Great Planes Super Decathlon 40 Kit - GPMA0185 - Manual (Page 7)

D 3. From the 1/4" x 1/2" x 30" sticks, cut "braces" to fit
between the rudder framework, and glue them in place.
NOTE: It is not necessary to get these braces in the exact
position shown on the plan.
D 4. Examine the rudder framework and add thick CA
glue to any open joints, then use your T-bar with medium grit
sandpaper to sand both sides of the rudder framework smooth.
hole is drilled slightly oversize to allow for positioning, and
to create a hard epoxy "sleeve" around the wire). Then
groove the rudder leading edge to accept the tailgear wire .
(See the photo at step 5 on page 15). HINT: Using an Xacto
knife, sharpen the inside of one end of a 1/8" diameter brass
tube, and use it to cut the groove in the leading edge of the
rudder.
D 5. Carefully draw a centerline all around the edges of
the rudder (this will help to maintain symmetry when sand-
ing).
BUILD THE FIN
D 6. Using a sanding block and coarse (50 or 80-grit)
sandpaper, sand both sides of the rudder to a taper as shown
on the plans. The trailing edge should end up approximately
3/32" wide and have a rounded shape. (Do not sand to a sharp
edge). Sand the top edge to a rounded shape. Sand the
leading edge to a "V-shape" as shown on the plan.
D 7. Check the plans and mark the location of the
tailgear on the rudder. Drill a 7/64" hole in the rudder (the
D 1. In the same manner as the rudder, build the fin using
the 1/4" x 3/4" and 1/4" x 1/2" balsa sticks. Also, cut 1" from
the 1/4" x 3/4" x 36" balsa stick, and from this small piece cut
the triangular gusset for the front comer of the fin.
D 2. Carefully draw a centerline on the leading and
trailing edges of the fin.
D 3. Sand the leading edge (only) to a round shape.
NOTE: The trailing edge, bottom edge and top edge
must not be rounded or V-shaped, instead, just sand
these edges flat and square.
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