Constraining Sketch Point or Work Plane to Assembly's Center of Gravity with iLogic

[danielcLJDRZ]

I've been working on an assembly and I'm facing some difficulties. My objective is to constrain a component's sketch point or work plane to the assembly's center of gravity (CoG). Despite trying various methods, I haven't been successful.

I was wondering if this task could be accomplished using iLogic? I'm relatively new to iLogic, so any guidance on this would be incredibly helpful.

Here's what I've attempted so far:

1. Determining the Center of Gravity: Using the "Center of Gravity" command, I can visualize the CoG of the assembly. However, utilizing this point directly for constraints has proven to be challenging.

2. Reference Geometry Creation: I tried creating reference geometry (such as a work point or work plane) at the CoG. While I can create these references, constraining my component’s sketch point or work plane to these references hasn't yielded the desired results.

Is there a way to leverage iLogic to simplify this process? If so, a step-by-step explanation or any example codes would be immensely valuable.

[bradeneuropeArthur]

Could you share a component that needs to be constraint in the assembly, the assembly file is not needed in this case?

Could you also give me the sketchpoint you need to use?

[danielcLJDRZ]

I'm trying to constrain the sketch point center of the 6.010 rectangle to the CoG.

[bradeneuropeArthur · Accepted solution]

Here you have a piece of code that created a UCS at the center of Gravity (Center Of Mass).

Herewith you can constraint the component....

Sub main
  
    Dim oDoc As AssemblyDocument = ThisAssembly.Document

    Dim oCompDef As AssemblyComponentDefinition
    oCompDef = oDoc.ComponentDefinition
	
    Dim acg As MassProperties = oCompDef.MassProperties
    Dim p As Point = acg.CenterOfMass

    Dim oTG As TransientGeometry
    oTG = ThisApplication.TransientGeometry

    Dim oMatrix As Matrix
    oMatrix = oTG.CreateMatrix

    Dim oTranslationMatrix As Matrix
    oTranslationMatrix = oTG.CreateMatrix
    Call oTranslationMatrix.SetTranslation(oTG.CreateVector(p.X, p.Y, p.Z))

    Call oMatrix.TransformBy(oTranslationMatrix)

    Dim oUCSDef As UserCoordinateSystemDefinition
    oUCSDef = oCompDef.UserCoordinateSystems.CreateDefinition

    oUCSDef.Transformation = oMatrix

    Dim oUCS As UserCoordinateSystem
    oUCS = oCompDef.UserCoordinateSystems.Add(oUCSDef)
End Sub

[danielcLJDRZ]

Thank you so much!!

[bradeneuropeArthur]

Appreciated...

Let me know if I can do something else for you.

[danielcLJDRZ]

Is there a way to have the UCS update when the CoG changes?

[bradeneuropeArthur · Accepted solution]

sure:

Sub main
    ' Create a new part document
    Dim oDoc As AssemblyDocument = ThisAssembly.Document

    Dim oCompDef As AssemblyComponentDefinition
    oCompDef = oDoc.ComponentDefinition
	
	Dim acg As MassProperties = oCompDef.MassProperties
	Dim p As Point = acg.CenterOfMass

    Dim oTG As TransientGeometry
    oTG = ThisApplication.TransientGeometry

    ' Create an identity matrix
    Dim oMatrix As Matrix
    oMatrix = oTG.CreateMatrix

    Dim oTranslationMatrix As Matrix
    oTranslationMatrix = oTG.CreateMatrix
    Call oTranslationMatrix.SetTranslation(oTG.CreateVector(p.X, p.Y, p.Z))

    Call oMatrix.TransformBy(oTranslationMatrix)

    ' Create an empty definition object
    Dim oUCSDef As UserCoordinateSystemDefinition
    oUCSDef = oCompDef.UserCoordinateSystems.CreateDefinition

    oUCSDef.Transformation = oMatrix

    Dim oUCS As UserCoordinateSystem
	
	Try
		
	oUCS = oCompDef.UserCoordinateSystems.Item("UCS_COG")
	oUCS.Transformation = oMatrix
	
	Catch
	oUCS = oCompDef.UserCoordinateSystems.Add(oUCSDef)
	oUCS.Name = "UCS_COG"	
		
End Try
End Sub

[bradeneuropeArthur]

I think now you are asking me, it is better to create a add-in for Inventor because you could use the Events better.

[danielcLJDRZ]

How do I create an add-in to achieve this update?

[bradeneuropeArthur · Accepted solution]

Are you a bit familiar with Vb.net?

For now you can also add the rule to the save Event found in the Ilogic Event Triggers...

[danielcLJDRZ]

Hi Arthur,

I'm not very familiar with VB.NET. Could you please provide some guidance or resources on how to add the CG auto-update rule to the save event using the iLogic Event Triggers?

Thanks,

Dan