Top Flite J-3 Piper Cub - Manual (Page 4)

11. Glue the bottom end of each full rib (W-2/W-3 (PLY), and
all W-4's to the 1/16" x 1" x 36" bottom T.E. sheeting. The
outboard W-4 rib is also glued to the inboard end of the
aileron spar, BUT NOT the aileron L.E. Notice the 1/32" re-
sulting gap between the inboard W-12 aileron riblet and the
outboard end of the W-4 rib. This is the correct spacing for
the wing/aileron relationship.
Glue each of the remaining partial ribs (W-5, W-5, W-6, W-7,
W-8 and W-8) to the aileron spar — remember that the AT-1's
on W-6 and W-7 must face each other.
Glue rib W-9 to the outboard end of the aileron spar — not
the aileron L.E.
The W-10 rib is left loose on the spars for the time being.
16. Prepare the top forward 1/8" x 1/4" x 36" sheeting spar for
installation by first trial fitting it into place into the rib slots —
relieve any rib slot that might force this spar out of true.
Score the spar just outboard of rib W-9 and lightly "crack" it
downward. Bevel the tip end of the spar to mate flush with
the wingtip as shown on the plans. Glue the spar in place,
into each rib and to the wingtip. Secure with pins and allow
to dry.
17. Remove all of the W-11 "false ribs" from their die-cut sheets.
These can now be glued in place onto the 5/16" sq. L.E. and
into the top (only) 1/8" x 1/4" sheeting spar. These ribs
should be aligned with the plans and held securely with pins
until dry.
12. The wingtip assembly W-16/W-17/W-18 should now be trial-
fitted in place. Note that this assembly must fit to the very
end of the W-9 rib while the spar slots line-up with the spar
ends and the forward tip piece, W-18, fits against rib W-9
and centered with the L.E. cut-out. At the same time, rib
W-10 must fit into the fore and aft slots provided in the tip
assembly. This is a matter of "fit and try" until you are
satisfied. Once the fit is correct, glue and pin the tip assem-
bly in place as described above. Glue rib W-10 in place in the
slots provided. Allow this assembly to dry completely.
13. Glue the 5/16" sq. x 36" leading edge in place. Secure firmly
against each rib and the cut-out provided in the leading edge
of the wingtip — allow to dry.
14. Using a scrap glue stick, carefully and completely apply glue
(preferably a white glue or an aliphatic resin type) to each
rib/spar joint. NOTE: it is not necessary to apply a large
amount of glue but rather to be sure that each joint is com-
pletely covered with adhesive, on both sides and top of the
joint.
15. Glue and pin the 3/32" x 1/2" x 36" trailing edge laminate
stock in place on the 1/16" x 1" bottom T.E., directly be-
hind the ends of each rib and aileron riblet. Like the bottom
T.E. sheet, this stock runs from the outboard W-12 riblet, in-
board past the W-2/W-3 (PLY) ribs. The excess will be
trimmed later.
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18. Use a small sanding block and coarse sandpaper to bevel the
3/32" x 1/2" x 36" T.E. laminate to the shape shown in the
plans. Bevel the laminate only, do not sand into the 1/16"
T.E. bottom sheeting.
19. Glue the 1/16" x 1" x 36" top T.E. sheeting in place. Pin
securely and allow to dry.
20. Prepare the forward wingtip for sheeting by sanding a bevel
into it from the 1/8" x 1/4" top L.E. spar, forward thru the
5/16" sq. L.E., to provide seating for the 1/16" sheeting.
21. Glue and pin the 1/16" balsa top sheeting in place. It is
helpful to lightly score the sheeting just outboard of W-9 to
facilitate the slight compound curve required. Let this
assembly dry completely.
22. Glue all top 1/16" x 1/4" cap strips in place on all ribs, W-12
aileron riblets and W-11 false ribs with the exception of the
W-2/W-3 (PLY) ribs, the inner-most W-11 false rib and the
first inboard W-4 rib. This section will be sheeted later.