Idea of the Onager

I am creating this Siege Weapon for a project in my Physics class. I decided to choose to build an Onager based on the axle and throwing arm-based movement. I followed through with this project with a process of prototypes, research, and trial and error in testing. My idea with the Onager was to create a torsion or solid axle that a throwing arm is on around the base rectangle.

My Materials were all provided including things like:

Dowels

Foamboard

Hot Glue

Rubberbands

Popsicle sticks

Wire

String

Tape

Miscellaneous items

Etc.

Making this Simple Machine Onager was quite fun. I started by creating a rough prototype of my Onager to understand and see what works and doesn't work for my design. I ran into some difficulties with creating a tension force but substituted this idea with a spring force that the elastic band applies.

Supplies:

My supplies for this build were just hot glue, popsicle sticks, a spoon, dowel, and rubber bands.

With my first iteration and design, I realized the problems and errors with the device and proceeded to make a second revision. I began with a sketch of what I presumed my Onager to look like. Creating a sketch of a base and then other measurements(?) that varied on preference when I got to the moment in the building process.

Here is the look of the final build of my Onager and how it shoots. Overall I just used the rough designs of my first prototype and created an inflated version with the necessary revisions.

Materials:

I used Foam board, dowel pieces, rubberbands, and hot glue.