Let's call this what it is. It's a reaction to a certain corporation getting too big for it's britches. They told us we shouldn't make 3D prints of their blocks and, you know what, they're right. 3D printing isn't suited for making interconnecting blocks that require super tight tolerances and high degrees of precision. Home 3D printers just aren't made for that. We need our own interlocking brick. One that will work even if your steps per mm for every axis aren't perfectly calibrated or if you don't have the most even filament ever. We need, a Generic Interlocking Brick.
And if it so happens to be compatible with off-the-shelf interlocking bricks, well, who's to say anything about that.
3D Printed GIB blocks have a number of features that distinguish them from store purchased interlocking blocks. Those features are outlined in the standards document you'll find attached. If you want to make your own interlocking blocks that will have the same advantages and that interlock with these blocks, please see that document.
However, GIB blocks also have some shortcomings that are probably going to prevent me from pursuing this any further. For one, the layered nature of 3D prints puts the stress points right along the layer lines, causing frequent breaks. Secondly, I discovered with a decent printer it's actually fairly easy to calibrate it so that you can print native interlocking brick models without needing the advantages of the GIB.
However, I have started a new project. PrintABloks are designed for 3D printing and take advantages of the medium. They can be built in 3 dimensions. And they're easy to accessorize. You can find out more at http://PrintABlok.com