I have written before about Thingiverse user fdavies’ ongoing project to produce a 3D-printer that requires no precision-ground shafting or bearings using printable hinged actuators based on the Sarrus linkage (Wikipedia). Why would you want to do that? Well, because precision shafting and bearings are currently beyond the abilities of most 3D printers, and if you can build the printer itself using printable substitutes for them, then you’re that much closer to a truly self-replicating home fab system. His latest effort has produced a working two-axis system that he hopes to outfit with an extruder in the near future. Keep it up, man!
2-axis printable shaftless linear actuator