THANK YOU, Michael, for your response and examples.
You are a fantastic reference point for any problems and difficulties. Sincerely thank you.
Mario R.

This is oh-so frustrating when Michael shows how to solve a particular problem. It's always easy, elegant and evident.

And I struggle drawing a circle ... ;)

Thanks Michael

Hi Ditto, it can take a while to get used to the optimal strategy for NURBS modeling.

Usually though it's about constructing larger extended shapes that are cut with booleans. If you find yourself building surfaces by filling in a patchwork between 3D edges rather than primarily using 2D curves that can be a sign you're going in the wrong direction.

It's very different than the strategy used in polygon mesh modeling.

There are some tips here for people coming from a polygon mesh modeling background:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4865.2

- Michael