thin walls with sliding and spheres

[Marco02]

Good morning, I am making a cover project, the object in question is a scroll with spheres, and I have to get a shell through the thin walls
I can't make thin walls

(slim wall head until I get to the balls works)

 

[Be_on_edge]

from the difficult description to help you, maybe if you show us some pictures... or

 

[Marco02]

the object is the cover of a hand, if I make a cut under the balls without touching the thin wall works (e.g. in photo)