying
Starting 1/2A engines
construction is very much the same as all of our foamy kits however I
will take you from start to finish - as if this is your first plane.
First it would be helpful to have a few basic tools handy.
Nylon reinforced filament tape.
Packing tape, either clear or colored. Most kits come with 1 roll included
Possibly 5 min. epoxy
Possibly fiberglass cloth and Epoxy resin and carbon fiber (for super strength wings if using larger than .15 engine)
Razor blades and/or large snap blade knife.
Silicone sealer or builders construction adhesive.
Goop type glue (use only on taped up Styrofoam, it will melt plain styro)
Sanding board and loose sheets of sandpaper, 50 grit for rough sanding 100-150 grit for finish sanding.
tools for gouging out the cavities for the radio gear. Try sharpening
an old flat blade screwdriver to a chisel tip. Wood carving tools or
potato peelers work great too!
Flat table that you can cut against.
A can of 3-M 45 spray glue or something similar that will not melt the foam (if 45 is not available, you can assemble the "war bird" without it but the tape may not stick as well and is not recommended)
You can hurt yourself building this kit! Please use caution and
follow proper safety procedures when using the tools and the adhesives
needed to assemble this kit.
Powered models are
dangerous! All models airplanes present a certain amount of danger to
the operator and anyone in the vicinity. Please be careful when
starting the motors and use good safety practices when operating this
model. Wear eye protection.
We at JK Aerotech, have no
control over how this product is used. You, as the operator of this
equipment assume full responsibility during the building and flying of
this model to operate it in a safe manner. Do not start the engine
with anyone, including yourself, in line with a spinning prop or
directly in front of a running motor (I have seen props come off.)
Always keep hands and fingers and other body parts out of the spinning
prop. Do not fly over people, or in populated areas. BE CAREFUL!!
By building and flying this model you have agreed to take full
responsibility for any property damage and/or personal injury or death
caused by this model.
Building and flying should always be done with adult supervision.
First and foremost, this is what we call a starter kit. Our intention is to furnish a kit that is;
#1- inexpensive enough to be used as a durable combat plane,
#2- quick building,
#3- FUN, and
versatile we mean that you may build it in one of several ways. First,
they are designed to fly well on ½ A power using our "Slick Mount" and
lightweight radio gear. Built this way, the 1/12th scale should weigh in at a little over 11/4 Lb. and the 1/20th
scale should tip the scale around 11oz, and will fly very well on a
stock control-line .049. Use a hot engine such as a Norvel and you will
have a pocket rocket to play with. Second, if you ordered the slope
version, they can become a semi-scale slope soarer or powered plane if
you wish. Thirdly, for the daring, "shoe-horn" a .15 to .25 into the
1/12th plane and beef up the flying surfaces and fuse for
1/12 scale power combat. The main point is to have un-fettered fun
without worrying about destroying the plane. So be creative and come up
with your own ideas and variations…
object is to make the plane strong yet flexible in order to withstand
mid-air collisions and inevitable "ground plant". I usually start with
the tail group and wing.
our war birds we have supplied a die-cut tail group to make building
simple. You will have to use a razor blade to separate the pieces from
the flashing. The elevators are formed by slicing along a rib according
to the addendum for your particular plane. BE SURE TO ONLY CUT THE BOTTOM SKIN OF THE CORO-PLASTIC
because the top skin will become the hinge. After slicing the bottom
skin, fold the elevators back and trim both of the cut edges back to
the next rib so the elevator will bend down with out binding on itself
(see fig. 1). After cutting the elevator hinges, use an Ex-acto knife
to slice through the hinge at about ¼ inch intervals along the hinge
line to make the elevator bend easier. Think of it as cutting a dashed
line into the hinge. You may leave the tail the way it is or just tape
the leading edge to help aerodynamics. If you want to use rudder also,
just make a hinge in it the same way you did for the elevator and run
slip the completed elevator into the slot on the fin and locate the tab
into the slot on the elevator. Tip: hold the fin sort-of side ways to
the elevator and flex the slot up then slide the elevator in, to where
the tab will drop into the slot. Then bring the fin upright.
a small bead of "Household Goop", or something similar, along the
tailpieces on the top and bottom, block them up so they are
perpendicular and set aside to cure. If you are in a hurry, use thick
CA and accelerator. This will stick well but is not as flexible and
crash resistant as goop.
This is for the ½ A and slope soaring version.
For 1/2A and slope, we recommend building LIGHT!!!! I can’t emphasize
that enough. Stock .049 power is marginal, so a plane will fly best if
the weight doesn’t exceed 1-1/2 lbs. Slope planes at that weight will
fly in light lift but if you intend to ballast it 8oz or more, it is
recommended that the wings be built with more strapping tape or hard
balsa or spruce spars (see instructions below).
you intend to install a large engine, i.e. .10 to .25 c.i. see the
section on modifications at the end of this instruction manual).
Wing and Ailerons
you ordered the slope version and decide to make it powered, trim the
wing at the tip. We make a generic tapered wing for all our war birds
and how they are trimmed will help give each plane it’s semi-scale wing
plan form. The slope wing is shipped in two halves to give about a 48"
span on a slope glider. If you want a 1/2A powered plane that will fly
easy and glide well you can build it at full length. The 1/12 scale
powered wing is in two halves + center section also but will be closer
to the scale wing span. We have included a center section that has the
dihedral cut into it. So decide what span length you want and follow
the trimming and sanding directions on the pattern specific to your
kit. Sand the top and bottom surface of the wing and the center section
smooth and dust off thoroughly. This helps the tape to stick. Decide if
you want a spar in the wing or not. When using 1/2A power, no spar is needed
besides the filament tape top and bottom, remember – build LIGHT! If
you want a spar anyway, or intend to ballast a slope version heavily,
use hard Balsa or Spruce and sand a groove to fit snugly along the wing
panels at about 1/3 of the chord from the leading edge, (glue a thin
strip of course sandpaper to the edge of a piece of wood the width of
your spar and gently draw it along the wing against a straight edge
until the correct depth is reached for your spar). Spars could be
square stock of 3/16 or ¼ inch, or go high tech and use carbon fiber.
Use carpenters glue or epoxy to install spars and let harden.
Prepare the wings for the ailerons. Most of our combat warbirds have tapered wings. Tapered wings tend to get thin at the trailing
edge towards the tip. Our aileron stock will be either 4 mil (about 1/8
inch thick) or 2 mil (about 1/16 inch thick) coro-plast, depending on
the kit. So before you glue the wing halves together, you will need to
trim and sand the trailing edge. Make it a constant thickness, root to
tip, that will approximately match the coro-plast supplied with your
kit. Usually the root is at about the right thickness. If it is thicker
than the aileron stock, sand it down a little first. Then use a
straight edge and mark a line from the root to the tip so that when the
wing is trimmed, the trailing edge is a constant thickness. In effect
you will be making the wing a little more tapered by maybe ¼ to 3/8
inch at the tip of the trailing edge. This is OK, we have sized the
wing to take the trimming into account. For the ailerons to work
efficiently and smoothly, the trailing edge has to match the thickness
of the ailerons.
take the wing halves and use #45 spray glue or 5-min epoxy, and stick
the two halves to the center section. Spray a light coat of #45 over
the whole wing, top and bottom. Let it dry off thoroughly. Starting
with the wing top, apply one to three (one is fine for the 1/20th
scale planes, to three or more for a sloper-see the addendum for your
plane) strips of strapping tape at the spar area (see fig. 2) using a
very slight stretch to the tape. On dihedral and tapered wings
it is easiest to start the tape from the center of the wing and pull
out to the tips, let the tape run long about 1" past the opposite
joint, this will help strengthen the center of the wing. Also,
trim the tape at the wing tip so about ½ inch will wrap around the tip.
Turn the wing upside down and apply strapping tape in the same manner
using a slight stretch to help straighten the wing back out. This will pre-stress the wing and will greatly increase the strength.
one strip of packing tape along the center seams (leading to trailing
edge) top and bottom, stretching them a little will help them mold to
the curves of the airfoil. The goal is to get 100% adhesion all the way
into the "V" of the dihedral joint. You should begin to see a fairly
strong joint shaping up. Then cover the center section with several
more strips, front to back, top and bottom.
When covering wings or elevators,
the basic taping convention for foam-and-tape planes is to always start
at the back and work forward so that an overlapped tape edge is never
into the wind. See fig. 2.
Prepare the Ailerons
applying the strapping tape to the wings, it is time to prepare the
ailerons. The kit includes corrugated plastic stock for the ailerons. Refer to the addendum for the recommended width of aileron for your kit. Trim the outboard ends of the ailerons to blend with the wing tip curvature and the inboard should clear the fuse easily.
will be encapsulated in tape before they are attached to the wing (see
fig. 4). Thin ailerons can be covered easily with one strip of tape but
wide ailerons, such as slope gliders have, might need two strips .
Tip: when covering the ends of thin parts, trim one side off at the
edge and wrap the other over it---just like when using iron-on covering.
After covering the ailerons, lay the aileron upside down on the wing
(see fig. 4). Run a strip of tape along the back of the wing and the
aileron, smoothing the tape down on both surfaces, then open it up, lay
the aileron flat and apply a strip of tape along the top of the hinge
line. Turn the wing upside down and use a blunt object (window screen
tool works perfectly) to press the top and bottom tapes together to
complete the hinge. Do this to both ailerons and after they are
attached, stretch the regular 2" packing tape across the wing from the
middle to tip. Again, let the center over lap the far seam about 1".
Let the tape run long, leave the ends stuck to the table until the surface is covered, then with a razor blade trim to about an inch long and
fold around the wing tips before covering the opposite side (this gets
a little difficult when taping the bottom of a dihedral wing so I lay
the wing upside down on the edge of a table with half the wing hanging
off the table, then work on the half that is supported by the table).
Again, always apply the tape from trailing edge to the leading edge
with the typical ¼" overlap. The leading edge should have a couple
layers of tape wrapped around it by the time the top and bottom
covering is done. We recommend adding another layer or two of tape to
the leading edge for extra protection. Stretching the tape modestly
while sticking it down will help it go on smoothly but be sure to
balance the stretching or you could have a wing that bends up or down.
when trying to tape a curved surface (such as wing tips) with packing
tape it will tend to bunch and pucker. Before pulling the ends over the
wing tip, slice the edge that is hanging over about every ½", then
starting at the back, working forward, smooth each little flap of tape
over the curved edge. The little flaps will overlap each preceding flap
and the curve will be much smoother.
war bird fuselage can be left blocky just as it came out of the hot
wire machine or you may round it out (fig. 3); making contours for the
canopy and such, it depends on how much effort you want to go to. You
will now need to build a suitable firewall for the motor you will use.
We, of course, have designed this plane around our SLICKMOUNT, which
simply makes small engine running a pleasure instead of a pain. However
you can rig your own engine-firewall-tank combo if you wish but how you
do it is up to you. I will only outline the installation of the
Setting up for the Slickmount
Note: the firewall has a built in down-thrust
the Slickmount you will need a piece of 3/16 or ¼ inch plywood. After
sanding the desired shape in to the fuselage, hold the nose of the fuse
to the wood and trace around it for the shape of the firewall. Mark the
center of the hole for the Slickmount and drill a 1-1/4 inch hole with
a spade bit or Forstner bit. Then cut the firewall out. Check the
addendum sheet for the recommended distance from the top edge to the
center of the mount for your particular plane. Glue the firewall on the
nose with 45 spray and carefully drill out the foam with your 1-1/4
inch bit. Try to drill right through the center of the fuse,
perpendicular to the plane of the firewall and just deep enough for the
Slickmount tank. Tip: lay the fuse down on its side and
cover the other side with a block of wood so you won’t break through
and drill your hand! I have used #4 sheet metal screws to
mount the Slickmount to the firewall and it works OK. The best way,
though, is to drill the holes at the four corners and install 4-40
T-nuts. If you have the T-nuts with the big flange you may have to cut
a flat in them to clear the tank. If your screws tend to strip out you
can run a bead of silicone in the hole before you re-install the
Slickmount. This will hold it together and is not too difficult to
sure all surfaces are sanded with about 150 grit, then spray with 45
glue, let dry. In a nutshell, the object is to use nylon strapping tape
to strengthen all four sides of the fuselage and seal the nose against
fuel and oil infiltration. After the strapping tape, the fuse doublers
are glued on and the whole thing is sealed up with the colored packing
tape. Note: when applying tape to a fuselage, DO NOT STRETCH IT, unless you intend to correct a warped fuselage.
the strapping tape on one side at the tail and tape all the way around
the nose and back to the tail with one strip of ¾" to 1" or a couple
strips of ½" side by side. Do the same on the top and bottom. Go ahead
and tape over the slot for the tail then run a razor blade gently along
the slot to open it up and push any tape flaps into the slot. If your plane has a pad to set the tail group on, make sure that it is taped flat and wrinkle free. Whatever
covers the firewall hole can be sliced and turned into the hole. Use
strips of strapping tape, side by side, from about the front of the
wing around the face of the firewall so that there is none of the pink
foam or firewall showing. This will strengthen the nose and seal it
Again, slice the
tape and turn it into the hole for the Slickmount. If your 1-1/4 inch
bit makes the same size hole as mine, you should still be able to slide
the tank of the Slickmount into the hole with a snug fit. Remember we
still have the colored tape to stuff into the hole yet too. If it is
too tight, trim some of the strapping tape from the hole and use the
final colored taping to seal up the firewall hole. If it is still too
tight, sand the hole out a little. You want a snug fit because it will
seal the interior of the plane from the fuel and oil.
the strapping tape is done, it’s time to stick the fuse doublers to the
sides of the plane. Trim them from the die cut piece. They will be
glued on with 45 spray glue. Match up the sides with the angle of the
nose and the wing saddle. Be sure they are the same on each side before
you stick them. After the doublers are on, it is a good idea to wrap a
couple strips of strapping tape around the nose at the firewall area.
That just kind of cinches everything down tight and if you sand the
fuse round, the doublers will bend to conform to the shape of the nose.
For strength, I have started to use a staple gun
to staple through the doublers into the edge of the firewall. This
creates an incredibly strong nose that will take a very hard hit before
loosening up. Just be careful not to staple into something you didn't
the strapping tape is done and the doublers are on, you can proceed to
cover with the colored packing tape. I like to start with the bottom
then the sides and finally the top. That way the sides will wrap around
and seal to the bottom and the top will wrap over the sides and seal.
You can do it however you want, just make sure to completely cover the
foam, including the wing saddle, and overlap the successive tape strips
by about ½ inch. Again, tape over the slots for the tail group and
slice them open after covering
sure to cover the firewall. I run the end of the bottom tape up and
over the top of the firewall and the top tape down and over the bottom
of the firewall. When taping the doublers, the side tapes can be left
long enough to wrap around the profile of the doublers and folded
around to the inside of the engine compartment all the way to the
firewall. That way the top or bottom tape can seal the side tapes to
the firewall. Make some slices at the hole for the Slickmount and push
the flaps into the hole. If you are running a Norvel, you will need to
cut the doublers to clear the muffler and allow access to the needle
valve. A needle valve extension might be handy.
when trying to tape a curved fuselage surface with packing tape it will
tend to bunch and pucker. Stick the tape along the flattest surface and
slice the edge that is hanging over about every ½", then starting at
the back, working forward, smooth each little flap of tape over the
curved edge. The little flaps will overlap each preceding flap and the
curve will be much smoother. After the fuselage is taped up, use a
razor blade to open the wing slots and wrap the excess tape flaps into
this point you should have a fuselage that is completely taped up. The
tail group should be dry and ready to install now. I use a coat of
45-spray glue on the part of the tail that slips into the fuselage.
Now, you have to be fast so have the slot(s) in the fuse open and ready
to receive the tail group. Then, quickly spray a wet coat of 45 glue on
the parts of the tail that fit into the fuse. Before the glue starts to
set, slide the tail into the slots of the fuse. Make sure the fin is
straight and true with the centerline of the fuse and squish the sides
of the fuse onto the fin. If you are not careful, it is easy to give
your plane a permanent right or left turn by bending the back of the
fuse one way or the other. The goal here is to assemble the tail group
and fuse while the glue is still wet to allow a little slippage so they
can be aligned properly---good luck, work fast! Apply a strip of
packing tape under the fuse to close up the tail slot, then run a small
bead of Goop on either side of the fin to stick and seal the tail to
fuse joint. Check your addendum sheet for any specific instructions on
gluing the tails in. Block the fuse and tail so they will cure in good
You should now have a completed airframe ready for radio gear and wing installation!
the wing in place and refer to the drawing in your addendum for a rough
layout of the radio and servos. On a low wing plane, balance it upside
down on suitable supports. Lay your gear out so that the airplane balances with the center of gravity according to your specific kit. This
is a starting point and can be shifted fore or aft a bit. Use the
battery and radio gear to adjust the balance point and add a little
weight if necessary. The elevator servo can be cut into the side of the
fuse. The aileron servo should be cut into the wing as per the
addendum. In no instance should you ever cut into the center area of
the wing where the strapping tape is because it will weaken it and make
it more susceptible to bending. The ailerons can be actuated with one
servo in the center by hogging out the foam in the fuse to clear the
servo arms and pushrods. Or you could use two mini-servos hooked
together with a Y connector, one on each side of the fuse or in each
wing panel if you want. When you have determined the best positions for
the servos and radio, then mark a line around them and use a knife to
cut the holes in the fuselage. Use your gouge to dig the holes out and
be sure to keep the fit as snug as possible. Find a convenient place
for the switch. Make a hole for it or cover it with tape and use a
piece of piano wire to operate it. Leave the charge cord accessible
also. After the gear pockets are cut, bore a hole from pocket to pocket
to route wires through for a neat looking job. A 3/8 diameter tube
sharpened on one end works great.
the wires through the holes and hook up the plugs. Now is a good time
to center each of the servos. Before sliding the servos in for the
final time, coat the pocket sides with silicone sealer. This will hold
the servo in place and the silicone is not too impossible to remove.
Try not to get silicone on the plane because tape will not stick to it!
If you do, wipe it off with mineral spirits (paint thinner). Tip: wrap the servo with tape so the silicone can be easily peeled off if you take the servo out.
Tape over the servos leaving the shank sticking out. I must stress
again to make the servos fit snugly. If you want them to fit flush with
the surface you are imbedding them in, you will have to create a pocket
that is sort-of two stepped to clear the mounting flanges on the
servos. This will allow the servo to sink further in and will keep the
control arm as close to the fuselage as possible. Another great idea is
this: If you intend to do a lot foamie plane flying, just cut off the
servo mounting flanges and sand the bumps smooth. This will allow the
servo to slide down into a nice, neat, straight-sided pocket. Of-course
you won’t ever be able to screw the servo down again, but if you get
into foamies you won’t ever need to!!!
great idea is to split the fuse in half and hog the inside out with a
wire brush mounted in a drill (do this before taping). Then you can
install all of the radio stuff inside the fuse. More work but looks
that the radio gear is in, mount control horns on the elevator, and
ailerons. Check to see that the elevator bends up and down easily. If
they seem a little stiff, you could lengthen the slices in the hinge
line. Install the servo arms and use the supplied piano wire with Z
bends in each end to hook them up. If you want the airplane to handle
easy, the control surfaces should be set up for the least control
throw. Set the throw according to the addendum for you plane. After a
certain comfort level is gained the deflection can be increased for
very tight loops and rolls.
Trimming and flying
is generic, check and follow the specific instructions included with
your particular kit. The best way is to check to see that the center of
gravity is where it should be, then find a soft grassy spot and give it
a test glide. You should be able to detect most trim problems at this
point. Keep in mind that this plane, while a quick tape-together plane,
will suffer from the same alignment problems as any other plane. So
keep checking the alignment of all flying surfaces and build as
straight as possible. But, keep in mind that this is a foamie that is
meant to get beat up. So things will get knocked out of whack—that’s
why we have trim levers on our transmitter! You should be able to give
a toss and get a nice even glide. Trim and balance until you are happy
with the results and then you are ready to put power to it. The other
way is to fire it up and trim on-the-fly, as they say.
Need help getting those little half-A "devil" engines running?
engines can be so frustrating that you wouldn’t be the first to feel
like stomping the plane into the ground and walking off. Here are some
tips to help get things going.
I would recommend using our Slickmount, if you don’t already have one!
This is not merely an unabashed attempt to sell more products but
simply a way to help keep you a sane and happy flier for years to come.
The Slickmount allows the little engine access to the fuel in the
shortest amount of time. With a remote tank, the fuel lines are too
long for the tiny suction of a stock 049. Plus the size of the 35mm
film container will give about a 15-20 minute run.
049 reed valve engines can be especially frustrating but when you know
a few tricks, they aren’t so bad. First if it hasn’t been run for a
while and you can’t get it to run except for a short burst after
priming, it is probably a sure bet that the fuel inlet and reed valve
are plugged with oily gunk. You should take it apart and clean the jets
and reed, and wash the inside of the engine out with solvent. Check the
reed to see that it isn’t cracked or bent. If it is, replace it. Make
sure the glow head is working too. If everything checks out OK, then
try starting it again. Incidentally, use an electric starter, hand or
spring flipping is nuts! Prime the little guy with a little bit of fuel
at the exhaust port and open the valve about 3.5 turns. If it zooms and
dies open the needle valve a half turn more and try again. If you keep
turning the needle out and it still zooms and dies, try this next
little trick. If you have a squeeze bulb to fill the tank, hold your finger over the bottom vent (Slickmount) and gently
squeeze a little air pressure into the fuel filler vent for a couple
seconds. This will force fuel into the venturi of the reed valve and
kind of jump-start the engine. This trick has never failed to start a
cold engine for me and once you have it running you can set the needle
valve for the best run. If the engine is screaming and then sputters
out, turn the needle counter-clockwise until it sounds rough then turn
back to peak. Needle settings are different for each engine. I find
that it works best to set these engines at just under peak RPM because
they tend to lean out as they run. If you use our Slickmount, put a cap
on the top fill vent, it will make the engine run much steadier and
keeps the fuel in the tank, (the low pressure area behind the cylinder
head can actually siphon the fuel from the tank).
beam-mounted engines, such as the Cox TD and Norvel Big Migs, have a
carburetor on the front. These are much easier to start but again, use
an electric starter. Just open the needle valve about 3-4 turns and briefly
choke the carb with your finger. Be careful of the prop and don't flood
the engine! If the engine revs up then dies, open the needle valve a
half turn at a time until you get a steady, rich run. Then slowly turn
the needle in to get the best rpm but do not lean it out too much. If
you flood the engine, screw the needle valve all the way it and spin
the engine, it should fire then die. That should clean the excess fuel
out of the system. Experience has shown that these small engines tend
to lean out as they run, so experiment with the setting until you get
the feel of how your particular engine runs best during actual flight.
If your engine or muffler has a tank pressure tap, use it! They really
do help the engine run more consistently. If you have our Slickmount,
run a tube from the pressure tap to the bottom vent on the mount. Then
make some sort of plug for the top vent tube. An automotive vacuum cap
works well or a short piece of fuel line with a plug in it works well
too. This will pressurize the system and will increase your flying
Always be careful when starting any engine because they can do lots of damage to hands and fingers.
new engines will benefit from proper break-in procedures. It would do
the new engine a lot of good to bench run several tanks of fuel through
it at a rich setting. During the run, lean the mixture periodically,
than set it back to rich. Let the engine cool before the next run.
After 3 or 4 runs the engine should be ready to go.
could install bigger engines than ½A. Why you would want to, I’m not
sure. But it does present some interesting possibilities. The first
thing to do is set the nose up for the tank, engine and firewall you
intend to use. The supplied doublers should make the nose plenty
strong, but you may want to use an extra amount of strapping tape
wrapped around the nose. You may need to embed some hardwood or plywood
beams to tie in to either side of the firewall depending on how strong
you need it. Then I would suggest glueing and stapeling through the
doubler, into the beam and firewall. I would also apply more strapping
tape to the wings and/or install wood or carbon fiber spars. If you
intend to break the sound barrier, I might suggest doubling the tape up
on the aileron hinge top and bottom. Good luck and if you do this, be
sure to send us pictures and a description of what you did and we will
post it on our web site! In fact we always like to hear what customers
are doing with our products so don’t hesitate to drop us a line. Very
soon now we will be installing a .15 size engine into one of our
planes. When we do we will have pictures here in the web.