Top Flite TOPA0410 - Manual (Page 40)

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BUILD THE INBOARD FLAPS
❏ ❏ 1. From the remaining 1/2" x 15/16" balsa stick, cut a
6-7/8" [174.6mm] long inboard flap LE.
❏ ❏ 2. Sand one end of the stick to match the contour of
the belly pan at the TE of the wing.
6-1/4" [158.8mm]
3" [76.2mm]
6-1/2" [165.1mm]
❏ ❏ 3. From one of the remaining 3/32" x 3" balsa sheets,
cut in step 2 of Build The Outboard Flaps, make a top
inboard flap skin as shown.
❏ ❏ 4. Position the flap skin over the inboard flap plan,
align the skin with the TE of the flap and mark the rib
locations on the skin. Draw a line 3/16" [4.8mm] from the
aft edge of the flap skin.
❏ ❏ 5. Glue the three outer die-cut 1/8" [3.2mm] balsa
flap ribs in position, perpendicular to the flap skin. Align
the aft edge of the ribs with the line at the aft edge of the
flap skin.
❏ ❏ 6. Use a sanding bar to bevel the short edge of the
inboard LE so that it fits tightly against the forward edge of
the ribs and flap skin. The LE will hang over the forward edge
of the flap skin. When satisfied with the fit, glue it in position.
❏ ❏ 7. Glue the inner rib to the flap skin and flush with the LE.
❏ ❏ 8. Use a razor plane and sanding bar to bevel the LE
and the TE of the flap skin to the same angle as the ribs.
❏ ❏ 9. From the 1/2" x 1/2" balsa stick, cut 3/4" [19mm]
long hinge point backups and glue them in position on the
back of the LE. Sand the hinge point backups flush with
the LE and top of the ribs.
❏ ❏ 10. Glue the remaining balsa flap skin to the LE, ribs
and top flap skin.
❏ ❏ 11. Sand the LE and flap skins flush with the end ribs.
❏ ❏ 12. Glue the die-cut 1/8" [3.2mm] plywood flap ends
to the ends of the inboard flap, aligning the front of the
plywood flap end and the LE. The flap end with the two
punch marks goes on the outboard end of the flap with
the larger radius LE on the flap end toward the bottom of
the flap. Use a leftover piece of 3/32" [2.4mm] balsa to fill
in the corner between the LE and the flap skin.
❏ ❏ 13. Use a sanding bar to sand the LE and flap skins
flush with the plywood flap ends.
❏ ❏ 14. Drill a 3/32" [2.4mm] hole through the flap end, at
each punch mark. Use a hobby knife to finish making the
slot.
❏ ❏ 15. If you will be installing Robart Hinge Points, drill
3/16" [4.8mm] holes into the wing TE about 1/4" [6.4mm]
above the bottom of the bottom wing sheeting at the
previously marked hinge locations. These holes should
angle slightly toward the center of the wing. (See step 13
of previous section.)
❏ ❏ 16. Hold the inboard flap against the wing, so that it is
spaced approximately 1/16" [1.6mm] away from the belly
pan. Mark the hinge locations on the flap. Drill 3/16"
[4.8mm] holes in the LE of the flap in the same manner as
the wing. Trial fit the flap on the wing making any
adjustments as necessary. As the flap moves down make
sure the hinges do not pull out. If they do, increase the
radius on the bottom of the LE of the flap.
❏ 17. Return to step 1 of Build The Inboard Flaps and
build the other inboard flap.