Trebuchet scale model for feasibility testing

I plan on building a trebuchet for a summer camp I volunteer at next summer. The idea is to teach kids about physics - lever arms, energy transfer, centripetal force, etc. To test the feasibility of my design, I first created a scale model based on the dimensions of wood I would use. I created this model using the Part Design (CATIA) app in Dassault Systemes 3DExperience 2015x.

One of the major design parameters is that the machine must be able to be fully disassembled for storage between uses. I needed to get an idea of what parts would be needed and how tightly they could be packed. For this I printed the constituent parts of the trebuchet using the Auburn Hills FabLab's Makerbot Replicator.

As you can see when stacking the parts side by side they are relatively compact. Transporting these shouldn't prove too difficult an obstacle.

To test the feasibility I printed a complete set. I added a couple of small triangular pieces to aid in the printing process so I wouldn't need supports. I cut a paper clip to use for the axles and used a socket, thread, and a small piece of cloth to finish it off.

My first test of launching a small lego piece was a success! Time scale it up!