Mechanical Hopper

For my first prototype, I focused on designing the timer mechanism, which used a rolling dowel to travel down a long zig-zag path and trigger the hopper. I carefully chose angles for the path, avoiding steep inclines to ensure that the dowel would take at least 8 seconds to reach the bottom. During testing, the dowel’s descent was inconsistent, so I was advised to use a thicker rod and fine-tune the angles to achieve a smoother roll.

After establishing a reliable timing mechanism, I moved on to designing the trigger and hopping mechanism, which involved using the dowel to knock something at the bottom to activate a torsion spring attached to a wooden panel. In my second prototype, I successfully incorporated the hopping mechanism with the torsion spring, but I faced difficulty connecting the timer trigger to the hopping mechanism.

The torsion spring, along with an MDF sheet and wooden rod, formed a system where the hopper would jump when a piece, bent by the spring, was released. However, I widened the zig-zag path to accommodate a thicker dowel, which caused it to travel too quickly—less than 8 seconds—something I planned to address in my final design.

Compared to my previous prototypes, I made significant improvements to the aesthetics of my design, making it resemble a frog more closely. Instead of using an elastic band, as I had originally planned, I opted for a fence wire that I shaped into a hook. Using three wooden dowels, I created a fulcrum, beam, and latch system for the hook. The hook would latch onto the wooden latch, with the beam positioned directly underneath it.