I am writing a macro that takes a preexisting model and adds specific features to it. To do this I need to be able to pull dimensions from the model and set them as variables.

I have gone on several threads in this forum that concern this topic, but every solution that I find gives me a "run-time error 91 - Object varialbe or with block not set"

Here is my code, error occuring at the line in red

Dim PartDia As Double

DIm PartLgth As Double

Const Metric = 0.0254

Option Explicit

Dim swApp As SldWorks.SldWorks

Dim swModel As SldWorks.ModelDoc2

Dim swModelDocExt As SldWorks.ModelDocExtension

Dim swSketchMgr As SldWorks.SketchManager

Dim swFeature As SldWorks.Feature

Dim swFeatureMgr As SldWorks.FeatureManager

Dim vSkLines As Variant

Dim boolstatus As Boolean

Dim longstatus As Long

Dim Part As Object

Dim PlaneFeature As Object

Dim newName As String

Dim myRefPlane As Object

Dim skSegment As Object

Dim myDisplayDim As Object

Dim myDimension As Object

Dim swSketch As Object

Dim Dimension As Object

Dim Doc As String

Dim skPoint As Object

'Retrieving Dimensions

'Part Diameter, pulled from original model, in metric

Set myDimension = Part.Parameter("Outside_Diameter@GrindCylindricalForm Sketch@Template - General Cylindrical Tool.SLDPRT")

PartDia = myDimension.SystemValue

PartDia = PartDia / Metric

Part.ClearSelection2 True

I am rather confused why I am getting this error considering that I am setting the object value. Also later in my code I use the same line of code and it works.(Found in blue)

'Sets wheel Radius

Set myDimension = Part.Parameter("D1@Grinding_Wheel_Sketch")

myDimension.SystemValue = WheelRad

Part.ClearSelection2 True

Why does it work in one section of my code, but not another? Is there another way to pull dimension values from a model?

Thanks,

Elizabeth