27 November 2017
For the “Archimedes Challenge” we had to build an ancient machine, the machine me and my group constructed over a course of 4 days is called a trebuchet. The trebuchet was invented in China in 300 BC. It is unknown who exactly invented the trebuchet but the machine was used by the Mohists as early as the 4th century BC, Mohism was an influential philosophical, social, and religious movement in ancient China. The trebuchet was invented for the purpose of war but more specifically sieging. Sieging is when military forces surround a town or city with the purpose of cutting off supplies, forcing a surrender. The trebuchet was not invented simultaneously in different places but eventually made its way to the west due to the Avars. The Pannonian Avars were a group of Eurasian nomads of unknown origin during the early Middle Ages. The short term effect was that whoever had access to the trebuchet had a great advantage when sieging because nobody would have prepared for such a weapon yet. Long term effect is that cities were forced strategized against the trebuchet like maybe building walls differently which could lead to some new discoveries in engineering.
The trebuchet we made in class is a little different than a traditional ancient trebuchet. Instead of a rotating axis for the throwing are to slide on, we used a hinge instead to attach the arm to the beam and still give it a very large throwing radius. We have elastic bands attached to one side of the throwing arm, on the opposite side of the payload basket. When the side of the payload basket is pulled down, more and more potential energy builds up the farther you pull it down. When you let go, all that potential energy turns into kinetic energy and the throwing arm throws whatever object with great force.
We spend the class discussing as a group what we would like to build, we settle on a catapult and plan to fully design our catapult the next day.
We have a bit of a debate wether or not we should make a catapult because we notice a lot of other groups have the same idea as us. We make our idea more unique by making a trebuchet, which is sort of a catapult but really isn’t and our idea will be totally original. We make a very rough sketch of what our trebuchet will look like.
We secure 4 pieces of wood into a frame very strongly together using a hot glue gun, it is crucial we get this part perfectly or our trebuchet will not be strong enough to handle the recoil of the force it is putting out.
We use nails to make the rest of the body, we then attach the beam using a hot glue gun, we attach the throwing arm to the beam using a hinge and nails. we test the trebuchet out and the beam fails or straight up flies off so we decide to use nails to secure the beam instead, we test out the trebuchet several times and it is fully functional. The building process is now complete.