This variant of the Hexagonal Column does away with the FlatRoll concept and goes for interlocking tabs instead. No need for a flexible substrate, six of these segments should lock together to form a box.

The 45 degree overhang rule is met, and the individual parts are much bigger (no need to share the printing volume with the other five) with finer details, so this should print out fine.

EDIT: Added an anaglyph picture, bring out your red/blue glasses!

You will need six to make a box.

All the locking tabs at a single join work perpendicularly to the join, so you should be able to assemble two box halves, then clip the halves together.

EDIT: I STRONGLY recommend using the later version of this, this version is not a manifold mesh and Skeinforge won't process it correctly. You can get the corrected version here:
http://www.thingiverse.com/thing:500