Hi again, I am sure this must have come up before. Obviously there is quite a deviation from reality of the physical properties calculated by Alibre for 3d printed parts, as the partial infill is not taken into consideration. I am considering to create some dummy materials with adjusted densities to take account of that issue. The easiest way of course would be to have the choice of manually assigning a mass to a part that would be used for all further calculations, but of course the CG would be ill defined except for the simplest part shapes. In any case I submitted a feature request for that manual mass assignment. If anybody found a simple way out of this, please let me know. I am designing compound objects that include many 3d printed parts and other materials and knowing the precise CG is quite important for proper design modifications.