Instructables user Bctcteacher writes:

My students love to build things and throw stuff so let’s put both together! Now, for the green part. Let’s see if we can make something that is recyclable and fun! Looking around the classroom, I see lots of cardboard (used shipping boxes) and a good supply of Elmer’s glue. So, with a little help from Autodesk’s CAD program Inventor, I whipped up a nice little Catapult (Hence “CAD-A-Pult“).