I had a number of ideas for structural frames I wanted to build, so I bought some OpenBeams (http://www.openbeamusa.com/), and quickly became tired of screwing things together just to decide to take them apart again, so I created these to make it easier and faster to put beams together and take apart again, in trying out different arrangements. These are not intended as full structural support, and they may even break or snap off, I have not tested how much weight they can handle. The measurements for the OpenBeam are here: https://www.flickr.com/photos/openbeam/7524275616/ For these models I intentionally made them narrower than spec and they actually fit snug and some plastic is even peeled off as they slide in the first time. I used OpenJSCAD (http://openjscad.org/) to create it. Once I had measurements it was pretty easy.