I am attempting to create a trebuchet that is able to launch a 1ft boulder (approximately) 100 yds using a trebuchet mechanism. My current idea is basically to use three 80 lbs bags of cement as the counterwieght and use a sling system at the end of the arm as the launching component. On to the reason of my post: Do any of you have suggestions that might make this attempt easier? Mind you, this isn't a homwork project. It is slightly related to a tiny trebuchet we are making, but this is, first and foremost, a personal project. Thank you for any and all help provided.