GREAT PLANES Ryan STA EP Instruction Manual page 13

6. Cut a V-notch part way through the spar, at the
mark, so that the spar can bend at W4.
7. From one of the 1/16" x 3" x 30" [1.6mm x 76.2mm
x 762mm] balsa sheets, cut four 1/2" x 3/4" [12.7mm x
19mm] shims. Place the shims over the spar location on the
plan, starting between ribs W1 and W2 and alternating
every other rib bay. Pin the main spar, cut in step 6, over the
shims, aligned with the wing plan at the W5 tip rib.
8. Pin the die-cut 3/32" [2.4mm] balsa sub trailing
edge, perpendicular to the building board. The tapered end
should be positioned at the wing tip.
9. Pin and glue the die-cut 3/32" [2.4mm] balsa W2,
W3, W4 and W5 ribs onto the main spar and the sub TE,
perpendicular to the building board. The TE of the ribs do
not touch the building board. Note the direction of the W3
ribs with the landing gear doublers and the W3 and W4 ribs
with the rib doublers. The main spar will need to be bent
upward to contact the W5 rib.
10. Position the die-cut 3/32" [2.4mm] balsa W1 root
rib over the main spar. Place the die-cut 1/8" [3.2mm] 3-ply
dihedral gauge against the W1 root rib, between ribs W1
and W2. Glue the root rib to the main spar and the sub TE.
Note that the notch in the sub TE is cut at the proper angle.
11. Cut a V-notch in the basswood top main spar the
same as you did in the bottom main spar. Glue the top main
spar to the ribs, making sure that the W2 through W5 ribs
are perpendicular to the building board. Also make certain
that the main spar is fully seated in each rib. The top of the
main spar should be flush with the front of each rib.
12. Center the 3/32" x 1/2" x 30" [2.4mm x 12.7mm x
762mm] balsa sub LE on the front of the ribs. Check that
the sub TE is against the building board. Then, glue the sub
LE to the front of the ribs. The excess 3/32" x 1/2" [2.4mm x
12.7mm] will be used for the wing tip braces.
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