diff --git a/Machining.cpp b/Machining.cpp
index 8d56406..1aea549 100644
--- a/Machining.cpp
+++ b/Machining.cpp
@@ -561,7 +561,7 @@ Machining::MyPrepareToolPreview( bool bDouble)
 
 //----------------------------------------------------------------------------
 bool
-Machining::PrepareToolPreview()
+Machining::PrepareToolPreview( void)
 {
   // verifico validità gestori DB geometrico e CAM
    if ( m_pGeomDB == nullptr  ||  m_pMchMgr == nullptr)
@@ -580,6 +580,7 @@ Machining::PrepareToolPreview()
          return false ;
       m_pGeomDB->SetName( nStId, MCH_ST) ;
       m_pGeomDB->SetLevel( nStId, GDB_LV_TEMP) ;
+      m_nLookFlag = MCH_LOOK_TAB_TOOL ;
    }
   // altrimenti lo svuoto
    else
@@ -621,7 +622,7 @@ Machining::PrepareToolPreview()
       if ( ! EqualNoCase( sTool, GetToolName()))
          bOk = ( m_pMchMgr->SetCalcTool( GetToolName(), GetHeadName(), GetExitNbr())) ;
      // creo la preview
-      bOk = bOk && MyPrepareToolPreview( false) && MyChangeToolPreviewShow( MCH_LOOK_TAB_TOOL, false) ;
+      bOk = bOk && MyPrepareToolPreview( false) && MyChangeToolPreviewShow( m_nLookFlag, false) ;
    }
    if ( bOk  &&  nStdIdDBL != GDB_ID_NULL) {
      // imposto l'utensile per la lavorazione in doppio
@@ -629,7 +630,7 @@ Machining::PrepareToolPreview()
       bOk = ( GetDoubleToolData( sTool, sHead, nDblExit)) ;
       if ( bOk) {
          bool bOkToolSet = ( m_pMchMgr->SetCalcTool( sTool, sHead, nDblExit)) ;
-         bOk = bOkToolSet && MyPrepareToolPreview( true) && MyChangeToolPreviewShow( MCH_LOOK_TAB_TOOL, true) ;
+         bOk = bOkToolSet && MyPrepareToolPreview( true) && MyChangeToolPreviewShow( m_nLookFlag, true) ;
          if ( bOkToolSet)
             bOk = ( m_pMchMgr->SetCalcTool( GetToolName(), GetHeadName(), GetExitNbr())) && bOk ;
       }
@@ -660,7 +661,6 @@ Machining::RemoveToolPreview( void)
    m_nPreviewToolTipDBL = GDB_ID_NULL ;
    m_vPreviewAxisIds.clear() ;
    m_vPreviewAxisIdsBBL.clear() ;
-   m_nLookFlag = MCH_LOOK_NONE ;
    return true ;
 }