Gears have always fascinated the human psyche. Symbolizing human ingenuity through cooperation, watching gears spinning in unison is a captivating activity for our otherwise busy brains.
With the rise of 3D printing, gears have grown in popularity and a great deal of blog-media focus has been placed on "gear spheres". Gear spheres are highly-complex mechanical globes where each gear cog must be in perfect alignment in order for all gears to rotate properly. What truly boggles the mind is that the many gear spheres being created are 3D printed fully assembled.
Watching each cog turn in mathematical harmony, one is reminded of 3D printing's vast potential to create objects that would be nearly impossible to manufacture by any other means.
Conceptually, the idea of a gear sphere is nothing new – some date back to ancient Greece. Known as celestial spheres or armillary spheres, the ancient gear-like spheres were used in Medieval China, Europe, and Islam as celestial maps to determine the positions of the Earth, Sun, Moon and stars. Now gear spheres of greater sophistication, precision and complexity can be 3D printed, allowing digital artists to reimagine the celestial globes of a past era.
Pushing the boundaries of gear spheres forward are Toru Hasegawa's recent Mechaneu, Eric Cox's SCORG (which stands for spherical configuration of rounded gears), and Henry Segerman's multi-geared inventions. While Hasegawa, Cox, and Segerman's gear works have been getting much notoriety lately, there is one gifted engineer who has been setting the standard for gear sphere mechanics, and that is Paul Nylander.
In the community of gear sphere enthusiasts Paul Nylander's web site is held in high esteem. A maker before the term became indoctrinated in our cultural lexicon, Paul has an underground following of gear fanatics, designers, artists and engineers.
Nylander's web site is a virtual museum of beautifully-designed mathematical visualizations. Dedicated to using computer graphics to illustrate math-based art, it is a perfect resource for educators, artists, and engineers who want to better understand engineering principles through computer generated simulations. He is very generous with the information he releases to the public, openly posting code snippets and his various techniques using Mathematica, Pov Ray, and 3-D Studio Max.
Inspired by his friend and fellow gear-fanatic John Pettyjohn, Nylander has been driven to create gear spheres in countless variations such as conical, hypoid, brain, and spiral. With a desire to create spheres of increasing complexity, he developed a software program that would generate gears of various ratios and designs. This treasure trove of gear information is showcased on his site and is a valuable asset for those who wish to get started creating gear spheres of their own.
Nylander notes that to successfully print a fully assembled gear sphere, selective laser sintering (SLS) is the preferred method. However, the SLS process uses a powder material that is fused to make the final assembly. Small crevices between the gears can trap powder from the SLS printing process, causing them to get stuck. The gears may sometimes need to be initially forced or broken in before they can rotate smoothly. Nylander also recommends using silicone to help lubricate and seal the printed sphere.
Nylander's next project may be printing one of his 242 gear spheres. He has been hesitant to print the more complicated design but after seeing what was possible with his 92 gear sphere, he is no longer worried about the additional torque and friction issues that could possibly be associated with the much smaller gears found in the 242 gear sphere.
While Nylander's 92 gear sphere is not for sale, those interested should stay tuned to his Shapeways page, where he will eventually present a version of his 92 gear sphere for sale.