Rebuilding My Tellurion

There’s something endlessly fascinating about mechanical motion — especially when it’s tied to the movement of planets. Back in 2020, I built my first Tellurion, as a follow up to a Copernican Orrery, combining laser-cut wood, acrylic, gears, and hand-crafted planetary marbles into a working mechanical sculpture. Over time, though, I learned a lot about the limitations of that original build, which eventually led me to completely redesign and rebuild the entire project from the ground up, using some of the original parts.

 

This post is a look at both versions of the tellurion: the original concept and the rebuilt Version 2 that improved nearly every part of the design.

What's the difference between a tellurion and an orrery?

An orrery and a tellurion are closely related mechanical models of astronomy, but they focus on different things.

Orrery

An orrery is a mechanical model of the solar system that shows planets orbiting the Sun.

 

Typically, an orrery includes:

  • The Sun at the center
  • Multiple planets orbiting around it
  • Gear systems that simulate orbital motion
  • Sometimes moons or additional celestial bodies

 

The main goal of an orrery is to visualize the motion and relative positions of planets in the solar system.

Tellurion

A tellurion (sometimes called a tellurium) is more specialized.

 

It specifically demonstrates:

  • The relationship between the Earth, Moon, and Sun
  • Earth’s rotation
  • Earth’s orbit around the Sun
  • Moon phases
  • Seasons
  • Eclipses

 

A tellurion is essentially an educational model focused on explaining:

  • Why seasons occur
  • Day/night cycles
  • Lunar phases
  • Solar and lunar eclipses

 

The word comes from Tellus, the Latin word for Earth.

The Design

I started this project by using an online gear generation tool to get the rotation of the earth and moon correct.  I couldn’t get the moon rotation exactly 12.36 with the available GoBilda gear sizes, but got pretty close at 12.5 moon rotations per one earth orbit.

The Original Build

The original tellurion was one of those projects where I kept pushing myself to see how far I could take laser cutting and mechanical design. I wanted something that blended art, astronomy, and engineering into a functional kinetic sculpture.

 

The build featured layered laser-cut wooden components, acrylic supports, planetary marbles, and a gear train designed to rotate the planets around the sun. The zodiac ring around the outer edge added an astronomical touch while helping frame the entire piece visually.

 

At the time, most of the gearing system relied on laser-cut gears. While they looked great and worked surprisingly well initially, I eventually discovered one of the biggest challenges with wooden gears: friction and wear over time. As the mechanism aged, the gears gradually became stiffer. Eventually, someone forced the mechanism a little too aggressively, causing slippage and damaging the motion system.

 

Even though I still loved the concept, I knew the design deserved a second chance.

A Complete Redesign

Instead of trying to repair the old mechanism, I decided to completely rethink the structure and motion system. The new design re-used only a few elements from the previous build, including the hand-made planetary marbles and one bearing assembly. Everything else was redesigned for smoother motion, improved durability, and a cleaner presentation.

 

I used Adobe Illustrator to create the design mockup to be laser cut on my Glowforge.

 

The Base

The new base design was another major improvement. I never fully liked the original stand, so this rebuild gave me the opportunity to create something more substantial and refined. The layered walnut base gives the orrery a much stronger visual presence, while the clear acrylic gear supports create a floating mechanical look that really highlights the movement of the system.

 

One of my favorite details in the redesign is the transparent acrylic structure supporting the planetary marbles and gearing system. Being able to see through the mechanism adds a completely different feel compared to the heavier original build. It almost makes the gears appear suspended in midair.

 

The rebuilt orrery feels less like a prototype and more like a finished kinetic sculpture.

Aluminum Gears

One of the biggest upgrades was replacing the original laser-cut gears with precision metal GoBilda gears from ServoCity. I also incorporated aluminum D-shafts and proper bearings throughout the mechanism. The difference was immediate — the motion became dramatically smoother, more precise, and far more reliable.

Lessons Learned

Projects like this are always iterative. Every version teaches something new about materials, tolerances, movement, and design.

The original tellurion taught me a tremendous amount about gear mechanics and laser-cut precision. The rebuilt version taught me when it’s worth switching materials entirely and investing in better mechanical components.

 

That balance between artistic design and functional engineering is what keeps these projects interesting for me. I love building pieces that not only look visually striking but also invite people to interact with them and explore how they work.

 

And honestly, seeing the planets smoothly rotate now without resistance makes the rebuild completely worth it.