That’s the idea behind [HomoFaciens]’ latest build: a direct-extrusion 3D-printer. And like all of ... itself just a simple aluminum block with holes drilled into it. That worked, albeit ...

[Teaching Tech] sprung about $80 or a kit to add dual extrusion to his 3D printer, plus another $20 ... The auto level sensor requires a metal bed, although you could fix that pretty easily.