This penny catapult derived from that in the 2013 Seej Starter Set (http://www.thingiverse.com/thing:116450) has all components in a single stl file for printing convenience (including some added pieces of ammo which kids can safely play with in the vicinity of your tv set). The catapult itself and the length of the atlas component can be scaled, the latter resulting in a different launching inclination and trajectory height. The provided stl files: The provided zip file contains all Zheng3's original stl files and an openscad file which includes these and allows you to set the scaling factors yourself.