Inspired by our own experiences of struggling to get drinks at a crowded bar on a Friday night, my senior design capstone group and I decided to design a machine that would automate the process of creating one of the most popular yet complex drinks ordered at a bar. BAR2-D2 serves as a bartender's best friend by creating a chosen margarita type from scratch, complete with a salted rim, a fruit garnish, and of course a fully mixed drink. This project was completed in a group of seven with a five-month timeframe and showcased to students and faculty in the Mechanical Engineering Department.

As lead for the Fruits & Limes Subsystem, I was responsible for designing & implementing a system that accurately dispenses a single lime slice into the standard margarita and a set number of raspberries into the fruit margarita. Loosely based on a cereal dispenser, I designed a wheel-and-hub system powered by a single NEMA-17 stepper motor. Since my subsystem requires less moving parts than the drink shaker and cup salter, the fruit and lime dispensers were designed to be highly compact, fitting within a total horizontal footprint of 3" x 7".

The only difference between the raspberry and lime dispensers is the rotating wheel, with each configured to comfortably store its given garnish. The NEMA-17 was chosen over alternative stepper motors due to its compact size and having sufficient strength to crush any stuck raspberries that may cause the motor to stall.