[Suggestions] Wireless drink dispenser

tl;dr I am looking for suggestions for pumps that can pump liquid reliably and relatively quickly (~24 oz/min).


I'm planning on making a drink dispenser for parties. For those that are interested, the general idea is this: someone sends me money through Venmo or similar service, I search my email receipts for their email and confirm the amount is sufficient, then send a code back to their email. The code is then added to the dispenser module, and once it is entered, a pump dispenses liquid (only milk, of course ;) ).

I need a pump that will reliably and somewhat accurately dispense a consistent amount of liquid. It also needs to pump at a reasonable rate; it should ideally take no longer than 30 seconds to fill a standard 12 oz cup. I've looked into peristaltic pumps, but all of the ones that I've found have either been much too big and expensive, or pump at too slow of a rate. Peristaltic pumps seem like they would be ideal since they would give good control over the amount of liquid moved, and would not allow more liquid to pump out after the pump has stopped.

Does anyone have any suggestions? I'd greatly appreciate it.



Another thing to consider is whether the pump is rated food safe. Bar bots are a very common project. You will find a lot of information on this topic with some searching. I remember reading the writeup for one that initially used windshield wiper fluid motors but they eventually had to replace them because the subject of whether the pump was polluting the drinks was brought up frequently. That’s the last thing you want to hear when you’re showing off your awesome creation at the party. Remember, alcohol is a solvent.

I saw one that used air (or maybe tanked CO2) to pressurize containers that held the drink components, which then forced the liquids through tubing.