Hi Michael and BurrMan,

Thank you both for your help!

From Michael's previous post :

> Another way you could make things easier for shelling could be to build more of your part
> all from one larger Loft rather than doing it in separate pieces and blending,
> if you want it to look like one large flowing surface.
> See the attached file where I used Loft with the Loft style = "Loose" option to build the starting piece.

Thank you very much for your suggestions and for giving me a different point of view.

Now....a strange thing that, believe me guys, is driving me crazy!

From BurrMan's previous post :
> And shelled it .1 (He said it failed)
> Doing a drilldown selection of that top surface, the success or failure can be achieved by the selection position.

Well....
I reloaded the file that i posted in http://moi3d.com/forum/index.php?webtag=MOI&msg=7912.13, and, worked on it many times....

As shown in this current attached picture (curveRebuild3_B.png), if i try to shell the original object marked as "Solid 1",
the shell command is always correctly performed, regardless of selected area on the top surface.

But...if i do the same thing on the cloned copy of the "Solid 1" the shell ALWAYS FAILS!!!
Also, like before, regardless of selected area on the top surface!!

WHY ?????

What the cloned object (copy...pasted or ctrl dragged from the original), has in it that leads the shell command to fail ???

At this point, i'm not understanding anything more...

Please help !!

Nice day to everyone,

Marco.