Great Planes Extra 300S 40 Kit - GPMA0235 - Manual (Page 16)

TE at the wing centerline as shown on the plan–the bottom
of R-1 at the front should align with the bottom spar. Check
for proper positioning, then glue the rib in position with thin
or medium CA.
❏
2. Use a hobby knife to remove the top jig tabs (the
small ones on every rib), then use your bar sander to sand
away any remaining jig tab “stubs.” If needed, use your bar
sander to remove any glue blobs and trim the shear webs
so they are even with the top spar.
❏
3. Replace the wing on your flat building table so it is
resting on the bottom jig tabs. Place weights on top of the
wing to hold the jig tabs down. Make the left and right top
LE sheets by gluing together two 3/32" x 3" x 30" balsa
sheets, then glue them to the top of the wing the same as
you did for the bottom.
❏
4. Use two 3/32" x 7/8" x 30" balsa sheets to sheet the
top TE of the wing.
❏
5. Test fit but do not glue the die-cut 1/8" plywood aileron
servo tray supports and the aileron servo tray in rib R-1.
Adjust the cut-out in rib R-1 if needed so the aileron servo
will fit.
❏
6. Use medium CA to glue the aileron servo tray and
supports in position, then glue the die-cut 1/8" plywood
aileron servo tray doublers to the bottom of the aileron
servo tray.
❏
7. Cut the 3/32" x 3" x 36" balsa sheet into one 17-1/4"
sheet and one 18-3/4" sheet. Cut the 17-1/4" sheet in half
and use each piece to sheet the forward portion of the top
center section of the wing on both sides of the aileron servo
tray. Note that the end of the sheets at the front extend
approximately 3/32" before they reach rib R-4 and the end
of the sheets at the rear extend approximately 3/32" past
rib R-3. Fit the sheets to the wing, then glue them in
position with medium CA.
Hint: The “curve” in the sheet doesn't have to match the
plan exactly but once you cut the first sheet, use the piece
you cut as a pattern to make the curve in the ends of the
other sheets.
❏
8. Use a 3/32" x 3" x 30" balsa sheet to sheet to the
middle portion on the top center section of the wing. Save
the rest of the sheet for the middle portion of the bottom
center section.
16