For the dispensing system, the team decided to have two sections: one that would hold dry goods such as granola bars and another that held standard 1-L water bottles. For the dry goods, I modeled a rotating set of four columns (gray in the pictures below), mounted it on a lazy Susan bearing, and mated it to a shaft that was driven by a servo motor. When a certain item was selected for vending, the dolly would then spin to the correct orientation. Then, I modeled a standard four bar mechanism with a set of prongs pointed vertically. When driven by a motor, the prongs would insert through slots below the dolly and push the lowest dry good in the stack out the front of the machine. The water bottles were slightly simpler. They were laid on their side on a series of ramps with a raised lip at the bottom to hold them in place. To vend them, I modeled a crank-slider mechanism that pushed the lowest bottle up from the bottom and high enough to clear the raised lip. The weight of the bottles down the line then pushed the water bottle out and settled into place when the mechanism retracted.

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