Great Planes Sportster Bipe 40 Kit - GPMA0510 - Manual (Page 10)

3. D GLUE THE DOUBLERS TO THE FUSELAGE SIDES
Using Bulkhead #1 as a spacer, install the 1/8" balsa
doublers crossgrain on the inside of the fuselage sides. Cut the
doubler pieces from 1/8 x 3 x 36 balsa first, position and then
glue in place. Use slow set epoxy or thick cyanoacrylate. The
doubler should extend 1/4"beyond the position of bulkhead #3.
Trim the doublers to the fuselage contour.
Note: Be careful when you cut the doubler stock as you need
to use what is left in the next step.
4. D BUILD THE THREE REAR FORMERS
Make Formers #4,5 and 6 from 1/8 x 1/4 x 36 balsa.
Use the plans as a guide and cut the balsa to size. Glue the
parts together to make the three formers. Make push rod braces
from scrap 1/8 x 3 x 36 left over from the doubler stock in the
step you just did. The widths of the braces are the same as
that of each of the formers. The braces will be installed when
the pushrods are installed later. STOP! Did you read the 4-cycle
engine instructions if you plan to install a 4-cycle?
D MARK BULKHEAD POSITIONS
Mark the positions of bulkheads #2 and #3 on the
fuselage sides. Also mark the position of the balsa dash between
#2 and #3. Mark the positions of the cabane blocks now if you
wish.
6. D DRILL PUSHROD EXIT HOLES
Mark and drill the holes in the fuselage sides for the
pushrod exits for the elevator and rudder. See the plans for
suggested positions of the pushrods to estimate the hole posi-
tions. A piece of brass tubing sharpened on the inside with an
X-Acto knife blade makes a neat, clean angled hole for tube-
style pushrods.
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