Standoff threaded fasteners make the expandable backbone of the STRUIX system. Metal standoffs serve both a structural and electrical function. Plastic standoffs provide physical framework and serve to isolate localized bus structures from the rest of the stack.
M3 x 12mm standoffs are chosen because they are both strong and give clearance & proper spacing between boards that stack atop the STRUIX CPU. Shorter or longer fasteners can be used depending on the components installed on a given layer.
The stack can be secured to a base plate by using F/F standoffs as the first layer of structure, then use screws through the bottom of the base plate.