Here's something to show that there's more to print than just hobby stuff. It's a replacement for the bike lamp mount on hubbie's folding bike. The curved black part incl. the big screw is printed. My husband got the base from Thingiverse and modified it a bit to fit his specific model of bike.

It broke quite fast, though, since the curved part was too thin. That part had raised some suspicions with us before, but perhaps the author's lamp weights less and so it worked for him. By now hubbie modified the model to be thicker and printed it again. Now it works.