Make 6: Catapult!

     So here's the thing: I wasn't sure about this week's make, for a couple of reasons. First, it's a kit, and I struggled with the idea of using a kit to make something, or make something from scratch. Second, it technically wasn't even my kit, as I had bought it for my son for Christmas. I decided to go through with this make because it is practice for making something similar (and bigger) later in the year (expect a summertime catapult or trebuchet) and my son has shown zero interest in the kit himself. Besides, I really wanted to make this! What is it? A tabletop catapult, of course!

     I have long been fascinated by all manner of large-scale pre-gunpowder weapons. The Greeks, Romans, and Chinese all had some version of a tension/torsion weapon, and all were deadly. Shows such as Mythbusters and Deadliest Warrior have recreated some of these weapons, and the sublimely absurd Punkin' Chunkin' takes the process and physics of such weapons to ridiculous new heights. Still, all of these devices are designed to do basically the same thing: launch a stone, bolt, flaming ball of pitch, or, well, pumpkin, as far as possible, with as accurate a shot a possible. Sounds simple right? It's not. In fact, the physics and logistics of such devices are surprisingly complicated.

     Now my little tabletop catapult is not a weapon by any means, and its accuracy and power are limited. Still, the principles of operations that it uses are the same as the large devices, and let's face it: launching a ball of tinfoil across the room is fun! So let's get started, shall we?

     The kit I used for this Make was purchased at Barnes & Noble, and included a great book by William Gurstelle. A quick Googling of Mr. Gurstelle reveals that he has written quite a few books on backyard siege engines, and the book that actually came with the kit was both informative and entertaining. The book, along with the pieces of the kit, are pictured here:

The actual build was  pretty simple, and only took a few minutes. First, the frame was assembled:

Then, the strings, which create the torsion, were threaded through the base of the frame:

Finally, the arm of the catapult was inserted into the torsion strings, and the strings were turned to create the torsion necessary to launch the ballistics material, er, tinfoil ball:

That's it! With this lovely tabletop device, I was able to launch a ball of foil across the dining room and living room. If only I could take this to work...

     So that's it this week. Nothing fancy, but I had fun! Tune in next time to see what I make!