Great Planes Piper J-3 Cub 20 Kit - GPMA0158 - Manual (Page 32)

D 5. Secure the landing gear straps to the main landing
gear rail with #2 x 3/8" sheet metal screws.
Note: The wing struts are for scale appearance only.
Built according to the plan and instructions, the
airframe has sufficient strength for normal acrobatic
flying without the struts. We suggest that the wing
struts be removed if the plane will be flown in a fast,
non-scale manner, because the struts will flutter at
high speeds. Before proceeding, make sure that you
have the wing seated and installed on the fuselage in
its final position.
D 1. Round the LE and TE of the four 3/16" x 1/2" tapered
balsa wing struts with 150-grit sandpaper.
D 4. Refer to the fuselage plan for the location of the wing
strut mounting blocks inside the fuselage. Mark their
locations lightly with a pencil.
D 5. Drill a 1/16" hole in the center of each of the four strut
mounting plates in the wing. Attach the struts to the strut
mounting plates with #2 x 3/8" sheet metal screws.
D 6. Lay the wing struts so that they are positioned across
the fuselage at the marked wing strut mounting blocks.
Mark where the wing struts cross the edge of the fuselage.
Cut the wing struts off at the marks and check their fit.
D 2. Cut six CA hinge pieces 1/4" x 1".
D 3. Cut a slot 1/2" deep in one end of each wing strut.
Insert the CA hinges and glue them in place with thin CA.
Drill a 1/16" hole through the center of the protruding
CA hinge.
D 7. Position the unfinished end of the forward strut at the
wing strut mounting block on the fuselage. With the aft strut
positioned on top, draw a line on the forward strut where
the aft strut crosses it. Remove the front strut and cut away
the balsa behind the line you drew.
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