Projectile Launcher

Our trebuchet version 2 was a slightly bigger model of our version 1. This version will be using 5% of the energy we will use in the final product. To construct this treb, we used all two by two boards and screws, while building the sling out of duct tape and string. This version worked relatively well, producing an initial X velocity of roughly 2.975 m/s.

Version 3:

Our third and final version of the trebuchet used all 100 joules of energy we were allowed. Constructed of 2-by-4's, the trebuchet stood about four feet tall. I welded a metal arm as to provide extra support to withstand the weight we would be using. The arm had loops at the end to adjust the position of the weight. This allowed us to change how far the weight would drop, changing the amount of joules used. We built a trigger that held the arm in place while loaded and allowed us to efficiently fire the trebuchet.

Results:

The Version 3 resulted in a relative success. The trebuchet launched a softball 72 feet, the second best in the class. Although we did very well in comparison to the other launchers in our class, our version 3 only operated with about 42.5% efficiency. Using 100 joules and a softball with a mass of 185 grams, a 100% efficient system would launch at 32.87 meters per second. Our trebuchet had an initial velocity of 13.98 m/s.

Conclusion:

In conclusion, I believe our trebuchet was an overall success. We designed and built a trebuchet that fired successfully and with an alright efficiency. If we were to do the project again, I would make my tebuchet even smaller and use a larger weight. Given more time, I would have shortened the strings used on the sling.

Thanks for a great 3 years Varvil. Have a great summer!