Rounding off this very short list of sites that offer at least some free 3D printable models is MyMiniFactory, which has a strong emphasis on gaming and geek culture. It has close ties with iMakr, an online store that sells 3D printers and accessories. The site offers 3D printer files with a guarantee that they’ve been quality tested. They also offer online design challenges to 3D professionals. I found the printable kinetic 3D whale with DC motor appealing as it actually moves.
|Image Source: JWoong via MyMiniFactory|