diff --git a/OptionPanel/MachiningOptionPanel/OperationExpander/MachiningParameterExpander/MachiningParameterExpanderVM.vb b/OptionPanel/MachiningOptionPanel/OperationExpander/MachiningParameterExpander/MachiningParameterExpanderVM.vb
index 0ecd914..9c9ecba 100644
--- a/OptionPanel/MachiningOptionPanel/OperationExpander/MachiningParameterExpander/MachiningParameterExpanderVM.vb
+++ b/OptionPanel/MachiningOptionPanel/OperationExpander/MachiningParameterExpander/MachiningParameterExpanderVM.vb
@@ -13,7 +13,7 @@ Public Class MachiningParameterExpanderVM
    ''' </summary>
    Friend Event m_EventFocusOnButtonPreview()
 
-   Private m_nPreviewMachiningTool As Integer
+   Private m_nPreviewMachiningTool As Integer = MCH_LOOK.NONE
    Public ReadOnly Property nPreviewMachiningTool As Integer
       Get
          Return m_nPreviewMachiningTool
diff --git a/OptionPanel/MachiningOptionPanel/OperationParametersExpander/OperationParametersExpanderVM.vb b/OptionPanel/MachiningOptionPanel/OperationParametersExpander/OperationParametersExpanderVM.vb
index 0c73a29..61b91da 100644
--- a/OptionPanel/MachiningOptionPanel/OperationParametersExpander/OperationParametersExpanderVM.vb
+++ b/OptionPanel/MachiningOptionPanel/OperationParametersExpander/OperationParametersExpanderVM.vb
@@ -179,10 +179,11 @@ Public Class OperationParametersExpanderVM
                Map.refProjectVM.SceneSelMode = OptionModule.m_SelGeomProbing
          End Select
          ' Imposto visualizzazione utensile
-         Map.refMachiningParameterExpanderVM.SetPreviewMachiningTool(MCH_LOOK.TAB_TOOL)
-         Map.refMachiningParameterExpanderVM.SetToolPreview_Image("pack://application:,,,/Resources/ToolPreview/Tool.png")
-         Map.refMachiningParameterExpanderVM.SetSlider_IsEnable(True)
+         'Map.refMachiningParameterExpanderVM.SetPreviewMachiningTool(MCH_LOOK.TAB_TOOL)
+         'Map.refMachiningParameterExpanderVM.SetToolPreview_Image("pack://application:,,,/Resources/ToolPreview/Tool.png")
+         'Map.refMachiningParameterExpanderVM.SetSlider_IsEnable(True)
          EgtPreparePreviewMachiningTool()
+         Map.refMachiningParameterExpanderVM.PreviewMachiningTool()
          EgtDraw()
       End If
       OnPropertyChanged("ParametersIsExpanded")