One more question.... is there a plug in to calculate and assign weight values?

Thank you Martin!!! could you describe the steps u made to create that?
I tried to use the that tool but I was unable to get the results you got...

just tried it it works wonders on simple geometry but seems to lock up when i try to use it on my model....

I'm new to sketchup.I would like to model a airplane that i will build in the future as RC model but im having dificulty making faces on curved surfaces
So is there a plug in or specific tool that will allow me to do that?
Attached is a imige of the actual plane in question the fusalage is what im tring to make at this point. any help will would be awsome in solving this issue thx!!!

AutoSave_hawker new plane.skp