PROJECT SUMMARY
The project was one assigned to me during Engineering Design class. It was more of a unit on launchers, which a rubber band-based launcher and then a catapult. Both designs were successful, with much space to improve.
WHY?
I created this project in part because I had to, but I also held genuine interest for the design I was completing. While the project was not generally framed around a question, the objective was to create a launcher that could throw the ball the farthest.
HOW?
Both the launcher and catapult started with rough sketches of different ideas and a bit of research on the internet. Especially for the catapult, I looked up the basics of how a catapult works. A proof of concept was made for the final idea, and a completely new design would be made using the experience from building the prototype/proof of concept.
WHAT?
Many times, I found out that the design decisions I had made in order to reduce friction were simply not enough. This resulted in a complete revamp in the launcher and a major last-ditch saving effort for my second catapult. The catapult works by attaching many rubber bands to the upper side of the arm, creating large amounts of tension whenever the arm is pulled down. Releasing the arm throws the locked ball out at a 45º angle above the ground. The launcher worked by attaching two rubber bands to two metal towers spaced apart and attaching both bands to opposite sides of a cup. You would then simply pull on the cup and release it with a ball inside for the ball to go flying.
SO WHAT?
The catapult was a success, capable of throwing a small plastic ball about 10 metres, which is impressive for such a small catapult and such high air resistance on the ball. From my results, I learned that I need to put more consideration into pivot points in designs as their load was too high and the catapult was too weak to be considered long-lasting. The launcher was even more effective, probably because of the lower friction, although it sacrificed precision.
WHAT'S NEXT?
The catapult specifically could be improved through a more consistent preparation and release mechanism. Pulling down the arm manually and releasing it manually brings a human component to the launch that severely hurts precision and consistency. I've always had many ideas on how to fix this problem, and predicted it would be an issue before I started building, but ran out of time before I could implement a solution.
REFERENCES & ACKNOWLEDGMENTS
Youtube had some great videos on the physics of catapults. G. G. helped a lot with the structure of the catapult as well as testing.
JUDGES FEEDBACK
You have created a brilliant looking launching device. I love the fact that you continued to adapt your model through trial and error, testing what worked and what did not. This may have been a project you had to do but it is evident you enjoyed it and definitely learnt many things from this task. Well done.