diff --git a/VolZmapVolume.cpp b/VolZmapVolume.cpp
index 99de0c9..e672cab 100644
--- a/VolZmapVolume.cpp
+++ b/VolZmapVolume.cpp
@@ -639,10 +639,10 @@ VolZmap::MillingStep( const Point3d& ptPs, const Vector3d& vtDs, const Vector3d&
         // Versore utensile parallelo all'asse Z
          if ( vtLsXY.SqLen() < EPS_SMALL * EPS_SMALL) {
 
-            Vector3d vtMove = ptLe[i] - ptLs[i] ;   vtMove.Normalize() ;
+            Vector3d vtMove = ptLe[i] - ptLs[i] ;
 
            // Foratura
-            if ( vtMove.SqLenXY() < EPS_SMALL) {
+            if ( vtMove.SqLenXY() < EPS_SMALL * EPS_SMALL) {
                switch ( m_Tool.GetType())  {
                case Tool::GEN :
                   GenTool_ZDrilling( i, ptLs[i], ptLe[i], vtLs[i]) ;
@@ -704,10 +704,11 @@ VolZmap::MillingStep( const Point3d& ptPs, const Vector3d& vtDs, const Vector3d&
         // Versore utensile nel piano
          else if ( abs( vtLs[i].z) < EPS_SMALL) {
 
-            Vector3d vtMove = ptLe[i] - ptLs[i] ;  vtMove.Normalize() ;
+            Vector3d vtMove = ptLe[i] - ptLs[i] ;
             Vector3d vtMLong = ( vtMove * vtLs[i]) * vtLs[i] ;
             Vector3d vtMOrt = vtMove - vtMLong ;
 
+            double dSqLLong = vtMLong.SqLen() ;
             double dSqLOrt = vtMOrt.SqLen() ;
 
            // Foratura
@@ -732,7 +733,7 @@ VolZmap::MillingStep( const Point3d& ptPs, const Vector3d& vtDs, const Vector3d&
                }
             }
            // Fresatura con vettore movimento perpendicolare all'utensile
-            else if ( 1 - dSqLOrt < EPS_SMALL * EPS_SMALL) {
+            else if ( dSqLLong < EPS_SMALL * EPS_SMALL) {
                switch ( m_Tool.GetType())  {
                case Tool::GEN :
                   GenTool_Milling( i, ptLs[i], ptLe[i], vtLs[i]) ;
@@ -771,7 +772,7 @@ VolZmap::MillingStep( const Point3d& ptPs, const Vector3d& vtDs, const Vector3d&
 
         // Versore utensile con direzione generica
          else {
-            Vector3d vtMove = ptLe[i] - ptLs[i] ;  vtMove.Normalize() ;
+            Vector3d vtMove = ptLe[i] - ptLs[i] ;
             Vector3d vtMLong = ( vtMove * vtLs[i]) * vtLs[i] ;
             Vector3d vtMOrt = vtMove - vtMLong ;