I saw a different hex box design that had rectangular slots and ridges and I thought it would be better if the boxes could be joined in a way that kape them together (and thus neater.) So I made this design which turned out to be more difficult than I had imagined. (What a surprise!) The difficulty came in determining the proper amount of clearance to leave for the top and the joints.
I finally hit on values that seem to work well - the tops and boxes fit together pretty easily,so you can use them individually or in a group of as many as you like. Because I use parametric design software (http://birkbinnard.com/blog/parametric-modeling/) doing this was easier than it would have been with other software.
Using a print speed of 80 mm/sec and a layer height of 0.200 mm the box prints in 5 1/4 hours and the top in just over 1 hour.