Pocket watches are all well and good, but they have some caveats. They either need regular rewinding, or they need batteries. Sundials on the other hand need only the light from our One True Sun. [JGJMatt] has just the project to convert your broken or disused pocket watches to the solar way of telling the time.
The key is to replace the clockwork internals and face of the pocket watch with a sundial instead. The first step is to create a face for the watch marked out for sundial use. [JGJMatt] explains how to do this with a variety of CNC, painting, or etching methods. He also explains how to use simple tools to generate a sundial design that’s ideally suited to your geographical location. This includes methods for aligning the sundial to True North or True South with an offset compared to Magnetic North or Magnetic South. This allows the sundial to be as accurate as possible. [JGJMatt] describes the general techniques while also building a sundial of his very own. The resulting piece is a handsome bit of brass with a lovely gnomon standing tall to cast a shadow on the dial.
It’s not a quick way to tell the time, by any means. However, the next time your friends ask you what time it is, and you whip out a compass to line up your sundial, they’re sure to be impressed. We’ve seen some creative sundial designs before, too, and if you’ve been creating your own fancy timepieces, don’t hesitate to let us know on the tipsline!
We see a lot of clocks, and many of the better ones have some 3D printed elements to them. But [Carl Sabanski] shows us his kits for making sundials for either hemisphere using a conventional printer (you know, one that puts ink on paper), some styrofoam, and possibly some other materials like wire coat hangers, threaded rods, thumbtacks, glue, and different papers like transparencies or card stock.
In all, there are 21 different kinds of sundials. Some are pretty standard-looking fare, but there are others, like the pinwheel equatorial sundial or the cycloid polar sundial, which might be surprising. One even uses a CD as a kind of indicator.
The US Senate has approved the “Sunshine Protection Act”, a bill to make Daylight Saving time the default time and do away with the annual time changes. While I can get behind the latter half of this motion, redefining Daylight Saving time as Standard time is, in my opinion, nonsense.
It’s particularly funny timing, coming right around the Vernal Equinox, when the sun stands at its highest right at Noon Standard Time, to be debating calling this time “one PM” forevermore.
Right Idea, Wrong Time
Let’s do a quick overview of the good idea here — doing away with time changes. These are known to cause sleep disturbances and this leads not just to sleepy heads on Monday morning, but to an increased risk of heart attack and accidents in general. When researchers look into the data, it’s the “springing forward” that causes trouble. People who’ve slept one extra hour don’t seem to suffer as much as people who’ve lost one. Go figure.
So maybe it makes sense to stop changing times. If we’re going to settle on one standard time, do we pick Standard time or Daylight Saving time? Admittedly, this is a totally unfair way to pose the question, but there are a number of good reasons to prefer all-year Standard time. The biggest one is winter. Basically, it’s already tough enough to get up on a cold January morning when the sun is not due to rise for another hour or two. Add another hour of darkness on top, and you know why the two previous attempts to run all-year Daylight Saving were short-lived. And why the Swedes drink so much coffee.
There’s also the fundamental logic behind our measurement of time that’s stood for centuries, and is embedded in most of our cultural references to time. Ante Meridian and Post Meridian. High Noon, when the hour hand on the clock points straight up, represents the sun itself. But even before clocks, the sun’s halfway point along its daily journey marked the halfway point of the day. That’s not only why we eat lunch when we do, it’s the origin of man’s time-telling itself.
If we change the definition of noon permanently, we’ve decoupled time from the sun. How will we explain time to future children? I’ll accept Daylight Saving time when we start reprinting analog watches with 1 o’clock at the top and start referring to 12 AM as the one that’s just before the sun reaches its peak. As soon as “one noon” replaces “twelve noon”, I’ll get on board. Midnight, when the clock strikes one, just doesn’t send the same shiver down my spine. Sorry, Dracula.
If culture and physics point to Standard Time, why would you want Daylight Saving to be the new normal? When people think of Daylight Saving, they naturally think of those nice long summer days that stretch out into the night. My personal bet is that many folks are confounding summertime with Summer Time. Heck, even the name of the bill proposes to protect sunshine itself, rather than just move the hands of the clock around. These are not good reasons.
We’re always a fan of an interesting or unique clock build around here, which often use intricate pieces of technology to keep time such as weights and gears, crystal oscillators, or even a global network of satellites in the case of GPS. While these are all interesting methods of timekeeping, the original method of tracking the sun is often forgotten. With this clock, the sun is the main method of keeping track of time, but unlike traditional sundials it has a number of advancements that let it keep surprisingly accurate time. (Google Translate from German)
While most sundials can only show hours, this one from [leon andré], a retired physicist, has a method for displaying minutes as well. It uses pinholes instead of shadows to keep track of the position of the sun, with the pinhole casting a bright spot of sunlight onto a diagram below. The diagram keeps track of the minutes, and consists of curved lines which help account for the sun’s changing path throughout a typical year. The dial keeps track of local solar time, as any sundial would, but by rotating it along its vertical axis it can be calibrated for the timezone that it’s in regardless of its position.
As far as clock builds go, one that is completely passive like this semi-digital sundial is fairly unique, especially for its accuracy. And, when set to local solar time, it will be the most reliable method of keeping time long-term than possibly any other clock we’ve seen before, as long as it’s not too cloudy outside. On the other hand, it is possible to augment a sundial with some modern technology as well.
Sundials, one of humanity’s oldest ways of telling time, are typically permanent installations. The very good reason for this is that telling time by the sun with any degree of accuracy requires two-dimensional calibration — once for cardinal direction, and the other for local latitude.
Switch it on, set it down, and the sundial spins around on a continuous-rotation servo until the HMC5883L compass module finds the north-south orientation. Then the GPS module determines the latitude, and a 180° servo pans the plate until it finds the ideal position. Everything is controlled with an Arduino Nano and runs on a 9V battery, although we’d love to see it run on solar power someday. Or would that be flying too close to the sun? Check out how fast this thing calibrates itself in the short demo after the break.
[Xose Pérez] set out to make a sundial wristwatch by combining a magnetometer a small nylon bolt for the gnomon, but it doesn’t work like you’d think. Instead of using the magnetometer to point the sundial north, you angle the watch until the bolt’s shadow matches the white line on the PCB, and the ATmega328P computes the azimuth of the sun and determines the time thereby. To display the time he used one of those QDSP-6064 bubble displays, because sundials are retro.
His description of the project build includes a lot of fun anecdotes, like him attempting to solder the LCC connections of the HMC5883 magnetometer before giving up and making use of Seeedstudio’s PCBA service. He got 10 boards back with the ATmega and magnetometer populated while leaving the rest for [Xose] to fill in.
One fun detail of the project? You can’t tell what time it is without the sun, but you can’t read the bubble display in bright sunlight.
You don’t get much more old school than a sundial, and more new school than 3D printing. So, it is nice to see these two combined in this impressive project: the 3D printed digital sundial. We have seen a few sundial projects before, ranging from LED variants to 3D printed ones, but this one from [Julldozer] takes it to a new level.
In the video, he carefully explains how he designed the sundial. Rather than simply create it as a static 3D model, he used OpenSCAD to build it algorithmically, using the program to create the matrix for each of the numbers he wanted the sundial to show, then to combine these at the appropriate angle into a single, 3D printable model. He has open-sourced the project, releasing the OpenSCAD script for anyone who wants to tinker or build their own. It is an extremely impressive project, and there is more to come: this is the first in a new podcast series called Mojoptix from [Julldozer] that will cover similar projects. We will definitely be keeping an eye on this series.
