Calculating the center of mass when designing real objects in 3dsmax

[tammo]

I am working on a remote controlled craft for aerial video.
I don't know how to use CAD software like Autocad and i designed it in 3ds max.
The frame will be laser cut from aluminium.
It will carry a DSLR and has six rotors.
The problem is that i don't know how to calculate the center of mass.
It should be in the center of the six rotors and it will fly badly if its too far off.

I was thinking about using physX or reactor but that may take a long time to setup.

If its not possible in 3dsmax what software can do that
and is easy to use for a max user?

[ior=0]

Max maybe able to do what you need: in the utilities rollout, measure button. This will give you a (basic) center of mass.
I guess it doesn't account for different substance weights of different components. In fact I think it might only work for a single object
I can't check right now as I'm render. But it's a start

[wxyz]

Maybe using Reactor or Phys-X would be a good start