Four of my favorite sites for 3D printing models that you can easily print (although some may be more difficult than others): Thingiverse, MyMiniFactory, Cults 3D, and Sketchfab.

The 3D-printed lower receiver of an AR-15, which until recently could be found on the 3D-printing website Thingiverse. You have the right to bear arms. But you don't necessarily have the right to ...