11 ms·
3D printed sundial whose precise holes cast a shadow displaying the current time
- gulpahum 11y agoInteresting, on the Southern hemisphere, the sundial needs to point to the South Pole and the design needs to be altered: "in the Openscad script you can set a flag that will simply rotate upside-down the whole swiss cheese inside the gnomon, and build a ‘Southern-hemisphere’ version of the gnomon. This way, the ‘roo can simply use this Southern-hemisphere sundial exactly the same way a cow or a penguin would use their Northern-hermisphere version the sundial, with just one difference: the ‘roo will have to point the tip of his sundial toward the South Pole." [1] [1] http://www.mojoptix.com/2015/10/25/mojoptix-001-digital-sundial/ http://www.mojoptix.com/2015/10/25/mojoptix-001-digital-sund...
- clouddrover 11y ago> a cow or a penguin would use their Northern-hermisphere version the sundial But penguins live in the southern hemisphere. Conspiracy?! Maybe! It must be a Galapagos penguin: https://en.wikipedia.org/wiki/Galapagos_penguin https://en.wikipedia.org/wiki/Galapagos_penguin
- TazeTSchnitzel 11y agoA YouTube commenter offered a possibly more plausible explanation: > Angela Brett 1 month ago > +Tainer Waynes Maybe he confused the English word penguin with the French word pingouin, which means auk (a bird similar to a penguin which lives in the Northern Hemisphere.) The French word for penguin is actually manchot. :) https://www.youtube.com/watch?v=wrsje5It_UU&lc=z13uhf54clysu1keb23pwrmxhryzcrqbt04 https://www.youtube.com/watch?v=wrsje5It_UU&lc=z13uhf54clysu...
- celticninja 11y agoAn auk has a black beak, the penguin in the video is of the orange beaked cartoon type of penguin.
- ArcticCelt 11y agoMaybe, but as a french speaker I can confirm that it's easy to confuse. I just learned that Pingouin and Penguin are not the same. There is even a whole section explaining more subtleties about why it's often missuses in the french language. Confusion habituelle Par abus de langage, le pingouin est souvent confondu avec les manchots, des oiseaux de la famille des sphéniscidés qui vivent dans l’hémisphère sud et ne volent pas. La principale raison de cette confusion est la ressemblance avec la plus grande des deux espèces de pingouin, le grand pingouin. Une autre source d’erreur est la parenté étymologique entre le mot français pingouin et celui désignant les manchots dans les principales langues européennes comme pinguïn en néerlandais, pingüino en espagnol, Pinguin en allemand, pinguino en italien, penguin en anglais, пингвин (pingvin) en russe, ou encore pinguim en portugais. Dans de nombreuses langues, deux termes différents sont utilisés pour désigner les deux espèces de pingouin, ce terme n’a donc pas de traduction exacte. En anglais, le terme Great Auk désigne le grand Pingouin, auk étant un terme générique désignant le plus souvent l’ensemble des alcidés. Le petit Pingouin est quant à lui appelé razorbill. En catalan ou en italien, respectivement les termes de gavot et alca sont en revanche utilisés comme en français pour désigner les deux espèces.
- clouddrover 11y agoThe Oxford dictionary has an entry on the origin of the word penguin: http://www.oxforddictionaries.com/words/what-is-the-origin-of-the-word-penguin http://www.oxforddictionaries.com/words/what-is-the-origin-o... And they made a short video on the same: https://www.youtube.com/watch?v=M09oIwSQ6q4 https://www.youtube.com/watch?v=M09oIwSQ6q4
- ttctciyf 11y agoThis point is addressed by the inventor in the comments at TFA: Ernest Shackleton October 29, 2015 at 10:21 am Penguins at the North Pole?? Julldozer October 29, 2015 at 10:56 am If you were a penguin on a touristic trip, where would you go for the Xmas holidays ?
- haberman 11y agoWhat if you're on the equator?
- ploxiln 11y agouse the northern-hemisphere sundial stick, arrange it parallel to the ground and "top" pointed north (or use the southern hemisphere sundial stick and point it south. this just swaps what end the base is on.)
- bcook 11y agoWould you not align it parallel with the equator, and therefore get a more squished (horizontally compressed) time display?
- tobr 11y agoVery clever! Is there any reason why you couldn't just carve out tunnels shaped like the numbers, using a stencil typeface?
- soheil 11y agoYou'd need a lot more carvings.
- soheil 11y agoThis is just incredible, would love to see a version with milliseconds support:) It'd also be nice if the numbers didn't fade in/out but had a sharp cut off point where they'd quickly switch.
- pjc50 11y agoThink about how it works and you'll realise why those are incredibly difficult to achieve.
- periodontal 11y agoWhile theoretically possible, it'll be very difficult to realize physically. If you allow fractal constructions, purely unrectifiable sets can fit the bill. For example, here's an example in 2-dimensional space that casts a solid shadow when the light source is along one axis but not from any other: https://books.google.com/books?id=usjNBQAAQBAJ&lpg=PP1&dq=&pg=PA34#v=onepage&q&f=false https://books.google.com/books?id=usjNBQAAQBAJ&lpg=PP1&dq=&p...
- nightcracker 11y agoWith millisecond precision I think it's even theoretically impossible as the slits would become so small it destroys the shadow in an effect seen in the double slit experiment. But that's just a gut feeling.
- vacri 11y agoAre you planning on having a javascript sundial? :)
- deutronium 11y agoVery cool! Also apparently a 'digital' sundial was patented at one point - https://en.wikipedia.org/wiki/Digital_sundial https://en.wikipedia.org/wiki/Digital_sundial http://www.hineslab.com/digital-sundial/ http://www.hineslab.com/digital-sundial/ - The notebook drawings are cool
- cfcef 11y agoSo would OP be the 'fractal sundial'?
- deutronium 11y agoYeah I think it would be
- deckar01 11y agoI would consider it a holographic sundial. A fractal is "any of various extremely irregular curves or shapes for which any suitably chosen part is similar in shape to a given larger or smaller part when magnified or reduced to the same size"[0]. A hologram is "a three-dimensional image reproduced from a pattern of interference produced by a split coherent beam of radiation"[1]. The 3rd dimensional component of the hologram is modulated by the position of the sun instead of the observer. [0] http://www.merriam-webster.com/dictionary/fractal http://www.merriam-webster.com/dictionary/fractal [1] http://www.merriam-webster.com/dictionary/hologram http://www.merriam-webster.com/dictionary/hologram
- rahul286 11y agoAmazing! I am wondering how much extra time it will take for 3D printing as we add support for 10 minute time interval, 1 minute interval and then seconds (extra set of digits HH:MM:SS). Also will it be practically possible to have second-level granularity?
- dnate 11y agoThe change in the direction of light per second will be way too little to create a digital sun dial of this style. It would need some sensors to detect it which kind of defeats the purpose again. It's not a shortcoming of 3D printing but of optics/physics
- theoh 11y agoConsider the size of the sun: it's not a point source. Even if it was, the "seeing" (astronomical term for sharpness of objects in the sky) is usually on the order of arcseconds at night, probably much more (due to convection) during the day. So even with image-forming optics, 1 sec temporal resolution is very tricky. (earth turns 15 arcseconds in one second)
- chongli 11y agoYeah, not to mention the simple problem of diffraction you get when light encounters obstacles such as narrow slits.
- jessriedel 11y agoYou'll only get diffraction when the slits are comparable to the wavelength of the light, i.e., on the order of a micron. I believe you can see light peeking out through a micron slit if you're looking directly at it in a dark room, but I don't think it's feasible to see diffraction in shadows. The fuzziness you see in normal shadows comes from the finite angular size of the light source, not the wave nature of light.
- skykooler 11y agoThe width of the Sun in the sky is wide enough that it takes about 1 minute and ten seconds to cross its own diameter. So optically speaking, it would be pretty much impossible to have any resolution finer than a minute, no matter how small the holes are.
- theoh 11y agoThere's a high profile public digital sundial in Paris, installed in 1989: http://www.cadrans-solaires.fr/cadran-halles-paris.html http://www.cadrans-solaires.fr/cadran-halles-paris.html
- kweks 11y agoUnsure this is still there, Les Halles has been under major works for the last 4 years - haven't seen the sun dial for years.
- edejong 11y agoProbably just as impressive is this (patent just expired) digital sundial: http://www.digitalsundial.com/ http://www.digitalsundial.com/
- IvyMike 11y agoThis older one is pretty neat, too. I've owned it for a while and still can't really figure it out--the shadow mask is incredibly thin, and as far as I can tell it works on magic. http://www.digitalsundial.com/product.html http://www.digitalsundial.com/product.html
- emptybits 11y agoHere is the patent for that product. Perhaps this will shed some light on how it works. I'll see myself out. http://www.google.com/patents/US5590093 http://www.google.com/patents/US5590093
- tyingq 11y agoVery, very, cool. This got me searching for other implementations of a digital display sundial. This one is interesting...uses a mask of slits http://www.fransmaes.nl/genk/welcome-e.htm http://www.fransmaes.nl/genk/welcome-e.htm (iframes, ugh...click #8 in the left sidebar) Edit: Another cool implementation http://www.voshart.com/SUN-CUBE-prototype http://www.voshart.com/SUN-CUBE-prototype
- kilovoltaire 11y agoI bought one of those a while ago, very clever. They are sold at http://www.digitalsundial.com/ http://www.digitalsundial.com/
- kbart 11y agoWow, this site took me back to 1995.
- medmunds 11y agoOn original site: http://www.mojoptix.com/2015/10/25/mojoptix-001-digital-sundial/ http://www.mojoptix.com/2015/10/25/mojoptix-001-digital-sund...
- dang 11y agoOk, we changed the URL to that from http://boingboing.net/2016/02/09/a-digital-3d-printed-sundial.html http://boingboing.net/2016/02/09/a-digital-3d-printed-sundia.... Thanks!
- pen2l 11y agoThanks. Also, I encourage everyone to donate to the guy, which you can do here: http://www.mojoptix.com/donations-page/ http://www.mojoptix.com/donations-page/ What he is doing is just so wonderful and inspiring in so many ways, and to top it all off, he's doing it without muddling up his content with ads and other gimmicks. Please repay him for what he is so selflessly giving out for free and without strings attached. (He is sharing all files, all 3d designs etc... of such complicated things, a lot of people don't do that, so this guy is just super brilliant). I don't make a lot of money but I'll be giving him $50. I hope you can give even more. :)
- ant6n 11y agoSkip the intro and see it in action: https://youtu.be/wrsje5It_UU?t=12m58s https://youtu.be/wrsje5It_UU?t=12m58s
- Beltiras 11y agoI found the explanation of the technical challenges well done and worth the time.
- jhallenworld 11y agoIt should display the time with Roman Numerals... then ancient Romans could use it. This is very cool, I'm going to have to play with OpenSCAD.
- MrBra 11y agoso this proves that time really exists ;)
- deleted 11y ago[deleted]
- mitchtbaum 11y agoIf you see that when it casts these shadows, then you could call it real, sure. You could also look at it as celestial bodies aligning and their patterns of shades of light. Accuracy helps a lot when using understanding of some things' existence to find another thing and its attributes (incomplete understatement). Proof making and checking helps a lot for someone to stay true to their beliefs and maintain a consistently accurate path.
- bdg 11y agoI doubts the claim about only being able to produce with a 3d printer. I can imagine easily making the layers in mass out of wood and sliding them through bandsaws to mass produce these.
- hop 11y agoThat sounds orders of magnitude more difficult. You might as well 5-axis machine them.
- DannyBee 11y agoYou don't need 5 axes to machine what he machined. It looks like you can do it with 3 (at least, my CNC seems to think it will do it). 4 at the worst if you want to spin it for some reason. Truthfully, the problem they have is that it's still cheaper, easier, and more accurate to do this with a subtractive CNC machine. Plus you aren't material limited.
- jessewmc 11y agoThis can't be done in a single setup on a 3-axis, its not xy-monotonic (there are overhangs). Theoretically you could do it on a 3 axis by manually remounting the piece at different angles, but it would be hundreds if not thousands of setups. 4 axis is definitely the practical minimum to machine it.
- alephnil 11y agoYou could not make it with a 3-axis CNC machine in one piece, but you could modify the design to make it possible without too much trouble. One way could be to make the base separately, and then insert the "blinds" that makes the digits separately.
- DannyBee 11y agoIt looked like the the overhangs can be machined with a small rabbeting bit (remember that we can use more than just end mills :P), and like i said, both my pieces of HSM software seemed to think it wasn't trouble (IE the simulated finished piece is within 0.001). You are right that in practice, you would likely want a 4th axis rather than messing around, but a 4 axis setup is just not a big deal (the 4th axis on my woodworking CNC cost < 4k)
- StavrosK 11y agoCan anyone tell me how OpenSCAD compares to something like SolidWorks for designing objects? I'd much prefer to learn something open and programmable, but if SolidWorks is much easier to use for common cases, then I'd go with that. I've never used any 3D designing program other than SketchUp.
- mberning 11y agoOpenSCAD is completely prorgammatic. You write scripts to generate solids and manipulate them. There is no graphical editing. With something like solidworks most of your work is done visually on drawings. I really enjoy cubify design which is a cheap alternative to solidworks. I have designed a ton of stuff with it. They both have their virtues. I use both for designing my 3d models depending on what I need. I think being experienced in both will make you better on each piece of software.
- oxplot 11y agoI've only ever used FreeCAD and OpenSCAD. I assume SolidWorks is something like FreeCAD, an interactive 3D editor. Out of the two, I'd pick OpenSCAD any day. Here're some reasons: * If you're a programmer, the learning curve of OpenSCAD is almost non-existent. Assuming you're familiar with 3D modelling concepts, it should take an hour or two to go through and play with the entire feature set of OpenSCAD [1] (which I did). * It's simple and the defaults are sensible. * Your model is basically a line based source file which can be put under git and improved through pull requests, etc. * Your model is easily made parametric. Last model I made was a tripod mount where I could simply change the angle of the legs or wall thickness and everything would adopt. * OpenSCAD can be used as an 2D vector modeler as well. For me, it's replaced Inkscape 90% of the time. There are however things that are not as easily doable with OpenSCAD. One feature lacking is constraint solver so you have to do some back of the napkin trig for such things. I've also found it non-trivial to simply "chamfer" an edge, like I could in FreeCAD. [1]: http://www.openscad.org/cheatsheet/ http://www.openscad.org/cheatsheet/
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- leeoniya 11y ago
- wetmore 11y agoSomething like this came up on hn a while back: https://news.ycombinator.com/item?id=8042673 https://news.ycombinator.com/item?id=8042673
- DickingAround 11y agoThis kind of creativity is really something special to the 21st century; not just that people can make things but that they can make things which are so complex and otherwise would have been cost prohibitive before CNC technologies like 3d printing.
- lvs 11y agoYou're serious? There are a few centuries of history in amazing timekeeping engineering -- long before, guffaw, CNC. Just a random link to a Breguet, for instance: http://www.breguet.com/en/house-breguet/manufacture/marie-antoinette-pocket-watch http://www.breguet.com/en/house-breguet/manufacture/marie-an...
- supahfly_remix 11y agoHow does the error vary with how far you are from the edge of the time zone?
- madaxe_again 11y agoAs much as local solar time differs from your time zone. This would be of limited use in China, for instance, where the entire country is on a single timezone, despite solar time having a four and a bit hour spread.
- ansible 11y agoIt would be relatively easy to modify the script for your own location in China to display the correct time. So that it is not displaying 12:00 when the sun is directly overhead.
- tempestn 11y agoThere shouldn't be any error, because you can rotate the top piece to calibrate the time. He also mentions in the video that because of that you can account for daylight savings time changes.
- JoeAltmaier 11y agoSeems cool. But a 15-minute video? Pictures or it didn't happen.
- dominotw 11y agofinally a killer app for 3d printing. Future is here.
- mitchtbaum 11y agoCool! Perhaps someone could cast a piece like this with concrete or baked clay inside a larger, sturdy building to display an alphanumeric message to future generations, only during specific alignments. I can see one potential benefit compared to hieroglyphs, tablets, pillars[0], and other megalithic messages that some of our ancestors left us; it would take different skills to warp its message than simply a chisel or spray paint. One fictional story that comes to mind, Indiana Jones' Staff of Ra[1], makes this seem like even if only for a treasure hunt game, it would make for a fun story later on. 0: https://en.wikipedia.org/wiki/Ashoka_Pillars https://en.wikipedia.org/wiki/Ashoka_Pillars 1: http://indianajones.wikia.com/wiki/Headpiece_to_the_Staff_of_Ra http://indianajones.wikia.com/wiki/Headpiece_to_the_Staff_of...
- nbohra 11y agohttp://longnow.org/clock/ http://longnow.org/clock/
- zeristor 11y agoI loved this. Then I thought how about if you could use words which appear in the shadow over the day. As ever someone had already had the same idea written the code to produce the OpenSCAD files for different wordings and put it on Github: https://github.com/roipoussiere/Customizable-Shadow-Display https://github.com/roipoussiere/Customizable-Shadow-Display
- techlover14159 11y agoWow. This is amazing!