Top Flite TOPA0140 User Manual
Page 19

BUILD THE CENTER SECTION
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1. Align the center section wing plan over your
building board and cover it with waxed paper.
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2. Glue the die-cut 1/8" [3.2mm] plywood rib
doublers 1B and 2B to rib 1 and both 2’s respectively
as shown on the plan. Glue both die-cut 1/8" [3.2mm]
plywood wing bolt plates together.
Use this photo for the next six steps.
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3. Cut the top and bottom center section
spars to the length shown on the plan from the
1/4" x 3/8" x 24" [6.4 x 9.5 x 610mm] basswood
stick. Place the bottom spar over its location on the
plan and pin it to your building board.
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4. Place the ribs of the center section over the
plan on the bottom spar. Place both die-cut 1/8"
[3.2mm] plywood aft wing dowel plates and the
die-cut 1/8" [3.2mm] plywood servo mount plate
base between the #2 ribs. The holes in the dowel
plates are closest to the bottom of the wing.
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5. Add both die-cut 1/8" [3.2mm] balsa center
TE’s and the top spar.
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6. Pin the ribs to your building board the same
way you did for the outer panels (pin down the jig
tabs and the
low point of the ribs).
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7. Make sure the ribs are in the correct location
with the doublers as shown on the plan. Remove
the T-pins that are holding the bottom spar down.
Pull the bottom spar up into the notches of the ribs
and glue it to the ribs the same as you did for the
outer panels. Avoid gluing the aft dowel plates at
this time.
Note: Make sure both #3 ribs are vertical when
you glue them to the spars.
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8. Align the top edge of both aft dowel plates
with the top spar and glue them in position. Glue
the rest of the joints made by the ribs, the top spar,
the servo plate and the center TE’s.
Use this photo for the next two steps.
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9. Use a straightedge to draw a line 1/8" [3mm]
from the edge of a leftover 1/8" x 1" [3.2 x 25.4mm]
sub LE you used for one of the outer panels. Glue
both die-cut 1/8" [3.2mm] plywood forward dowel
plates, centered, to the sub LE, aligning them with
the line you marked with a 1/8" [3.2mm] space
between them (to accommodate center rib 1).
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10. Cut a 10" [250mm] center leading edge
from the 36" [914mm] long shaped balsa leading
edge stock. Center the sub LE on the back of the
center leading edge and tape them together. Use
the holes in the forward dowel plates as a guide to
drill 1/4" [6.30mm] holes through the sub leading
edge and the center leading edge for the 1/4"
[6.4mm] wing dowels.
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11. Glue only the sub LE to the front of the ribs
with the forward dowel plates centered on ribs 1
and 2.
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12. The same way you did for the outer panels,
trim the top of the sub LE to accommodate the
top sheeting.
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13. Remove any T-pins that will be concealed
under the sheeting after you glue it to the top of
the center section.
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14. Cut ten 9-1/2" [242mm] long sheets from
four 1/16" x 3" x 30" [1.6 x 76 x 762mm] balsa
sheets. Make two 15" x 9-1/2" [380 x 242mm]
center section skins by gluing together two sets
of five sheets.
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15. Glue one of your skins to the top of the
center section. The front should extend past the LE
by approximately 1/16" [1.6mm] and the TE should
extend past the end of the ribs by 3/8" [9.5mm].
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