So the key thing is - don't try to model that curved cup piece only directly to the cross outline, that would be difficult to form very well as one big smooth piece.

Instead you want to make a broader extended curved surface for the cup portion, and you introduce the cross outline by doing a boolean using that broad surface so that the surface gets cut by that cross boundary.

Often times it is much easier to build a curved object when you initially ignore any irregular boundaries on the outside and instead just build an initially larger and more extended and simple piece.

This overall concept of modeling extended surfaces and then using booleans to introduce the final edges by removing material can take a while to get comfortable with, especially if you're coming from a polygon modeling background since it's a very different process from polygon modeling.

See here for some links to discussions and some tips that may help people who are coming from a polygon modeling background:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4865.2

- Michael

The spacepilot video is doing "surface modeling" and is a more advanced method. There will be many things to understand to do that correctly.. Start with "solids modeling" as a beginning point.

Great !!!! Thank you both of you.
It's perfect. I have not the taper method on the extrude function, probably because i use MoI V2.

It's right that i'm coming from poly modeling and this kind of method is not very good. But here, it is very nice and simple. I need to change my reflex :)

""""""""""I have not the taper method on the extrude function, probably because i use MoI V2.""""""""""""

Check out the tutorial by Danny at:

http://moi3d.com/resources#Tutorials

Named "Accurate tapers using Expressions by Danny"

for tapering your extrude.

Excellent, this forum is a real goldmine
Thank you

Cool example BurrMan..

Peace,
Rich_Art. ;-)