This is a project I've been working on for a couple of years. I know there's lots of robot cocktail makers that have been made so there's nothing really unique about the idea. It's just a fun project to play with.
It consists of a steel frame that supports a refrigerator at the bottom which can hold mixers and three rotating carousels at the top for liquor. The carousels each have six bottle stations that rotate into serving position via steppers and user's glass is positioned to each carousel by a ball screw and linear rail.
Controlling the bot is an Arduino board attached to a 16 output FET driver board of my own design. These outputs control a mix of solenoid valves and pumps. The pumps transfer non-carbonated liquids and the valves transfer carbonated liquids under CO2 pressure from the onboard refrigerator.
The bottles on the carousels have 50ml Beaumont optic measurers that are engaged by servos. I am planning to design a more robust system to dispense sugary liqueurs as these tend to gum up the Beaumonts if not cleaned regularly.
Everything is controlled by a home made app over Bluetooth. The app not only contains the logic to interface with the Arduino but also contains several databases for drink recipes, Bar back inventory control, user favorites, calibration data etc.
The drink menu will show all the drinks (currently 156) or it will show only what can be made from inventory that the bar back module contains. Users can "favorite" a drink but not remove it from favorites as this list is common to everyone and we don't want a user removing someone else's favorite. I thought about having individual users but this brings up the uncomfortable (for some) question about data tracking (drink consumption) and I didn't want to even get into all that.
The bar back module tracks what liquor or mixers you configure to a carousel or mixer position and keeps track of volume remaining. It will update the menus if volume is zero and will show that this drink cannot be made with this ingredient, although the drink can still be made if the user requests it.. The module automatically adds the liquor to a list for re-order. From the bar back module, you can also purge lines to empty and clean.
So far, the biggest obstacle is dispensing carbonated liquids. Most valves and pumps will remove the carbonation before it gets to the glass resulting in a flat tasting drink. I have a plan to 3d print pinch valves that use latex tubing that provides a straighter path to the glass.
At some point, I plan to dress the machine up a bit by adding a wraparound LED matrix to play intersting light shows- and of course Bluetooth speakers to make this an all-around party machine.
Let me know your thoughts and what additions you would make.