Great Planes F4 Phantom - GPMA0440 - Manual (Page 21)

7. Remove the wing tip from the building board. Glue
the shaped balsa LE, centered on the front of the ribs. The
notch for rib T-2 will need to be modified to match the angle
of T-2. Be careful not to twist the wing tip.
10-13/16"
1-7/8"
8. Cut a 1/16" x 3" x 29-7/8" balsa sheet in half.
Follow the sketch to make a top and bottom LE sheet out
of each half.
9. Sand a slight bevel on the front of the LE tip sheet.
Trim the aft edge of the sheet so that it covers the forward
half of the forward main spar. Position the front of the sheet
against the LE and glue it in position with thin CA.
sheet. The cap strips on ribs T-2 and T-6 are flush with the
outside of the ribs.
12. Trim the LE, LE sheet, spars and TE sheet close
to the sides of ribs T-2 and T-6. Sand the LE flush with the
top LE sheet.
13. Remove the crutch bases from the main tip
crutches. Install the crutch bases on the die-cut 1/8"
plywood tip root crutch (TRC) and tip tip crutch (TTC).
Note: The forward crutch base on the TTC will need to be
trimmed to allow the wing tip to seat against the crutch
without touching the base.
14. Remove the jig tabs from the bottom of the ribs.
10. Carefully lift the sheet away from the ribs and
Sand the ribs and spars flush. Sand the TE sheet that
extends past the ribs to the same angle as the ribs. Do not
sand the LE.
15. Position the wing tip in its crutch with the bottom of
the wing tip facing up. Weight the wing tip down and follow
the same procedure to glue the LE sheet, as in step 10, to
the wing tip.
apply a bead of medium or thick CA to the top of the ribs.
Working quickly, pull the sheet back toward the forward
main spar as you press it down against the ribs and glue it
to the forward main spar.
16. From the remaining 1/16" x 3" x 30" balsa sheet,
cut a 12" long piece to make the TE sheet. Glue the TE
sheet to the aft end of the wing tip ribs and bottom TE
sheet, starting at the front of the aft main sub spar.
17. From the remaining 1/16" x 3/8" x 30" balsa stick,
cut and glue cap strips on the top of the ribs from the LE to
the TE sheet. As before, the cap strips on ribs T-2 and T-6
are flush with the outside of the ribs.
11. From a 1/16" x 3/8" x 30" balsa stick, cut and glue 18. Sand the LE, LE sheet, spars and TE sheet flush
cap strips on the top of the ribs from the LE to the TE with the sides of ribs T-2 and T-6.
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