Interdisciplinary Education Group Materials Research Science and Engineering Center on Nanostructured Interfaces University of Wisconsin - Madison

Assembling the units movie

Assembling tetrahedral units.
Put a 1/2" blue pompom (or other color if desired) in a triangular pyramid. Snap a triangular base onto the triangular pyramid to form tetrahedral pieces. Note the alignment pins on the parts. It is generally easier to align one edge and then use that edge as a hinge to fold the parts together.

Assembling octahedral units.
Put a 1" yellow pompom (or other color if desired) in a square pyramid. Snap two square pyramids together to form octahedral pieces. Note the alignment pins on the parts. It is generally easier to align one edge and then use that edge as a hinge to fold the parts together. Be sure to reserve 24 square pyramids for assembling square pyramidal units.

Assembling square pyramidal units.
Put a 1" pompom in a square pyramid. Snap the square base onto the square pyramid to form square pyramidal pieces. Note the alignment pins on the parts. It is generally easier to align one edge and then use that edge as a hinge to fold the parts together.

Assembling square planar units.
Put a 1/2" pompom in a square base. Snap a square base onto the square base to form square planar pieces. Note the alignment pins on the parts. It is generally easier to align one edge and then use that edge as a hinge to fold the parts together.

Assembled units

Choosing connectors
Which connector to use is not a critical issue and the choice is not specified in the directions. In general the 2-prong connector works well with the tetrahedra and the 4-prong connector works well with the octahedra. In some structures six vertices meet and a 6-prong connector would be ideal. In this case you will need to use the 4-prong connector and leave some vertices adjacent but unconnected. Again the choice of which vertices to connect is not critical but can be guided by the need to hold layers together.

To disassemble a unit
While not a routine step, disassembly can be done a few times without damage to the pieces. Insert a pointed cylinder such as a pencil or pen into the opening next to a joint (not the apex of the square or triangular pyramid piece) and pry off the base. Reassemble as before, perhaps with a different color pompom inside.

Unit disassembly