diff --git a/EgtMachKernel.rc b/EgtMachKernel.rc
index a22cde5..bc01485 100644
Binary files a/EgtMachKernel.rc and b/EgtMachKernel.rc differ
diff --git a/MachMgr.h b/MachMgr.h
index b772a3e..4832cd3 100644
--- a/MachMgr.h
+++ b/MachMgr.h
@@ -93,6 +93,7 @@ class MachMgr : public IMachMgr
      // Tables and Fixtures
       virtual bool SetTable( const std::string& sTable) ;
       virtual bool GetTableRef1( Point3d& ptPos) ;
+      virtual bool GetTableArea1( int& nAreaId) ;
       virtual int  AddSubPiece( const std::string& sName, const Point3d& ptPos, double dAngRotDeg) ;
       virtual bool ShowOnlyTable( bool bVal) ;
      // Machine
diff --git a/MachMgrFixtures.cpp b/MachMgrFixtures.cpp
index 3d30818..168a566 100644
--- a/MachMgrFixtures.cpp
+++ b/MachMgrFixtures.cpp
@@ -47,6 +47,26 @@ MachMgr::GetTableRef1( Point3d& ptPos)
    return pDisp->GetTableRef1( ptPos) ;
 }
 
+//----------------------------------------------------------------------------
+bool
+MachMgr::GetTableArea1( int& nAreaId)
+{
+  // verifico DB geometrico
+   if ( m_pGeomDB == nullptr)
+      return false ;
+  // recupero la macchina corrente
+   Machine* pMch = GetCurrMachine() ;
+   if ( pMch == nullptr)
+      return false ;
+  // recupero la tavola corrente
+   int nTabId = pMch->GetCurrTable() ;
+   if ( nTabId == GDB_ID_NULL)
+      return false ;
+  // recupero l'oggetto che ne definisce l'area utile
+   nAreaId = m_pGeomDB->GetFirstNameInGroup( nTabId, MCH_TAREA + "1") ;
+   return ( nAreaId != GDB_ID_NULL) ;
+}
+
 //----------------------------------------------------------------------------
 int
 MachMgr::AddSubPiece( const string& sName, const Point3d& ptPos, double dAngRotDeg)
diff --git a/MachMgrParts.cpp b/MachMgrParts.cpp
index 022b916..33a207e 100644
--- a/MachMgrParts.cpp
+++ b/MachMgrParts.cpp
@@ -90,6 +90,8 @@ MachMgr::AddPartToRawPart( int nPartId, int nRawId)
    if ( nGroup == GDB_ID_NULL  ||
         ! m_pGeomDB->GroupSwap( nPartId, nGroup, true, true))
       return false ;
+  // impongo il livello system al gruppo
+   m_pGeomDB->SetLevel( nGroup, GDB_LV_SYSTEM) ;
   // mi assicuro sia visibile il pezzo e nascosto il gruppo
    m_pGeomDB->SetStatus( nPartId, GDB_ST_ON) ;
    m_pGeomDB->SetStatus( nGroup, GDB_ST_OFF) ;
@@ -126,6 +128,8 @@ MachMgr::AddPartToRawPart( int nPartId, const Point3d& ptPos, int nRawId)
    if ( nGroup == GDB_ID_NULL  ||
         ! m_pGeomDB->GroupSwap( nPartId, nGroup, true, true))
       return false ;
+  // impongo il livello system al gruppo
+   m_pGeomDB->SetLevel( nGroup, GDB_LV_SYSTEM) ;
   // mi assicuro sia visibile il pezzo e nascosto il gruppo
    m_pGeomDB->SetStatus( nPartId, GDB_ST_ON) ;
    m_pGeomDB->SetStatus( nGroup, GDB_ST_OFF) ;
@@ -246,8 +250,9 @@ MachMgr::SwapRawPartParts( int nRawId, bool bToRawPart)
          int nBase ;
          if ( m_pGeomDB->GetInfo( nId, GDB_SI_BASE, nBase)) {
             m_pGeomDB->GroupSwap( nId, nBase, true, true) ;
-           // mi assicuro sia nascosto
+           // mi assicuro sia nascosto e di livello utente
             m_pGeomDB->SetStatus( nId, GDB_ST_OFF) ;
+            m_pGeomDB->SetLevel( nId, GDB_LV_USER) ;
          }
       }
      // passo al successivo
@@ -264,7 +269,8 @@ MachMgr::ShowRootParts( bool bShow)
    int nId = m_pGeomDB->GetFirstGroupInGroup( GDB_ID_ROOT) ;
    while ( nId != GDB_ID_NULL) {
      // se pezzo, lo nascondo
-      if ( ! IsMachBase( nId)  &&  ! IsMachAux( nId))
+      int nLevel ;
+      if ( m_pGeomDB->GetCalcLevel( nId, nLevel)  &&  nLevel == GDB_LV_USER)
          m_pGeomDB->SetStatus( nId, ( bShow ? GDB_ST_ON : GDB_ST_OFF)) ;
      // passo al successivo
       nId = m_pGeomDB->GetNextGroup( nId) ;
diff --git a/MachineStruConst.h b/MachineStruConst.h
index 0c89296..c9db8b8 100644
--- a/MachineStruConst.h
+++ b/MachineStruConst.h
@@ -69,6 +69,8 @@ enum MchHeadType { MCH_HT_NONE = 0,
 //----------------------------------------------------------------------------
 // Identificativo iniziale riferimenti di tavola
 const std::string MCH_TREF = "R" ;
+// Identificativo iniziale area di tavola
+const std::string MCH_TAREA ="A" ;
 
 //----------------------------------------------------------------------------
 // Identificativo iniziale gruppo uscita di teste