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.


Straw polyhedra and other nets

Straws and pipe cleaners

Bendable drinking straws

A straw story

Tim Tyler | Contact |