couldn't you mill a knob out of aluminuim (aluminum) or anything else just on a lathe?

I thought about that but then looked at the detail of the knob. It is so small and the inside of the knob does have relief work in it that using a lathe and chisel could be a major pain in the booty. Casting seemed a better aternative to me because the mold would be a duplicate copy of a knob I know works already, pouring metal is much easier than lathing metal, and I don't have a lathe or chisels for metal work. You probably could make wooden knobs on a lathe easily. But that again, this is all new teritory for me.