One of the most common varieties of a spring is the compression or a torsion spring, which is the type of spring that you would find in a standard clothes pin, or on a clipboard. A tension spring is used to stretch or extend as weight is applied to it, like a trampoline or a garage door opener. And of course everyone knows what a coil spring is as they make things like ballpoint pens function. Since 3D printers are not really capable of producing a functional spring, what exactly does a 3D printer have to do with a spring? Rapid prototyping of course. The spring manufacturing industry relies on precision to make springs that function exactly as needed in the limited space that they tend to be installed inside of. You can read more about how 3D printing helps manufacture springs over on