We have finished our prototype mangonel, after many setbacks we are finally ready to begin our final design. When we built our mangonel we decided to put a sling instead of the usual firing mechanism, to get that extra little bit of power at the end. Things we will change in our main design is the pullback mechanism, we intend to use a more efficient way of pulling the firing arm to the back of the structure for more power. To do this we will experiment with different techniques and design ideas.