This is a single printable object that launches Nerf Mega Darts. Printed by PLA it possesses more than enough strength to work as a spring. Not sure what will happen if you print it using other material. It was designed for the Nerf contest of the 3D printing group on Facebook. Since there are very strong contestants in the "serious" categories, i decided i stood a better chance in the "minimalistic design" category. That's why i set out to create a launcher that would print easily as 1 single object, requiring no assembly, and no difficult to print parts, like in-object-hinges. Launch method: place on a flat surface. Add a Nerf Mega Dart on top. Hold down the bottom using one hand, pull the top back with the other. Release to launch the dart. Chase after cat hunting dart. Retrieve dart using scratched arms. Repeat.