I am trying to generate geometry of Propeller KA 4 70 . But whenever I draw the shaft the shape of the tip gets changed. I have 3D airfoil section at various radius. I have imported them using curves through xyz and then I filled the each curve using surface fill option. Afterwards, i am lofting each surface to get solid blade. But, when I extrude the shaft the shape of tip of blade gets changed. I have attached my drawing and when you unsuppress the extrude feature you will see shape of tip getting changed.

Thank you in advance.