Coffee Auto-Stirrer
Penguin DIY's custom stirrer creates a vortex of liquid in your coffee cup.
Manually stirring coffee after adding cream and/or sugar is a process that many of us accept as part of one’s morning routine. However, what if there was a better, or at least more electromechanically interesting, way to properly mix things together? To this end, Penguin DIY made an auto-stirring device that not only looks beautiful, but is capable of spinning liquids at an impressive rotational speed.
This build takes the form of a slightly wider-than-normal coaster with mechanical and electrical parts inside. The body is made out of 10mm plexiglass cut into a ring shape, with a wooden top and bottom attached with screws to complete the build in style.
Three Ni-mH batteries are used to power the device, which are slightly wider than the 10mm ring. To deal with this challenge, the bottom cover is hollowed out slightly where the batteries are placed. Buck and boost modules are implemented, along with a charging board that takes power input via a USB-C connector.
Control of the device is handled through a variable resistor with an on/off switch built-in, which causes the drive motor to spin at different speeds. A series of gears translates this motor input to spin a plate of neodymium magnets directly underneath the coffee cup, which rotates a magnetic capsule inside the cup to induce coffee motion. While one might expect this stirring to be a rather slow process, it actually creates a rather impressive vortex.
The project also features a series of LEDs for illumination. Be sure to check it out in the video below, including a clever SD card ejection trick around the 4:45 mark.