Construction Manual
www.oldschoolmodels.com
Page 13
This completes the airframe assembly of the Trophy Racer.
You should now have a completed airframe ready for
covering, as well as radio and power installation. Here’s a
picture of the prototype Trophy Racer at this stage.
These next steps of covering, hinging, radio and power installation
are not in any particular order. Some modelers like to cover
everything first, then outfit the rest. Others like to hinge and
pre-install the components, working out the installation before
covering. Use the method that works best for you.
We prefer to pre-install many of the components to make sure
there are no surprises in the way things fit or might have to be
modified for aftermarket items. We find it much easier to fix these
problems now, before covering, as there’s nothing worse than
ruining a good covering job by having to hack a hole or provide
clearance for something.
Radio pre-installation.
Radio installation is fairly straightforward.
Standard sized servos will easily drop into
the aileron, rudder and elevator mounting
holes. If you’re using a glow engine for
power, you’ll need to use a little of the
scrap 3/16” x 3/8”
basswood to create
mounting blocks for
the throttle servo.
We found it best
to mount the servo
underneath the TR
tank/battery tray, on
the starboard side.
It’s easy to access,
helps in balance and
makes for a shorter throttle pushrod. Refer to this photo where we
chose to mount our throttle servo.
Inside the wing, under the radio hatch (in the port wing) is where
the receiver will be mounted. Use a bit of scrap 1/8” sheet to
make a floor. that will
span between the R1 and
R2 ribs. This can then be
glued to the cutouts of
these ribs.
If powering with a glow
motor, you’ll also need
to mount a receiver
battery and a power
switch. Location of the
battery will most likely
be determined when
balancing the model in
later steps. We mounted
ours under TR tank/
battery tray, on the port
side. The switch was
mounted into the radio
hatch.
Power pre-installation.
Regardless of your choice of powerplant it will need to be installed
to the firewall using your own installation hardware.
Downthrust is already
designed into the
fuselage, but you might
want to add a little right-
thrust. The easiest way
to do that it so shim the
left side of the mount
away from the firewall
by adding a couple of
washers. It’s quick, and
allows you to adjust as needed. We ended up with about 2° of
right thrust.
For electrics, we chose to install the ESC underneath the TR tank/
battery tray, on the starboard side using a bit of hook&loop tape.
The battery was also held in by hook&loop, resting in the center
of the tray.
Wires were held in place with a touch of tape and a few tie-wraps.
ESC / Throttle servo wire cutout
If you choose to mount the
ESC or throttle servo similar
to how we did, you’ll need
to make a cutout under the
wing so the signal wire can be
connected into the receiver.
Shown here is a sample
cutout that is done just aft of
the spar and rear sheer webs
between R1 and R2.
Covering
When time to cover your Trophy Racer, remove any of the hardware
you may have installed (landing gear), hatches, powerplant,
pushrods, and radio. These components will get in the way of
applying the covering.
Double check that all surfaces are smooth and ready to cover. Sand
as necessary, then cover the entire airframe with the covering/finish
of your choice.
How you cover your Trophy Racer is entirely up to you. For some
designs there are several full-scale color schemes that were used
back in the day. Or, come up with something completely fresh and
new. That’s part of the joy when building your own sport model -
you can finish it however you like and make it entirely unique.
Servo
