The A-cube is derived from Yoshimoto's cube no. 3, recast in origami from the A-format.
Use 12 pcs A6 for the modules, preferably stiff paper which makes crisp folds, e.g. 160 gsm copy paper. Using 4 colours provides for interesting patterns. For hinges, 12 pcs A7, in thinner and softer paper, e.g. standard 80 gsm copy paper.
The model was designed summer 2015.
1. Start with A7. Mark middle of short edges.
9. Diagonals in top layer only.
10. Like this. Turn over.
11. Mark the corners in so the lines meet in an orthogonal triangle.
13. Use a hinge as a template for the angle. Repeat in the other side.
15. Mark the crease as valley.
16. Fold according to this crease pattern.
19. Finished, seen from two sides.
Assembling the modules
20. Use an unfoldet module...
21. ...and a couple of hinges.
22. Put the hinges around the module.
23. Close the module again.
24. Thus. Ready to assemble with other modules (without hinges).
25. Use either this assembly pattern or the next (the ends must also end up together.
26. The other solution that can be both a cube and inverted for a rhombic dodecahedron.