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Take a few minutes to have a quick read through this entire instruction manual prior to starting so
that you have a basic overview of the steps involved. Please don’t be tempted to deviate from these
instructions unless you are an experienced builder and are confident that your changes won’t
negatively affect the structural integrity or flying performance of the Duck. These instructions are
based in metric units but I have also tried to include the equivalent imperial measurement as much
as possible. For your reference, 1 inch (”) equals 25.4 millimeters (mm). An online version of these
instructions, with colour photos, is located on Wowings website at:
www.wowings.com/instructions/duck.doc
INITIAL WING ASSEMBLY
1.
Remove the two wing halves from their beds and glue the wing together using hot-melt
glue, contact adhesive or spray adhesive (epoxy is not ideal because it’s hard and brittle).
2.
Locate the two balsa trailing edge pieces. Cut along the angled lines marked using a sharp
blade (many light cutting strokes are better than trying to cut through in one or two goes).
The remainder will be used later for the “elevons” (moveable control surfaces for combined
elevator and aileron function). Place the balsa trailing edge pieces up against the foam sub-
trailing edges (rear edge of the EPP foam wing cores) in the middle of the wing to make sure
that their angled centre joint fits nicely together. The BOTTOM surface of the balsa trailing
edges is the one that had the cut-out lines marked on them (and the surface that meets its
leading edge at a 90 degree angle). When butted up against the foam sub-trailing edge, the
bottom surface of the balsa trailing edge piece should form a straight line continuation of the
foam airfoil shape.
3.
Once you are happy that they will fit
nicely, round off the top and bottom edges
of the outer end only of each balsa trailing
edge piece (not where they join together in
the middle) to make covering easier later.
4.
Use 5 minute epoxy to glue one of the
balsa trailing edge pieces to the foam. Use
a straight edge (ruler) held against the rear
section of the bottom surface of the wing
and the bottom of the balsa trailing edge to
ensure correct alignment (straight line).
Once the glue has cured repeat this process
for the second balsa trailing edge piece,
also end gluing to the first piece where
they meet at the center of the wing.
5.
Measure approximately 25mm (1”) in from
each wingtip along the foam sub-trailing
edge. This will be the width of your
trailing edge fin supports made from small
sections of the two remaining lengths of
balsa trailing edge.
6.
Hold one of the lengths of balsa trailing
edge up against the foam sub-trailing edge
at a wingtip so that its end is aligned with
the line you just marked (25mm in from
