Center of MASS

Question

I have a 3D component that is made of steel and concrete, is there a way to associate a density with each volume so that I can get an accurate location of the center of mass for the entire assembly?

Lorys · Answer

doesnt look like it any time soon, ..didnt we discuss a solution for this before .. oh well for those who are new to the post and have similar problem and for the poster 
 I think you can do it by combination of Cad and first principles ..( forgive me if I'm teaching grandma to suck physics ok) 
 Bare with me as I try to recall how to solve this from college applied Mech class back in the 80's 
 So ustn can show you the COG or CoM for each part so lets call those CG1 and CG2 , you can connect these two points even though the model is 3d... 
 Lets call this Total distance L now both CGs act at the ends in the same direction so sum of the moments down = reaction up 
 down M1gx +M2gy = g(M1+M2)(L) up .. ( about the real CoG for equilibrium..). 
 now the ratio of (M1 to M2) / M1+M2 will be the ration of (x to y)/L so you should be able to solve x and y by the mass ratios to the distance.. you now now relative to either end where x or y will be and what fraction of L , now where the CGs is known, and the L is known so the ratio of the masses will tell you where the real CG acts at along L... that seems right to me but its been 30 years ....