Few hackers have trouble understanding basic electric motors. We’ve all taken apart something that has a permanent magnet DC motor in it and hooked up its two leads to a battery to make it spin. Reverse the polarity, reverse the spin; remove the power, stop the spin. Stepper motors (and their close cousins, brushless DC motors) are a little tougher to grok, though, especially for the beginner. But with a giant 3D printed stepper motor, [Proto G] has made getting your head around electronically commutated motors a little easier.
While we’ve seen 3D printed stepper motors before, the size and simple layout of this one really lends to understanding the theory. With a 3D-printed frame, coils wound on nails, and rare-earth magnets glued to a rotor, this is an approachable build that lays the internals of a stepper motor out for all to see and understand. You can easily watch how the rotor lines up as the various coils are energized in a circular pattern, although it might be more revealing to include bi-color LEDs to indicate which coils are energized and what the polarity is. Those would be especially helpful demonstrating the concept of half-stepping. We’d also like to see more detail on the controller electronics, although admittedly all the video-worthy action is in the motor itself.
Continue reading “Giant Stepper Motor Gets You Up To Speed On Theory”