My fourth 4x4x4 cube puzzle design is 4cm wide, with four pieces and a unique solution that includes rotation (hence the punny name).

This is a brand new concept for me. Cost-conscious, as ever, I have tried to create a puzzle cube consisting of hollow cubelets. To make the shapes more interesting I have designed my basic Curly Corner Cube in TopMod and then constructed the puzzle pieces from alternating left- and right-handed unit cubes in Blender.
This means it is possible to create a much larger puzzle without it being too expensive.

Another innovation of the design is the flexibility of the cube pieces (when printed in White Strong & Flexible material). The springiness of the Curly Corner Cube shape means that the puzzle pieces should always fit snugly together without being too loose or too tight.