Desktop Catapult

The STEMFIE Desktop Catapult is perfect for shooting ping-pong balls or crumpled paper. The ball-holding beam moves using the energy stored by two rotor springs. To arm this catapult, you rotate the beam until it locks into place held by the trigger. You can shoot ping-pong balls into cups or hit and flip the STEMFIE shooting target, which this project includes.

Assembly Tools

You will need the STEMFIE spanner and the STEMFIE driver to assemble this project.

Download the complete set of files here 

Click for a larger image.