Printing springs

I want to build a totally 3D printed engine and use it to power some little things. So while I'm waiting for my red filament to come in so I can finishe the chess sets my current experiment is this:

The hope is to make something that will store enough energy and return it, but not too harsh. So far my best one is a wave that is as tall as the period printed without fill layers, zero infill, 4 extra layers. Now I have to build test frame for it.