diff --git a/EXE_Trimming.cpp b/EXE_Trimming.cpp
index 998ee3e..d63a883 100644
--- a/EXE_Trimming.cpp
+++ b/EXE_Trimming.cpp
@@ -874,7 +874,7 @@ ExeTrimmingGetSurfBzSyncPoints( int nParentId, int nEdge1Id, int nEdge2Id, doubl
 
 // ---------------------------------------------------------------------------
 bool
-ExeTrimmingGetToolOrientationLines( int nParentId, int nMainEdgeId, int nOtherEdgeId, int nSyncLayerId, int nLineSId, int nLineEId,
+ExeTrimmingGetToolOrientationLines( int nParentId, int nMainEdgeId, int nOtherEdgeId, bool bMainIsFirstBorder, int nSyncLayerId, int nLineSId, int nLineEId,
                                     double dThetaStart, double dPhiStart, double dThetaEnd, double dPhiEnd, double dInterpLenS,
                                     double dInterpLenE, double dLinTol,
                                     int& nInterpStartId, int& nStartId, int& nEndId, int& nInterpEndId)
@@ -1007,12 +1007,22 @@ ExeTrimmingGetToolOrientationLines( int nParentId, int nMainEdgeId, int nOtherEd
   // Recupero la superficie Bezier rigata
    PtrOwner<ISurfBezier> pSurfBzRuled ;
    if ( bOk) {
-     // Se non ho linee di sincronizzazione
-      if ( vSyncPoints.empty())
-         pSurfBzRuled.Set( GetSurfBezierRuledSmooth( pCrvMainEdge, pCrvOtherEdge, vSyncPoints, ISO_PAR_SAMPLE)) ;
-     // Se ho linee di sincronizzazione
-      else
-         pSurfBzRuled.Set( GetSurfBezierRuledGuided( pCrvMainEdge, pCrvOtherEdge, vSyncPoints, dMyLinTol)) ;
+      if ( bMainIsFirstBorder) {
+        // Se non ho linee di sincronizzazione
+         if ( vSyncPoints.empty())
+            pSurfBzRuled.Set( GetSurfBezierRuledSmooth( pCrvMainEdge, pCrvOtherEdge, vSyncPoints, ISO_PAR_SAMPLE)) ;
+        // Se ho linee di sincronizzazione
+         else
+            pSurfBzRuled.Set( GetSurfBezierRuledGuided( pCrvMainEdge, pCrvOtherEdge, vSyncPoints, dMyLinTol)) ;
+      }
+      else {
+         // Se non ho linee di sincronizzazione
+         if ( vSyncPoints.empty())
+            pSurfBzRuled.Set( GetSurfBezierRuledSmooth( pCrvOtherEdge, pCrvMainEdge, vSyncPoints, ISO_PAR_SAMPLE)) ;
+         // Se ho linee di sincronizzazione
+         else
+            pSurfBzRuled.Set( GetSurfBezierRuledGuided( pCrvOtherEdge, pCrvMainEdge, vSyncPoints, dMyLinTol)) ;
+      }
       bOk = bOk && ( ! IsNull( pSurfBzRuled) && pSurfBzRuled->IsValid()) ;
    }
 
diff --git a/Lua_Trimming.cpp b/Lua_Trimming.cpp
index 657fef5..a12aad1 100644
--- a/Lua_Trimming.cpp
+++ b/Lua_Trimming.cpp
@@ -287,7 +287,7 @@ LuaTrimmingGetSurfBzSyncPoints( lua_State* L)
 static int
 LuaTrimmingGetToolOrientationLines( lua_State* L)
 {
-  // 13 parametri : nParentId, nMainEdgeId, nOtherEdgeId, nSyncLayerId, nLineSId, nLineEId,
+  // 14 parametri : nParentId, nMainEdgeId, nOtherEdgeId, bMainIsFirstBorder, nSyncLayerId, nLineSId, nLineEId,
   //                dThetaStart, dPhiStart, dThetaEnd, dPhiEnd, dInterpLenS, dInterpLenE, dLinTol
    int nParentId ;
    LuaCheckParam( L, 1, nParentId)
@@ -295,30 +295,32 @@ LuaTrimmingGetToolOrientationLines( lua_State* L)
    LuaCheckParam( L, 2, nMainEdgeId)
    int nOtherEdgeId ;
    LuaCheckParam( L, 3, nOtherEdgeId)
+   bool bMainIsFirstBorder ;
+   LuaCheckParam( L, 4, bMainIsFirstBorder)
    int nLineSId ;
-   LuaCheckParam( L, 4, nLineSId)
+   LuaCheckParam( L, 5, nLineSId)
    int nLineEId ;
-   LuaCheckParam( L, 5, nLineEId)
+   LuaCheckParam( L, 6, nLineEId)
    int nSyncLayerId ;
-   LuaCheckParam( L, 6, nSyncLayerId)
+   LuaCheckParam( L, 7, nSyncLayerId)
    double dThetaStart ;
-   LuaCheckParam( L, 7, dThetaStart)
+   LuaCheckParam( L, 8, dThetaStart)
    double dPhiStart ;
-   LuaCheckParam( L, 8, dPhiStart)
+   LuaCheckParam( L, 9, dPhiStart)
    double dThetaEnd ;
-   LuaCheckParam( L, 9, dThetaEnd)
+   LuaCheckParam( L, 10, dThetaEnd)
    double dPhiEnd ;
-   LuaCheckParam( L, 10, dPhiEnd) ;
+   LuaCheckParam( L, 11, dPhiEnd) ;
    double dInterpLenS ;
-   LuaCheckParam( L, 11, dInterpLenS)
+   LuaCheckParam( L, 12, dInterpLenS)
    double dInterpLenE ;
-   LuaCheckParam( L, 12, dInterpLenE)
+   LuaCheckParam( L, 13, dInterpLenE)
    double dLinTol ;
-   LuaCheckParam( L, 13, dLinTol)
+   LuaCheckParam( L, 14, dLinTol)
    LuaClearStack( L) ;
   // Inserisco i tratti lineari associati calcolati lungo il percorso
    int nInterpStartId = GDB_ID_NULL, nStartId = GDB_ID_NULL, nEndId = GDB_ID_NULL, nInterpEndId = GDB_ID_NULL ;
-   bool bOk = ExeTrimmingGetToolOrientationLines( nParentId, nMainEdgeId, nOtherEdgeId, nSyncLayerId, nLineSId, nLineEId,
+   bool bOk = ExeTrimmingGetToolOrientationLines( nParentId, nMainEdgeId, nOtherEdgeId, bMainIsFirstBorder, nSyncLayerId, nLineSId, nLineEId,
                                                   dThetaStart, dPhiStart, dThetaEnd, dPhiEnd, dInterpLenS, dInterpLenE, dLinTol,
                                                   nInterpStartId, nStartId, nEndId, nInterpEndId) ;
    LuaSetParam( L, bOk) ;