The bow fires using elastic energy. Since the bamboo bow is flexible, but still desires to return to its original shape once bent, pulling the bowstring back results in elastic potential enrgy building up in the crossbow. Once the string is released, most of the elastic potential energy is transformed into kinetic energy that flings the string forward, which, in the process, also flings the arrow.
The area that we were very successful in was the create and improve strand. My partner and I were constantly worried about stress breaking the wood apart, but with proper techniques, thankfully nothing broke. We also found the trigger mechanism that was originally designed would not work, as creating space for the trigger would break the wood. Instead, we designed a lever system than would simply push the string up when pushed down.
One area that we could have improved on is the design and planning strand. We had specific measurements for all of the design, but the plan was far too ambitious at times, which led to us having to improvise a different way to do the same thing while in the process of making the bow.
One thing I am proud of his how my partner and I were able to improvise solutions to problems that presented themselves during the process of making the crossbow. As mentioned above, when we discovered that our planned trigger mechanism would be impossible to implement, we were able to quickly devise a solution that would still let the crossbow function as intended. Additionally, when making the string for the bow, we learned it would be far too strong and dangerous for the intended audience, which was children. So, we made multiple strings, all of different strengths, and chose the one that would maximize force without being too dangerous. We also kept the spare strings, in case we wanted to change the strength of the bow.