Utter the words “7-segment display” amongst hackers and you’ll typically get people envisaging the usual LED and LCD versions that we all come across in our daily lives. However, mechanical versions do exist, and [ord] has assembled a couple of designs of their very own.
The first uses what appears to be two LEGO motors to drive individual segments of the display. Each segment consists of a pair of yellow axles thrust up through a black grid to represent parts of the number, as well as a minus sign as needed. [ord] demonstrates it by using it to display angle data from a tilt sensor inside a LEGO Powered Up controller brick. Further photos on Flickr show the drive system from underneath.
The second design relies upon a drum-like mechanism that seems to only be capable of displaying numbers sequentially. It works in a manner not dissimilar to that of a player piano. The required movements to display each number are programmed into sequences with Technic pins sticking out of beams in a drum assembly driven by either a hand crank or motor. It’s again demonstrated by [ord] using it to display angular data.
While it’s unlikely we’ll see LEGO displays used as angle of attack meters in light aircraft, you could do so if you wanted a cheap and unreliable device that is likely to fall to pieces if unduly jostled. In any case, it’s not the first time we’ve seen LEGO 7-segment displays, but it’s always great to see a new creative take on an existing concept. We’d love to see such a design implemented into a fancy clock, or perhaps even a news ticker running on a 16-segment version. Video after the break.