Now for the fun part. . .
❏
10. Fit the ribs onto the die-cut 1/8” [3.2mm]
plywood
center spar web W19
. Make sure the ribs
go all the way down in the center spar web. Deepen
the notches (in the ribs or the spar web) if
necessary. Fit the assembly onto the bottom spar.
❏
11. Join the die-cut 1/8” [3.2mm] plywood
aft center
spar W20
, the center leading edge assembly (W21 and
W21A), the 9” top spar, and the wing bolt plates to the
ribs. Make sure the ribs align with the plan.
❏
12. Pin small blocks of leftover balsa to the plan
next to the W1 ribs, aligning them over the plan, and
place weights on top of the ribs and spars to hold the
jig tabs to the building board. Use a small square to
make sure the W1 ribs are vertical.
❏
13. Use medium or thin CA to glue all joints
with
the exception of the top spar
. Do not use large
amounts of CA and do not build up large fillets. This
will make it easier to join other parts to the assembly.
You will be reminded to reinforce all glue joints later.
❏
14. Remove the top spar and apply medium CA to
the spar notches in the ribs and to the top of the spar
web. Put the top spar back in place and hold it in
position until the CA cures.
SHEET THE TOP CENTER SECTION
❏
1. Sand the top of the leading edge, spars and ribs
so they blend together. You may remove the center
section from your building board if necessary, but pin
it back down after you’re done sanding.
❏
2. Make sure the center section accurately aligns
with the plan. If necessary, pin two more balsa blocks
to the building board near the fronts of the ribs.
❏
3. Use two 3/32” x 3” x 30” [2.4 x 76.2 x 762mm] balsa
sheets to make one 7” x 9” [177.8 x 228.6mm]
forward
top center section wing skin
and one 11” x 9” [279.4
x 228.6mm]
aft top center section wing skin
.
❏
4. Sand the sheets so they are flat and smooth. Trim
the forward skin so the aft edge aligns with the center
of the top spar and the front extends past the LE (W21
and W21A) by approximately 1/8” [3.2mm]. If you find it
necessary, wet the top of the forward top skin first,
before gluing it to the center section of the wing.
You’re
an expert at sheeting now, so this should be easy.
❏
5. Trim the aft skin so the front edge joins the
forward skin and the aft edge extends past the ends
of the ribs 1/2” [12.7mm]. Trim the ends of the aft top
skin so it extends past the W1 ribs by approximately
1/16” [1.6mm] to allow for sanding later.
❏
6. Glue the aft skin to the center section.
❏
7. After the glue dries, remove the center section
from the plan. Trim, then sand the bottom spar and
the top sheeting flush with the end ribs.
Do not
sand
off the tabs on the ends of the aft spar W20. They will
key into ribs W2 and align the outer panels with the
center section.
❏
8. Remove the jig tabs and sand the bottoms of
the ribs and spars so they all blend together. Bevel
the trailing edge of the top sheeting the same way
you did for the outer panels.
❏
9. Drill 1/4” [6.4mm] holes through the LE of the
center section (W21 and W21A) where shown on the
sketch. Slightly round one end of both 1/4” x 2-1/2”
[6.4 x 63.5mm]
wing dowels
. Test fit, then glue the
wing dowels into the center section with 30-minute
epoxy. The rounded end should point out the front of
the LE.
❏
10. Reinforce all glue joints that don’t look strong.
Do not build up any glue fillets where the dihedral
braces will be fitted.
T-34 Fact:
The service life of the T-34A was very
short in the USAF. The aircraft was used as a
primary trainer from 1953 until 1961. The USAF
then shifted to the Cessna T-37 and Northrop T-38
in an all jet training system.
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Summary of Contents for T-34B MENTOR
Page 7: ...7 DIE CUT PATTERNS...
