How to draw a parabolic shaped solid?

Hi there,

I am trying to draw a parabolic shaped solid to present an AFM tip. I can draw a parabolic curve in 2D using the paramatric curve function. Then I can do revolve of the prabolic curve. Finally I get a parabolic shell structure insdead of a parabolic solid?
Can you tell me how to get a parabolic solid? Thank you very much!