Terminology: Solids, CADLine, Kinetostatic Force
To calculate the Forces correctly, it is important that the Mass Properties of each machine part are entered correctly.
MechDesigner has three sources of MassProperties:
•  MassProperties that are user defined on the CADLine. 
•  Mass Properties imported to a CADLine with a SolidWorks document. 
•  Mass Properties derived from Profile/Extrusions on a Part. 
Mass Properties may be defined with:
•  Mass [kg] 
•  Position/location of the CentreofMass [X,Y] [mm] 
To define the distribution of the mass around the CentreofMass you can enter:
•  MomentofInertia [kg.m2] 
or
•  RadiusofGyration [mm] of the Mass [kg] about the CentreofMass [XY] 
Note: RadiusofGyration has no physical meaning. The distribution of mass in real machine elements is function of its real shape. RadiusofGyration simply indicates at what radius from the centreofmass you could concentrate all of the mass in the machine element to give an equal MomentofInertia [about the CentreofMass] of the real mass distribution in the machine element
Separators


If you enter MomentofInertia, then MechDesigner calculates the equivalent RadiusofGyration If you enter RadiusofGyration, then MechDesigner calculates the MomentofInertia Parallel Axis Theorem MechDesigner uses the Parallel Axis Theorem to calculate the MomentofInertia, Io , about the Part's rotational axis: I0 = Ix +M.h2 where h is the distance from the Rotational Axis to the CentreofMass. 
If you import a SolidWorks document, its MassProperties are also imported. This dialog shows the MassProperties of the imported SolidWorks document. You can remove the MassProperties completely, or update the Mass Properties to become equal to those of the active SolidWorks document. 

Update Mass Properties to those of the Active SolidWorks Document MechDesigner imports the Mass Properties of the active document in SolidWorks, as ReadOnly values:
Clear/Remove SolidWorks Mass Properties button Remove the Mass Properties of the imported SolidWorks document, then:

Each AddedPart has a CADLine from its startPoint to its endPoint. As a reminder: you may also add CADLines to a Part. All CADLines in a Part may have User Mass Properties and SolidWorks MassProperties The Total Mass Properties include the superposition of:
These are ReadOnly. 

ParallelAxis Theorem Inertia about Part's Origin = Inertia about CentreofMass + Mass × (Distance to Part's Origin)2 Relationship between MomentofInertia and Radius of Gyration MomentofInertia (about CenterofMass) = Mass × (RadiusofGyration)2 Total Mass of Part = Mass of all Extrusions + SolidWorks document Mass Properties + User Mass Properties + Total mass of other CADLines in the same Part. Total MomentofInertia about the Part's Origin = Inertia of all Extrusions + SolidWorks document Inertia Properties + User Inertia Properties + Total Inertia of other CADLines in the same Part. 