Great Planes Giant Extra 330L Kit - GPMA0250 - Manual (Page 14)

❏ ❏ 16. Select the 9/16" x 1-3/8" x 2-3/4" balsa
counterbalance leading edge and glue it centered on the
leading edge of the counterbalance portion of the elevator
with excess overhanging both ends. Sand both leading
edges flush with the sheeting, S1 and S9, S10.
❏ ❏ 17. Bevel the elevator LE and round the counterbalance’s
leading edge.
❏ ❏ 1. Select a 1/4" x 1" x 24" balsa stick, for the stab
leading edge. Leaving 1/4" of LE stock extending beyond
the inboard edge of S1 and keeping the LE centered
vertically on the LE web, glue the LE to the front of the wing
with medium CA.
❏ ❏ 2. Trim the LE flush with S1 and S10. Sand the LE to
blend with the stab, forming a smooth airfoil shape.
❏ ❏ 3. Sand the trailing edge web flush with the sheeting
top and bottom.
❏ ❏ 4. Use HobbyLite
™ balsa colored filler to fill in the gaps
in the trailing edge web at the ribs as well as any other
minor blemishes in your stab or elevator. Allow the filler to
dry completely before sanding it to shape.
❏ ❏ 5. Using leftover 3/32" balsa, cap the outboard ends of
both elevator halves and stab halves. Trim and sand the
caps smooth.
❏ ❏ 6. Using giant scale hinges (not included — we used
Robart Giant Scale Pin Hinges on the prototypes), hinge
the elevator to the stab.
❏ 7. If this is the first time through, go back to the start of
BUILD THE STAB/ELEVATORS and build the other stab
half. If it’s your second time through, get a good night’s
sleep! You’ve got a great start! At this rate, your Extra will be
framed up in no time.
Build the Fin and Rudder Sheeting
❏ 1. While your work surface is clear, now is the perfect time
to build your fin and rudder sheeting. Select six 3/32" x 3" x
36" balsa fin and rudder sheets. Cut all 6 sheets into two
pieces, one 19" long and one 15-1/2" long, and set aside the
leftover. Edge glue two sets of three 19" sheets. Cut these
two 19" long sheets into two rudder sheets which are 19" long
and 9" wide at one end and 4-1/2" wide at the other.
❏ 2. Edge glue the six 15-1/2" long sheets together. From
one end, cut one 15-1/2" long stab sheet which is 9-3/8"
long at one end and 3-3/4" long at the other. From the other
square edge, cut the second stab sheet.
Build the Fin & Rudder
If you are going to double bevel your elevators, glue an
additional 1/2" x 1-1/4" x 16" balsa stick (not included) to
the trailing edge of the stab. Bevel this new trailing edge
as you did the elevator leading edge.
Finish the Stab Panels
If you are going to double bevel your elevators, glue an
additional 1/2" x 1-3/8" balsa counterbalance leading
edge to your counterbalance (not included).
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