Top Flite TOPA0140 - Manual (Page 27)

SHEET THE TOP OF THE WING
❏
1. If you haven’t already done so, make the top
wing skins as described in steps 1, 2 and 3 on
page 23.
Sheet the left side of the wing first.
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2. Trim the end of one of the skins to join the
top sheeting of the center section (the skin will
have a slight
curve due to the curvature of the
airfoil and the dihedral of the wing). When the skin
accurately fits the center section, trim it about 1/4"
[6mm] larger than the outline of the rest of the wing
to allow for positioning errors and trimming later.
❏ ❏
3. Build the die-cut 1/8" [3.2mm] plywood
upright wing jigs. Place the wing on the jigs and
place weights over the center section to hold it
down. Place the tip jigs under the wing tips.
❏ ❏
4. Use a piece of leftover balsa or something
similar to support the trailing edge of the wing near
the tip of the flap. This will keep the wing from
bowing when you place weights on it to hold the
top skin down.
❏ ❏
5. Apply aliphatic resin to the top spar, outer
trailing edge and all the ribs except tip rib 13. Do
not apply glue to the inner trailing edge, tip rib 13
or the sub leading edge. Position the wing skin and
use weights and T-pins to hold it down.
❏ ❏
6. Glue the front of the sheeting to the sub
leading edge and the tip of the sheeting to rib 13
with medium CA. Do not disturb the wing until the
glue is fully dried.
❏ ❏
7. Remove the weights and T-pins. Trim the
top skin even with the sub leading edge, tip rib 13
and the outer trailing edge. Use a straightedge to
trim the skin to the center of the inner trailing edge.
❏
8. Return to step 2 and sheet the right side of
the wing the same way.
❏
9. Coat the top sheeting inside the wheel wells
with fuel proof paint the same way you did to the
bottom sheeting.
BUILD THE FLAPS
Perform steps 1 through 4 only if you are not
building flaps.
❏
1. Use one of the die-cut 1/16" [1.6mm]
plywood flap skins as a template to make four
balsa flap skins from leftover 1/16" [1.6mm] balsa.
Note: The top sheeting tends to buckle near the
wing tip because it is trying to bend in two
directions at the same time (toward the tip and
toward the leading edge). Place plenty of
weights over the sheeting near the tip to prevent
or minimize this tendency. This is also why we
recommend you glue the sheeting to tip rib 13
with CA—because you can hold it down with
your hand momentarily until the CA cures.
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