Top Flite TOPA0500 - Manual (Page 37)

bottom of the LE as necessary at ribs 11, 12 and 13 so
you can center the LE vertically on the front of the ribs.
Glue the LE to the wing ribs, centered, as indicated in
the sketch.
❏ ❏ 14. Remove your wing panel from the plan. Test fit
your aileron servo between ribs 8 and 9 where shown on
the plan. Make sure the servo you intend to use will fit.
Most standard servos will fit but if your servo is too wide
(or too
high when placed on its side), you will have to
mount your aileron servo one rib bay inward between
ribs 7 and 8. If this is the case, make new notches in the
ribs to accept the hatch mounting rails as shown on the
plan
(If it’s a close fit, some modelers may not be
opposed to filing a little off the servo mount—look ahead
to the photo at step 14 on page 47.)
❏ ❏ 15. Cut two aileron servo hatch rails from a 1/4" x
3/8" x 36" basswood stick and glue them in the notches
of the ribs.
❏ ❏ 16. Cut the jig tabs from the bottom of the ribs. Cut
the spars and LE even with tip rib 13. Blend the LE, TE
spars and spars to the ribs by sanding.
❏ 17. Return to step 1 and build the right wing panel the
same way.
JOIN THE OUTER PANELS TO THE
CENTER SECTION
❏ 1. Make two spar joiner wedges as shown in the
sketch from the two 1/4" x 3/8" x 2- 7/8" basswood sticks
you cut earlier.
❏ 2. Test fit the left wing panel to the center section with
the spar wedge, a die-cut 1/16" plywood top and
bottom spar joiner and a die-cut 1/8" plywood TE
joiner (the top spar joiner is shorter than the bottom
spar joiner). Make adjustments where necessary so the
panels fit well. The photo illustrates the joining panels
and associated parts as viewed from the front. We’ve
darkened the bottom spar wedge in the photo so it is
easy for you to identify.
❏ 3. Place the center section and left panel on your flat
building table. The bottom spar at tip rib W13 should be
approximately 2-1/2" off your table. Make adjustments if
necessary to achieve this.
❏ 4. Test join the right outer panel to the center section
the same way. When measuring the distance of the right
wing tip from your building table, keep in mind that it
doesn’t have to be exactly 2-1/2" – as long as it’s the
same as the other panel.
❏ 5. Glue the left panel to the center section using
30-minute epoxy. Wipe away excess epoxy before it cures
and do not disturb the wing until after the epoxy has cured.
❏ 6. After the epoxy is fully cured, measure the dihedral
again. Join the right panel to the center section using
30-minute epoxy, setting the dihedral so it’s the same as
the left. Clamp the assembly together and wipe away
excess epoxy before it cures. Do not disturb the
assembly until the epoxy has fully cured.
MOUNT THE ENGINE NACELLES
Remember, steps that start with “R” are for retract
builders only.
❏ R1. Notch the bottom of the ribs for the 1/16" ply spar
braces the same way you did the top (refer to the photo
at step R25 on page 35 if you need a reminder). Glue
the braces in position using 30-minute epoxy.
❏ R2. Cut both 1/2" x 3/4" x 4-3/4" grooved basswood
forward landing gear rails to a length of 3-1/4".
❏ R3. Fit together but do not glue both nacelle
assemblies using the inboard and outboard nacelle
sides, the nacelle tops and bottoms and the firewalls. Fit
the nacelles into the wing using the forward landing gear
rails to hold them in place. Make sure you have installed
the nacelles correctly so the engine thrust is the same
as the plan—both engines have
outward thrust and are
mounted on the side of the firewall closest to the fuse.
The notch you cut in the nacelle sides for the air cylinder
should be on the same side as the passage in the center
spar web for the air cylinder. The photo at this step
shows the left engine nacelle viewed from the top. Note
that the groove in the rail faces upward.
❏ R4. Bevel the top of the rails to match the airfoil shape
of the ribs for a nice fit. Make any other adjustments if
needed so the nacelle sides fit correctly.
IMPORTANT: Be certain the aft edge of each
nacelle side fully contacts the center spar web.
This is what determines the position of the nacelle
sides and therefore determines the degree of
outward engine thrust. All four nacelle sides must
be positioned in this manner so both engines will
have the correct outward engine thrust.
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