Jim Propp>Why does the Goscube fly apart the way it does? Is there some potential energy that got stored in the Goscube in the assembly process (did the prongs have to bend a bit)? No. I think you could summarize it as high stiction with low friction. Whereas the cube faces are smooth thanks to the glass build-plate, the slanted "3D dovetail" surfaces are finely stepped with physical jaggies, so they stridulate rather loudly as they slide apart. But the ABS is hard and slippery enough that friction doesn't much damp the separation velocity, giving the impression of a mild explosion. The hollow shape of the plates probably contributes to the noise, which is surprising even when you open it by merely spinning on a corner. And why is it called the "GITD" Goscube? Jim Propp It glows in the dark. http://gosper.org/kryptocube.jpg (Photo by Peter Bickford.) --rwg [...] I exported the object inhttp://www.youtube.com/watch?v=pvT5ySMnO8U as a (hugely "illegal") .STL, which took tedious wizardry on NeilB's part to actually print. --rwg