I have a buddy that likes to homebrew, so I made him this stir plate for making a yeast starter for his birthday (which happens to fall on NYE!).
Yeast initially require plenty of oxygen for the cells to become healthy and multiply in number, so a “starter” is made which is composed of a sugar solution and a pitch of yeast constantly being aerated by the stir plate.
A laser cut box encloses a PC fan with magnets attached on top. A stir bar (plastic coated magnet) is inside the flask and is spun via the magnetic pull of the spinning magnets below.