bjones
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Building a full-size catapult is a major undertaking requiring a lot of materials and space. If you are in a city, the building code inspectors will not be too pleased either. Luckily, there are several available designs for miniature catapults that can be made from household items or even office supplies. I like the office supply catapult, myself. It requires only 11 pencils, several rubber bands, a zip tie, a tack, and a water bottle cap. Start off making a square by tying 4 pencils together with rubber bands. This is the base. From the base, you need two supports going straight up on one side. The supports on the other side of the base will angle toward the vertical supports about a ½ inch from the top, creating two right triangles on either side. The supports are also attached by rubber bands. A crossbeam must now be attached where the angled supports meet the vertical supports. About two inches down, another crossbeam must be attached between the angled supports. On this crossbeam, a rubber band must be looped around the ends, running the length of the beam. The final pencil is placed, eraser-side-up, through the rubber band and attached to the center of the front base beam. This is the arm. Use the tack to attach the water bottle cap to the end of the arm, and tighten the zip tie around the metal part of the pencil supporting the eraser. The catapult is complete.
To operate the catapult, support the base with one hand. Place a small object in the cap, and pull the zip-tie down to lower the arm. Release the zip-tie to fire.
 Posted 5159 day ago
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