OurTrebuchet

The contest rules our class received for the pumkin throwing contest specified certain limitations for the dimensions for the trebuchet's desgin:

Height: 6 ft Length: 8 ft Width: 4 ft Arm Length: 8 ft from axle to finger, 10 ft total For our trebuchet, we used 2.5 ft for the counterweight end, and 7.5 ft for the axle to finger

The trebuchet was supposed to be made out of wood as much as possible, however the axles could be made of metal, and load bearing areas could be reinforced with metal. For our trebuchet, we used a 2 inch solid aluminum pipe for our main axle, 1 inch steel pipes for the wheel axles and the counterweight axle, and 1 1/4 inch pipe for bearings. We used screws and bolts to put the frame and arm together, but used metal reinforcements only in areas where the trebuchet broke. Here is one such example: During class, we tested the trebuchet using a 9 pound bowling ball, which surprisingly gave us more distance than the lighter 8 pound, 7 pound and 6 pound pumpkins we threw on the day of the contest.

In class, we threw about 300 ft, whereas at the competition, we threw 274 ft.

For our counterweight, we used twelve 80 pound weights carried in a 75 pound carriage, for a total of about 1035 pounds. This appeared to be much more than the weight used by the other schools at the contest. We expressed our hick roots by using tractor weights instead of lifting weights, which the other schools used.

Our wheels were made out of wood, and were 2.5 inches wide and 12 inches in diameter. For our design, we used both wheels and a swinging counterweight in an attempt to maximize straight line drop distance, and therefore velocity and force, without going to the floating arm design, which needs to be much more precise and isn't as sturdy.

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