[uoaei]

I wonder how much the rotation speed really matters. It comes down to the tensile strength of the material required to hold everything together I suppose but most metals should be able to handle 1g just fine. Once it's rotating you don't need much energy to keep it going, just enough to overcome any frictional losses from whatever interfaces happen to be required.

[iampivot]

There's also the issue of dizziness if rotating fast with a small radius.