Winding a single strand of wire onto a cylinder when creating a homemade coil can be a very tedious process, and worse, the spacing between each rotation is inconsistent or has overlaps rather than a smooth, even surface. To make things a bit more easier and efficient, YouTuber Mr. Innovative created a DIY machine that accomplishes the task with very little human involvement. 

The core of the device is an Arduino Nano, which is connected to a pair of A4988 stepper motor drivers and a screen, all mounted onto a custom PCB. 

The 3.5” LCD functions as a touch display that lets the user select both the length of the wrapping and the width of the wire. This allows the number of windings to be calculated by dividing the length (such as 100mm) by the wire’s diameter (such as 200um for a total of 500 windings). 

With the figure calculated, the first stepper motor spins the attached cylinder to wind on the wire. While that happens, a secondary stepper turns a threaded rod that moves the head across the cylinder at a fixed rate. The resulting coil has a smooth, even finish that nearly any hobbyist would be proud of, and better yet, it was created automatically.