Hi Pilou,

> Shelling is "vertical" 90° !
> Or the original edge is inclined ;)

Yeah, if you want a constant thickness throughout a piece, that's how it works!

The original piece also has pieces that don't line up with one another, do you want to keep that as well? :)

You could also do an Extrude of that surface that I posted previously instead of a Shell, does that give more of the desired result? It looks like that may be more of what was intended here since one side is nearly straight up vertical.

- Michael