Building:
The first step in conducting an experiment on a trebuchet is to build the trebuchet. Appendix A is a set of schematics detailing the construction of the trebuchet. Page A1 shows the assembly of the beam and counterweight bucket, page A2 shows the assembly of the body of the trebuchet, page A3 show a detail of the base, and page A4 shows the release mechanism. These drawings are not to scale, but are meant as a guide to the general structure of the trebuchet. Specific instructions are as follows.
First, build the base of the trebuchet, made completely of 2-by-4s. This consists of building a rectangle 2 feet 6 inches wide by 5 feet 9 inches long. Make a 5¼-inch wide notch in the center of each of the long sides, halfway into the beam. Then take three 5 foot 6 inch boards and notch them so that they will fit into the previously made notches such that they extend 1 foot 6 inches past the rectangle on each side. Lastly, fit diagonal pieces into the base such that they meet at the center. Next, construct the uprights so that the pivot bar of the trebuchet is at a height of seven feet. Brace these uprights with braces extending from just below the pivot bar to the ends of the 1 foot 6 inch sections of the base.
Now build the arm of the trebuchet out of 2-by-2s. The total length of the arm is 16 feet, with a pivot hole 4 feet from one of the ends. Brace the arm on the sides of the arm not containing the pivot hole with boards extending 1 foot 3 inches away from the hole on the 4-foot side to six inches away from the end of the 12-foot side. At the end of the 4-foot side, attach two 2-by-2s on the same sides as the previous braces, then attach two 2-by-6s on the sides containing the pivot hole, creating a 6-inch by 6-inch box at the end of the beam. Make a hole for the hinge of the counterweight in the same direction as the pivot hole inside the box.
Next build the counterweight box. This is made of two equilateral triangles, 3 feet to a side, held apart by 1-foot 6-inch pieces of 2-by-4. Cover the box in hardboard and seal with caulk. Lastly, build the fining mechanism. This consists of a sling made out of rope woven like a hammock, two U-bolts, and a large bolt with the threads removed for a firing pin. The U-bolts secure one end of the sling and the firing pin to the end of the arm. To complete the trebuchet, assemble all of the pieces using the two metal rods as the pivot and hinge points.