An Ingeniously Simple Brushless DC Motor
This 3D-printed motor runs on a single coil, controlled only by a reed switch and magnets.
When you consider brushless DC (BLDC) motors, generally this means a rather complicated controls setup, perhaps as a part of a quadcopter or other advanced craft. As shown in this 3D-printed brushless motor demo by Rishit R, however, all that’s really needed to create a custom system is a pair of magnets and a reed switch.
The project uses a single coil go pull the magnet into place over and over, creating rotary motion. Naturally, these “pulls” have to be precisely timed, but Rishit’s device doesn’t use any sort of microcontroller, or transistor-age electronics for that matter. His build instead just has to be turned on with the magnets in the correct place. This placement actiates a reed switch, which completes a circuit and turns on the electromagnetic coil. The other magnet is pulled to the coil, while the first moves out of range of the reed switch to deactivate the coil.
This process happens over and over again, spinning things to a very high top speed. In the case of 12V, things spin up so fast, in fact, that it simply pops loose, though it works quite nicely with lower voltages and even a single AA battery.
Print files are available in Rishit's write-up, and you can see it running (and failing) in the video below.
