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After the turntable, we assembled the initial assembly designed to constrain the topping container and oscillate it on the upper rail system as the crank slider mechanism moved. This rail system, shown in the video below, did not work as intended. Ideally, the follower would have been able to create an upward force on the rail system and raise the food dispenser as it slid on the crank slider shafts. We assembled the parts and tested the rails and saw that the follower created a large rotational moment on the linear bearings which caused them to seize whenever the follower shafts pushed up into the rail system.
Multimedia name hand_driven.mov
This forced us to reconsider our design for the follower rail system and find another method to raise the food dispenser. We could not add another follower on the track to remove the moment without making the design considerably more complex. Our solution was to drastically reduce this moment by moving the food dispenser closer to the follower and reduce the mass the follower pushed by simplifying the way the food dispenser was held. This simplification reduced part count overall and allowed the follower to function well without making the linear bearings seize due to a large moment pulling them off-axis.
We inserted pictures of the final CAD for this device below. The three output motions are highlighted in different colors: the turntable is green, the crank-slider is orange, and the follower is blue. Structural parts are transparent or gray. There is also a video showing the assembled final device not in motion. Videos of the device in motion are in the Final Prototype section.
