Dynaflite GPMA0570 Bird of Time - Manual (Page 8)

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“A” ribs between the top and bottom spar cutouts and
glue this to the end of the innermost shear web. Make
sure the webs are aligned with the spars in the two
bays with plywood shear webs.
❏ ❏
15. Fit the four plywood shear webs to the
inboard panel. Sand the inner “AA” rib to fit as
needed. Do not glue at this time. Cut and fit two
balsa shear webs from leftover 1/16" sheeting for
the tube areas not covered by the ply shear webs.
These will act as dams to prevent epoxy from
running out of the wing tube cavity in the next step.
NOTE: In the next step you will use epoxy to glue
several parts in the inner wing tube area. Use
30-minute epoxy
for this as 6-minute epoxy cures to
rapidly. You will need several clamps; spring type
clothespins work well.
1/16" PLY SHEAR WEBS
3/8" BALSA SHEAR WEBS
1/4" METAL
ROD
90°
❏ ❏
16. Mix approximately 1/2 ounce of
30-minute epoxy in a mixing cup. Using a liberal
quantity of epoxy, install the filler blocks and tube
from step 12. Next, glue the four 1/16" plywood
shear webs and two 1/16" leftover balsa shear webs
to the lower spar, 3/8" balsa shear webs and tube
assembly with epoxy. Finally, epoxy the top
hardwood spar to the polyhedral brace, “A” ribs,
3/8" balsa shear webs, tube assembly and inner
“AA” rib. Clamp the parts together and check the
alignment of the parts before the epoxy sets up. Insert
the 1/4" metal rod into the tube and check that it is at
a 90° angle with the side of the inner “AA” rib.
While the epoxy cures, it’s a good time for a cup of
coffee. The rest of the wing goes quickly after all the
glue has cured.
❏ ❏
17. Cut the remaining four “AA” ribs and one
“A” rib to fit and install with CA. Pin the rear of the
ribs securely to the building board. Do not install the
“A” rib at the polyhedral joint yet.
❏ ❏
18. Install the outboard ribs “B” through “K”
and glue to the spars and leading edge sheeting
with CA as before. Pin the rear of the ribs securely to
the building board.
❏ ❏
19. Cut the short trailing edge piece at the
polyhedral joint from the piece of 1/4" x 1-1/8"
balsa. Glue all three trailing edge pieces to the ribs
with CA. Do not glue the inner and outer panels to
each other.
❏ ❏
20. Trim the outboard lower sheeting and the
outboard spar to fit the die-cut wing tip. Laminate
three wing tip pieces together with thick CA. When
dry, glue the wing tip and tip gusset in place with CA.
Note there is no rib at the tip. The tip block will be
carved and sanded to the section shown on the plan.
❏ ❏
21. Using leftover 1/16" balsa sheet, trim
four shear webs and install them in the outboard
panel as shown. If you plan to land on the wing tips
very often you may want to add shear webs all the
way to the tips; but remember, on a 10' airplane, the
lighter the tips the better the response.
❏ ❏
22. Using thin CA, apply a liberal fillet
around each rib on the lower sheeting.
❏ ❏
23. Remove the outer panel from the
worktable and sand the trailing edge joint to the
proper angle. Insure the polyhedral brace fits
properly at rib “B” and between the spars. Block the
wing tip to the height shown on the plan. Using
6-minute epoxy, glue the polyhedral brace to the
outer spar. Do not glue the top spar in position yet.
Glue the trailing edges together with epoxy.