When mixing or agitating delicate solutions in the chemistry lab, a magnetic stirrer is often the tool of choice. They’re able to be easily sterilized and cleaned, while maintaining isolation between the mechanical parts and the solutions in question. While they can be purchased off the shelf, [Max Siebenschläfer] whipped up a design that can easily be built at home.
The build consists of a 3D printed base, containing a simple brushed motor. This is hooked up to a motor controller fitted with a simple potentiometer for adjusting the speed of rotation. The motor is then fitted with a small 3D printed spinner containing two magnets. A similar 3D printed part acts as a stirrer, and is fitted with a matching pair of magnets, and dropped into the solution. The magnets in the stirrer are attracted to the ones on the end of the motor, and so when the motor spins, the stirrer spins in the solution, with no physical contact required.
It’s a simple way to build a magnetic stirrer at home without having to shell out big money for a laboratory grade unit. We imagine this could be put to fun use for stirring coffee or cocktails, too – if built with a food-grade spinner. More advanced designs are also possible for the eager home scientist. Video after the break.