Building Separable
Wingtips BY JOE BESHAR
An accurate, hassle-free method of segmenting aircraft components
Install the wingtip back on the wing center-section.
Make sure the ribs line up. Clamp the framework
together to ensure that the alignment holds. It is
unnecessary to “stick” the wings together with the
foam tape; it’s just a spacer. 3
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ONE OF MY recent projects has been building a turbine-powered
model of a full-scale aircraft that was designed by the Germans and
scheduled to be flown in 1946. Construction of the first Messerschmitt
P.1112 was halted during World War II by the invasion of US troops in
April 1945.
I became interested in the P.1112 when I learned that shortly after
the war, its designer, Waldemar Voight, found employment with
Chance Vought in the US. It is no coincidence that the Navy F7U-1
Cutlass features the P.1112’s wing design.
The Messerschmitt’s planform includes a root wing section that
spans a considerable part of the fuselage and includes a large part of the
airplane’s structure. Designing the model’s wing to be removable was
the challenge in making it transportable; the effort had to preserve the
outline but not compromise the structure.
The wing sections are built and sheeted during assembly, as is
normal practice. But my method provides enough space at the parting
line to cut the tip sections apart. This system works so well that they
meet accurately and don’t add a great deal of time to the overall build.
This article is a photo essay, and step-by-step pictures will walk you
through the procedure. I’ve learned that this method can also be used to
find elevator/rudder parting lines and could be adapted to make other
parts of a model removable.
I hope you find the technique as rewarding and helpful as I have. MA
Joe Beshar
[email protected]
Skeleton construction of the model wing. Two identical
ribs are built in the location where the parting line is
desired—typically around the wing-tube spar, which has
already been assembled, as shown. 1
The wing section is separated and several 1/16-inch-thick
pieces of pressure-sensitive foam tape have been applied
along the rib section. 2
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Sheet the bottom half of the wing. The sheeting is
edge-glued on the bench beforehand to create large
sections and then is applied starting with the center
and running spanwise. Weights and clamps are applied
to hold the sheet balsa in place while the glue cures.
The wing is fully supported to avoid warps.
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44 MODEL AVIATION
Add the TE sheeting using slow-curing adhesive or wood
glue. Applying the balsa sheeting is continued toward
completion of the bottom side of the wing. Have many
clamps handy to assure a tight, warp-free bond. 5
Sharpen a 4-inch length of .045-inch-diameter piano
wire to be used as a drill with a Dremel-type motor
tool. Clean the wire to remove any oil, and polish it
with steel wool. 6
Insert the motor tool between the two parting ribs
from the open side of the wing. With the tool at low
speed, pierce the wing sheeting every inch or so. 7
The pierced holes define the wing-section parting line.
The same process was used to outline the aileron.
Don’t worry about poking through the foam tape; the
spinning wire will go right through. 8
Photos courtesy the author
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Carefully and accurately connect the holes defining the
parting line of the wing separation. The quantity of
holes is important; they help define the unique joint. 9
The parting line is cut through the balsa sheeting
with a razor saw. Applying a coat of softened soap
at the sides of the saw helps ease the friction and
makes cutting go more smoothly. 10
After the top side of the wing is sheeted, use the
motor tool to perforate the sheeting and mark the
cut line of the wing. 11
After cutting through down the marked line with a
razor saw, the wing is ready to be separated. The
thin razor saw should cut down the middle of the
1/16-inch gap between the ribs. 12
A small amount of sheeting should overhang each
part. Block-sand each section flush, leaving a crisp
edge. The parts will fit back together and show
only a thin visible line. Finish-sand all the sheeting
and final-shape the surrounding edges.
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