Miniaturizing technology isn’t always about making it smaller, it’s also about retaining the main function of the object while modifying it to fit its new form factor. A small manual transmission may be cool, but it’s even cooler if the design matches the technology used to create it. This miniature three-speed manual transmission built by YouTuber PolyProject3D is a perfect example.
It’s a manual transmission, of course, but in principle it works much more like an automatic transmission, using planetary gears and brake marks to shift gears. It is not a manual as we know it, but the design is very well adapted to 3D printing, which is not necessarily the case with a classic manual.
Nor is it a simple device existing in a vacuum. It pairs with one of PolyProject3D’s other interesting creations, a small four-cylinder engine powered by compressed air. As such, it features a bell housing and other design considerations, such as a recessed servo motor on the front, to allow for clean mating between the two entities.
The actual gear change is carried out by the servo, which operates a three-lobe camshaft. Rotating it to a certain position will tighten a specific shift band, which will brake one of the ring gears. Braking each ring gear provides a different ratio. Failing to brake on any of them means the transmission is in neutral.
The design, on the contrary, is a nice mix of mechanical and aesthetic elements. He doesn’t just achieve something, he enjoys the way it is achieved. It’s a balance that we don’t see often and is certainly worth emphasizing.
