KNEX Stressed Icosahedron

This is a Platonic solid made from standard K'NEX parts. The parts all fit together generally. No hinges or rotating parts were used.

It is named Stressed as the bars must be slightly bent to fit. Remember: wear Safety Glasses when bending plastic. The bends are slight, but you only got two eyes. If this is a concern, just use long bendy rods.

The hubs are based upon a K'NEX star. This build has the same parts list as the K'NEX Normal Dodecahedron. This build has bigger hubs.

To understand this build it might be useful to look at the “KNEX Stressed Tetrahedron”. It is an extremely simple model to show how the technique operates.

The color of parts will affect the appearance of this build. The builder is encouraged to find different color parts for artistic effect.

30 rods 190-mm or larger.
120 16-mm rods.
60 2-connectors angled.
60 3-connectors angled
(270 total)

Twelve hubs are made from the parts. Each has 5 2-con , 5 3-con and 10 16-mm rods. It is important to have the same chirality in all the hubs. That is they all go clockwise or anti-clockwise. This is important to keep the model from becoming lopsided.

With three hubs and three long rods, make a flat triangle.
All the 2-con point up as the inside bottom is up.
Attach six more long rods to the open 3-con slots.

Add hubs where two or more

rods gather. The 2-con should point inward. The rods will have to be slightly bent to fit. Wear safety glasses when bending plastic, even slightly.

Continue adding rods where possible and hubs where possible. When the rods seem to not want to stay, check chirality and connections.

As the model grows, it takes a stable shape. Sometimes a hub collapses on itself and has to be shaped back into a circle. The bending is shared within the entire model, so the last rods do not need much “convincing” to go into their proper place.