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Open source “split-flap” mechanical display

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Re: Open source “split-flap” mechanical display

#51

Post by numpad0 »

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…

They offer high resolution full color semi-dynamic display without needing any semiconductor circuitries.

You can simply fabricate the flap by cutting the flap to dimensions and affixing letterings onto them. That’s not possible with LCDs or LED arrays.

Re: Open source “split-flap” mechanical display

#52

Post by michaelt »

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 flip-dot display. And a lot of places that were equipped with them in the 1980s still had them in the late 1990s.

These days you'd use an LED display, or a sunlight-readable TFT.

Re: Open source “split-flap” mechanical display

#53

Post by wayoutthere »

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…

As someone who used to travel a lot by rail in the not so distant past, every station that replaced one of these boards was a downgrade. Most stations had maybe 1 or 2 of these signs with the rest of the smaller ones already LCDs, so it’s not like there weren’t already places to get the info you couldn’t show on a sign like this.

Part of the problem with the LCD signs is they show too much information. It’s not really an advantage to show the next 30 trains incoming on the big board when only the closest 2 or 3 have gates assigned. They also tend to be themed in colors that are harder to read (Amtrak does blue on white, which is harder to read than white on black). Some stations tried replacing the split flaps with single-character LCD displays to mimic, but they always ended up breaking faster (and never getting fixed) for some reason.

From what I recall in an article about these signs, industrial versions were ungodly expensive to begin with, but the real reason they’re being replaced is that the companies that originally made them are all out of business and you simply can’t get parts for them. It’s cheaper to replace an entire LCD panel than it is to fix one of the mechanical signs once and you don’t have to wait 6 weeks with a broken sign for parts to be manufactured.

Re: Open source “split-flap” mechanical display

#54

Post by vidarh »

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…

When I was a kid our hifi-system had a split-flap clock built in (around 1980 or so)

Re: Open source “split-flap” mechanical display

#55

Post by tyingq »

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…

Worth noting not all LED displays are sunlight readable. Typically, outdoor requires old fashioned through-hole, separate LEDS, and at least 1/4 duty pwm refresh.

Re: Open source “split-flap” mechanical display

#57

Post by jamestenglish »

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:…

Subscribed to all 3 of those, one of my new fav's

Stuff Made Here: https://www.youtube.com/channel/UCj1VqrHhDte54oLgPG4xpuQ

Re: Open source “split-flap” mechanical display

#58

Post by fortran77 »

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.

We need to vent our laser cutter to the outside. There's also considerable danger that what you're cutting catches on fire, so they need to be supervised. It's not just the cost of the machine--they're not just "plug and go"

Re: Open source “split-flap” mechanical display

#59

Post by theodric »

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…

Zero power needed to retain image, not encumbered by e-ink patent and manufacturing monopoly, simple and repairable, and you can build it yourself at home

Re: Open source “split-flap” mechanical display

#60

Post by thechao »

leoedin wrote: post #27
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.

My local makerspace has a really good laser cutter which members can use. It works well for that kind of usage as there's not too many ways you can kill it or yourself. Generally cheap machines have compromises which mean more work for you - less reliable, less accurate, weaker laser, worse software - all of that means a lot more trial and error, a lot more burnt material and a lot more stuff you just can't do. If yo…

Do you have a suggestion? I feel like the last time I looked into laser cutting, it was either SEOd hits that were crazy expensive or shops that looked dodgy. Nothing in-between.
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