This is a model of a medieval swinging counterweight trebuchet that I built for my Freshman high school History class. Construction took about two weeks. The materials used include two by fours, plywood for the counterweight box, a 1/2″ threaded rod for the axle, and two 30 pound concrete core samples for the counterweight. The trebuchet is triggered by two eyehooks on the base and one eyehook on the arm of the trebuchet. The pin goes through the three eyehooks and is pulled out by a long string for safety. The angle of the release hook at the end of the arm that lets the pouch release the ammo is adjustable.

Dimensions are as follows:

Height: 42 inches

Width: 54 inches

Arm Length: 55 inches

Ammo: Baseballs and softballs

Range: 75 yards to 150 yards