diff --git a/EgtMachKernel.rc b/EgtMachKernel.rc
index 558da75..656af43 100644
Binary files a/EgtMachKernel.rc and b/EgtMachKernel.rc differ
diff --git a/SawFinishing.cpp b/SawFinishing.cpp
index d1f8f2b..91524e7 100644
--- a/SawFinishing.cpp
+++ b/SawFinishing.cpp
@@ -1104,7 +1104,10 @@ SawFinishing::CalculateAcrossToolPath( int nAuxId, int nClId)
       BBox3d b3PL ;
       PL.GetLocalBBox( b3PL) ;
       double dMaxElev = min( dDepth, b3Raw.GetMax().z - b3PL.GetMin().z) ;
-      dAddStart = (( dMaxElev < 0.5 * m_TParams.m_dDiam) ? sqrt( dMaxElev * m_TParams.m_dDiam - dMaxElev * dMaxElev) : 0.5 * m_TParams.m_dDiam) ;
+      if ( dMaxElev > 0.0  &&  dMaxElev < 0.5 * m_TParams.m_dDiam)
+         dAddStart = sqrt( dMaxElev * m_TParams.m_dDiam - dMaxElev * dMaxElev) ;
+      else
+         dAddStart =  0.5 * m_TParams.m_dDiam ;
    }
 
   // Imposto dati comuni
@@ -1432,7 +1435,7 @@ SawFinishing::CalcAlongVerticalCuts( ICurve* pSect, int nUmin, int nUmax, const
       }
       dElev = max( dElev, dElev2) ;
       if ( dElev < EPS_SMALL)
-         dElev = max( dRawMaxZ - ptStart.z, dRawMaxZ - ptEnd.z) ;
+         dElev = max( max( dRawMaxZ - ptStart.z, dRawMaxZ - ptEnd.z), 0.) ;
      // la confronto con il massimo affondamento e con la massima lavorazione della lama
       double dMaxDepth = min( dDepth, m_TParams.m_dMaxMat) ;
       if ( dElev > dMaxDepth) {
@@ -1519,7 +1522,7 @@ SawFinishing::CalcAlongStdCuts( ICurve* pSect, double dUmin, double dUmax,
       }
       dElev = max( dElev, dElev2) ;
       if ( dElev < EPS_SMALL)
-         dElev = max( dRawMaxZ - ptStart.z, dRawMaxZ - ptEnd.z) ;
+         dElev = max( max( dRawMaxZ - ptStart.z, dRawMaxZ - ptEnd.z), 0.) ;
      // la confronto con il massimo affondamento e con la massima lavorazione della lama
       double dMaxDepth = min( dDepth, m_TParams.m_dMaxMat) ;
       if ( dElev > dMaxDepth) {
@@ -1575,7 +1578,9 @@ SawFinishing::CalcAlongOneWayCut( const Point3d& ptStart, const Point3d& ptEnd,
    }
    else if ( m_Params.m_nLeadLinkType == SAWFIN_LL_OUT) {
      // distanza XY tra centro e bordo taglio
-      double dDeltaT = (( dElev < 0.5 * m_TParams.m_dDiam) ? sqrt( dElev * m_TParams.m_dDiam - dElev * dElev) : 0) ;
+      double dDeltaT = 0 ;
+      if ( dElev > 0.0  &&  dElev < 0.5 * m_TParams.m_dDiam)
+         dDeltaT = sqrt( dElev * m_TParams.m_dDiam - dElev * dElev) ;
      // modifico inizio
       ptNewStart = ptStart - vtDir * ( dDeltaT + dAppr) ;
    }
@@ -1631,7 +1636,9 @@ SawFinishing::CalcAlongZigZagCut( const Point3d& ptStart, const Point3d& ptEnd,
    // se attacco/uscita/collegamento esterno allungo inizio e fine a fuori grezzo
    else if ( m_Params.m_nLeadLinkType == SAWFIN_LL_OUT) {
      // distanza XY tra centro e bordo taglio
-      double dDeltaT = (( dElev < 0.5 * m_TParams.m_dDiam) ? sqrt( dElev * m_TParams.m_dDiam - dElev * dElev) : 0) ;
+      double dDeltaT = 0 ;
+      if ( dElev > 0.0  &&  dElev < 0.5 * m_TParams.m_dDiam)
+         dDeltaT = sqrt( dElev * m_TParams.m_dDiam - dElev * dElev) ;
      // modifico inizio
       ptNewStart = ptStart - vtDir * ( dDeltaT + dAppr) ;
      // modifico fine
diff --git a/SawRoughing.cpp b/SawRoughing.cpp
index cc549d9..b66051b 100644
--- a/SawRoughing.cpp
+++ b/SawRoughing.cpp
@@ -1172,7 +1172,9 @@ SawRoughing::CalculateOneWayCut( const Point3d& ptStart, const Point3d& ptEnd, c
    Point3d ptNewStart = ptStart ;
    if ( m_Params.m_nLeadLinkType == SAWROU_LL_OUT) {
      // distanza XY tra centro e bordo taglio
-      double dDeltaT = (( dElev < 0.5 * m_TParams.m_dDiam) ? sqrt( dElev * m_TParams.m_dDiam - dElev * dElev) : 0) ;
+      double dDeltaT = 0 ;
+      if ( dElev > 0.0  &&  dElev < 0.5 * m_TParams.m_dDiam)
+         dDeltaT = sqrt( dElev * m_TParams.m_dDiam - dElev * dElev) ;
      // modifico inizio
       ptNewStart = ptStart - vtDir * ( dDeltaT + dAppr) ;
    }
@@ -1269,7 +1271,9 @@ SawRoughing::CalculateZigZagCut( const Point3d& ptStart, const Point3d& ptEnd, c
    // se attacco/uscita/collegamento esterno allungo inizio e fine
    if ( m_Params.m_nLeadLinkType == SAWROU_LL_OUT) {
      // distanza XY tra centro e bordo taglio
-      double dDeltaT = (( dElev < 0.5 * m_TParams.m_dDiam) ? sqrt( dElev * m_TParams.m_dDiam - dElev * dElev) : 0) ;
+      double dDeltaT = 0 ;
+      if ( dElev > 0.0  &&  dElev < 0.5 * m_TParams.m_dDiam)
+         dDeltaT = sqrt( dElev * m_TParams.m_dDiam - dElev * dElev) ;
      // modifico inizio
       ptNewStart = ptStart - vtDir * ( dDeltaT + dAppr) ;
      // modifico fine