Top Flite Wristcrat - Manual (Page 4)

W-10 will butt against this rib when it is installed).
Continuing to work inboard, toward the center, in-
stall the next three W-2 ribs. From their die-cut
sheets, remove ply dihedral braces W-8 and W-9
and polyhedral braces W-10 (balsa). The two re-
maining inboard W-2 ribs must now be cut to com-
pensate for the installation of the W-8 and W-9
dihedral braces; use these braces as a thickness
guide and trim the ribs as shown on the plans.
Finally, root rib W-1 must also be trimmed into two
pieces also to fit in front of and behind the dihedral
braces. Once this is done, again use W-8 as a
guide, by holding it in place, and glue all of the re-
maining forward rib ends in place to the bottom
leading edge sheeting; remove W-8 from the struc-
ture. Using W-9 as a guide, glue all remaining rear
rib ends in place and remove W-9 from the struc-
ture. The remaining outboard W-2 rib must be trim-
med in a similar manner since it is intersected by
polyhedral brace W-10. Using the same procedure
as described, trim this rib into a front and rear piece
and glue in place using W-10 as a spacer; remove
W-10 from the structure.
D 3. Cut, fit and glue the 1/4" sq. leading edge in place.
D 4. Carefully remove this structure from your work sur-
face. Use a sanding block to lightly sand the out-
board edges (the polyhedral break) smooth. Place
the structure back on the plans and block up the
center 2-
1
1/2". Using the same construction as
described earlier, the outer wing panel is now built
directly over the plans and directly to the inner
panel. Take pains to bevel the trailing edge butt
joint for a good fit. Be sure to install W-10 first
before the front and rear segments of W-2, followed
by W-3, W-4, etc.
D 5. With all of the ribs in place, cut, fit and glue the top
spruce spar in place from W-7 to the W-2 at the
polyhedral break. From your parts bag, locate the
bundle (10 provided) of vertical grain shear webs.
Carefully trim one of these to fit precisely between
W-3 and W-2 and against the spars and W-10 with
the top flush with the top of the spar. Once
satisfied, glue this web in place.
D 6. As shown on the plans, the 1/4" sq. leading edge
must now be sanded down to match the top con-
tours of the ribs. The judicious use of a razor blade
followed by using your sanding block to finish the
job is the way to go here. Once you're satisfied you
can cut, fit and glue in place the top 1/16" leading
edge sheeting (note that this top sheeting is plac-
ed slightly forward on the top spar thus creating a
bit of a "shelf"). Lastly, cut, fit and glue in place all
of the top 1/16" x 3/16" cap strips with the exception of
the one which will cover the W-2 ribs at the
polyhedral break. Remove the thus far completed
left wing panel from your work surface. Use your
sanding block to smooth the outboard face of W-7
in preparation for the wingtip. Inspect the bottom
polyhedral joint and lightly sand as needed to
smooth it out.
D 7. The right wing structure is now built using the
same procedures just described.
D 8. In this step, we're going to join the right and left
wing halves together. Preparation for this re-
quires that the two inboard ends of the wing
halves be sanded smooth and beveled to create a
good, straight fit. Do this now. Pin or weight one
of the wing halves (let's use the left) flat to your
work surface. Next, make sure the rib curve in the
bottom leading edge sheeting is supported with a
length of trailing edge stock. With everything
secure, trial-fit the right wing half in place with
it's polyhedral break supported 2-5/8" off of the
work surface. The resulting butt joint should be
as flush fitting as possible and the leading and
trailing edges of both inner panels should be
straight; take your time here and ensure that the
fit is the best you can produce, with all parts
lining-up correctly. Once satisfied, apply a thin,
even coat of glue (5-minute epoxy is great here) to
the inboard end of the right wing panel and
carefully fit it to the pinned down left panel, again
making sure the right panel is raised 2-5/8" at the
polyhedral break. Carefully wipe off any oozing
adhesive. Now fit W-8 dihedral brace in place,
trimming if needed for a good fit. Glue W-8 in
place. Cut, fit and glue the left panel's spruce
spar in place. Rear dihedral brace W-9 can now be
glued in place.
D 9. With the left wing still down flat to your work sur-
face, locate the vertical grain shear webs (1/16"
balsa). Cut, fit and glue these in place between
the remaining W-2 ribs, out to the polyhedral
break.
D 10. Remove the joined wing structure from the
bench. Pin or weight the right panel in place to the
bench and glue the remaining top spruce spar in
place followed by the remaining vertical grain
shear webs.
D 11. A s you did with the tip panels, carefully shave and
sand the inner panel's leading edges to conform
with the top contours of the wing ribs. Use your
sanding block to lightly sand any high points on
the panel's top surfaces. Once you're satisfied
that the inner panels are ready to sheet, pin or
weight one side or the other in place on your work
surface. Cut, fit and glue the leading edge
sheeting in place (again leaving a bit of a "shelf"
at the rear edge of the top spar). Cut, fit and glue
the center section sheeting in place using the
patterns shown on the plans. Finally, add all of
the remaining 1/16" x 3/16" cap strips out to and in-
cluding the polyhedral break. Repeat this pro-
cedure on the opposite wing panel.
D 12. Locate and remove wingtip parts W-11 from their
die-cut sheets. Sand their inner edges lightly to
render them flat and straight. Note the tip rein-
forcement option shown on the plans. This addi-
tion of a length of 1/8" x3/16" spar stock really serves
to "beef-up" an otherwise accident prone area,
you might give it serious consideration. Glue the
W-11 wingtips in place as shown on the plans
("End View of Wingtip", left panel). Also as
shown, cut a few scraps of 1/8" balsa to fill in the
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