Can you stack these gyroid modules into a pyramid? It can be a little tricky to get them to all line up properly, but you'll know you have it because the larger gyroid you create is highly symmetric, as evidenced by the gridwork of holes that run through it in many different directions.

Each module is a rhombic dodecahedron intersected with the gyroid, and hence this puzzle involves forming a face-centered cubic packing. Due to the way the module is oriented, it prints beautifully without support (better than the cubic original).

You can make this puzzle as large as you like; the more you print, the more you can stack.

The size shown here requires six base pieces and ten gyroid modules. The gyroid modules are small enough that you can print a pair using JoeyC's script with the Replicator (http://www.thingiverse.com/thing:24195). The Multiply function in Skeinforge is also handy for printing plates of these pieces.

If you want to print a larger puzzle, you can run the OpenSCAD script and input a number of edge modules into the totalAssembly module, which will not only render a view for you, but also output the required number of base and gyroid modules. gyroidThin1 and gyroidThick1 are what the OpenSCAD function uses; they were created in Matlab, see ancestor.