yes, the two support dowels in a face vise. The holes and alignment dowels must be perfectly smooth and aligned for it to work without binding. Also, the threaded holding block should be about 2" thick, which also helps. And after gluing the roughed-out hub into the threaded dowel, you concentrate on getting the dowel perfectly centered. I am buying exact size dowels from a company so there is no wiggle-room to mess around with where it will be off-centered in the final product. Trial by Fire, is what I think they call it. The learning curve is a bit more than I expected, but, I'm getting there.
The last resort is to glue the hub onto a piece of square stock and turn the whole thing.. Then, there will be no issues.