Great Planes Piper J-3 Cub 40 Kit - GPMA0160 User Manual
Page 31
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6. Refer to the fuselage plans to determine the placement
of the 3/16" x 3/16" x 36" balsa Fuselage Side Stringer
(CUB4F15). Cut a notch 6-1/4" from the front of each stringer
to allow it to bend. Glue the stringer in place with thin CA.
Round off the edges of the stringer with a sanding block so
the it will look more like a tube after the covering has been
applied. Also, taper the front and aft ends of the stringer as
shown on the plans. NOTE: Use the exposed former tabs to
help you position the stringer.
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7. Cut two 1-1/4" lengths and two 2-1/2" lengths from
what is left of the 3/16" x 3/16" balsa stringer (CUB4F13).
Mark the 1-1/4" stringers as shown in the sketch. Cut each
stringer on the diagonal line with a razor saw.
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8. Place two diagonally cut pieces onto each of the 2-1/2"
stringers as shown in the photo and glue them together as
shown in the photo with thin CA. These will support the
covering around the pushrod exits. NOTE: Be sure to make
a Left and Right support.
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9. Slide the support pieces in place against the fuse side
stringer so the pushrods are surrounded by the supports.
Glue the pieces in place with thin CA. Trim the pushrod outer
tubes flush with the covering supports. Sand a slight taper
into the covering supports so they will not bulge the covering
when it is applied.
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10. Place a 3/4" x 3/4" x 6-1/2" balsa Tail Fairing Block
(CUB4F21) in each corner of the stabilizer and fin. Sand the
forward ends of each block to fit against the turtle deck
former. Mark a line on each block, from the outside edge of
former F6 to the TE of the fin. Also mark the outline of the
former TF4 on the front edge of each block.
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11. Remove the blocks and shape them using a razor
plane and sanding blocks. Use the lines you just drew as
reference. Blend the rounded forward shape into the straight
aft edge as shown in the photo.
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12. Glue the blocks in place and final sand them to match
former TF4 and the dowels. Sand the LE of the fin to blend
with the center dowel and the fairings. Fill any gaps with
HobbyLite
™
filler.
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13. Glue a 1/4" x 1/4" x 2-1/2" piece of scrap balsa wood
in each of the fuselage corners behind former F2. See
plans. These blocks will give support for the screws in step
5 of this page.
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