Great Planes Giant Extra 330L Kit - GPMA0250 - Manual (Page 20)

❏ ❏ 10. Position the remaining 13 ribs in place on the main
web and spar. NOTE: If you happen to crack or break one
of the ribs during installation, simply take it out of the wing,
position the pieces together and glue them with thin CA.
Allow the rib to dry and reinstall it.
❏ ❏ 11. Carefully slide the wing LE and TE webs you
assembled earlier over the ribs in their notches until the top
of the webs are flush with the top of each rib. Take your time
and be gentle; this balsa structure is still fragile at this point,
but when finished will provide you a strong, light structure.
❏ ❏ 12. Position the LE and TE jigs in position, pinning
through the support blocks you attached previously.
Note: The TE jig is aligned at the rear edge of the aileron
spar slot.
❏ ❏ 13. Remove the aluminum tube from the tube socket.
Fit the tube socket into the 5 laser-cut ribs until the wing
tube socket is into the R5 rib and flush with the end cap.
Hint: It is easiest to install the wing tube socket by turning
it gently in a rotating motion like turning a screw.
❏ ❏ 14. Confirm that your spar is pinned firmly to the
building board and all ribs are pressed down tight against
the jigs and spar. Glue all wing joints in place with thin CA,
being careful not to get thin CA on the socket and being
careful NOT to glue the jigs to the wing structure. Use
medium CA to secure the socket in place. Note: The ribs
are angled slightly in the webs. Do not attempt to force the
ribs vertical.
❏ ❏ 15. Test fit (DO NOT GLUE) the top spar into the ribs.
When you are confident you can fit the spar in place,
remove the spar. Lay a bead of medium CA along the top of
the main web and wing tube socket and the corners of the
rib slots, and reinstall the spar.
❏ ❏ 16. Use a sanding block to shape the LE web so it
aligns with the tops of the ribs and the shape of the airfoil
as shown in the sketch. Be careful not to gouge the ribs or
LE web.
❏ ❏ 17. Using medium CA, glue a LE sheet you made
previously to the LE web. Allow the CA to cure completely
before proceeding. Note: Make sure the sheeting
overhangs the tip rib and the center of the wing slightly.
❏ ❏ 18. Carefully lift the sheeting away from the ribs, then
apply a bead of medium or thick CA to the top of each rib
and the front half of the main spar. Working quickly,
reposion the sheeting as you press it down to the ribs and
the spar. Use weights to hold the sheeting to the ribs and
spar until the CA cures.
❏ ❏ 19. Once the glue is dry, lift off the weights and remove
the T-pins from the spars. Do not remove the wing from the
building board.
❏ ❏ 20. Glue the 1/8" x 1/4" x 48" basswood top TE spar to
the ribs and the TE web. Glue the 1/8" x 1/4" x 48"
basswood top aileron spar in the slots in the ribs.
❏ ❏ 21. From a 3/32" x 3" x 36" sheet, cut four 8" long
sheets. Edge glue these 4 sheets together, creating the
main center sheet.
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