Page 18
www.oldschoolmodels.com
Construction Manual
German
Sunday Fighter
Heinschmitt
holes where you can snake the outside of the flexible tubing system
of your choice, then continue out through the exit holes pre-cut in
the sides of the fuselage.
If you choose to use this type of pushrod, make sure you glue
this outer sleeve to each of these center supports. If you choose
a different system, these supports can be cut away as needed for
clearance.
Make sure that when installing the control horns, they are placed
in-line with the pushrods, and that the line of holes where the
clevises attach are positioned over the hinge line.
For the average pilot, we recommend that clevises are attached to
the outermost hole on each control horn.
Servo mounting (rudder & elevator)
The rudder and elevator servo should be mounted in the two
rectangular holes pre-cut in the back of TR2.
From scrap 1/8” lite ply, cut four strips to double-up the wood
where the servo mounting screws will be install.
Servo mounting (throttle - glow engines)
If you are powering your Sunday Fighter with a glow engine, then
you’ll also need to mount a throttle servo into the forward hole in
TR2.
Radio installation
Finish the installation of your radio gear by adding the receiver,
flight pack battery and the switch. We mounted the receiver using
a bit of self-adhesive hook-and-loop (not included).
If you’re using a flight pack battery, there is no set place to install
it. It’s location should be dictated more by the C.G. than anything
else. As we mentioned before, when we used a flight pack battery
with our glow-powered prototypes, we chose to mount it in the
space between TR1 and LG5.
Also any switches (whether radio or arming for the electric power
system) can be mounted in the tank/battery compartment. The
magnetic hatch is quickly released to get to them.
Power system
Installing your power system of choice is up next. We’ll show
photos for regarding electric and glow installations. Note that
these are suggestions only as your power system might vary from
what’s shown here.
Glow power
Your engine mounts
so the crankshaft is
positioned over the
center of the circular
cutout on the firewall.
It can be mounted
upright, side or even
inverted. We chose
side mounting it as
shown here with a
“Pitts-style” muffler
as it worked best
in our prototypes.
Mounting the engine
using a regular muffler
typically requires a
muffler extension to
move the muffler far
enough out to clear
the fuselage side.
Holes will also need
be drilled for the
throttle pushrod to
pass through into the
fuselage.
You’ll also need to
install a fuel tank,
which rests in the
compartment behind
the firewall, on TR1.
We used a bit of
hook-and-loop tape
to hold the tank in
position as shown here.
Electric power
When mounting an electric motor, we have provided a motor
spacer box that can be used. Note that it is not universal but has
worked with the motors we’ve tried.
This box consists of the parts
from LP6. M1 is the base as
shown in this photo, then the
M3’s make up the sides, and
M2 the top.
Before gluing these pieces
together, drill M2 to accept
your motor’s mounting
bracket, then attach t-nuts (not
included) on the back side of
M2. When that’s worked out,
you can then glue it all together, mount your motor and then
mount it to the firewall.
To mount to the firewall, we simply epoxied it in place. To align it
properly, orientate the fuselage vertically, with the firewall facing
up. Then test fit the motor box in position. Because of the built in
right and down thrust of the firewall, you’ll need to have the motor
box slightly off-center to allow the prop shaft to “appear” to be
centered in the front of the cowl opening.
