I love clock projects. Mankind has found many ways to track the passage of time throughout the years and each new technology finds its way into telling time. 3D printing is no different. From attempting to build fully-printed clocks to making watch straps, Makers continue to find ways to tell time with their printers.
Mojoptix, a new video podcast, has created an amazing blend of old and new tech to create an incredibly unique time telling project: a digital sundial. Like a traditional sundial, the Mojoptix digital version relies on the angle of the sun to tell the time. Instead of reading the position of the shadow though, the digital sundial projects the time into the shadow in 20 minute increments.
Each pixel in the readout is created by a channel that passes through the gnomon (the shadow casting arm of a sundial). Laying out the pattern for each of these channels would be a difficult process at best if you had to arrange each one manually. Instead, Mojoptix‘s Julldozer used OpenSCAD to programmatically lay out each channel. The OpenSCAD script included in the Thingiverse post really shows how powerful OpenSCAD is as a tool.
Since sundials rely on the position of the sun to accurately tell the time, and the angle of the sun can be different depending on your position on the earth, Mojoptix has created gnomon for both the northern and southern hemispheres. The design also includes two rotation points, allowing the user to fine tune the position to account for their location and even adjust for daylight savings time.
This design requires a well tuned-in printer on the larger side to pull it off. The creator suggests a really high resolution to be able to have clear channels that properly create each of the pixels. The creator used an Ultimaker 2 in this case, with high resolution and large build plate to fit the need.