Locking joint for 3D printed objects

I needed to find a way to connect two halves of a puzzle together as strongly and cleanly as possible so I invented this symmetrical joint. The first version was knocked up quickly in Tinkercad (https://tinkercad.com/things/d24xPMwBq9T?) and then the final version was made using OpenSCAD so that the joint can be reused and resized for other applications. When printed at the correct resolution the hole will be a very tight fit for the peg. I used a small G-clamp with soft rubber jaws to press the two halves together. The layers ratchet past each other and lock very tightly. I also added a drop of acetone to the inside face of each half to really lock the parts permanently together. Printed at 0.25 mm layer height in ABS on a Mendel90 RepRap 3D printer. Download the file at http://www.thingiverse.com/thing:27695