An ESC (electronic speed control) is a circuit for controlling an electric motor — particularly brushless DC motors. These kinds of motors are very commonly found in hobby RC vehicles and in multi-rotor drones. With the massive jump in the popularity of homemade drones, standalone ESC prices have dropped dramatically; a low-end ESC can be had for less than $10.
Of course, that doesn’t mean there isn’t any reason you can’t make your own ESC! For under $20, you can follow GreatScottLab’s great Instructable to build your own robust ESC. This project just requires an Arduino Nano, an L6234 motor driver, and a handful of common electronic components (resistors, capacitors, etc.).
Following along with the instructions to create your own ESC does take some soldering chops, and the ability to read and understand electrical schematics. But, it’s a fairly simple build that would be a fantastic resource for learning about the theory behind brushless DC (BLDC) motor control.
From a practical standpoint, it would be easier for many drone and RC builders to just buy a premade ESC off the shelf. However, this is Hackster.io, and we always advocate the DIY approach when feasible. With a few cost-cutting measures (like ordering components in bulk), it would be entirely possible to approach the cost of even the most low-budget ESCs on the market. The result would be a sophisticated, programmable, and capable ESC at a price even that the most frugal hobbyist would be happy with.