Calculating COM for Jelly Structure

####################################################
# 					Functions
####################################################
def find_com_conical_frustum(h, R1, R2):
    # Calculating denominator and numerator 
    # of COM formula separately.
    denom = h * (pow(R1, 2) + 2*R1*R2 + 3*pow(R2, 2))
    numer = 4 * (pow(R1, 2) + R1*R2 + pow(R2, 2))
    
    # Calculating conical frustum COM distance from 
    # a point and returning it
    return (denom / numer)

def find_struct_com(m1, r1, m2, r2, m3, r3):
    # Double check with textbook - it should has a similar
    # to example situation.
    denom = m1*r1 + m2*r2 + m3*r3
    numer = m1 + m2 + m3 # Total mass of structure
    
    # Calculating structure COM distance from a point
    # and returning it
    return (denom / numer)
    
    
####################################################
#					Calculations
####################################################
# Masses of objects in the structure.    
mass_poly_base = 0.01 #kg
mass_cone = 0.3 #kg
mass_egg = 0.1 #kg

# Geometry of Conical Frustum
h = 0.5 #m
R1 = 0.1 #m
R2 = 0.2 #m

# Measurements of COM distance from some point for each object.
# Perhaps choose this point as the absolute bottom of the structure.
# You can come up with estimates knowing object symmetry and or com 
# formulas for cones, spheres, cubes, etc, or by doing experiments.
r_com_poly_base = 0.05 #m
r_com_cone = find_com_conical_frustum(h, R1, R2) #m
r_com_egg = 0.5 #m

struct_com = find_struct_com(mass_poly_base, r_com_poly_base, mass_cone, r_com_cone, mass_egg, r_com_egg)
print "COM Distance of Structure from My Chosen Point is %f." % struct_com

Python Fiddle

Python Cloud IDE