It seems like all I write about in this blog, when I bother writing, is about Camp Quest. It’s not like that’s all I do but it is the highlight of my summer. At the time of this writing I’m about two weeks from taking the trip to the higher elevations of Arizona and the Piney woods of Prescott National Forest. While I’m there, the phone connection will be spotty. I’ll have to climb up to a ridge to get enough “bars” on my ATT phone to download podcasts and call my wife. That’s not a complaint; that’s a feature! I suppose the 3-minute cold water shower is a feature too.
My part in the program this year is to teach the young campers the joy of being a maker and fixing things. We will be doing a lot of upcycling which I also enjoy.
Earlier, I wrote about “The Runner” robot that some of the campers will be able to construct in the post about building a new set of shelves https://azatheist.com/2019/03/12/a-new-set-of-shelves/).
Happily, the camp director selected as one of the programs that all the campers will participate in involves catapults. Little did she know that that was one of my earliest interests. When I was as young as most of the campers, I used to build catapults out of Popsicle sticks that were designed to chuck marbles at card house castles. My parents liked to play Pinochle and I had a lot of used cards for the castles.
The missiles we’ll be firing won’t be marbles. We’ll be using small foam “Nerf” balls that look like tiny golf balls. It’s going to be great to show the campers how to construct these simple devices using common materials such as Popsicle sticks, tongue depressors, fishing sinkers, rubber bands, and plywood circles. We’ll also be using hot glue so the building should go quickly.
Each camper will build two catapults. One will be a Trebuchet and the other will be a Mangonel. When someone pictures a “catapult” they more than likely picture the Mangonel. They used twisted rope to store the energy which is delivered to the missile causing it to fly. The Trebuchet is a bit more elegant. It uses a falling a weight to store and impart the energy to the missile.
The two models to the left normally decorate my home office. Both are capable of hurling metal balls about 30 yards, but you’ll notice that the Mangonel on the left in the picture is sturdier in construction. It uses twisted nylon rope to store the energy. There is very beefy stop in the front of the throwing arm to stop its forward motion and loose the payload. There is a lot of potential energy left in the system once the missile flies. On the other hand, all the potential energy in the Trebuchet is expended and transferred to the missile. Therefore, the device can be built a bit lighter.
These siege engines were constructed of wood primarily. They were in fact used in the middle ages and before but there are none that survive to this day. However, there are a few surviving key metal parts. After deployment and use, it is likely the wood had more immediate uses such as fuel and building materials. Most of the models in existence were constructed from drawings.
The campers are going to have a fun time building these and I’ll bet they come up with some inventive ways to used them at camp and after.
Eleven days and counting!