Building a digital sundial

A Sundial displaying the time inside its shadow, with actual digits ! There is a tiny bit of magic inside…

No batteries, no motor, no electronics… It’s all just a really super-fancy shadow show. The shape of the sundial has been mathematically designed to only let through the right sunrays at the right time/angle. This allows to display the actual time with sunlit digits inside the sundial’s shadow.

The sundial displays time (with actual digits !!) from 10:00 until 16:00, updating every 20 minutes.

You can find the Openscad script and the STL files on thingiverse:

Sundials and Kangaroos

There is a tiny subtlety if you want to use this sundial in the Southern hemisphere:
Try to visualize an kangaroo in Australia. Just like everyone else, this ‘roo has to orient the tip of its sundial toward the north pole. For him, that means having the tip of the sundial pointing toward the ground…. this doesn’t seem very practical. Our hinge mechanism doesn’t even allow to tilt the sundial below horizontal.
The trick here is simply to build a subtly different magical black box (also called a gnomon) for kangaroos: 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. 

Fun fact about this sundial

You will most likely never see it in a supermarket or a department store. The swiss cheese inside the sundial is so intricate, that you can’t realistically use injection molding, or some other mass-production method. 3D printing seems actually to be the only practical way to build this digital sundial ! (is that really true ?? let me know what you think in the comments !)

Open Source model

One day I might write a proper wall of text in this blog, about the zoology of business models based on Open Source hardware. By the way, I really hope space aliens are also fond of Open Source Hardware (otherwise we might not be allowed to copy their technology). Here, this digital sundial is an interestingly exotic case:
It seems almost perfectly well-suited for an Open Source Hardware business model. You can only craft it with hobby/prototyping tools, and only very slowly (one every 1.5 days): basically it’s ideal for ” High-Tech Artisans “.

 Gift Shop

…which (almost naturally) brings me to say a couple of words about my gift shop on Etsy :
It was envisionned with two types of public in mind:
— Makers without a 3D printer, or the patience for 35hours of printing (it is a somewhat challenging print). This should still give them the opportunity to build their own digital sundial, and then hack it / modify it / invent something else.
— Geeks that might be interested in a cool gadget that won’t be available anywhere else.
And at the same time, I am hoping it will help a bit with the financing of the R&D for the next few inventions/episodes !

If you like this episode…

… please consider supporting the podcast:
— Share it around !
— Leave me some feedback !
— Come and visit the gift shop. 

From now on, I will aim to release both the English and French versions at the same time. This should limit any risk of spoilers before the release of an episode in English (:Until next episode….Keep on inventing !

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