Autodesk's Tinkercad platform now has a fun tool for making 3D models using programmable code blocks. Here is a simple example of how a STEMFIE beam can be made. Give it a try; change the BlockUnits variable, and press the play button. Export as STL format, 3D-print it and enjoy playing with your new construction set toy. :-)

STEMFIE.org Tinkercad BeamMaker Codeblock