DC motors are ubiquitous in everything from vehicles, to microwaves, to a wide variety of DIY robot builds. Making a DC motor isn’t that complicated in theory, but practically speaking it’s not easy involving, among other tasks, wrapping wires around sections of the armature over and over in order to form an electromagnetic coil.
Rather than doing this very repetitive task by hand, Mr Innovative built his own 3D-printed device to assist him. The main feature is a stepper motor that rotates a hollow fork-like assembly to wind wire around one section of the motor being assembled. A second stepper holds this motor in a vertical orientation, and rotates it as needed so that — with a little bit of manual manipulation — each motor section can be wound appropriately.
An Arduino Nano is used for control, along with a pair of A4988 stepper driver modules. Everything is housed nicely in a 3D-printed enclosure with a small OLED display and buttons that form the user interface.
Wire drawings and Arduino code can be found here, and the 3D-printed parts that you’ll need are on Thingiverse. Check out the assembly process in the video below, which includes a few neat tricks, like sewing a timing belt together and press-fitting bearings into 3D-printed parts to keep them secure.