About Mass Properties
Mass properties determine how your mechanism resists a change in its speed or position upon the application of a force. To run dynamic and static analyses, you must assign mass properties to your mechanism. If you have not assigned mass properties to your assembly, you can do it in Mechanism Dynamics.
The mass properties of a mechanism are its density, volume, mass, center of gravity, and moment of inertia.
• You can set values for mass, center of gravity, and inertia. If the part has non-zero volume, you can specify its density, and its mass is calculated accordingly.
• You can only specify an assembly's density for the mass to be calculated.
• A body's mass properties can be reviewed but not edited.
Mass property information as defined in Mechanism Dynamics is valid only in Mechanism Dynamics and overrides all other assigned mass property definitions during any Mechanism Dynamics session.
Right-click your mechanism in the Model Tree and choose
Info >
Mass Property from the shortcut menu or click
![](../../../simulate/mech_des/images/mech_mass_info16x16.png)
to view your mechanism's mass property information in the browser.