Hello,

I am fairly new to CAD and the SolidWorks community so I apologize if my questions seem simple or elementary. I am using SolidWorks 3D CAD 2013. I am familiar with making parts and  basic assemblies. I am working on a project in which I am redesigning an RC helicopter frame.  It is based on another helicopter but I want to change the power train and placement of add-on components.

First: The helicopter is based on some currently existing parts and I am designing some new ones. I need to build/design the model around the center of gravity of the heli. In order to get the correct placement of all the components can I build basically  mock ups of the components and give them a specific weight in order to model for CG, or do I have to build each component as accurately as possible as a subassembly giving them real properties? Or will I get an accurate model if I simply make all the components from the same material? If I can assign a part a specific weight how do I do that?

Second: Is COM in SW the same as CG? If so how do I go about testing for it in my model? I have read forum posts regarding COM so maybe I'm missing something. Part of the model is fixed because of mechanical geometry but the rest of the model can be somewhat "fluid" as need be to get proper CG. Does COM reflect current COM or does it represent where you want COM to be in an assembly?

Thank you for your time and assitiance.

V/R

Jonathan