How to make a Soma Cube from Sonobe Cubes

The Soma Cube is a famous puzzle made from seven Tetris-like pieces that fit together to make a 3x3x3 cube. The pieces are made up from smaller cubes, and I show you how to fold a Soma Cube from Sonobe Cubes.

In the Soma Cube version from James Grime, which inspired me to build my own cube, each piece is built as one block:
youtube.com/watch?v=UNiFELOL42w

Some time ago, I noticed that Sonobe cubes can be interlocked if they are mirror reversed, and I show you how!

There are already many tutorials for making Sonobe units and combining them into a Sonobe cube, e.g. this one:
youtube.com/watch?v=uF72h-7xe0g


For a Soma Cube made from 27 Sonobe Cubes, you need 162 (27 x 6) square sheets of paper:
* 24 sheets of the same color for each of the six 4-cube pieces
* 18 sheets of the same color for the one 3-cube piece

A cube from Sonobe units of one orientation can be connected to a cube from units of the mirror reverse orientation.

For the A, B, L and Z Soma Cube pieces, you need to fold 12+12 units of each mirror orientation. For the T and P pieces, you need 18 + 6 units. For the V piece, you need 12 + 6 units.

This video shows how to fold the B piece.

Please excuse the annoying autofocus. I was using my smartphone to record this, and have not yet found an option to disable autofocus when recording.