diff --git a/Milling.cpp b/Milling.cpp
index 488e2cc..bd5d82e 100644
--- a/Milling.cpp
+++ b/Milling.cpp
@@ -1702,7 +1702,7 @@ Milling::ProcessPath( int nPathId, int nPvId, int nClId)
 
   // verifico che lo step dell'utensile sia sensato
    double dOkStep = ( m_Params.m_dStep > EPS_SMALL ? m_Params.m_dStep + EPS_ZERO : 0) ;
-   const double MIN_ZSTEP = ( m_TParams.m_nType != TT_MILL_POLISHING ? 1.0 : EPS_SMALL) ;
+   const double MIN_ZSTEP = ( m_TParams.m_nType != TT_MILL_POLISHING ? 0.1 : EPS_SMALL) ;
    if ( dOkStep >= EPS_SMALL  &&  dOkStep < MIN_ZSTEP) {
       dOkStep = MIN_ZSTEP + EPS_ZERO ;
       string sInfo = "Warning in Milling : machining step too small (" +
diff --git a/MillingData.h b/MillingData.h
index bc219ad..98df5cd 100644
--- a/MillingData.h
+++ b/MillingData.h
@@ -72,8 +72,8 @@ struct MillingData : public MachiningData
         m_bToolInvert( false), m_nFaceUse( 0), m_bInvert( false), m_nWorkSide( 0),
         m_dStartPos( 0), m_dOverlap( 0), m_dStep( 0), m_nStepType( 0), m_dSideAngle( 0),
         m_dStartAddLen( 0), m_dEndAddLen( 0),
-        m_bLeaveTab( false), m_dTabLen( 0), m_dTabDist( 0), m_dTabHeight( 0), m_dTabAngle( 0), m_nTabMin( 0), m_nTabMax( 10000),
-        m_bOscEnable( false), m_dOscHeight( 0), m_dOscRampLen( 0), m_dOscFlatLen( 0),
+        m_bLeaveTab( false), m_dTabLen( 10), m_dTabDist( 100), m_dTabHeight( 5), m_dTabAngle( 45), m_nTabMin( 0), m_nTabMax( 10000),
+        m_bOscEnable( false), m_dOscHeight( 10), m_dOscRampLen( 5), m_dOscFlatLen( 10),
         m_nLeadInType( 0), m_dLiTang( 0), m_dLiPerp( 0), m_dLiElev( 0), m_dLiCompLen( 0),
         m_nLeadOutType( 0), m_dLoTang( 0), m_dLoPerp( 0), m_dLoElev( 0), m_dLoCompLen( 0) {}
    MillingData* Clone( void) const override ;
diff --git a/Operation.cpp b/Operation.cpp
index 6f62bd4..30816ce 100644
--- a/Operation.cpp
+++ b/Operation.cpp
@@ -344,6 +344,11 @@ Operation::GetPointUnderRaw( const Point3d& ptP, const Vector3d& vtTool, double
 {
   // punto a metà lunghezza utensile
    Point3d ptQ = ptP + vtTool * dToolLen / 2 ;
+  // box di ingombro dell'utensile
+   BBox3d b3Tool ;
+   b3Tool.Set( ptP) ;
+   b3Tool.Add( ptQ) ;
+   b3Tool.Expand( dToolRadForElev) ;
   // direzione di fuga per l'elevazione
    Vector3d vtDir = vtTool ;
    if ( vtDir.z < - EPS_SMALL)
@@ -358,7 +363,7 @@ Operation::GetPointUnderRaw( const Point3d& ptP, const Vector3d& vtTool, double
          int nStmId = m_pGeomDB->GetFirstNameInGroup( nRawId, MACH_RAW_SOLID) ;
          BBox3d b3Raw ;
          m_pGeomDB->GetGlobalBBox( nStmId, b3Raw) ;
-         if ( ! b3Raw.IsEmpty()  &&  ( b3Raw.EnclosesXY( ptP) || b3Raw.EnclosesXY( ptQ)) &&  ptP.z < b3Raw.GetMin().z - 10 * EPS_SMALL) {
+         if ( ! b3Raw.IsEmpty()  &&  b3Raw.OverlapsXY( b3Tool) &&  ptP.z < b3Raw.GetMin().z - 10 * EPS_SMALL) {
            // determino elevazione del punto rispetto al grezzo a metà altezza
             Point3d ptTest( ptP.x, ptP.y, (( b3Raw.GetMin() + b3Raw.GetMax()) / 2).z) ; 
             double dNewElev ;