Stage 2: Building Vertical And Horizontal Stabilizers, Rudder, And Elevator; Building The Vertical Stabilizer; Building The Rudder - Model Airways CURTISS JN-4D JENNY Instruction Manual

STAGE 2: BUILDING VERTICAL & HORIZONTAL STABILIZERS, RUDDER, & ELEVATOR
Plan Sheet 4 provides all the details for
constructing the tail surfaces. The plan also
shows the landing gear, but this will be dis-
cussed in a later stage. Also, consult Plan
Sheet 6 for the control horns and other
bracing wires. These brace cords can be
accomplished during this stage. The follow-
ing parts are required for this stage:
Laser-Cut Wood Parts
Horizontal stabilizer ribs – 5 of S1, 2 of S2
Elevator ribs – 4 of S3, 2 of S4
Britannia Castings
Rudder & elevator control horns – 6 of C2
Photo-Etched Copper Parts
Vertical and horizontal stabilizer brace
wire single eye rig fitting, and fittings in
the ends of the wooden horizontal stabi-
lizer struts – 18 of R1
Elevator and rudder control horn brace
wire double eye rig fitting – 8 of R2
Turnbuckles – 18 of R3A (short)
Wood Strips
(cut to length as required)
Horizontal stabilizer vertical rib stiffeners –
0.020" x 1/32"
Horizontal stabilizer and elevator rib cap
strips – 0.020" x 1/16"
Horizontal stabilizer and elevator, rudder
diagonal stiffeners – 1/32" x 1/32" and
1/32" x 5/32"
Rudder ribs – 1/32" x 1/16"
Horizontal stabilizer chock blocks – 3/32"
x 1/8"
Horizontal stabilizer trailing edge and ele-
vator leading edge –1/32" x 1/8" and
1/16" x 3/32"
Vertical stabilizer leading and trailing
edge, and rudder leading edge – 1/16" x
1/16"
Vertical stabilizer stiffeners and chocks –
1/32" x 1/32" and 1/32" x 1/16"
Vertical stabilizer bottom stiffener and
corner chock blocks – 1/16" x 1/8"
Steel Rod
(cut to length as required)
Elevator and rudder trailing edge –
1/32"-diameter
Horizontal stabilizer leading edge –
1/16"-diameter
Brass Strip
(cut to length as required)
Rudder/elevator fake hinges – 1/64" x 1/16"
Self-Adhesive Copper Tape
(cut to size as required)
Horizontal stabilizer leading edge and
elevator and rudder trailing edge bands
Rigging Cord
(cut to length as required)
Brace wires from vertical to horizontal sta-
bilizer and brace wires for control horns –
0.010"-diameter gray nylon cord
Wrapping cord for splices – 0.008"
diameter black nylon cord

1. Building the Vertical Stabilizer

The vertical stabilizer is an all wooden struc-
ture. Assemble the stabilizer over the plan.
Pin down the leading edge, trailing edge, and
bottom piece. Preshape the curved bottom to
fit the top of the horizontal stabilizer center
FIG. 2-1 VERTICAL STABILIZER ASSEMBLY
LOCATE THIS STIFFENER
SAND ROUND
1/32" X 1/32" STIFFENERS
ARE FLUSH WITH LEFT
SIDE OF STABILIZER
1/32" CHOCKS
SHAPE TO FIT HORIZONTAL STABILIZER
FROM 1/16" X 1/8" STRIP
TAPERED RIBS
CONTROL HORN
CASTING C2
(BOTH SIDES)
SHORTEN PIN SO BOTH
HORNS WILL FIT IN HOLE
FAKE HINGE
rib. All these pieces are the same thickness.
Next, add the diagonal stiffener that fits flush
with the right side of the stabilizer. Then fit
the small horizontal and vertical stiffeners
with their small triangular chocks. The ones
crossing the diagonal stiffener fit flush on
the opposite (left) side of the stabilizer. The
top horizontal one fits on the center of the
leading and trailing edge. Finally, round the
leading edge.
Add the fittings (R1) for the brace wires at
the top of the stabilizer, one on each side.
Cut the photo-etched copper parts to the
length required.
In the trailing edge, cut the slots that will fit
the fake rudder hinges. See the note in Para-
graph 2 below.
illustrates the entire vertical
Figure 2-1
stabilizer assembly.

2. Building the Rudder

Some had a rudder with a steel trail-
Jenny's
ing edge and wooden leading edge, and stiff-
eners, similar to the elevator. Others had an
14
ON CENTERLINE
LEADING EDGE
1/16" X 1/16"
1/16"
CHOCK
1/32" CHOCK
1/16"
CHOCK
FIG. 2-2 RUDDER ASSEMBLY
COPPER TAPE
CHOCKS
EPOXY FILLER
all tubular steel rudder. We have selected the
former for the model because of difficulty in
casting an all metal rudder.
On the real aircraft, the trailing edge was a
V-shaped bent steel plate. For the model you
will use a round steel rod. Bend the 1/32"
steel rod trailing edge to the shape shown on
the plan. Cut the 1/16" square wooden lead-
ing edge to length and slot the top and bot-
tom to fit the trailing edge. Glue the trailing
edge rod in place and add a small amount of
filler between the leading and trailing edge
at top and bottom.
The horizontal ribs are made from 1/32" x
1/16" basswood strip. Cut to length and taper
the ribs from 1/16" at the leading edge to
1/32" at the trailing edge. Glue the ribs in
place. For the vertical and diagonal stiffen-
ers, cut from 1/32" x 1/16" basswood strips.
At each location shape the stiffeners so they
are flush with the ribs and taper to 1/32" at
the trailing edge rod. Add the small chocks at
the intersections of rib and stiffeners. Add
self adhesive-copper tape strips over each
BRACE WIRE FITTINGS R1
CUT SLOTS TO FIT
RUDDER FAKE
HINGES
1/32" X 1/16" DIAGONAL
STIFFENER IS FLUSH
WITH RIGHT SIDE OF
STABILIZER
TRAILING EDGE
1/16" X 1/16"
BRACE WIRE
FITTING R2
STEEL ROD