ITERATIVE DESIGN PROCESS
We performed iterative design starting with the Gear Model which was manufactured with metal and catalog components. The Gear model was robust and provided enormous torque to hold the bottle tightly during motion, but it is relatively heavy in weight.
We then redesigned our mechanism to simulate a pulley system with strings. Using the String-Pulley system, we no longer need any metal catalog components which reduced the weight to 1/2 of its original value. However, the torque applied to the bottle is therefore reduced that leads to a greater possibility of failing the motion test.
While keep performing testing, we made modifications iteratively to reduce the weight as much as we can. Our final prototype weighed only 116 grams.