Thank you "TIG", indeed I am very "french" !!
I had pretty much understood. I did a flat test (see picture, like this?)

and in the normal position. It's about the same.
On the other hand without the high and low frame. Because when they are there, it gives a bad result (597kg instead of 119.7kg !! and CofG bad !!!)

it does not matter, because the high and low frames are the same weight, so it does not change the center of gravity.Maybe a story with the "z" axis (blue).

i dont understand

Hello, I have a problem With the same component, I get 2 different volumes and a different center of gravity depending on the position of the component ??

j'ai un soucis. Avec le même composant, j'obtiens 2 volumes différents et un centre de gravité différent suivant la position du composant ??