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By George Hart for the Museum of Mathematics

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The rise of personal rapid prototyping machines, such as the Makerbot, RepRap, or Fab@Home, allows one to make a variety of geometric models. Polyhedral models, such as this 5 cm ABS dodecahedron, are fairly straightforward.

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Next is an 8cm model of a hyperboloid of one sheet, showing how it is made of straight lines. (A version made from bamboo skewers was shown in this Math Monday column a year ago.)

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And here is a tricky assembly puzzle made of twelve identical notched rods. They were dyed four different colors to help clarify the structure.

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If you have access to a 3D printer, you can build your own copies of these models from the STL files available here.

More:
See all of George Hart’s Math Monday columns

Gareth Branwyn

Gareth Branwyn

Gareth Branwyn is a freelancer writer and the former Editorial Director of Maker Media. He is the author or editor of over a dozen books on technology, DIY, and geek culture. He is currently a contributor for Boing Boing and WINK Books. And he has a new best-of writing collection and “lazy man’s memoir,” called Borg Like Me.


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