Introduction A catapult is a device that was used to throw an object to a remarkable distance during war. It was used for killing enemy from a great distance. This paper will be describing the building of a model catapult and its mechanical properties.
General description
There were a variety of catapult of different sizes, but the catapult model, as seen in Figure 1, is about 8 inches long, 6 inches wide and 7 to 8 inches tall. The main parts of the Catapult are the arm, tension bundle and the frame that support the entire structure. The entire device is made of wood except the tension bundle which is made of white strings.
Figure 1: Catapult
Supporting frame
Supporting frame consists of a rectangular base of four beams as shown in Figure 2. Two parallel beams are separated by two other parallel beams. The four beams are supporting each other to make the base. Another rectangular shape structure, made of four beams is placed vertically on the base. Two small dowels joined the top beam with the vertical beams. These three beams are working together as stopper for the arm. …show more content…
All the joints are made with dowels. Figure 3: Inclined beam to support arm stopper
Tension Bundle
A tension bundle of strings is placed in the base as seen in Figure 4. It has a good elastic property to provide the torsion force. The bundle is twisted to its limit over a set distance. The ends of the strings are tied to dowels on the outsides of the base. There are torsion stops made of dowels used to keep the bundle from untwisting as shown in Figure 5.
Figure 4: Tension
General description
There were a variety of catapult of different sizes, but the catapult model, as seen in Figure 1, is about 8 inches long, 6 inches wide and 7 to 8 inches tall. The main parts of the Catapult are the arm, tension bundle and the frame that support the entire structure. The entire device is made of wood except the tension bundle which is made of white strings.
Figure 1: Catapult
Supporting frame
Supporting frame consists of a rectangular base of four beams as shown in Figure 2. Two parallel beams are separated by two other parallel beams. The four beams are supporting each other to make the base. Another rectangular shape structure, made of four beams is placed vertically on the base. Two small dowels joined the top beam with the vertical beams. These three beams are working together as stopper for the arm. …show more content…
All the joints are made with dowels. Figure 3: Inclined beam to support arm stopper
Tension Bundle
A tension bundle of strings is placed in the base as seen in Figure 4. It has a good elastic property to provide the torsion force. The bundle is twisted to its limit over a set distance. The ends of the strings are tied to dowels on the outsides of the base. There are torsion stops made of dowels used to keep the bundle from untwisting as shown in Figure 5.
Figure 4: Tension