4. BUILD THE WINGS
You can build both wings at the same time if you have room on your building board. Be certain to build
a right wing and a left wing, not two of the same!
4a. Pin the 1"×¼" triangular trailing edge sections onto the plan, cutting and fitting the supporting pieces
that curve forward at each end. Carefully mark and cut the 5"× 1" notches where wing ribs R3–R15 fit into
the trailing edge. A knife or razor saw will work, but a loose hacksaw blade is better.
4b. Re-pin the trailing edges to the
plan in place. Fit, glue, and pin down
the supports, W1 and W2, and the
spruce spar, sanding to match the
plan if necessary.
4c. Add (cut, fit, glue, and pin) the
bottom center sheet piece that lies
aft of the spar and spans ribs R1 and
R2 underneath. Add wing ribs R2
through R15. Let the glue set for 30
minutes, then fit and glue the hard
balsa ¼" square leading edge into
the ribs’ triangular front notches.
Pin and let dry overnight.
4d. Cut the wings’ curved tips using
the Step 2c method, transferring the
curve to the flat undersides. Sand the
tips smooth and round.
4e. Sand spanwise the leading edge
to a uniform semicircular cross-section, as shown on the plan.
TIP: The ribs’ notches
may need some sanding,
but never force them
NOTE: A lot of aerodynamic activity
occurs at the wingtips,
so pay attention and
do clean work.
4f. Using the sanding block, sand an approximately 3° bevel into the wing roots where they will mate.
Be very hygienic with making clean joints here: the wing center section absorbs more flight stresses than
any other part of the aircraft!
4g. Pin one wing back to the plan
and join it to the other wing by gluing
together the inside edges of the center
sheet pieces. Use a hardcover book or
something similar to prop the opposite
wing tip 6½" above the building board.