Straw and string models
Straw and string icosahedra
Plastic straws represent cheap and convenient modelling materials for the
dome builder.
One way of attaching them firmly together is by running
threads down their centres - and tying them together.
The following icosahedron illustrates the technique.
Straw and string - small icosahedron
The resulting models are tensegrities - they make
use of tension-only components which are essential for the
integrity of the resulting structures.
The method effectively avoids much of the complexity of using a hub.
Scaling up
This construction method has some significant attractions on
small scales.
This raises the question of whether a similar approach be
used to construct larger models.
For larger models some sort of hub would probably be required.
A hub could consist of a ring (or, for multi-layer models, a hemisphere)
with holes drilled in it.
Something like a cork with a hole drilled down the middle
could act to prevent any motion of the struts from side to
side at the point where they meet the hub.
Pros and cons
A disadvantage of the structure are that it uses separate
components to handle compression and tensile forces - instead
of re-using the same structure to perform both roles - which
would save a little weight.
The main advantage is that hub construction can be simplified -
and the issue of how to attach the struts to the hubs in a
way that can handle tensile forces is neatly resolved.
Links
Straw polyhedra and other nets
Straws and pipe cleaners
Bendable drinking straws
A straw story
Tim Tyler |
Contact |
http://hexdome.com/
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