[HN Gopher] NASA solved a $100M problem for five bucks (2012)
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NASA solved a $100M problem for five bucks (2012)
Author : rbanffy
Score : 199 points
Date : 2023-01-23 15:53 UTC (7 hours ago)
(HTM) web link (gizmodo.com)
(TXT) w3m dump (gizmodo.com)
| ryzvonusef wrote:
| Reminds me of an apocryphal story about a packaging line in a
| cereal factory. They created a complicated weighing system to
| make sure no box was packed empty because of a cereal bag
| accidentally falling out....only to realize the line workers had
| already solved the problem by placing a pedestal fan that blew
| away the light empty boxes as the went on the line.
| Retric wrote:
| If I recall the story continues where the complex system
| included a sensor to detect an empty box. Realizing the fan
| worked they disabled the complex system until one day the fan
| quietly failed without anyone noticing and empty boxes where
| sent out. This created a great deal of embarrassment for
| everyone involved.
|
| Even more time and effort was spent after the problem was
| already 'fixed' _twice_ at which point they used both the fan
| and the more complex system.
| Mountain_Skies wrote:
| Though this was back in the 90s and things might have changed
| since then, when I stocked the cereal aisle, Kellogg's had
| somewhere in the range of 0.5% to 1% empty boxes. Really weird
| the first time you pull one out of the shipping box to find the
| individual box fully sealed but empty.
| bluedino wrote:
| Right after high school I worked at one of the big office
| furniture companies (you've sat in one of their chairs/cubes if
| you've worked in an office job). At some point, a couple
| hundred batches of $1200 chairs went out with one of the legs
| cast wrong. The easy thing to do was to have a piece of the
| packaging stuffed in the leg during assembly.
|
| The problem was, the service techs never knew about this, so
| when they'd go out and warranty a caster, they'd find a bunch
| of cardboard or whatever jammed in the leg, put the caster back
| on without replacing the cardboard, and the chair wouldn't be
| level. So, they would come back out next week with a new leg.
| cjrp wrote:
| Wait.. so the cardboard was structural?
| brewdad wrote:
| It sounds like the equivalent of placing a bunch of napkins
| under the foot of your restaurant table to keep it from
| wobbling except the napkins were inside the table rather
| than on the floor. Pretty amazing hack. :)
| russdill wrote:
| This seems a bit unlikely given that air has long been very
| widely used in production lines to remove objects that are too
| light. But it makes a neat story.
| vpribish wrote:
| "steam-actuated dials" - this article is trash. they are trying
| to say "steam gauges" but for some reason are up-complicating it
| and since they don't know the subject they made nonsense.
| tantalor wrote:
| Immediately raised a red flag, since I've never heard of "steam
| gauges" until today, it took me a minute to realize they had
| confused the term, and obviously have no idea what they are
| talking about.
|
| > Analog gauges, commonly called "steam gauges" because their
| faces resemble a steam pressure gauge
|
| https://www.aopa.org/news-and-media/all-news/2017/march/flig...
|
| Contrast with "glass panels" or "glass cockpit" which just
| means "using a LCD" or similar (nevermind that the "steam
| gauges" also have a glass front)
| criddell wrote:
| > NASA has a patent pending on the technology
|
| That kind of bugs me. Why should our government be able to patent
| things?
| abathur wrote:
| To keep others from patenting publicly-funded inventions?
| kens wrote:
| To answer your question, NASA has the authority to grant
| licenses on its domestic and foreign patents and patent
| applications pursuant to 35 USC 207-209.
| bsan3 wrote:
| Great engineering. Elegant solution while solving the general
| case - usually these avoid the general case
| messe wrote:
| The Ares I had an even bigger flaw in that any abort during the
| first minute would result in the capsules parachute intersecting
| with fragments from the SRB plume, killing the crew.
| amelius wrote:
| So instead of relieving the astronauts from an additional
| vibration force of 0.7G, they decided to take the cheap route?
|
| Also how are the astronauts supposed to reach for the control
| buttons if they can't see them?
| marmetio wrote:
| If the vibration still meets the requirements, then yes.
| They're not going to chase arbitrary ideas of "better". In the
| physical world, you add some margin to the design so you can
| tolerate stuff like this.
|
| They can see the physical buttons because they don't refresh
| and momentarily disappear like a digital display.
| cratermoon wrote:
| 2012. Incidentally, the single test flight of Ares I rocket ended
| in what would likely have been a disaster, or at least an abort,
| with a real crew. Those vibrational issues ended up causing the
| the upper stage simulator to enter a flat spin upon separation
| from the booster.
| adastra22 wrote:
| Yeah the whole premise of the article is off. I guess "NASA
| tried a $5 fix but it wasn't sufficient and the program got
| cancelled" doesn't generate as many clicks.
| agloeregrets wrote:
| My favorite thing is "Our new design is so screwed that it
| violently vibrates to the point that the crew cant read
| screens...How can we modify the screen to work?" rather than
| "Hey..uh, how do we make it not violently do this?"
| parasti wrote:
| Quickly-approaching-deadline mentality.
| adastra22 wrote:
| More like "You're only getting paid to do this because
| the solid rocket motor company is politically connected.
| Either use them, or the program goes away and you get
| fired."
|
| Nevermind that solid rocket motors is and always have
| been a terrible idea for crewed launch systems, and were
| probably the worst mistake made on Shuttle.
| nikanj wrote:
| I wonder how often they do the opposite, and spend $100M because
| nobody had the flash of insight needed to turn it into a five-
| buck problem
| dctoedt wrote:
| > _I wonder how often they do the opposite_
|
| _[From my contract-drafting course materials:]_ The parties in
| a 2020 Vermont supreme court case might have been better served
| if they had done periodic check-in calls -- in that case:
|
| - In a project to rebuild a railroad bridge, a subcontractor
| was supposed to handle one aspect of the project.
|
| - The subcontractor encountered an unexpected problem.
|
| - The subcontractor spent weeks trying to fix the problem --
| and billed the prime contractor an extra $120,000 for its
| efforts.
|
| - At trial, however, it came out that -- for only $9,600 --
| there had been a simpler way to solve the problem.
|
| - If the prime contractor and subcontractor had just talked to
| one another -- perhaps using the SPUR agenda, discussed at
| 7.2.6 -- they just might have solved the problem sooner, at
| much-lower cost (and without having to go to litigation).
|
| See Construction Drilling, Inc. v. Engineers Construction,
| Inc., 2020 VT 38 PP 6-7, 236 A.3d 193, 196-97 (2020) (affirming
| denial of subcontractor's breach-of-contract claim).
| https://scholar.google.com/scholar_case?case=144056062390412...
|
| _[The SPUR agenda is a general-purpose meeting agenda: Status;
| Problems; Uncertainties; Risks.]_
| _fat_santa wrote:
| The best engineers come up with the simplest solutions.
| bloomingeek wrote:
| I think it's because they know the correct questions to ask.
| madengr wrote:
| [dead]
| [deleted]
| tezzer wrote:
| I was a guinea pig for this experiment- they spun us up in the
| centrifuge, vibrated the chair in a simulation of launch forces,
| and had us doing reading and manual tasks. There are parts of
| your brain that nope out at certain frequencies, it's a
| remarkable feeling.
| bandyaboot wrote:
| > We did our best to show the before/after by putting our camera
| on the sled, but the image-stabilization was just too damn good
| (well played, Sony. Well played). You'll have to take my word for
| it.
|
| Alternate solution: send crew up with image stabilized cameras.
| fbn79 wrote:
| Remind me scene of movie Contact. Earth engineer fixed a seat to
| the alien craft as minimar support for Jodie Foster but the
| vibration was too much. Ended up that have no seat and
| fluctuating free on air was easiest most secure solution.
| Finnucane wrote:
| Did any other industry actually use this solution as suggested at
| the end of the article?
| moloch-hai wrote:
| It was not really a solution.
|
| But those vids on YouTube of helicopters flying around with
| still rotors, and hummingbirds with their wing held out, are
| great.
| yboris wrote:
| TL;DR summary:
|
| _Problem_ : cabin would inevitably vibrate at some point and
| astronaut's chairs would too, making displays impossible to read.
|
| _Soution_ : put a sensor on the chair and synchronize the
| displays to only pulse their light when the chair (and thus
| astronaut's eyes) returned to the same location.
| dotnet00 wrote:
| As far as I'm aware, this problem (and associated 'solution')
| still exists on SLS, which would make sense considering that it
| too gets a large portion of its thrust from those giant SRBs.
|
| Of course the proper solution would have been to not mandate the
| use of such large SRBs since the vibrations still make SLS near
| useless for launching scientific payloads. The reason for
| choosing Falcon Heavy for Europa Clipper instead of SLS was that
| on top of the rocket price difference, it'd cost $1B extra to
| make Clipper able to handle SLS's vibrations, Congress was
| insistent on Clipper launching on SLS but backed down when they
| informed that they'd have to spend an additional $1B on science
| instead of corruption.
|
| But alas, that sort of dumb stuff is what design by Congress gets
| you.
| eliaspro wrote:
| > Special thanks to Mark Rober, Jessica Culler, Dan Goods, Val
| Bunnell, and everybody at NASA JPL and NASA Ames for making this
| happen.
|
| Well, that's Mark Rober before bis YouTube fame.
| miga wrote:
| 1. Does the solution includes pay for the people to think?
|
| 2. Does it include opportunity cost of waiting for the 5$
| solution?
|
| 3. Does the cost include extra prototyping and engineering time?
|
| The title of the article is a lie based on misunderstanding of
| engineering.
|
| After all engineering is done, the __remaining cost__ is the same
| as bill of materials...
|
| Until you need to update the system with new components. And
| rockets made by NASA are made in few copies... so the Non-
| Recurring Engineering cost dominates the whole business.
| rvnx wrote:
| 5 USD of material, millions of USD spent to train, hire,
| motivate and retain the engineers who are finding such
| solutions.
| ozim wrote:
| Exactly like old joke:
|
| There was a problem with machine on factory floor, company
| tried to do everything already so they called specialist. To
| cut story short, specialist went around the machine took
| hammer out and smashed in one place - machine fixed. Invoice
| for the company $500 - so manager was angry
|
| - "one swing of hammer $500?" - "swing of hammer was free,
| knowing where to hit $500"
| xenophonf wrote:
| It's no joke, dude. That was Charles Proteus Steinmetz.
|
| https://www.smithsonianmag.com/history/charles-proteus-
| stein...
| selectodude wrote:
| Ford, whose electrical engineers couldn't solve some problems
| they were having with a gigantic generator, called Steinmetz
| in to the plant. Upon arriving, Steinmetz rejected all
| assistance and asked only for a notebook, pencil and cot.
| According to Scott, Steinmetz listened to the generator and
| scribbled computations on the notepad for two straight days
| and nights. On the second night, he asked for a ladder,
| climbed up the generator and made a chalk mark on its side.
| Then he told Ford's skeptical engineers to remove a plate at
| the mark and replace sixteen windings from the field coil.
| They did, and the generator performed to perfection.
|
| Henry Ford was thrilled until he got an invoice from General
| Electric in the amount of $10,000. Ford acknowledged
| Steinmetz's success but balked at the figure. He asked for an
| itemized bill.
|
| Steinmetz, Scott wrote, responded personally to Ford's
| request with the following:
|
| Making chalk mark on generator $1.
|
| Knowing where to make mark $9,999.
|
| Ford paid the bill.
| BizarroLand wrote:
| I guess great minds think alike but fools rarely differ. I
| posted a link to the story you copied just below you, lol.
| mjburgess wrote:
| This also goes a long way to explaining why service
| economies are richer than goods-based ones; and why
| "manufacturing jobs" as a political project are mostly
| populist nonesense.
| cjbgkagh wrote:
| A lot of intelligence goes into manufacturing and a lot
| of innovation comes out of it. The overemphasis on
| financial engineering causes substantial market
| distortions and in my view is the principal driver of our
| increasingly dysfunctional economies. I.e. you don't need
| to be a populist to care about manufacturing jobs
| mjburgess wrote:
| As a solution to class mobility, you do. And as a route
| to increases in high-paying low-skill labour.
|
| My comment about "service jobs" is kinda evidenced with
| your own remark: the existence of high-value
| manufacturing jobs. The _high-value_ here is always in
| the cognitive dimension, rather than the physical.
| cjbgkagh wrote:
| My assertion that more intelligence is required than
| commonly thought scales all the way down to the low value
| manufacturing. I'm often quite surprised at the ingenuity
| and skill that goes into low value manufacturing. In
| addition a substantial low value manufacturing base
| reduces the incremental cost of resources and tooling
| required by the high value manufacturing increasing the
| viability. Effectively setting up a cross subsidy.
| mjburgess wrote:
| Sure, but the political project is supposed to provide
| such jobs to people who are otherwise not very skilled.
|
| My point being that the relevant political project for
| increasing class mobility, prosperity etc. is
| skills/education/training/etc. _rather than_ this false-
| belief that there is something called "Manufacturing"
| which pays well without such things.
|
| Or, to use the example given, it's "knowing where to put
| the chalk", rather than removing the metal plate. There
| is no modern rich economy which can sell "removing metal"
| as the route to prosperity.
|
| That used to be the case, but all that labour has been
| automated away or is otherwise _not_ well-paying,.
|
| Now it is all about value-add via skills.
| cjbgkagh wrote:
| My concern is 'modern rich economies' are a temporary
| aberration due to financialization and that the
| intelligence vs work schism will fall apart due to the
| under-appreciation of the importance of maintaining a
| manufacturing base. I would agree with you if the
| windfall of having been intelligent was invested in
| becoming more intelligent and thus an advantage is
| maintained but by my observation that has not occurred.
| It seems people will instead use their relative luxury to
| hold increasingly illogical ideas. Not only will we not
| have a manufacturing base but we won't be intelligent
| either. For now financialization is propping up our way
| of life but that won't last forever.
| mjburgess wrote:
| Interesting view, imo, probably wrong.
|
| We imagine the "value-add" due to advanced cognitive
| skill is somehow "less real" than that which could be
| replaced with a machine arm.
|
| What we have discovered, and will do so, is that knowing
| where to place the chalk was always the basis of profit.
| wongarsu wrote:
| I think one point worth appreciating (apart from the
| political reasons to drive manufacturing jobs) is that
| manufacturing provides jobs where people who are
| uneducated/low-skilled but intelligent can make
| significant contributions.
|
| Putting a fan next to a conveyor to filter out empty
| boxes doesn't require a college degree (if anything a
| college degree makes it more difficult to find that
| solution), but it is nonetheless a significant process
| improvement.
| pmontra wrote:
| Great story but I had no idea who he was. Found on
| Wikipedia
| https://en.wikipedia.org/wiki/Charles_Proteus_Steinmetz
| moloch-hai wrote:
| There is a great series on YouTube:
|
| https://m.youtube.com/@KathyLovesPhysics/videos
|
| Really took Tesla down a peg. (No, Tesla did not invent
| the 3-phase power system we use today. That was a Russian
| in Switzerland, Dolivo-Dobrovolsky.)
| zikduruqe wrote:
| Picasso was at a Paris market when an admirer approached
| and asked if he could do a quick sketch on a paper napkin
| for her. Picasso politely agreed, promptly created a
| drawing, and handed back the napkin but not before asking
| for a million Francs.
|
| The lady was shocked: "How can you ask for so much? It took
| you five minutes to draw this!"
|
| "No", Picasso replied, "It took me 40 years to draw this in
| five minutes.
| BizarroLand wrote:
| Like Charles Proteus who sent Henry Ford a bill for $10,000
| for drawing a circle on a generator with chalk, it was $1 to
| draw the circle and $9,999 to know where to draw it.
|
| https://www.smithsonianmag.com/history/charles-proteus-
| stein...
| gooseyman wrote:
| Interesting bit about the patent application by NASA. I didn't
| realize NASA filed for patents. Does a NASA patent essentially
| make this public?
| mannykannot wrote:
| So the astronauts could read the numbers, but could they do
| anything about them? I'm guessing that it is difficult to make
| manual actions with any precision while being subjected to that
| sort of vibration. Alternatively, if there was nothing they could
| do at that stage, did they need to read the numbers?
| tezzer wrote:
| Yes, in the experiment we had to touch highlighted groups of
| numbers on the screen during some phases, do simple math on
| groups of numbers, or read out numbers. One of the harder parts
| is repeatedly reaching out to touch the screen under G forces,
| your arms get really tired really fast.
| dang wrote:
| Related:
|
| _NASA solved a $100M vibration problem cheaply by strobing the
| display_ - https://news.ycombinator.com/item?id=28109420 - Aug
| 2021 (15 comments)
| seanalltogether wrote:
| Would this also be fixed by using a display with a high refresh
| rate? For instance, would a 240hz display be subject to the same
| vibration smearing?
| remram wrote:
| Yes, the blurriness comes from the movement of your eyes. A
| constantly-lit piece of paper would also look blurry.
| remram wrote:
| I meant "yes, it would be subject to it" so "no, it wouldn't
| fix it". In case it's not clear which question I was
| answering.
| drKarl wrote:
| Reminds me of that old joke (not sure if it's true or not) that
| NASA spent millions of dollars developing a ballpoint-pen that
| could work in zero gravity, and the soviets just used a pencil.
| coredog64 wrote:
| The Fisher space pen was developed outside of NASA. The Soviets
| used a pencil, but it came with the very real downside risk of
| graphite particles migrating everywhere.
| hinkley wrote:
| Flammable materials migrating into circuitry.
| p_l wrote:
| The complete story is that NASA was spending millions on
| _space pencils_ , because of floating, very sharp, bits of
| graphite creating various risks.
|
| This was also after the tragedy of Apollo 1.
|
| Meanwhile Soviets used grease pencils, which while safer,
| were horrible in usability.
|
| Fischer's private development of space pen was quickly picked
| up by both US and Soviet space programs to solve the problem
| of writing in space.
| stonogo wrote:
| NASA spent no money developing pencils. They bought a batch
| of already-existing mechanical pencils, from a regular
| pencil manufacturer, and they paid too much. The total bill
| came to something around $140 per pencil, for a total
| expenditure of just over $4,000. This caused an outcry and
| eventually evolved into the "millions of dollars" urban
| legend.
| p_l wrote:
| I didn't say they developed them. However, they did a lot
| of tests on top of that $140 per pencil purchase which
| helped propel the extrapolation of "millions" (probably
| in TCO, spread over time)
| moloch-hai wrote:
| I bought a Fisher Space Pen, as a teener. It leaked. Not
| very badly.
| KMag wrote:
| To expand a bit on what you wrote. The Fisher space pen was
| developed entirely with private funds, and sold to NASA to
| fill a real need to not release graphite to be inhaled or
| cause short circuits.
| rvnx wrote:
| Cool stuff! How it's made / how it works:
| https://www.youtube.com/watch?v=3mjmAzf4oKs
| dilyevsky wrote:
| Free graphene!
| deelowe wrote:
| A story that is 100% B.S.
| jjtheblunt wrote:
| not sure if you are aware of this
|
| https://www.spacepen.com/
| beefman wrote:
| Reminds me of 2005 when I suggested BART cannibalize OTS noise-
| canceling headphones and put some speakers under the cars to
| attenuate the horrific screeching sounds
|
| http://lumma.org/microwave/#2005.07.22
| dylan604 wrote:
| are they using a pencil? /s
| russdill wrote:
| This would turn out to be the absolutely incorrect solution. The
| core design of the system was driven by politics creating all
| kinds of engineering problems that would eventually doom the
| program. The actual solution was to cancel Ares I.
| walnutclosefarm wrote:
| That's an 11 year old article. Might want to indicate that in the
| subject/title, as is customary.
| 93po wrote:
| And find a source with a less clickbaity title. It wasn't a
| $100M problem, it was a small hurdle on a $100M project
| Rebelgecko wrote:
| 1. NASA also made design changes like adding mass dampeners to
| the rocket to reduce the pogo oscillations (although I don't
| think the hardware was actually built before the program was
| canceled).
|
| 2. The fix described in the article definitely cost more than $5.
| The ICs might've cost <$100, but I wouldn't be surprised if the
| cost of the fix was six or seven figures after taking into
| account the design, installation, and QA steps
| just_boost_it wrote:
| It's like saying that software built using an open source
| languages and libraries was built for free.
| alhirzel wrote:
| Adding water to something (dampening mass) is less effective
| than adding something solid to it (damping mass). One of my
| favorite little pet peeve typos...
| Rebelgecko wrote:
| Thanks for the correction!
|
| Have you seen the designs for interplanetary spaceships that
| use the crew's water supply as a protective shield to block
| radiation? I wonder if they need mass dampers for their
| dampening mass.
| Baeocystin wrote:
| Huh. TIL. Do you know the reason for distinguishing between
| the two in this way?
| LarryMullins wrote:
| It's a play on words, to "dampen" something is to make it
| moist.
| Baeocystin wrote:
| Welp. That's what I get for commenting before coffee!
| [deleted]
| thanatos519 wrote:
| I did something like this once! I was BBSing and my CGA monitor's
| vertical coil died. So I blew through my lips to make a
| 'raspberry' sound which vibrated my eyes and allowed me to read
| what was being displayed on the single scan line.
| Moissanite wrote:
| So when people say "10x developer go BRRRR", they are
| specifically referring to you?
| mkaic wrote:
| At long last we've found the mythical 10x develobrrrrrr
| lpapez wrote:
| Thanks for sharing this story, I laughed out loud trying to
| visualize the notion of someone staring at a semingly blank
| screen doing that in order to read the "secret text".
| Brilliant.
| frakt0x90 wrote:
| I don't know what any of this means but making it up in my head
| comes up with a pretty amusing scene.
| martincmartin wrote:
| OP was reading text on an old Cathode Ray Tube monitor. It
| broke such that, instead of being spread throughout the
| screen, all of it was squished vertically into a single
| horizontal line. However, different parts of the line are
| written at different times, so if you vibrate your head,
| different parts will land at different parts of your eye.
| recuter wrote:
| Sadly blowing raspberries no longer works for debugging new
| fangled flat panel displays. On account of the ball
| bearings.
| westmeal wrote:
| You forgot to mention the pixel return springs but you
| seem like a nice guy so I'll let it slide.
| c22 wrote:
| OP is probably using something like a retroencabulator
| where rather than the power being generated by the
| relative motion of conductors and fluxes, it's produced
| by the modial interaction of magneto-reluctance and
| capacitive diractance. The original machine had a base
| plate of prefabulated amulite, surmounted by a malleable
| logarithmic casing in such a way that the two spurving
| bearings were in a direct line with the panametric fan.
| Thus no pixel return springs are necessary in this
| configuration.
| renewiltord wrote:
| Much less clever, but I had a microwave with far too opaque a
| grid to look through. By shaking my head left and right, it
| would sort of disappear though. The funny thing is how
| automatic these human things are. I didn't notice I was doing
| it until someone asked me why I was shaking my head at the
| microwave.
| quesera wrote:
| This also works when trying to focus on a distant object
| through a screened window.
| ChuckNorris89 wrote:
| _> I didn 't notice I was doing it until someone asked me why
| I was shaking my head at the microwave._
|
| Congrats, you became the human owl.
| spywaregorilla wrote:
| I think that's more of a ocular SLAM kind of thing for
| depth mapping
| sopooneo wrote:
| I've noticed the same thing happen when you walk quickly by a
| fence with slits too small to see through when you're
| standing still.
| _a_a_a_ wrote:
| I'll try doing that at my boss, see if it makes him any
| clearer.
| rlpb wrote:
| I'm puzzled as to how this works with respect to phase and
| "vsync". How is it that what you saw wasn't scrambled, even if
| spread out vertically again?
| detrites wrote:
| Displayed would have been a static unmoving screen of text (a
| typical BBS display), so the unsynced perturbations of
| haphazard raspberry motion should create enough randomly
| coincident content time-slices to form a complete image.
|
| EDIT to add: someone please make an emulation of this, with a
| slider to control the raspberry's pitch.
| throwawaysalome wrote:
| The strobe and accelerometers cost more than five dollars.
| WalterBright wrote:
| Back when I first started learning digital circuits, the first
| one would turn on an LED on and off, the rate was controlled by a
| potenciometer. I had a bit of fun changing the rate to see when
| the on/off became invisible. With a 'scope hooked up you could
| see the rate of the square wave.
|
| Fast forward decades, and some friends were working on a portable
| device with an LED display. It had a power consumption problem. I
| suggested instead of turning the LEDs on, to strobe them. They'd
| use much less power, and the difference would be imperceptible to
| the user.
|
| Then they had the idea of strobing the line of LEDs to form text
| messages you could see if you waved it back and forth, but was
| just a line of on LEDs if it was stationary. That worked
| surprisingly well, but as a toy it never caught on. But it was
| fun.
| alanbernstein wrote:
| I use these: https://www.monkeylectric.com/
|
| I'm surprised they're not more common
| FeepingCreature wrote:
| Those still exist! Search for USB LED fan.
| emiliobumachar wrote:
| There absolutely were popular-ish toys in which a spinning line
| of LEDs wrote messages, at least a few years ago in Brazil. I
| can't find a reference.
| wongarsu wrote:
| If you pack the LEDs more densely, you can display images as
| well, and in front of the right background it somewhat looks
| as if it was floating in the air. This makes them somewhat
| popular for advertising.
|
| The first one one google is https://holocircle.com/en/ but
| you will readily find devices on Amazon or at the retailer of
| your choice if you search for "hologram fan" or "hologram
| projector"
| zimpenfish wrote:
| I worked for a company back in 2009-10 that was trying to
| make giant (8ftx12ft ish) LED billboards by using 6
| spinners with LED arms that overlapped (IYSWIM.)
|
| Only saw it spin up once and it terrified me - all the
| wheels had to be chain-linked and -driven because they'd
| tried keeping 6 motors synced up at the same exact speed
| whilst spinning round hefty 4ft propellors and it just led
| to the arms hitting each other and "rapid unscheduled
| disassembly" - not what you want for your roadside adverts.
|
| They also made huge cylindrical ones that were actually
| deployed at a few places in London and around the UK. Never
| really took off because the mini-PCs inside[1] tended to
| shake themselves to bits after a few months of spinning
| around at 4000rpm.
|
| [1] I obtained my first Mac Mini from them free because
| they'd tried that in a cylinder, the _hard drive_ Did Not
| Like It, and they were just throwing it away.
| ignite wrote:
| There are a number of things like this. I can't find them now,
| but they used to make spinning displays. They had a single
| column of LEDs, but when you spun them, it would leave an
| afterimage behind, so the message "floated" in the air.
|
| Now, you can get fancier items, like
| https://www.etsy.com/listing/491059634/strange-light-up-led-...
| miahi wrote:
| Isn't the item in the link just an acrylic glass with
| patterns lasered on? With persistence of vision you can get
| animations, so I would say that's the fancier one.
| moloch-hai wrote:
| They are generally labeled with "persistence of vision".
| burntwater wrote:
| You're likely thinking of these displays from companies such
| as: https://hypervsn.com/ https://holofanco.com/
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