diff --git a/SurfFinishing.cpp b/SurfFinishing.cpp
index 9042df9..2327131 100644
--- a/SurfFinishing.cpp
+++ b/SurfFinishing.cpp
@@ -2472,6 +2472,9 @@ SurfFinishing::CorrectPathByCollision( ICAvToolSurfTm* pCAvTlStm, const Frame3d&
      // porto i dati geometrici in locale alle superfici
       Vector3d vtToolL = GetToLoc( vtTool, frSurf) ;         // direzione utensile
       Vector3d vtMoveL = GetToLoc( vtMove, frSurf) ;         // direzione risalita per collisione
+      const double MIN_DIST = 1. ;
+      const double MAX_DIST = 50. ;
+      double dDist = Clamp( m_TParams.m_dDiam / 2, MIN_DIST, MAX_DIST) ;
 
      // scorro le curve
       double dProgCoeff = 1. / max( int( vpCrvs.size()), 1) ;
@@ -2485,9 +2488,6 @@ SurfFinishing::CorrectPathByCollision( ICAvToolSurfTm* pCAvTlStm, const Frame3d&
          if ( ! vpCrvs[i]->ApproxWithLines( LIN_TOL_STD, ANG_TOL_STD_DEG, ICurve::APL_SPECIAL, PL))
             return false ;
         // eventuale aggiunta di punti per garantire max distanza
-         const double MIN_DIST = 1. ;
-         const double MAX_DIST = 50. ;
-         double dDist = Clamp( m_TParams.m_dDiam / 2, MIN_DIST, MAX_DIST) ;
          if ( ! PL.AdjustForMaxSegmentLen( dDist))
             return false ;
         // porto nel riferimento delle superfici
@@ -5703,7 +5703,7 @@ SurfFinishing::CalcOptimalZigZagCurves( ISURFFRPOVECTOR& vSfrZigZagProj, const F
          pSfrChunk->ToGlob( frSurf) ;
         // eseguo il calcolo della lavorazione ZigZag
          ICRVCOMPOPOVECTOR vpCrvs ;
-         if ( ! CalcPocketing( pSfrChunk, m_TParams.m_dDiam / 2., 0., m_Params.m_dSideStep, m_Params.m_dSideAngle, 5.,
+         if ( ! CalcPocketing( pSfrChunk, m_TParams.m_dDiam / 2., 0., m_Params.m_dSideStep, GetLocalSideAngle(), 5.,
                                nSubType, false, false, false, true, true, false, false, P_INVALID, nullptr, true, m_Params.m_dSideStep,
                                GetLeadInType(), m_Params.m_dLiTang, 0., GetLeadOutType(), m_Params.m_dLoTang, false, 0., 0., false, vpCrvs)) {
             m_pMchMgr->SetLastError( 3125, "Error in SurfFinishing : CalcPocketing failed") ;
@@ -5715,9 +5715,7 @@ SurfFinishing::CalcOptimalZigZagCurves( ISURFFRPOVECTOR& vSfrZigZagProj, const F
       }
 
      // porto i dati geometrici in locale alle superfici ( proeittando)
-      Vector3d vtAxL = vtTool ;
-      vtAxL.ToLoc( frSurf) ;
-      Vector3d vtMoveL = vtAxL ;
+      Vector3d vtToolL = GetToLoc( vtTool, frSurf) ;
       const double MIN_DIST = 1. ;
       const double MAX_DIST = 50. ;
       double dDist = Clamp( m_Params.m_dApprox, MIN_DIST, MAX_DIST) ;
@@ -5735,14 +5733,15 @@ SurfFinishing::CalcOptimalZigZagCurves( ISURFFRPOVECTOR& vSfrZigZagProj, const F
             if ( ! vCrvCompoZigZag[i]->ApproxWithLines( LIN_TOL_STD, ANG_TOL_STD_DEG, ICurve::APL_SPECIAL, PL)  ||
                  ! PL.AdjustForMaxSegmentLen( dDist))
                return false ;
+           // porto nel riferimento delle superfici
             PL.ToLoc( frSurf) ;
            // traslo della lunghezza utensile diminuita dell'affondamento
-            PL.Translate( vtAxL * ( m_TParams.m_dLen - dDepth)) ;
+            PL.Translate( vtToolL * ( m_TParams.m_dLen - dDepth)) ;
            // eseguo CAv
-            if ( ! pCAvTlStm->TestPath( PL.GetUPointList(), vtAxL, vtMoveL, m_Params.m_dApprox, ( i + 1) * dProgCoeff))
+            if ( ! pCAvTlStm->TestPath( PL.GetUPointList(), vtToolL, vtToolL, m_Params.m_dApprox, ( i + 1) * dProgCoeff))
                return false ;
            // contro-traslo della lunghezza utensile
-            PL.Translate( - vtAxL * m_TParams.m_dLen) ;
+            PL.Translate( - vtToolL * m_TParams.m_dLen) ;
            // elimino i punti allineati
             PL.RemoveAlignedPoints( 0.8 * m_Params.m_dApprox) ;
            // creo una curva composita a partire dalla polilinea
@@ -6242,8 +6241,7 @@ SurfFinishing::AreSameSfrChunkEpsilon( const ISurfFlatRegion* pSfrChunkA, const
 //----------------------------------------------------------------------------
 bool
 SurfFinishing::CalcOptimalZigZagRegion( const ISurfFlatRegion* pSfrCntLoc, const ISurfFlatRegion* pSfrZLevelColl,
-                                        const SURFLOCALVECTOR& vSrfLoc, const Frame3d& frSurf, const Vector3d& vtToolLoc, double dDepth,
-                                        double dSplitAngDeg, ISURFFRPOVECTOR& vpSfrZigZagProj) const
+                                        ISURFFRPOVECTOR& vpSfrZigZagProj) const
 {
   // verifico validità dei parametri
    if ( pSfrCntLoc == nullptr  ||  ! pSfrCntLoc->IsValid())
@@ -6324,7 +6322,7 @@ SurfFinishing::AddOptimal( ICAvToolSurfTm* pCAvTlStm, const SURFLOCALVECTOR& vSr
 
   // [3°] calcolo della regione di proiezione ZigZag ---
    ISURFFRPOVECTOR vSfrZigZagProj ;
-   if ( ! CalcOptimalZigZagRegion( pSfrCntLimit, pSfrZLevelColl, vSrfLoc, frSurf, GetToLoc( vtTool, frSurf), dDepth, dAngDegSplit, vSfrZigZagProj)) {
+   if ( ! CalcOptimalZigZagRegion( pSfrCntLimit, pSfrZLevelColl, vSfrZigZagProj)) {
       m_pMchMgr->SetLastError( 3124, "Error in SurfFinishing : region not computable") ;
       return false ;
    }
diff --git a/SurfFinishing.h b/SurfFinishing.h
index 2e7f455..40c019b 100644
--- a/SurfFinishing.h
+++ b/SurfFinishing.h
@@ -222,8 +222,7 @@ class SurfFinishing : public Machining
                             double dLimInfClippingAng, double dLimSupClippingAng, const Vector3d& vtAxL, const Vector3d& vtMoveL, ICAvToolSurfTm* pCAvTlStm,
                             ICRVCOMPOPOVECTOR& vCrvCompo) const ;
       bool AreSameSfrChunkEpsilon( const ISurfFlatRegion* pSfrChunkA, const ISurfFlatRegion* pSfrChunkB, double dMaxDist) const ;
-      bool CalcOptimalZigZagRegion( const ISurfFlatRegion* pSfrCntLoc, const ISurfFlatRegion* pSfrZLevelColl, const SURFLOCALVECTOR& vSrfLoc,
-                                    const Frame3d& frSurf, const Vector3d& vtTool, double dDepth, double dSplitAngDeg, ISURFFRPOVECTOR& vpSfrZigZagProj) const ;
+      bool CalcOptimalZigZagRegion( const ISurfFlatRegion* pSfrCntLoc, const ISurfFlatRegion* pSfrZLevelColl, ISURFFRPOVECTOR& vpSfrZigZagProj) const ;
       double GetRightFeed( const Vector3d& vtMove, const Vector3d& vtTool) const ;
       double GetRadiusForStartEndElevation( void) const ;
       double GetLocalSideAngle() const ;