This is a duplicate of a 3D puzzle in the shape of a cube that I got from my grandfather many years ago. There are 7 pieces that should be assembled to form a 3×3×3 block.
[Awaiting content since 7 Jan 2008.]
It has at least 5 solutions, but it can be annoyingly hard to find even 1.
The design was done in Blender. [Awaiting content since 7 Jan 2008.]
See the Machining Blender models using Modela Player 4 tutorial.
puzzle.blend Blender model