Video: They have been used by large companies for rapidly creating prototypes for at least a few decades, but finding a reason to put a 3D printer in every home hasn't been as successful. Making accessories for your vacuum? Boring. Building soft drink bottle bridges? Meh. Super-sizing LEGO? Hello holy grail of 3D printing.
Matt Denton used a Lulzbot Taz5 3D printer to create a giant version -- all 98 pieces -- of LEGO set #1972, a Technic go-kart originally released in the mid-'80s. Given the size limitations of his 3D printer (you can watch a making-of video here) Denton's over-sized go-kart is only about five times as large as LEGO's original. So while it's still too small for a kid to ride, the steering still works, it can be fully disassembled, and it even has 3D-printed rubber tires.
It's finally time to buy a 3D printer.