Hi there,

I've got this rather simple object here. This object should be made into a shell (extruding inwards). The yellow face represents the opening.

Even with only 1 mm wall thickness inwards the calculation fails. Outwards is no problem.

Why (or where) does MoI fail with such an object?

(Just a note here: No problem with Rhino v5, but I would like to understand the behavior of MoI in this case)