After looking around on Thingiverse for a spring, I found there were no plain and simple compression springs. So, I modeled one myself. This spring does everything you'd expect it to do: compress, extend, and even bounce! At some point I hope to print this with dissolvable support so that there will be less dipping. I'd recommend printing in PLA actually, as I'm concerned that ABS would be too flexible and soft to have the same physical properties as the springs I've printed.
spring.stl | 1.2MB |