4) Final Prototype and Demonstration

Final Prototype and Demonstration

Below is a photo of our assembled final prototype:

The electronics utilized in the final prototype are quite simple. The 12V 100RPM motor is controlled by a L 298N Motor Controller which is connected to an Arduino Uno, both of which is powered by a 12V AC to DC power supply/rectifier. The Arduino itself is coded to make the motor output at constant max power, and both the Arduino and the motor controller are protected by an acrylic cover. Below is a video of our final prototype in action, attempting to flip a quarter in the pan.

As shown in the video, while we are able to achieve the ideal position profile for our pan, the motor is unable to output a constant velocity due to a large torque load caused by the weight of the pan and linkage on the upswing of the pan. This means that the pan is unable to achieve the ideal linear velocity, and moves much slower than we analyzed. Because of this, the quarter is able to still get a bit of airtime, but is unable to flip. This issue would be more evident with a real egg, as it would be larger with more weight.

In an effort to achieve our ideal linear velocity of the pan, we had the idea to preload our system to help the upswing of the pan. We attempted this by holding a rubber band on the front link. Below is a video of that preloaded linkage. 

With the rubberband preload, we are able to get enough linear velocity on the pan and quarter to get a flipping motion. For future work, we could improve on our system by implementing a preloading system using rubberbands or springs, a more robust motor, an energy storingf flywheel, or even using another fourbar linkage to support the weight of the linkage.

Ultimately, our focus on the kinematics of our linkage allowed us to achieve the ideal position profile, but our neglect of the system’s dynamics prevented us from reaching the ideal velocity profile. In our analysis, we needed to take into account the weight of our system and torque on the motor such that in our design process we could purchase the correct motor or adjust our linkage to decrease motor load.