University of Michigan mechanical engineering students have built "the world's largest hand-solvable, stationary" Rubik's Cube. Fashioned primarily from aluminum, it weighs 1,500 pounds but can be manipulated by one person. The puzzle is available for solving in the campus's mechanical engineering building. From Michigan Engineering:
They realized they couldn't simply scale up the approach a handheld cube relies on because the friction would be too great. So to keep friction minimal, they devised a setup that utilizes rollers and transfer bearings.
"This is a truly amazing and unique kinematic mechanism that functions as a Rubik's cube," said Noel Perkins, the Donald T. Greenwood Collegiate Professor of Mechanical Engineering and advisor to the students.
"There is no other human-manipulable cube like this, to the best of our knowledge. That said, it is not technically the largest cube. We're aware of a larger cube that requires the user to literally roll it on the ground to solve and rotate the faces. None of that is required by our stationary design. So to be very precise, it is the world's largest stationary, human manipulable Rubik's cube."