Dynaflite GPMA0090 Butterfly - Manual (Page 13)

13
Note: Leave the leading edge at least 1/16" high
in front of ribs W-1, 2 and 3 to accommodate the
top sheeting. You will fi nal sand the LE after you
join the inner panels to the outer panels and glue
the top sheeting in position.
TIP: How To Use A Razor Plane
We highly recommend a razor plane to shape
the LEs because it is the safest, fastest and
most accurate method to remove large quantities
of balsa.
A. Adjust your razor plane so it removes about
1/64" or less balsa at a time.
B. Position the LE of the wing panel at the edge
of your work bench so it is supported and the
bench does not interfere with the razor plane.
C. Hold the razor plane at an angle to the grain
direction as shown in the photo.
D. Work slowly and inspect your work frequently.
Before you know it you will shave the LE down
quite far.
❏
21. Arrange the plan so the left inner wing panel
is over your building board, then cover it with wax
paper. Return to step 3 and build the left inner wing
panel the same way as the right.
Don’t forget to
switch to the left wing panel plan so you do
not build two right panels.
Build the Outer Wing Panels
Start with the right outer wing panel so your
progress matches the photos in the manual.
3/4"
Area to Trim Off
❏ ❏
1. Trim the end of a 3/8" x 1-1/4" x 30" tapered
balsa outer trailing edge so it matches the angle at
W-4 shown on the plan. Mark the tip end of the TE
3/4" away from the aft edge. Use a straightedge and
a ballpoint pen to mark a line on the TE connecting
the mark you made at the tip with the forward edge
of the other end (the root) of the TE.
❏ ❏
2. Use the line you marked (or a straightedge)
as a guide to trim the TE with a sharp #11 hobby
knife as shown on the wing plan.
❏ ❏
3. Cover the outer panel of the right wing plan
with wax paper, then use the “crossed T-pin” method
to pin the 1/8" x 3/8" x 30" basswood bottom
outer
main spar in position so the root end aligns with
the plan at W-4.
❏ ❏
4. Position the odd numbered ribs and
W-4 on the bottom spar, then pin them to your
building board.
❏ ❏
5. Pin the outer TE and the 3/8" x 3/4" x 30"
balsa outer LE to the building board so they tightly
contact the ribs and the ends align where indicated
on the plan at W-4.