15.3 --Design Process
Our initial research was focused on viewing different mechanisms and machines that followed our two most critical movements: machine maneuverability and butter handling. For the maneuverability of the design, we felt our car design maintained suitable capabilities for motion, and the programming we had as a part of the car could still be used for the final design. Thus, we decided to maintain the principles from that car to be translated to our final design.
The second part of maneuverability for our design focused heavily on the behavior of the arms that would move the butter. Our initial idea was to use a similar design (crank mechanism) as the first demonstration, where we were tasked with lifting a weight. This would have been modified to a set of arms that would slide back and forth with a plate attached. However, this idea was scrapped because it would force the robot to a single degree of freedom in terms of translation, thereby minimizing its effectiveness in moving the butter beyond a set height.
After further iteration, we landed on a design (Fig 3) that used a four-bar mechanism connected to a plate that could move the butter in two translational planes (up/down and forward/back). Although this was a step up from our old design, it would still leave one translational plane unbound and still fixed. Fortunately, we found a way to implement a grabbing mechanism to replace the plate model and allow for greater functionality of the car.
The new grip mechanism followed the idea behind arm extension grabbers while changing the actual gripping mechanism to use micro servos to actuate arm movement instead of a pull-grasp mechanism. Using online sources, we were able to find videos that best supported the intended motion of our grip mechanism and how we planned for it to work.