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Assembling the structure
The assembly stage should
take less than an hour provided that the students work together.
During the construction, when faces are joined along an edge,
the twist ties should be threaded through adjacent holes and twisted so
that the twisted ends are on the inside (labeled side) of the triangular
faces. The resulting hinge should be very tight. A common problem is that
the students leave too much slack in the twist ties, which results in
a non-rigid final structure.
With the colored sides face down, lay out the triangles so that
they form
the "net" as depicted in Figure 7. Each student should
stand by the face (or faces) that he or she decorated. Using twist
ties, the students should connect faces that are currently adjacent to
each other. This will require 4 twist ties for most of the vertices,
but only 2 and 1 twist ties for the vertices along the extreme
"West" and "East" sides. At this point Stage 1 of the
assembly is complete.
During Stage 2, the students will begin to fold the net upward. The
structure will not be rigid until the very end, so those students who
are not attaching faces should help to support the structure. The
order in which the faces are connected is important, so during the
second stage you may wish to remind the students not to connect faces
out of sequence.
The faces should be connected as described in Table 2.
| Step
|
Connect Faces
|
1
2
3
4
5
6
7
8
9
10
|
1S to 2S
4S to 5S
2S to 3S
3S to 4S
1S to 5S
1N to 2N
3N to 4N
1W to 5E
2N to 3N
Last Piece: 5N
|
Table 2: Order of assembling the icosahedron faces.
About halfway through construction, you might want to ask the
question, "how can we attach the very last face?" One way is to
thread the twist ties so that you can twist them from the outside of
the icosahedra.
If the side length of your icosahedron is large, you may need to
periodically rotate the structure during construction so that students
can crawl inside the structure to attach faces.
Up: Table of Contents
Previous: Coloring the faces
Next: Exercise: How big is your icoshedron?
| 
