Great Planes ElectroStreak Sailplane Kit - GPMA0385 - Manual (Page 20)

WING
BUILD THE WING PANELS
NOTE: It will be helpful to build the wing on a piece of "Celotex"
or other semi-soft (and flat) surface, into which you may easily stick
pins to firmly hold down the wing parts while building, to avoid
warps.
D 1. Turn the plan around so the wing drawing is facing
you. Tape the plan to your flat work surface, and cover the
wing drawing with waxed paper (so you won't glue the wing
to the plan!). NOTE; If your work space is limited, you may
cut the left and right wing half drawings apart.
D 4. Before using the 1/8" x 1/4" x 23" hard balsa
spars, examine them carefully for possible imperfections.
Look for knots, soft spots, diagonal grain and any other im-
perfections. If possible, position each spar so the imperfec-
tions (if any) are on the outer half of the wing panel (toward
the tip), where they will be least affected by high stress. If
the spars are warped slightly, try to "balance them out" by
installing the warped spars in opposite directions (see
sketch).
TWO WARPED SPARS INSTALLED
THIS W A Y WILL RESULT IN A
STRAIGHT WING
D 2. The shaped and notched wing leading edges (L.E.)
and trailing edges (T.E.) are fastened together by thin layers
of balsa. Separate them by folding until the balsa breaks.
Sand away the excess balsa that remains along the edges after
breaking them apart, using a T-bar with 100-grit sandpaper.
D 3. Before using the L.E. and T.E. pieces, you must
determine which pieces are to be used for the wing panel you
are building. Here's how;
A. Compare the leading and trailing edges with the
following drawings to determine the top and bottom of each
piece.
TOP TOP
L E . T.E.
B. Notice that there are three notches near one end
of each piece that are 1-7/8" apart. This is the end that goes
toward the center (root) of the wing.
C. Take one of the LE pieces and lay it on the right
wing panel plan with the top up. If the three closely-spaced
notches are toward the center of the wing, you have the
correct LE for the right panel.
TWO WARPED SPARS INSTALLED
THIS W A Y WILL RESULT IN A
WARPED WING
If you find that the spars in your kit are not satis-
factory (due to gross imperfections, damage, or extreme
warp), just give us a call or write a note requesting replace-
ments (see the "INTRODUCTION" on the first pages of this
book).
D 5. Carefully punch out all the die-cut 1/16" balsa
wing ribs. Sand the edges slightly to remove any die-cutting
irregularities.
D D 6. Pin one of the 1/8" x 1/4" x 23" spars to the plan.
NOTE: The spars are slightly longer than necessary, and
will be trimmed later.
D. Do the same thing to determine which TE piece
to use.
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D D 7. Set rib W-l in place on the plan, holding it perpen-
dicular to the surface, and glue it to the spar.