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Open source “split-flap” mechanical display

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Re: Open source “split-flap” mechanical display

#61

Post by dspillett »

michaelt wrote: post #52
argvargc wrote: post #23

Genuine question: what are some practical advantages of a split-flap display over, well... any other kind of dynamic character display? The only two I could think of are: - they don't emit light, so maybe there could be some kind of light-sensitive situation where this would be required (though in that case e-ink would surely surpass it). - the sound passively-alerting those present to updates. It's not obtrusive or…

The traditional uses of split-flap displays were sports arena scoreboards, airports and train stations. i.e. places where you want a very large display that's readable in direct sunlight. If you were equipping a train station or airport in the 1980s, your options were split-flap displays, CRTs with sunshades over them (maximum size ~20 inches), a multi-CRT video wall ($$$$$$$$), a vane display (numbers only) or a fli…

> And a lot of places that were equipped with them in the 1980s still had them in the late 1990s

Many UK rail stations had them into the early to mid 00s. If I'm not misremembering, the boards at London Kings Cross were not moved to different tech until at least 2005. Manchester Piccadilly had them replaced around 2001 (at the time I was passing through there a fair bit, travelling between York & North Wales).

Re: Open source “split-flap” mechanical display

#62

Post by ziml77 »

smnscu wrote: post #34
gibolt wrote: post #4

Related video on Flip Clocks from Technology Connections: https://youtu.be/ZArBfxaPzD8

I really enjoy Alec's videos and quirky humour. Beware though, this kind of channel is a massive, addicting time sink. Other similar channels that HN might appreciate (the first two are quite well-known, the last one I found recently and is definitely bingeworthy): - Smarter Every Day https://www.youtube.com/channel/UC6107grRI4m0o2-emgoDnAA - Tom Scott https://www.youtube.com/user/enyay - Practical Engineering https:…

Tech Ingredients is another good one with nice, long videos: https://www.youtube.com/user/TechIngredients

Re: Open source “split-flap” mechanical display

#63

Post by goodpoint »

gattilorenz wrote: post #32
argvargc wrote: post #23

Genuine question: what are some practical advantages of a split-flap display over, well... any other kind of dynamic character display? The only two I could think of are: - they don't emit light, so maybe there could be some kind of light-sensitive situation where this would be required (though in that case e-ink would surely surpass it). - the sound passively-alerting those present to updates. It's not obtrusive or…

similarly to an e-ink display, it doesn't take energy to show the current/last status, it's required only for transitions. If there's a blackout, the display is still visible.

> If there's a blackout, the display is still visible

And dangerously out of date in airports and train stations.

When they break down they had to be covered to prevent misleading passengers.

Re: Open source “split-flap” mechanical display

#64

Post by theodric »

huhtenberg wrote: post #21

> laser cut enclosure Had a quick look and the cheapest laser cutter appears to be around $400. The next one is $1500 and then the price just keeps on climbing. Any first-hand experiences with laser cutters? An option suitable for an (occasional) hobbyist use, but not a total junk either.

I bought a 50*70cm "60"-watt unit online for about €2000 shipped. It is the size of a chest freezer. It works reliably, except that if you don't power it up with the laser armed, and instead flip the safety switch after power up, it will not fire the laser. I had one Hall effect endstop fail, but everything apart from the enclosure itself is COTS commodity stuff, so I just got a pack of new endstops on eBay and fixed it. Cooling with an Ikea tub full of water, vent with a hose out the window.

Re: Open source “split-flap” mechanical display

#65

Post by goodpoint »

argvargc wrote: post #23

Genuine question: what are some practical advantages of a split-flap display over, well... any other kind of dynamic character display? The only two I could think of are: - they don't emit light, so maybe there could be some kind of light-sensitive situation where this would be required (though in that case e-ink would surely surpass it). - the sound passively-alerting those present to updates. It's not obtrusive or…

- Visibility angle is much better than any other alternative. This is crucial when one big display is used in a very large room instead of many small displays.

- Image sharpness and contrast is excellent. You can read text on an old flip display far away that you would struggle to read on a modern LCD if you have mild astigmatism.

- Perfectly readable on a sunny day.

- They can show colored logos and symbols (e.g. train type, airline, highlight warnings)

- Better failure mode than LCD: single digits fail independently from each other and can be replaced. But it's less likely that the entire display fails.

- They are either working or stuck - no fading out like CRTs.

Re: Open source “split-flap” mechanical display

#66

Post by mastax »

smnscu wrote: post #34
gibolt wrote: post #4

Related video on Flip Clocks from Technology Connections: https://youtu.be/ZArBfxaPzD8

I really enjoy Alec's videos and quirky humour. Beware though, this kind of channel is a massive, addicting time sink. Other similar channels that HN might appreciate (the first two are quite well-known, the last one I found recently and is definitely bingeworthy): - Smarter Every Day https://www.youtube.com/channel/UC6107grRI4m0o2-emgoDnAA - Tom Scott https://www.youtube.com/user/enyay - Practical Engineering https:…

- Marco Reps - Electronics, Metrology, Machining, etc. With a dry German sense of humor. Like electric This Old Tony https://youtube.com/c/MarcoReps

Re: Open source “split-flap” mechanical display

#67

Post by mastax »

michaelt wrote: post #52
argvargc wrote: post #23

Genuine question: what are some practical advantages of a split-flap display over, well... any other kind of dynamic character display? The only two I could think of are: - they don't emit light, so maybe there could be some kind of light-sensitive situation where this would be required (though in that case e-ink would surely surpass it). - the sound passively-alerting those present to updates. It's not obtrusive or…

The traditional uses of split-flap displays were sports arena scoreboards, airports and train stations. i.e. places where you want a very large display that's readable in direct sunlight. If you were equipping a train station or airport in the 1980s, your options were split-flap displays, CRTs with sunshades over them (maximum size ~20 inches), a multi-CRT video wall ($$$$$$$$), a vane display (numbers only) or a fli…

I had never realized that the original Sony Jumbotrons were CRT (one CRT per pixel) https://youtu.be/AclwH64eAkU

Re: Open source “split-flap” mechanical display

#68

Post by teh_klev »

gibolt wrote: post #4

Related video on Flip Clocks from Technology Connections: https://youtu.be/ZArBfxaPzD8

I watched that last night. Alec's a tremendous educator and come a long way since his early videos (which are also still good). I really enjoyed his deep dive into how dishwashers work :)

Re: Open source “split-flap” mechanical display

#69

Post by anonu »

I've looked into buying ready-made solutions. Vintage split-flap mechanisms go for close to $1000 per character on eBay. There is a company I found in China that manufactures these, but its still around $300 or so per character. Displaying a tweet would cost close to $100k after shipping, etc...
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