g   location relative to wheel (m)
2 motor 292 0.0065
battery 101 0.095
2 wheels 71 0.0
wheel mounts 29 0.0
screws and standoffs 65
computer board 60 0.051
metal plate 71 0.034
lower plastic plate 35 0.083
upper plastic plate 41 0.110
front plastic piece 18 0.020
motor mounts 45 0.025
my total: 828
weighted total: 826g

r_w 0.0323
m_w  71 + 29 + 292/4 = 246   wheel gets a quarter of the motor

moment of inertia of a cylinder is 0.5*m*r^2

I_w: include motor rotors, ignore wheel mounts
wheel: 71*0.0323*0.0323 -> 0.0000741 kg-m^2
Give 1/4 the motors weight 73
gear ratio is 30, contributes a factor of 30^2
radius is 0.01
30*30*73*0.01^2   -> 0.00657 kg-m^2  dominates

l_p:
pendulum gets 3/4 of motor

mass:
0.75*292 + 101 + 60 + 71 + 35 + 41 + 18 + 45 -> 590 (leaves out screws and standoffs)
mass*r:
0.75*292*0.0065 + 101*0.095 + 60*0.051 + 71*0.034 + 35*0.083 + 41*0.110 + 18*0.020 + 45*0.025
-> 25.3925
Center of mass is 0.043 from wheel.
com = 0.043

I_p
0.75*292*(0.0065-com)^2 + 101*(0.095-com)^2 + 60*(0.051-com)^2 + 71*(0.034-com)^2 + ...
    35*(0.083-com)^2 + 41*(0.110-com)^2 + 18*(0.020-com)^2 + 45*(0.025-com)^2
0.0008386 kg-m^2