Sundial Watch: the Original Smartwatch





Introduction: Sundial Watch: the Original Smartwatch

With all these newfangled smartwatches coming out, perhaps it’s time to get back to the basics. The sundial watch is the original smartwatch, with location specific design that utilizes the power of the sun to tell time. No batteries, no apps, no accelerometer, just classic design. Used for millennia, the sundial is the tried and true way to tell time, connecting you to the natural cycles of the sun. Your Sundial Watch will never run out of batteries or need a recharge, but cloudy days could pose a problem.

The 3D printed Sundial Watch Collection combines the latest in digital fabrication technology with ancient knowledge of the sun’s movement. The Sundial Watch allows you to escape “digital time” and the anxiety created by the constant seconds ticking away your day. The Sundial Watch focuses your attention on light and shadow, developing a relationship with the sun and a more fluid perception of time.

The Sundial Watch Collection includes four designs personalized for your location and lifestyle. Each Sundial Watch is made specific to your geographic coordinates, adjusting the gnomon and angle of the hours. Using a resin-based Objet 3D printer, each watch is crafted with digital precision and made from a fused combination of a flexible material in the watchband and hard material for the watch body. All watches contain a compass inlay to orient north and keep you moving in the right direction.

Step 1: The Sundial Watch Video

Step 2: Historical Precedents... Go Ancient!

From the Flintstones to 16th and 17th century Germany, portable sundials have been used as fashionable timepieces. The Sundial Watch Collection draws inspiration from the intricately crafted Ivory diptych dials made by the famous sundial and scientific instrument maker Leonhart Miller. These sundial could be set for use in various latitudes, making them helpful for merchants and travelers in Renaissance Europe. With the Sundial Watch you can go ancient! They were on to something in Egypt all the way back in the 13th century B.C..

Step 3: Making a Sundial Watch for Your Location

To be accurate, sundials need to be calculated for a specific local geographical latitude; the angle of the gnomon must equal the local latitude and aligned with true North. The Sundial Watch Collection are all horizontal sundials, with the exception of The Traveler, which is a diptych sundial, a combination of a vertical and horizontal sundial. While equatorial sundials have evenly spaced hour lines that are 15 degrees apart, horizontal sundials must calculate hour lines with the following formula:

tan(H) = sin(L) tan(15degrees x (t))

Where, L = latitude, H = angle between a given hour-line and the noon hour-line, t = the number of hours before or after noon


  • Daylight Saving Time Correction: Adjust time by one-hour
  • Time-Zone (Longitude) Correction: Standard time zones are 15 degree of longitude and each degree equals 4 minutes of time.
  • Equation of Time Correction: Sundial readings will need to subtract or add time due to the elliptical orbit of the Earth (see attached image).
  • True North Correction: The Earth's magnetic pole, read by a compass, doesn't correspond to a Geographic North Pole, and must be adjusted by geographic location (see attached image and reference below).

Note: A sundial for one latitude can be adjusted for use at another latitude by tilting its base upwards or downwards by an angle equal to the difference in latitude


Step 4: Designing Your Sundial Watch

Designing the Sundial Watch Collection, I first started in 2D, creating the outline of the watch body and band. I then drafted the hour lines and gnomon of the sundial following the procedures outlined in the previous step.I then researched sizes and types of compasses to inlay before completing the 3D modeling. The watch band and moving hinges were slightly offset with a gap, while the black text was Boolean subtracted from the solid watch body. This is important when preparing the file for a 3D print. .

If you don't have a 3D printer, no problem, there are numerous online services available that usually just require that you upload an .stl file. Attached are my .stl files that can be downloaded.


Step 5: 3D Printing Your Sundial Watch

I used a resin-based Objet printer with materials Vero White and Tango Black. The Objet printer uses a support material that allows for varied shapes and spacing between structural members. After printing, the support material is cleaned off by hand and with a high-powered water machine.

Step 6: The Classic

“The Classic” offers traditional sundial design with a full watchband flange for replacement and customization. The watch interior contains a 20mm air damped compass with an ultra-low friction bearing for fast and precise readings.

Step 7: The Sport

“The Sport” is a modern take on traditional sundial design, offering a sleek unified watch body and band with a flexible gnomon dial for those with active lifestyles. The watch interior contains a 20mm air damped compass with an ultra-low friction bearing for fast and precise readings.

Step 8: The Traveler

“The Traveler” is diptych sundial modeled after the famous 16th and 17th century pocket timepieces made in Germany. The Traveler can be customized to include the latitude for up to four cities, making it an ideal choice for business trips and vacation. The watch body contains a hinge and latch for smooth opening and closing. A string and stopper design allows the adjustment of latitude with ease. The watch interior contains a 5/8” diameter magnetic aluminum compass.

Step 9: The Adventurer

“The Adventurer” is designed for the outdoors. A sleek unified watch band and body opens with a hinge to reveal a flexible and replaceable gnomon dial. A 1/2” diameter magnetic aluminum compass on top keeps you moving in the right direction.

Step 10: Have Fun, Get Some Sun!

The Sundial Watch needs sun to operate (or bright moonlight), so get outside and have some fun! Make your own and join the emerging sundial watch community.

2 People Made This Project!


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I would love to make this! The only problem, I don't have a 3D printer. :(

Great idea, and thanks for sharing the designs. Worth mentioning, this won't work with bright moonlight (as suggested in step 10), for obvious reasons...

How did you print the numbers to go on the watch face? They seem to be two separate files rather than 1. Also I soooo vote for a version that has the pointer able to fold sideways so it is not sticking up until you need it to, but isnt a totally seperate piece that you have to stick in. Love these!


Really it is a orignal smartwatch....

I like "The Traveler"

I have a doubt! If you live in the South Hemisphere, how do you have to proceed! Either to build or to read hours?

A sundial at a particular latitude in one hemisphere must be reversed for use at the opposite latitude in the other hemisphere. Check out the link in Step 3 under "History and Description" for details.

Just to know, it have a Network of specialized technical assistance around the world? And how many embedded functions it have. It glows in the dark automatically or I have to push a button?
I think I want all of it!

I WANT ONE! (The Traveler would be nice) Christmas is coming, and this would be a terrific gift for us old fogies who feel a little behind in the tech world. Do you get a commission or something if I would take your downloaded file to an outside printing source? I mean, I appreciate reading instructable files even if I probably would never make one, but many of these ideas are potentially commercial products and you should benefit from your intellectual property.

This is free to share and modify. It's part of the Creative Commons as are many of the wonderful Instructables. So, please do download and print your own and join the Sundial Watch Community!