Arooj+-+Trebuchet


 * TREBUCHET **



= Trebuchet History =


 * A trebuchet is a machine used during medieval times to propel heavy objects vast distances. They were primarily used to bring down castle walls during a siege. The trebuchet is powered by gravity and centripetal forces from two axes.**
 * From about the middle of the thirteenth century, the trebuchet in great measure superseded the catapult. This preference for the trebuchet was due to the fact that it was able to cast stones of 300 lbs. and more in weight or five or six times as heavy as those which the largest catapults couldn't project.**


 * The word 'Trebuchet' is derived from the Old French word 'Trebucher' meaning to throw over. In England siege weapons, including the Trebuchet, was also known as the Ingenium from the Latin word ingenium meaning ingenious device! The Trebuchet is also referred to as the Trebucket.**


 * A trebuchet consists of a long beam attached to a pivot rod on a heavy frame. The beam is fitted into a guide chute to make sure the beam moves in a straight line. There is a counterweight on one end of the beam and a sling attached to the other. A heavy object, usually a rock, is placed in the sling which is then closed and secured to a release pin on the beam. Once the trebuchet is pointed toward the target, it is ready to fire. This, however depends on the type of trebuchet you make, and how you make it.**

=**Floating Arm Trebuchet**=

It is not fixed to the frame, but is supposed to be mounted on wheels that roll on a track parallel to the ground**
 * There are different types of trebuchets. One of them is the floating arm trebuchet. I chose this one to build because it was different from the common trebuchet.The floating arm trebuchet, if built right, throws longer distances. It is a modern variant of a Trebuchet. The difference in the floating arm trebuchet is mainly the axle.
 * The wheels help the trebuchet by carrying it further in a direct path. This increases the energy transferred to the projectile, making it more apt.**

**Purpose:** To provide the Physics 30 student with hands-on application of the principles of physics
=**Building a Floating Arm Trebuchet**=


 * Materials:**


 * Woodmedia type="youtube" key="uljPtcuYF04" height="344" width="425" align="right"
 * Nails/Screws
 * Nuts/Washers
 * Metal rods
 * Hammer/Pliers
 * Tape
 * Counter weights
 * Strainer (or whatever you want to use for the sling part)
 * Plastic wheels
 * Christmas ornament/small plastic ball
 * Drill Machine
 * A Saw ( or get it cut at Home Depot, :] )

  **Applied Physics:**


 * 1) Gravity - As we all know, applies to every object. Gravity was what brought the ornament down to the ground after it was launched.
 * 2) Newton's Laws - F=ma was the law that mostly applied to this project. The force of an object depends on the mass and the acceleration. The bigger the mass of the trebuchet, the bigger force is needed to propel it.
 * 3) Centripetal Force - Whenever there is a curved motion, a force directed toward the center of curvature is required. The trajectory of the christmas ornament is in a curved motion, therefore, a centripetal force that directs it toward the center is present.
 * 4) Projectile Motion - Projectile motion occurs if the only force acting on an object is gravity. In the case of the ornament, gravity is the major force that acts upon it.
 * 5) Kinematics - This is the extra power or energy an object requires. It is there due to the objects motion. Nothing just starts moving on its own, a force is required to get that object moving from its state of inertia.


 * Procedure:**

1. Take two 55cm long pieces of wood, and align them parallel to the base, leaving about 10-15cm in between and nail them in. 2. Then on either sides of those pieces (4), nail a 35 cm wooden beam straight up. 3. From the top of those beams, place 30cm pieces parallel to the ground. Leave about 2 inches between the two sides. 4. In that gap of about 2 inches, put four long 1m beams, in 90 degree angle to the base plank.Two on each side. Leave enough room, so that the metal rod can slide down between the two pieces, on either side. 5. Nail two small wooden pieces on the top of the four 1m sticks, to seal of the top. 6. Drill a hole into another 1m beam (the arm). Slide that onto a metal rod, and place the rod through the opening between the four 1m beams. 7. Add wheels to the arm, a little above half way, using a smaller metal rod. 8.By now, you are done most of the trebuchet ! :), the next step is to add counter-weight to the arm. You can fill a metal container with rocks or get actual weights. 9. Tape a piece of wood across on the 30cm piece, so that it bridges over, and stops the arm from leaning back too far. 10.The last step is to add a stainer or sling at the top of the arm. And to make sure everything is secure.


 * Testing & Fixing:**

The trebuchet was not launching even after the weights were on. For the trebuchet to work effectively, there needs to be a balance of weight on either side. If there isn't a balance, the rod tilts to one side and does not launch right.

Another problem was when the ball I was using kept falling over to the opposite side. This happened because, as the weight slid down, the arm went too far back, and dropped the ball. Putting a support on the back stopped the rod from falling back too far.

The last addition to the trebuchet were the wheels. The wheels helped the arm by giving it more reason to slide forward, and they also directed it.




 * Trial || Mass || Arm Length || Dist. || P=d/ml ||
 * 1 || 7.1 || .91 || 3.16 || .5 ||
 * 2 || 7.1 || .91 || 3.8 || .6 ||
 * 3 || 7.1 || .91 || 5.39 || .8 ||
 * 4 || 7.1 || .91 || 3.54 || .5 ||
 * 5 || 7.1 || .91 || 3.6 || .6 ||
 * 6 || 7.1 || .91 || 3.12 || .5 ||
 * 7 || 7.1 || .91 || 3.09 || .5 ||
 * 8 || 7.1 || .91 || 3,1 || .5 ||

=__**Conclusion:**__=

The result of my trebuchet was not as good as I predicted. Some of the mistakes I made were; not using light wood, making a big trebuchet instead of a small one, and not trying out a few trebuchets before the final one. I thought that a big trebuchet would throw the object further, but that was not the case. Because the mass of the trebuchet was much larger than the distance it threw, the results were on the bad side. I also learned that making a floating arm trebuchet is not easy work. It's very difficult to make an accurate floating arm trebuchet. So, if you are making a trebuchet of your own, make sure you start working on it quickly so that you can make test trebuchets before the final one ( something i did not do :[ ) & remember that a good trebuchet is small, light and effective.