3*3*3 4-Piece Interlocking Cube_Stewart Coffin

Difficulty Levels ★★★☆☆
                                                   

Designed by Stewart Coffin.

There is no way that a four-piece version can be very difficult, although the one shown in Fig. 51 does have the intriguing property of being serially interlocking, meaning that it can be assembled in one order only.

-The Puzzling World, Fig.51

For this model,

• Need support but can be easily removed