diff --git a/Machining.cpp b/Machining.cpp
index 1aea549..ec6d97e 100644
--- a/Machining.cpp
+++ b/Machining.cpp
@@ -25,6 +25,8 @@
 
 using namespace std ;
 
+#define DEBUG 0
+
 const string KEY_AXIS_GROUP = "PreviewAxisGroup" ;
 const string KEY_ROT_AXIS_VAL = "PreviewRotAxisVal" ;    // salvata per ogni gruppo di Preview
 
@@ -323,6 +325,19 @@ Machining::MyPrepareToolPreview( bool bDouble)
    for ( const string& sSetHead : vSetHead)
       vSetHeadIds.push_back( pMch->GetHeadId( sSetHead)) ;
 
+  // se presenti altre teste che non compaiono nell'headset le memorizzo
+   int nHeadParentId = m_pGeomDB->GetParentId( nHeadId) ;
+   INTVECTOR vOtherHeadIds ;
+   if ( nHeadParentId != GDB_ID_NULL) {
+      int nChildId = m_pGeomDB->GetFirstGroupInGroup( nHeadParentId) ;
+      while ( nChildId != GDB_ID_NULL) {
+         if ( nChildId != nHeadId  &&  pMch->IsHeadGroup( nChildId)  &&
+              find( vSetHeadIds.begin(), vSetHeadIds.end(), nChildId) == vSetHeadIds.end())
+            vOtherHeadIds.push_back( nChildId) ;
+         nChildId = m_pGeomDB->GetNextGroup( nChildId) ;
+      }
+   }
+
   // recupero la tavola corrente
    int nCurrTab = pMch->GetCurrTable() ;
 
@@ -471,7 +486,7 @@ Machining::MyPrepareToolPreview( bool bDouble)
             }
            // scorro i suoi figli
             int nChildId = m_pGeomDB->GetFirstInGroup( nParentId) ;
-            while ( bOk && nChildId != GDB_ID_NULL) {
+            while ( bOk  &&  nChildId != GDB_ID_NULL) {
               // se vettore ausiliario lo inserisco solo se asse padre rotativo
                if ( m_pGeomDB->GetGdbType( nChildId) == GDB_TY_GEO) {
                   if ( bRotary) {
@@ -488,13 +503,18 @@ Machining::MyPrepareToolPreview( bool bDouble)
                   if ( nChildId == nHeadId) {
                      if ( ! bDouble) {
                         m_nPreviewHeadId = m_pGeomDB->CopyGlob( nHeadId, GDB_ID_NULL, nNewParentId) ;
-                        bOk = ( m_nPreviewHeadId == GDB_ID_NULL) ;
+                        bOk = ( m_nPreviewHeadId != GDB_ID_NULL) ;
                      }
                      else {
                         m_nPreviewHeadIdDBL = m_pGeomDB->CopyGlob( nHeadId, GDB_ID_NULL, nNewParentId) ;
-                        bOk = ( m_nPreviewHeadIdDBL == GDB_ID_NULL) ;
+                        bOk = ( m_nPreviewHeadIdDBL != GDB_ID_NULL) ;
                      }
                   }
+                 // se altra testa non presente nell'HeadSet la inserisco
+                  else if ( find( vOtherHeadIds.begin(), vOtherHeadIds.end(), nChildId) != vOtherHeadIds.end()) {
+                     int nOtherHeadId = m_pGeomDB->CopyGlob( nChildId, GDB_ID_NULL, nNewParentId) ;
+                     bOk = ( nOtherHeadId != GDB_ID_NULL) ;
+                  }
                   else {
                     // se asse successivo nella catena cinematica, sarà il nuovo gruppo padre
                      auto NextIter = Iter ; ++ NextIter ;
@@ -648,6 +668,9 @@ Machining::RemoveToolPreview( void)
   // verifico validità gestore DB geometrico
    if ( m_pGeomDB == nullptr)
       return false ;
+   #if DEBUG
+      return true ;
+   #endif
   // recupero i gruppi per l'anteprima utensile
    int nStId = m_pGeomDB->GetFirstNameInGroup( GetOwner(), MCH_ST) ;
    int nStIdDBL = m_pGeomDB->GetFirstNameInGroup( GetOwner(), MCH_ST_DBL) ;