GOAL: ... 

SKILLS: use of solenoid and relay, Raspberry Pi, 3D printing, MakerBeams, wiring, mechanical design, python programming, teamwork

For the Intro to Robotics & Mech final project, my class made a fully robotic Latte Machine. The machine must be able to take orders and deliver lattes to customers with as little human involvemnet as possible. We were also required to use something from all the previous projects (picam, Airtable, gears, linkages, etc.) and may not use any glue or tape.

The budget was $500 and the provides supplies inclue: class kits (include raspberry pis, picams, breadboards, etc.), Create3 Robots, espresso capsules, and an espresso machine.

The class split up into teams to tackle this project. The teams were: transportation and cup dispensing (7 people), operating the espresso machine (10 people), milk frothing and pouring (6 people), and cinnamon art (4 people). 

I was on the cinnamon art team, and we were in charge of using a stencil to put add latte art to the frothed milk.

Video

Full Class Integration Video

Overview

Our robot uses a solenoid and a sifter to dispense cinnamon. We first tried a mixing motion to dispense cinnamon, but we found that hitting th top of the isfter worked but better.

in order to avoid overheating the solenoid, we had the solenoid stay in a normally off state and used a relay to turn it on for a very short amount of time to raise it, before turning it back off to drop it on the sifter.

When the sifter is hit by the solenoid, it dispenses cinnamon through a stencil and into the coffee cup.

The stencils are on a rotating circular piece of acrylic. When a customer orders, it updates an Airtable value, which tell our code what design the customer chose, and our stencil plate rotates tot he correct stencil. There are 3 stencil designs, one blank spot, and one slot. The blank spot is the resting position of the machine; this is so any extra cinnamon wont fall through and onto the transportation device. The slot is for cleaning. After the cinnamon is dispensed over the correct stencil, the stencil plate rotate back to the blank spot, and then does a full extra rotation. There is a fixed panel with fabric attached to the bottom that sweeps the cinnamon off during this extra rotation. There is a catch tray directly under the panel so that the cinnamon that is swept off is cleanly collected. Any cinnamon that doesnt fall through the stencil designs is swept easily through the long slot. Now the machine is ready to start again!

Wiring

Code

LatteArt.py.pdf

CAD

Fabrication

More Photos

Things to adjust in the future