Hi matur61, CAD programs like MoI are mostly focused on modeling precise shapes like machined parts, with much of the shape defined by 2D profile curves. The shape you're trying to do there is very different than that, organic forms like that are a much better fit for a polygonal modeler rather than a CAD program. Something like ZBrush or 3D coat would be much more suitable tools for that than MoI.

- Michael