Boltex: Bolt maze meets cryptex, kind of...

Update: v2 fixes some taller printing problems with more support and a better "ledge" to prevent the high torques that will topple the bolt. Also, improved the base and handle to make it easier to grab... and fixed a tolerance problem that made the bolt and outer shell waaaaay too tight on most printers.

Update: just found this http://www.thingiverse.com/thing:1481
which is a more original version of this thing... very cool and I wish had found it sooner!
Don't hate the bolt maze- embrace the bolt
maze!
An outer tube (with parameterized accents) protects an inner chamber which can be revealed by solving the underlying bolt maze.
Many folks don't know what a "bolt maze" is... it's not just a pattern of a maze on a bolt! To remove the bolt's nut you must rotate and translate the nut (which has a pin, not a thread) through the maze. It's surprisingly hard to do!
This contraption is a bolt maze proper with a nut attached to an outer tube which protects the hollow inards of the bolt. At 75% full build space of a Rep1 the chamber easily stores a cache of M&Ms or other small candies- great fun for kids, although, the default maze (see .scad) is a bit difficult for the 6 and under crowd. (i.e., they're more likely to simply crack the thing apart)