Hello Fredriksson and thx for your reply.

Well, the reason why I´m not happy about the solution by using the tesselation is because this takes only effect in the render process.

What I want is a good mesh --> and the good mesh I only can get if my surfaces are well done. I want to have the opportunity to use my model in other software, so it should be possibly to convert my oject into polys for export to other software.

You are right, no complex nurbs model consists of only one patch. I´m learing nurbs modelling, cause I think it´s a very good way to get a good result , and at this time, I´m trying to find different patchmodelling techniques.

I hope that I will find one, which will fix my problem.
But I got one hint, maybe this will solve my problem.

I should use more Isoparms, to get get the spaces between the surfaces away.

I wlll try , so thx for your help,
bernhard