Easy, Modular Alphanumeric Displays Are Full Of Flappy Goodness

There are plenty of ways to make large alphanumeric displays that are readable at great distances. LED signboards come to mind, as do big flat-screen LCD displays. But such displays feel a little soulless, and nothing captures the atmosphere of a busy train station like an arrivals and departures board composed of hundreds of split-flap displays.

In a bid to make these noisy but intriguing displays practical for the home-gamer, [Scott Bezek] has spent the last couple of years on a simple, modular split-flap display unit, and from the look of the video below, it’s pretty close to ready. The build log details the design process, which started with OpenSCAD and took advantage of the parametric nature of the scripting language to support any number of characters, within reason. Costs are kept low with laser-cut MDF frames and running gear, and cheap steppers provide the motion. Character cards are just PVC ID badges with vinyl letters, and a simple opto-sensor prevents missed steps and incorrect characters. The modules can be chained together into multi-character displays, and the sound is satisfyingly flappy.

[Scott] has put a lot of thought into these displays, and even if it’s not the simplest split-flap display we’ve seen, it’s really worth checking out.

[via r/DIY]

18 thoughts on “Easy, Modular Alphanumeric Displays Are Full Of Flappy Goodness

  1. From the top photo, I thought to myself, how could that work, the flaps are too close to the front, they have no room to fall.
    (Back in the day, my clock radio had its flaps set back from the lens to give them room to fall.)
    Then I watched the video…

  2. If it involves laser cutting, it’s not cheap. I’m on Disability, for example — as is my mother, with whom I live… we pool our incomes because we have to. $2100 sounds like a lot of money, until you have to live on it for a month… and for Disability folks, we’re fairly rich — most people on the dole get $500 or less, from what I hear.

    Suffice to say that a laser cutter is beyond unaffordable for me, and even the use of a laser-cutting service is quite a stretch. Ponoko, for example, only ships expensive UPS, so the price is really $25 or so more than the cost of the cutting… UPS is also severely unreliable in our area, so there’s a rather decent chance any order will actually have to be /duplicated/ after arriving in too many pieces and UPS refusing to accept responsibility (you do not want to know how likely this really is).

    I would LOVE to have a manual mill, BTW — I I can hardly even afford to dream about those awful eBay CNCs that go for $500+, and I really don’t need four or even three digit tolerances. I’ve got the idea to make my own CNC — lord knows I’ve enough raw materials in the form of dead printers — but I’m really not sure how to go about it. I’m not mechanically minded at all…

    1. You do not need a cnc you can do that easily with just a printer for templates and a small hand hacksaw and a drill(preferably with jig or small hand drill press adapter). May want to modify it to a belt drive from your printers so you don’t have to make gears. Good luck.

      1. I live in the town Aunt Bea retired to… not that she was around any more by the time my parents bought the house here, even… and I was born well after that.

        This little hick town would have a two- or three-member hackerspace at the most, and I already know the other would-be members. I hate to say it but all the intellectual curiosity in this town is either to do with firearms and a certain book, or could collectively fit in a thimble. How we even still have a local Radio Shack, I’m not sure. I know it’s a franchise store… the guy who runs it sort of knows electronics… I guess he’s a good salesman. I buy my parts on eBay — I can’t really buy from him, the prices are atrocious (well, that’s a given, considering it’s an RS), and his selection is horrible at best, even before you compare to Mouser or even eBay. Don’t get me wrong, I like the guy and I like the store — I just don’t have any real reason to go there any more.

        tl;dr, there’s no hackerspace for miles around, and there’s no point in starting one, because everyone else is too busy hunting for dinner or watching Fox.

    2. Look into wooden clock makers. They like the old ways and use hand operated scrollsaws to achieve fantastic results. But it requires lots of time first to build up the skills, then to actually do the thing. I tried to make a few gears using a table jigsaw, wasn’t very easy and the result wasn’t fantastic.

    1. The size of a flap display is always limited by the driving motor. If you need a bigger display, either find the smallest stepper motor that you can find and still be powerful enough for the job and gear it down if you need to.

      Or just build a bigger display with the digits shown above and watch it from 100 metres away. ;)

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