8 Replies Latest reply on Jun 1, 2009 7:18 PM by ian swenson

    Displaying Center of Gravity

    Van Stokes
      Is there a visual indicator you can turn on to view the COG?

      We are loading containers for shipping and it would be nice to have a visual representation as to the location of the COG to ensure we are within the W&B envelope in the assembly. I know we can get the coord offset from the tool, and that's great and all but a visual would be nice. Then you can draw and envelope and make sure the little dot stays in it.


        • Displaying Center of Gravity
          Deepak Gupta
          Create a point on the location and set the point X,Y & Z values after checking from the mass property.
          • Displaying Center of Gravity
            Deepak Gupta
            Some macro might be helpful.
              • Displaying Center of Gravity
                Sven-Erik Nilsson
                Here is a macro that points out the Centre of mass.
                It could maybe be helpful.
                  • Displaying Center of Gravity
                    Van,
                    In SolidWorks 2009 we added the ability to drive equations using default file properties. Default file properties include mass properties for the center of mass:
                    "SW-CenterofMassX"
                    "SW-CenterofMassZ"
                    "SW-CenterofMassY"

                    In the attached model, if you edit the equations, you will see how I linked the dimensions for three reference planes to the above default file properties. I then added a coordinate system at the intersection of these three planes. Any geometric changes to the model will cause the center of gravity to change.

                    As with all equations that are driven by a value derived from the model (i.e. file properties, reference dimensions, etc...) you must rebuild the model twice to see the correct values. The first rebuild occurs when you add a feature (you will notice that the equation values update to the values that result from the new feature). The second rebuild is required to apply the values of the changed equations to the model dimensions (in this case the reference plane dimensions). With this in mind, if you build geometry off of these center of gravity references planes or the coordinate system you may enter into an infinite loop where every shift in the CG changes the geometry. This is likely not desirable and you should be careful to avoid such cases.

                    With regards to the new SolidWorks 2009 equations functionality it is important to note that custom file properties can drive equations or be driven by equations.

                    You can access a list of default file properties and custom file properties using the expander button in the Add Equation dialog (see attached image).
                      • Displaying Center of Gravity
                        Alessandro Frattini

                        Marlon Banta wrote:

                         

                        Van,

                        In SolidWorks 2009 we added the ability to drive equations using default file properties. Default file properties include mass properties for the center of mass:

                        "SW-CenterofMassX"

                        "SW-CenterofMassZ"

                        "SW-CenterofMassY"



                        In the attached model, if you edit the equations, you will see how I linked the dimensions for three reference planes to the above default file properties. I then added a coordinate system at the intersection of these three planes. Any geometric changes to the model will cause the center of gravity to change.



                        As with all equations that are driven by a value derived from the model (i.e. file properties, reference dimensions, etc...) you must rebuild the model twice to see the correct values. The first rebuild occurs when you add a feature (you will notice that the equation values update to the values that result from the new feature). The second rebuild is required to apply the values of the changed equations to the model dimensions (in this case the reference plane dimensions). With this in mind, if you build geometry off of these center of gravity references planes or the coordinate system you may enter into an infinite loop where every shift in the CG changes the geometry. This is likely not desirable and you should be careful to avoid such cases.



                        With regards to the new SolidWorks 2009 equations functionality it is important to note that custom file properties can drive equations or be driven by equations.



                        You can access a list of default file properties and custom file properties using the expander button in the Add Equation dialog (see attached image).

                        Hi Marlon,
                        the problem is that centre of mass x,y,z can have negative value and at the moment SolidWorks equations doesn't support negative value.

                        P.S:You can dimension the 3D sketch point referred to the standard planes, without create others.
                  • Displaying Center of Gravity
                    Van Stokes
                    Wow! Thank you all! I appreciate it!