Adam Turaj built a functional FDM 3D printer from LEGO, and 92% of it is exactly that. The project, called StudPrint, is fully open source on GitHub and uses LEGO leadscrews to drive all axes of motion, not just the frame or the bed.
Print quality and build volume are not the point here, and Turaj does not pretend otherwise. The bed is unheated ABS brick, which limits filament compatibility significantly. He printed a Benchy. That is the benchmark. The non-LEGO remainder consists of a small set of custom CAD parts for mounting steppers and electronics, all included in the repo.
What makes this worth reading in full is the motion system detail. Using LEGO leadscrews as a functional drive mechanism is the engineering constraint that separates this from a novelty frame build. The 2013 predecessor used hot glue instead of a real extruder. This one does not. The gap between those two versions is the actual story.
[READ ORIGINAL →]