UPDATE: It's famous! The smaller version was featured in an Instagram video on the PhysicsFun channel:
https://www.instagram.com/p/CAvYkMiF-2g/
Last summer I saw a presentation of Akira Nishihara's in which he discussed geometrical shapes that he found interesting. He sells many of them on Shapeways and he has a website too:
https://www1.ttcn.ne.jp/a-nishi/index.html
The one that really caught my interest is what he calls "Illusion Lissajous Roller" which he says was inspired by Bill Gosper's "Lissajous Roller". I've also heard it called the "Dual Axis Illusion".
I've made two versions available here, a smaller one with a frequency ratio of 3:2 and a larger one with a frequency ratio of 4:3. The smaller one is shown in the first four pictures (and in the video below) and the larger one is shown in the first two and last two pictures.
Basically, when you roll them on a flat surface they undulate like a Lissajous curve but give the illusion that they're rotating around their vertical axis when in reality they are rotating around their horizontal axis. It's a cute little kinetic optical illusion!
IMPORTANT: Because Shapeways is no longer able to print the roller in metal with the original (3mm) wire thickness, I have made a version of the roller that has thicker (5mm) wire. The pictures and video show the 3mm version in white nylon plastic, not the 5mm version in metal.