This catapult is great for throwing cat treats many meters for the amusement of humans and exercise of felines. 

It requires a round toothpick and a rubber band to complete.

Place the rubber band around the tower. If the rubber band is a longer one, you can double or quadruple it up as it should be under some tension. 

Insert the fulcrum end of the throwing arm between the band and the bar. Pull the back part of the rubber band down and hook it over the bottom of the throwing arm. 

Secure it in place by threading the toothpick into the hole on the frame and through the hole on the arm. 

Then clip off the excess toothpick. press the wheels into place, and start flinging things.

Use at your own risk.

Print with support over build plate only. The horizontal piece on the tower needs support but the holes in the frame do not need support.