The early 3D printers of the 80s and 90s started off as cartesian bots, and this is what the RepRap project took a cue from for the earliest open source 3D printer designs. A bit later, the delta bot ...
About a decade ago, the only way the average hacker was getting their hands on a desktop 3D printer was by building it themselves from a kit. Even then, to keep costs down, many of these kits were ...