This is a modified vertex.scad that adds nut channels on the sides of the vertex. These should let one insert nuts into the outsides of the OpenBeam without disassembling the printer.

Print the STL for an upper vertex, and install it like the normal one. Alternately, put my vertex.scad in place of the "official" one, then re-render whichever vertex you want.

Attribution - Creative Commons

Kossel