Lego Technic Mechanical Seven Segment Display


Here’s a rather mesmerizing piece of Lego genius, displayed as a .GIF for your enjoyment. It’s a 7-segment display that is completely mechanical!

Built by [aeh5040], this beauty features 7 separate linkages that control each display segment. It’s powered off of a single motor which rotates a cylinder covered in small protrusions, similar to how music boxes work. As the cylinder rotates, the protrusions knock the main drive gears back and forth, flipping each segment between the ON and OFF states through a series of axle joints and bevel gears.

It makes rather satisfying sounds too!

Now if only the segments could be controlled individually…

Speaking of other amazing Lego creations, do you remember this Super 8 projector — built almost entirely out of Lego? How about a full 7 speed transmission (plus reverse)! Not to mention the entire full-size car made of Lego that hit 30km/h last year…

[via Reddit]

12 thoughts on “Lego Technic Mechanical Seven Segment Display

  1. I saw this posting in my email, and thought – hey, this is neat: Even though mechanical seven-seg displays have been done in the past (certain clock radios had them a long time ago) – a Lego version was interesting!

    I thought seven motors would be used – then I read the the full article: Completely mechanical (well, other than the power source – but I’ll forgive that)! That…is a true Lego hack.

    I love it!

  2. A great build. Very well engineered, and very creative.

    Like others have said, it would be interesting to see this expanded out to 4 digits. I wonder if it could still be done with a single motor…

  3. I wasn’t too impresed by the picture, but when you mention it’s just one motor, and a whole set of gearing to make it count, that’s pretty good!

    As much as anything, making it reliable, without any bits falling off through wear, is an achievement.

    You could make this into a clock, but you’d really need some sort of power-transfer system for the carry like the Pascaline used. So that the single motor doesn’t end up having to rotate all 4 digits worth of segments when they all change at once. Perhaps use four motors, and some mechanism for the carry. Maybe even as simple as have a cam press a switch.

    Then you’d have a counter. For a clock, a timing mechanism, maybe a pendulum? As long as the digits can change in less than a second. Or just stick to hours and minutes. I’m sure there’s a way of putting the gearwork round behind the display, out of the way. But anyway, nice looking and clever!

    Major complaint is the Youtube link, don’t people write about their projects any more?

  4. Flip segment displays used to be the state of the art for large industrial scoreboard displays, although typically they worked by using seven solenoids per digit to attract or repel permanent magnets on the segment armatures. They are considered obsolete now that LED’s bright enough to be read in direct sunlight are commonly available.

    Those industrial displays weren’t this mechanically clever and, of course, rarely made out of LEGO.

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