For many of us. the holiday season is coming up and that means hosting parties and mixing drinks, which can get tiresome. [GreatScott] has come up with a solution, what he calls a crude cocktail mixing machine. But don’t be fooled — it may look crude on the surface, and vibrate a bit while working, but the mechanism is plenty sound and functional.

The machine can mix three different liquids and does so using three peristaltic pumps. In typical [GreatScott] style, while he tears apart the pumps to replace the tubes, he gives us a good glimpse of just how they work. Using a knob and LCD screen, you can enter any quantity you want for the three liquids, though you’ll have to edit the Arduino code if you want to change the liquids’ names.

How does the machine know when to stop pumping a certain liquid? Each pump is rated for a specific quantity per second, though he tests this for each liquid anyway and finds a slight variation which he accounts for in the code. After the machine turns a pump on, a load cell located under the glass tells it when liquid has started arriving at the glass. A simple calculation based on the pump’s quantity per second and the desired quantity tells it how long to leave the pump on for. When the times up, it stops the pump. The result is a machine that’s sure to be a centerpiece for any hacker-filled party. Check out his build and the pump in action in the video below.

But parties need more than just drinks, they also need cookies. So to that end, check out [Ben Krasnow]’s equally cool cookie making machine.

After five weekends of work, [Alex] completed his automatic drink maker, the RumBot. What makes this automated bartender different from others is the fact that it is fast. VERY fast. It can serve drinks to five different locations in as little as 3 seconds per drink. By [Alex]‘s estimation, this could keep a party of 100 people going without anyone waiting on a drink.

The RumBot can make either of five pre-programmed drinks at varying levels of alcoholic intensity, ranging from 1 (“Virgin”) to 10. And for that extra push over the cliff, you can turn the knob to 11 (“Problem”).

Drink selection itself is handled by a simple digital I/O on an Arduino with a 1950s-styled user interface. The frame is built out of wood and uses 3D Printed plastic parts. It houses a very robust servo on a belt stage to move the drink nozzle, and special sensors placed at either of the five drink locations detect a cup ready to be filled. Any cup placed at any of the positions will automatically be filled based on the RumBot’s settings at any particular time.

Based on the quality of the build and the increased speed of this automatic drink maker, this should be a huge hit at any party. With all the knobs turned to 11 though, it might be a good idea to have a breathalyzer on hand! All of the code and schematics for the project are available at the project site as well.