Pipe edges tetrahedron phone stand

I wanted to 3Dprint phone stand based on simplest 3D polyhedron, the tetrahedron. It turned out to be too difficult for me doing “pipe edges” with Freecad, so I used OpenSCAD, and was surprised how easy this model was if you get it right (22 lines). In order to avoid model being moved away, “something” was needed below smartphone. I chose to tetrahedrons scaled down by ⅓.