Kaden (who has an excellent Machina Arcana biz) sent along this how-to on making springs. “If you’re trying to make a spring to replace a broken one, you don’t need to know a whole lot about design. On the other hand, if you’re making a prototype of a machine, for instance, and you don’t know exactly what you want, then this page is for you. Here you’ll learn some basic data about spring design, which is what you’ll need to know to make exactly the spring you want.” Link.