Mechanism Design

Our main goals were to achieve the following operations in said order:

• Crush a water bottle with high torque
• Quickly push the water bottle out of the machine
• Quickly return crushing link
• Return pushing link
• Repeat

Another limitation was to implement only 1 DC Moter to achieve all of these motions as a way to introduce complexity to our design.

With these goals in mind, we had to choose a mechanism that could employ not one but two quick return operations while maximizing torque on the crushing motion. We took our greatest inspiration from a Whitworth Quick return mechanism. Below is an example of said mechanism.

https://www.youtube.com/watch?v=UuTNtg7-Bwg&ab_channel=mekanizmalar

We liked this particular mechanism because it had the most torque 180 degrees away from the quick return. This fitted our needs as we could slowly crush the bottle at crank angle = 180 degrees with high torque and then quickly return the crushing arm as the crank angle approaches 0 degrees. The opposite could be said for the pushing operations. Moreover, we noticed that this mechanism was stackable in that we could employ a second Whitworth mechanism on top of the first to achieve two motions. The timing in between the two mechanisms could then be adjusted by the relative angle difference between the two ground pins. Below is an image of our stacked Whitworth configuration. The first image is our mechanism at the crushing angle while the second image depicts the mechanism at the pushing angle