-> Mass Properties tab

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-> Mass Properties tab

CAD-Line > Mass Properties tab

Use the CAD-Line > Mass-Properties tab to:

•Enter mass properties, which add to all other mass-properties on the CAD-Line

•Import the mass-properties of the active SolidWorks document

•Review the total mass-properties of a Part (Note: all CAD-Lines on the Part)

Bug

When you rebuild the model, the Center of Mass for a User Mass-Property can move to the incorrect X,Y coordinates in the Part. To locate the Center of Mass in a Part correctly: Home the model; start and immediately exit the Part-Editor for the Part, and rebuild the model two times.

CAD-Line dialog

Mass Properties tab

CAD-Line dialog > Mass- Properties tab

CAD-Line dialog > Mass- Properties tab

tog_minus User Mass Properties 
MD-Dialog-CADLine-MasProps_User

Mass (Units: )

center-of-Mass: X–axis ( ) (see also BUG, above)

center-of-Mass: Y–axis ( )

Moment of Inertia () - ( NOT )

The Mass Moment of Inertia about the Center-of-Mass.

You can enter the:

Radius-of-Gyration

or

Moment-of-Inertia

Note:

•The correct term for Moment of Inertia is Mass Moment of Inertia

•The X-axis is along CAD-Line, the Y-axis is at +90º and on the Mechanism-Plane.

•The 0,0 is at the start-Point of the CAD-Line.

Moment-of-Inertia: Radius-of-Gyration, and Point-Mass.

Case 1:

If you enter a Mass but do NOT enter a Radius-of-Gyration or Moment-of-Inertia, the Mass is termed a “Point Mass”.

The x,y position of the mass relative to the CAD-Line is at center-of-Mass: X–axis, and center-of-Mass: Y–axis.

CASE 2:

If you enter a Mass and a Moment-of-Inertia, then the Radius-of-Gyration, , is :

Case 3:

If you enter a Mass and a Radius-of-Gyration, then the Moment-of-Inertia, , is :

Parallel Axis Theorem

We use for you the Parallel Axis Theorem to calculate the Mass Moment-of-Inertia about the Part's instantaneous center-of-rotation.

= distance to the Center-of-Mass from the center-of-rotation.

Bug

The Center of Mass can move to the incorrect X,Y coordinates you have entered.

To move the Center of Mass to the correct X,Y coordinates in the Part: Home the model; start and immediately exit the Part-Editor for the Part; and rebuild the model two times.
tog_minus SolidWorks Mass Properties 

When you import a SolidWorks document onto a CAD-Line, you can also import its Mass-Properties.
MD-Dialog-CADLine-MasProps_SW

Button Red-14-1b IMPORT / UPDATE SolidWorks Mass Properties

Note: Before you click button Red-14-1b, make sure the active SolidWorks document is on the CAD-Line.

Mass (kg)

Mass of the active SolidWorks document.

center-of-Mass - X-axis (mm)

The distance to the center-of-Mass along the X-axis from the start-Point of the CAD-Line.

center-of-Mass - Y-axis (mm)

The distance to the center-of-Mass along the Y-axis from the start-Point of the CAD-Line.

Moment-of-Inertia

The Mass Moment of Inertia with respect to the Center-of-Mass

Button Red-14-2 Remove SolidWorks Mass Properties
tog_minus Total Mass Properties 

Total Mass Properties:

The Total Mass Properties include, for each Part, the addition of ALL of the:

•Mass and Mass-Properties that we calculate for you for ALL Profile/Extrusions in the Part

•User Mass-Properties as you define for ALL CAD-Lines in the Part

•SolidWorks Mass-Properties that you import for ALL CAD-Lines in the Part
MD-Dialog-CADLine-MasProps_Total

NOTES:

Parallel-Axis Theorem

Mass Moment of Inertia about a Part's Rotational-Axis =

Total Mass Moment of Inertia about Center-of-Mass

+ Total Mass × (Distance to Part's Rotational-Axis)2

Relationship between Mass Moment-of-Inertia and Radius of Gyration

Total Mass Moment of Inertia (about center-of-Mass) =

Total Mass × (Radius-of-Gyration)2