Model Airways CURTISS JN-4D JENNY Instruction Manual Download Page 33

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STAGE 7: INSTALLING THE COCKPIT COWL, WINGS, STABILIZERS, RUDDER,

AND ELEVATOR, AND COMPLETING THE RIGGING

Plan Sheet 6 shows the aileron, rudder, and
elevator control line rigging, and the struc-
tural rigging. In addition, refer to Sheet 3 for
the cockpit cowl that is to be installed during
this final stage. The following parts are
required for this stage:

Photo-Etched Parts

Cockpit cowl (aluminum) – 1 of F24
Turnbuckles (copper) – 33 of R3A
(short), 36 of R3B (long)

Rigging Cord

(cut to length as required)

All flying, landing, brace, and control
wires – 0.010"-diameter gray nylon cord

Rubber Tubing

Cockpit edging – 1/8"-diameter hollow
brown rubber tubing

Self-Adhesive Copper Tape

(cut to length and width as required)

Copper strip at bottom of cowl
windshields

Plastic Sheet

Cowl windshields – 0.010" clear
plastic sheet

1. Installing the Cockpit Cowl, Wind-

shields, and Cockpit

Edging

See

Figure 7-1

. The cowl (F24) is a flat

photo-etched aluminum plate, so must be
formed to fit the fuselage formers. Preform
the cowl to the formers curve as close as pos-
sible so it will fit reasonably well without
springing open. One way to do this; carefully
(to avoid any wrinkles or dents) roll the cowl
over a 3/4" to 1" wooden dowel, or tubing.
When the cowl is removed it should spring
out a bit, but it will be close to the correct
shape. Clamp one side of the cowl to the
longeron with several clamps (like clothes-
pins). Locate the clamps so as not to cover
the six protruding tabs at edges of the cowl.
The basic edges (excluding the tabs) of the
cowl should be flush with the bottom of the
longerons on both sides. If not, something
went astray. You may need to trim the bot-
tom of the aluminum cowl.
Make sure the cowl is located correctly,
which allows the center section wing struts
to come through the slots in the side of the
cowl. When you are sure that the cowl is cor-
rectly located, bend each tab under the
longerons and up on the inside. Touch with a
dab of epoxy on the inside.

Note:

The tabs on the cowl are purely a model

aid. You can cut the tabs off if you like and just
rely on correct forming of the cowl and gluing
to the longerons. If you do this, it might be a
good idea to drill a few holes along the bottom
of the cowl and insert small pins to better
secure the cowl to the longerons.
The forward end of the cowl is split at the
center, back to the opening for the fuel tank
gauge. The top of the cowl from the forward
end to the front instrument panel is almost

FIG. 7-1 INSTALLING THE COCKPIT COWL

.010" CLEAR PLASTIC

WINDSHIELD

(PATTERN IS ON PLAN)

FORMING THE COWL

BEND GAP CLOSED

BEND TABS UNDER

AND UP ON INSIDE

OF LONGERONS

COPPER TAPE –

FAKE SCREW PLATE

SLOTS FOR

WINDSHIELD

SLOT FOR WING STRUTS

PHOTO-ETCHED F24

F24

GLUE AND

TAPE

FIT COCKPIT EDGING

WITH SLIT BROWN

RUBBER TUBING

BEND OVER DOWEL

level (parallel to the upper longerons) and
tapers aft from there. The split allows clos-
ing the cowl to lower the height of the
cowl at the front. After closing the gap,
glue together at the joint. Add a piece of
tape under the gap if necessary to help
hold it together.
Next, install the cockpit edging. Slit the
brown hollow rubber tubing on one side,
then fit it over the cockpit edge. Where the
ends meet (make it at the center of each
cockpit at the back) add a little epoxy in the
joint. If the rubber does not want to stay put,
add some glue on the underside to glue it to
the cowl.
Cut the windshields from the clear plastic
sheet provided, using the pattern on the
plan. Insert the three tabs on each wind-
shield through the precut slots in the cowl
and glue. Cut a 3/64"- to 1/16"-wide strip of
self-adhesive copper tape and stick it to the
bottom edge of the windshields, overlapping
onto the cowl. This is to represent a screw
plate for the windshields.
Note that on the real aircraft, the shape of
the cockpit openings and the shape of the

windshields varied on many aircraft. I select-
ed a common configuration.

2. Installing the Vertical and

Horizontal Stabilizers, Rudder, and

Elevator

From here on, sit the fuselage on its wheels
on a level board. Your building board
should do. Fix the wheels to the board so
it’s secure. At the tail end, just forward of
where the horizontal stabilizer will be
installed, block up the tail so the top rear
fuselage longerons are parallel to the base-
board and secure the tail end with rubber
bands or tape. Now, the fuselage is fixed to
the board. Next, check to see if the top of
the fuselage, transversely, is parallel to the
building board. It should be, but if not, and
you have a little twist in the fuselage, you
may want to adjust the height of a wheel a
bit. Remember, when you finally mount the
model on a board, you will need to add a
little shim under one wheel. When the top
of the fuselage is parallel to the building
board, you can commence to install the
stabilizers and wings. All will be measured
from the building board.