That cube is meant as a collector's item, not to be messed around with. Any cube made of metal won't work well because it doesn't "give" as well as plastic does.
A note was packed with it saying something like, "This is not a speed cube. Sides must be precisely aligned for turning."
This was obvious to me, but not to the extent I experienced. I don't care if it does not cut corners well. I don't care if I have to align it well. But I was not expecting this.
The corners pull inward too much, so when you turn a face, the corners lock into the side cube edges without fail. The only way to complete a turn is to pull all 4 corners of the face
outward so they clear the edge cubies.
It is not a matter of simply aligning things well. You need to pull corner pieces outward as you turn, otherwise it will always jam up.
I think they might have been worried about the corners being slightly small, causing them to rattle. I think they over-compensated and now the corners are rock tight. The edges actually shift very slightly from the centers, but the corners are very tight. Because the edges give slightly, they might not stay tight against the center piece when a corner piece tries to spin by.
Each of the 8 corners has one interior face open (uncapped). The uncapped face and its inside edges do not affect the jamming.
The nickel cube could be designed to work properly without jamming intensely on every turn. They overlooked the physics involved with jamming.
A plastic cube designed the same way would jam just as badly. A simple cure would have been to round off all metal edges/corners. Then the pieces will tend to roll off one another more, rather than jam up. When I have the time, I will open it up and round off the jamming edges/corners.
