Installing The Drag Wires; Installing The Fake Hinge Rods In The Upper And Lower Wings; Building And Installing The Lower Wing Skids; Building , Installing, And Rigging The Kingposts - Model Airways CURTISS JN-4D JENNY Instruction Manual

of the wings
(Figure 1-16 and plan Detail 2-
. Actual rigging of the aileron control wires
C)
will be discussed in a later stage.
On the right side of the upper wing center sec-
tion add a similar U pin that will serve as a fair-
lead for the aileron control wire

13.Installing the Drag Wires

The turnbuckles have an eye on each end.
One end can be tied with thread to the rig eye
fittings (R1), or if you file out one side of the
eye they can be hooked into the fitting. On
the real aircraft the end is U-shaped for bolt-
ing to the fitting.
Add the short turnbuckles (R3A) and rig the
drag wires (nylon cord on the model). These
go between the compression ribs on the main
wing panels and also on the upper wing cen-
ter section .
(Figure 1-17)
Try to be neat with the cord. Don't get knots
too big. Touch all knots with super or white
glue so they won't come adrift.
14.Installing the Fake Hinge Rods in
the Upper and Lower Wings
On the real aircraft, the lower wing was attached
to the fuselage and the upper wing was attached
to the center section by a pair of heavy hinges
bolted to the beam webs. Until such time as the
rigging wires were installed, the wings were not
supported and would rotate on the hinge. For
the model, the hinge has been faked to provide
a more rigid connection, so when the wings are
installed they don't flop around, making instal-
lation of the struts and rigging easier. A simple
steel rod is provided as a fake hinge.
First, bend the steel rod to the angle of the wing
dihedral (1°). In order to maintain the 3/32" gap
between the outer wing panels and fuselage/
center wing section, an optional spacer inserted
onto the steel rod is suggested. This can be
made from a piece of wood, or of aluminum or
brass tubing with a 1/16" inside diameter.
Drill a hole in the end of the beams through
the precut guide holes in the inboard ribs for
inserting the fake hinge pin. Glue the rod
into the holes
(Figure 1-18)
hole into the beams of upper wing center sec-
tion. For the lower wing, there will be holes
drilled in the fuselage. This will be shown in
the fuselage building stage.
15. Building and Installing the Lower
Wing Skids
Using the 3/32" square flexible beech wood,
shape the strip into a 1/16" dowel. The beech
bends rather easily, but can be easier and hold
its shape better if it is wet first. Pin the dowel
over the plan pattern and let dry. It may tend
to flex back a little, but that's OK. When
installed in the skid fittings, it will be secure.
Fit the cast fitting (W21) at each end under
the lower wing, then glue the skids in the
holes. shows the process.
16. Building , Installing, and
Figure 1-19
Rigging the Kingposts
The kingposts are laser-cut, but you must
taper them and shape to a streamline section.
.
(See Figure 1-22)
. Drill a similar
The end fittings are so small they have been
omitted on the model. Paint the ends black or
copper color to "fake" a fitting that is similar
to the wing struts. Install the single eye rig fit-
tings (R1) into the posts. Drill a hole in the
bottom of the posts and insert a brass pin.
Insert the kingposts into the holes on top of
the upper wing, then add the steel rod at top
FIG. 1-16 AILERON CONTROL CABLE SHEAVES
CASTING C4
BRASS ROD
FIG. 1-17 WING DRAG WIRES
.010"-DIA. GRAY
NYLON CORD
R3A
FRONT WING
BEAM
FIG. 1-18 INSTALLING FAKE HINGE RODS
W1 (TOP WING)
W8 (BOTTOM WING)
DRILL 1/16" HOLE INTO BEAMS
THROUGH PRE-CUT PILOT
HOLES IN LASER-CUT RIB
12
CASTING C3
FITTING AT TOP AND
BOTTOM OF WING
CAP STRIP
WING FRONT BEAM
LEADING EDGE
COMPRESSION RIB
REAR WING BEAM
SHORT TURNBUCKLE
DRAG WIRES PASS
THROUGH HOLES
IN THESE
LIGHTENED RIBS
R3A
TYPICAL PANEL IN
LEFT WING
GLUE ROD IN HOLE
FAKE HINGE
(1/16"-DIA. STEEL ROD)
OPTIONAL SPACER
(WOOD OR TUBING)
between the front and rear posts. See
. Next, add the single eye rig fittings (R1)
1-20
on the wing for the kingpost brace wires. See
plan Detail 2-E.
The rigging for the kingposts can be accom-
plished at this time or wait until later. Refer
to Stage 7 and Sheet 6 for details. The short
turnbuckles (R3A) for the transverse wires
R3A
WEB BLOCK
WITH R1
FITTINGS
3/32" THICK
1 DEGREE
Figure