This is the newest member of the aMESS family of Arduino enclosures. Technically, it's not modular, or stackable, but I'm concentrating on boxes for RAMPS at the moment because I really need to tidy up my RepRap. My first print turned out fair. The bottom began to curl up around the corners, and the top 6mm became separated. For the second attempt, the one pictured, I used the Skirt option in Skeinforge. It helped a lot, and the print turned out much better, although there was still curling on the corners.
I'm going to put up a flat printable version with interlocking edges similar to thing:7340