Reflect on your prototype. What were some strengths? What needs refinement

A strength is that the catapult can shoot really far away, and when the arm is moving, the sticks won’t fall apart. However, the base of the catapult is too light, so when people shoot and move the swing arm, the base structure will move forward and wobble. I plan to add more weight by using more popsicle sticks at the front and back of the catapult.

Feedbacks from classmates and teachers:

Sharon- Add more weight on both front and back side, so when you shoot the balls the base structure will be stable.

Jason- Not stable when you play with it, the catapult will fall forward.

Ms. Karen- Add something that can pull the catapult back rather than using hands to press the catapult’s arm (ex. add a string or a rubber band at the back of the swing arm).

Josiah- Very well built, seems sturdy and stable, maybe add some colors.

Catapult before changes:

  • The base was kind of light because I did not use a lot of sticks.
  • The back of the catapult is lighter than the front, so when it shoot it will fall forward.

Catapult after changes and improvements:

  • I added more layers of popsicle sticks at the back of the catapult and the middle of the structure, as you can see in the second and third image.
  • I also added a rubber band around the catapult’s arm, so when people press the catapult down, they don’t have to press the arm, they can just pull the rubber band.
  • I also added a hook at the back of the catapult, to add more weight to the body frame, and to make the rubber band stay. Because without the hook, the long rubber band at the back is easy to fall or loosen.