Blog posts


by Luke Davenport

How do you add the centre of gravity into your Inventor Publisher documents? Mass properties and densities are not imported into Publisher, so to reference the C of G you have to produce a little work around. One method that works quite nicely (and doesn’t involve having to ask your Inventor user to tell you the X Y Z co-ordinates of the C of G) is to automatically run an iLogic rule that places a dummy part in the C of G location when you save you Inventor assembly. Here is the full iLogic code for this, and check out the video for more information:


Full iLogic code :

'Start of iLogic code

'Delete the C of G part if already present 


doc = ThisDoc.Document

Dim compOcc As ComponentOccurrence = Component.InventorComponent("COFG PART:1")



End Try

'Add C Of G part


pt = iProperties.CenterOfGravity


'Add custom iproperties with co-ordinates of C of G

iProperties.Value("Custom", "cx")=pt.X


iProperties.Value("Custom", "cy")=pt.Y


iProperties.Value("Custom", "cz")=pt.Z


'Correct units

COFGX=iProperties.Value("Custom", "cx")/10

COFGY=iProperties.Value("Custom", "cy")/10

COFGZ=iProperties.Value("Custom", "cz")/10


'set a reference to the assembly component definintion.

'this assumes an assembly document is open.

Dim oAsmCompDef As AssemblyComponentDefinition

oAsmCompDef = ThisApplication.ActiveDocument.ComponentDefinition


'set a reference to the transient geometry object.

Dim oTG As TransientGeometry

oTG = ThisApplication.TransientGeometry

' Create a  placement matrix

Dim oMatrix As Matrix

oMatrix = oTG.CreateMatrix 

'set the matrix coordinates

oMatrix.SetTranslation(oTG.CreateVector(COFGX, COFGY, COFGZ))


' Add the C of G part in correct location

Dim oOcc As ComponentOccurrence

oOcc = oAsmCompDef.Occurrences.Add("C:\CAD WIP\COFG PART.ipt", oMatrix)


'Show message box if there are no components in assembly

MessageBox.Show("No C of G Available - Please insert components!", "Error")

End Try

End of iLogic code