22.
Use a bar sander and 80-grit sandpaper
to sand the sheeting, spars and LE so they are
flush with root rib W2 and tip rib W14.
23.
Mark the locations of the aileron hinge
slots on the outer wing TE and the aileron LE, so
you will know where to cut the hinge slots after the
wing and aileron are sheeted. Mark the location of
the flap hinge blocks the same way.
24.
Return to step 1 on page 24 and finish the
left wing panel.
BUILD THE CENTER SECTION
1.
Position the center section wing plan (which is
attached
to
the right wing plan) over your building
board and cover the plan with wax paper.
2.
Use thick or medium
CA
to glue two die-cut
118"
plywood
dowel rib doublers W1D
and one
bolt plate rib doubler W1P
to the sides of the die-
cut 118" balsa ribs
W1
as shown on the plan. Pay
careful attention to which sides of the ribs the
doublers are glued.
3.
Glue two sets of 1/8" die-cut plywood
wing
bolt plates
together to make two 114" plates.
4.
Glue the 1/8" die-cut plywood
leading edge
doubler (W21)
to the die-cut 1/8" plywood
center
leading edge (W21A)
so the
bottoms
of the
notches
align. W21A is narrower than W21 so the
top and bottom edges will be offset 1/16".
5. Test fit the wing bolt plate in the notches of
the ribs where shown on the plans. Adjust the
notches if necessary so the bolt plates fit.
6.
Remove the balsa from both W1 ribs between
the notches of the dowel doublers.
7.
With a straightedge and a ballpoint pen mark
two vertical lines
1/16"
ahead of and behind the
spar notches on the
outside
of both of the W1 ribs,
that have only the W1P doublers glued to them.
Use a sharp hobby knife to cut halfway through the
balsa along the lines. This section of balsa will be
removed to accommodate the spar joiners when it
is time to join the wing.
8. Cut
one 11" long piece for the
bottom center
spar
and one 9-1/4" long piece for the
top center
- 2 7 -
spar
from a 1 / 4 x 3/8" x 24" basswood stick. Pin
only the ends
of the 11" bottom center spar to
your building board over its location on the plan.
Do
not stick the T-pins through the basswood spar but
insert them in a crossed fashion over the spar to
hold it to your building board.
Now
for the
fun
part.
. .
9.
Fit the ribs onto the die-cut 1/8" plywood
center spar web W19.
Make sure the ribs go all
the way down in the center spar web. Deepen the
notches (in the ribs or the spar web) if necessary.
Fit the assembly onto the bottom spar.
10.
Join the die-cut 1/8" plywood
aft center spar
W20,
the center leading edge assembly (W21 and
W21A),
the 9" top spar, and the wing bolt plates to
the ribs. Make sure the ribs align with the plan.
11.
Pin small blocks of leftover balsa to the plan
next to the W1 ribs, aligning them over the plan,
and place weights on top of the ribs and spars to
hold the jig tabs to the building board. Use a small
square to make sure the W1 ribs are vertical.
12.
Use medium or thin CA to glue all joints
excepting the top spar.
Do not use large amounts
of
CA
and do not build up large fillets. This
will make it easier to join other parts to the
assembly. You will be reminded
to
reinforce all glue
joints later.
13.
Remove the top spar. Glue it back in place.
