Top Flite TOPA0500 - Manual (Page 17)

❏ 5. The same way you did for the stab, use your 1/4" x
5/16" rib jigs to hold the fin ribs V1 through V7 over their
location on the plan. Use a square to align the ends of
the ribs with the TE on the plan.
❏ 6. From the 1/8" x 3/4" x 30” balsa stick cut the four
fin TE sections that fit between ribs V7 and V6, ribs V6
and V4, ribs V4 and V2, and ribs V2 and V1. Don’t forget
to cut the bottom two sections long enough so you can
bevel the ends to the correct angle shown on the plan.
All the TE sections must be cut accurately and the ends
must be square (vertical).
❏ 7. Glue the fin TE sections to the fin ribs as shown on
the plan. Make sure the jig tabs of the ribs and each TE
section are resting on your building board over their
locations on the plan. Make sure you provide the 1/16"
space for the three plywood fin hinges where required.
❏ 8. Drill a 1/8" hole at the punch mark through all three
sets of die-cut 1/16" plywood rudder hinges R2, R4 and
R6. Press down on each piece as you drill to prevent the
wood from splitting as the drill goes through.
❏ 9. Drill a #41 (or 3/32") hole at the punch mark
through the three die-cut 1/16" plywood fin hinges V2A,
V4A and V6A.
❏ 10. Round the aft edge of the fin hinges as indicated
in the sketch and as shown in the photo at step 13.
❏ 11. Slide the 3/32" x 10" brass hinge tube into the
holes of the ply fin hinges. Space the hinges along the
hinge tube as shown on the plan and insert the hinges
into the fin assembly (refer to the following photo).
❏ 12. Make sure the hinges and the hinge tube will align
with the plan. If necessary, trim parts of the TE sections
or glue bumps that interfere. Make two small shims
from the 3/32" x 7/16" x 24" balsa stick and place them
under the hinge tube near the top and bottom hinges.
These will hold the tube level and align the fin hinges
with the fin.
❏ 13. Make sure the fin hinges are accurately aligned
with the fin ribs and that the hinge tube is aligned with its
location over the plan. Confirm by measuring the height
of the tube at each hinge. Glue the fin hinges to the ribs
with thin CA.
❏ 14. Bevel the front of the fin ribs to accommodate the
fin LE. Cut the fin LE as shown on the plan from a 5/16"
x 15" shaped balsa stab/fin leading edge stick. Glue the
fin LE to the fin the same way you did the stab with the
excess protruding below the ribs.
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