3D printed – A maker calling his project [Jason]’s version of a split-flap display is taking on split-flap’s usual weak spot—mechanical accuracy—by using a 28BYJ stepper motor with a magnetic encoder and fully 3D-printed flaps. The setup is controlled with a Raspberry Pi P
Split-flap displays have always had a stubborn appeal: they’re low-power because they only use energy when a character changes. Compared with LCDs. that’s a real advantage—until you get to the part that typically kneels this technology in practice: the mechanics. Split-flap units are more complex than their sleek electronic rivals. and once LCD and LED displays became cheap enough. split-flap largely fell out of favor.
Still, the enthusiasts didn’t disappear. In a new demonstration, [Jason] shows a split-flap display he says is built for high accuracy—and built in a way that you can make at home, too.
The key to getting the text to land correctly is motor positioning. The motor sits in the center and spins the flaps around. so stopping at exactly the right point for each character is what determines whether the display looks crisp or just… close. For his system. [Jason] uses a 28BYJ stepper motor paired with a magnetic encoder to help ensure the correct flap is displayed.
The flaps themselves are completely 3D printed. [Jason]’s approach also aims to solve another practical problem for makers: getting two colors out of a setup even if the 3D printer is designed for only a single color. Once printed. the flaps are installed on the wheel—the outer ring of a planetary gear set—while the stepper motor sits in the middle.
Each character in the display is housed in a printed enclosure. For the specific project he’s demonstrating. [Jason] only needs five characters. and that’s where the control hardware comes in: he uses a Raspberry Pi Pico to run the display. If the design expands beyond five characters. [Jason] suggests it may still be possible to keep using a smaller microcontroller like the Pico—but he adds that a multiplexer may be needed.
The project also serves as a reminder that split-flap isn’t limited to letters. In the same spirit, [Jason] points to a different split-flap display with custom flaps used to show the current weather conditions.
In the end. the tradeoff at the heart of split-flap technology remains the same—mechanics for charm—but this build tries to move the weak point from guesswork to repeatable positioning. The setup is demonstrated in a video showing how the design comes together. including the 3D-printed flaps. the planetary-gear wheel. and the controller driving the characters through the stepper and encoder arrangement.
split-flap display 3D printing stepper motor magnetic encoder Raspberry Pi Pico maker project weather display
So basically it’s like an old train display but 3D printed? Kinda cool.
I don’t get why people still do split-flap when LCDs are literally everywhere. Seems like more parts to break. But the 3D printed flaps part is neat I guess.
Wait, is the Raspberry Pi P Split-flap like hacked from a keyboard or something? And the encoder part… doesn’t that mean it’s basically just stepper motor control, not really “precision”? I’m probably missing it.
The article says it’s low power because it only uses energy when the character changes… okay but doesn’t a stepper motor with an encoder still waste power every tick? Also 2 colors from one-color printer is wild, like do they just swap filament mid-print or something?