Great Planes Piper J-3 Cub 40 Kit - GPMA0160 - Manual (Page 9)

❏
8. Check the plans and mark the location of the tailgear
on the rudder. Drill a 7/64” hole in the rudder 3/4” deep (the
hole is drilled slightly oversize to allow room to create a hard
epoxy “sleeve” around the wire). Then groove the rudder LE
to accept the tailgear wire.
Using a hobby knife, sharpen the inside of one end of a
1/8" diameter brass tube, and use it to cut the groove in
the LE of the rudder as shown below.
❏
1. Tape waxed paper over the Fin drawing on the fuse
plans. Remove the 1/4” die-cut balsa R1 from (CUB4RO1).
Place R1 on the plan and pin in place.
❏
2. Cut the remaining fin frame parts from the 1/4" x 3/4"
x 24" balsa strip (CUB4SO3). Pin the parts in place and
make sure all the joints are good and tight. Securely glue all
the joints with thin CA. Note: The bottom end of the trailing
edge stops at the top edge of the horizontal stabilizer.
❏
3. Cut three Ribs from the 3/16" x 1/4" x 24" balsa stick
(CUB4SO4). Fit one rib in place and glue it with thin CA. Add
two more ribs for additional bracing above the lower frame.
❏
4. Remove the Fin from the building board and inspect all
the glue joints. Glue all the tight fitting joints on the bottom side
of the fin with thin CA and add thick CA to any open joints.
❏
5. Place the Fin on a flat work surface and lightly sand
both sides flat and smooth.
❏
6. Draw a centerline on the LE and TE of the fin. The
lines will assist you in the final shaping of the LE and hinge
positioning on the TE.
❏
7. Sand the LE only to a rounded shape to match the
cross-section shown on the plans. NOTE: The trailing edge,
bottom edge and top edge must not be rounded or V-shaped.
Instead, just sand these edges flat and square.
❏
1. Tape waxed paper over the Stabilizer drawing on the
fuse plan. Remove the die-cut 1/4" balsa parts S1, S2 and S3
from (CUB4SO1) and the two S4’s from (CUB4S02). Place
S2 and S3 over the plan to check their fit together. Sand the
parts as necessary to ensure a good fitting joint. Pin S2 and
S3 in place over the plans and glue them together.
Build the Stabilizer
Build the Fin
9