diff --git a/CalcPocketing.cpp b/CalcPocketing.cpp
index dccf849..b457daf 100644
--- a/CalcPocketing.cpp
+++ b/CalcPocketing.cpp
@@ -198,7 +198,7 @@ AssignFeedZigZagOneWay( ICurveComposite* pCompo, const bool bIsLink, const ICURV
   // controllo che la pCompoLine sia effettivamente una linea valida
    if ( pCompo == nullptr  ||  ! pCompo->IsValid())
       return false ;
-   
+
   // controllo se il Flag per assegnare la Feed è attivo
    if ( ! PockParams.bCalcFeed)
       return AssignMaxFeed( pCompo, PockParams) ;
@@ -841,7 +841,7 @@ IsSfrChunkMadeOnlyByClosedIslands( const ISurfFlatRegion* pSfrChunk, const Pocke
 //----------------------------------------------------------------------------
 static bool
 ExtendPath( ICurveComposite* pCompo, const ISurfFlatRegion* pSfr, const PocketParams& PockParams,
-            Vector3d& vtFirstOut, bool bEndOrStart, bool& bOkExtended)
+            const Vector3d& vtFirstOut, bool bEndOrStart, bool& bOkExtended)
 {
   /*
       Estensione della curva pCompo con un segmento lineare.
@@ -858,23 +858,25 @@ ExtendPath( ICurveComposite* pCompo, const ISurfFlatRegion* pSfr, const PocketPa
       return false ;
    bOkExtended = false ;
 
-  // recupero il punto iniziale/finale della curva
+  // recupero il punto iniziale/finale della curva con versore tangente
    Point3d pt ;
+   Vector3d vtTan ;
    if ( bEndOrStart) {
-      if ( ! pCompo->GetEndPoint( pt))
+      if ( ! pCompo->GetEndPoint( pt)  ||  ! pCompo->GetEndDir( vtTan))
          return false ;
    }
    else {
-      if ( ! pCompo->GetStartPoint( pt))
+      if ( ! pCompo->GetStartPoint( pt)  ||  ! pCompo->GetStartDir( vtTan))
          return false ;
+      vtTan.Invert() ;
    }
 
   // ruoto il versore di uscita cercando un'entrata valida
    Vector3d vtRotOut = vtFirstOut ;
    double dMinDist = PockParams.dRad + PockParams.dRadialOffset ;
    for ( int i = 0 ; i < 4 ; ++ i) {
-     // evito il 180deg
-      if ( i != 2) {
+     // evito il 180deg ( se c'è tangenza )
+      if ( ! AreOppositeVectorEpsilon( vtTan, vtRotOut, 25. * EPS_SMALL)) {
         // calcolo il punto di caduta dell'utensile
          Point3d ptFall = pt + vtRotOut * ( PockParams.dRad + PockParams.dOpenMinSafe) ;
         // controllo che sia sufficientemente distante dalla superficie limite
@@ -1721,18 +1723,6 @@ GetPocketCurvesByClosedEdges( const ISurfFlatRegion* pSfrChunk, const PocketPara
    for ( int i = 0 ; i < int( vCrvVroniOffs.size()) ; ++ i)
       vCrvCompoRes_tmp.emplace_back( ConvertCurveToComposite( Release( vCrvVroniOffs[i]))) ;
 
-  // controllo che effetticamente l'utensile svuoti la regione
-   PtrOwner<ISurfFlatRegion> pSfrNoRemoved( CloneSurfFlatRegion( pSfrChunk)) ;
-   if ( IsNull( pSfrNoRemoved)  ||  ! pSfrNoRemoved->IsValid())
-      return false ;
-   for ( int i = 0 ; i < int( vCrvCompoRes_tmp.size()) ; ++ i) {
-      PtrOwner<ISurfFlatRegion> pSfrRemoved( GetSurfFlatRegionFromFatCurve( CloneCurveComposite( vCrvCompoRes_tmp[i]), PockParams.dRad + PockParams.dRadialOffset + 50 * EPS_SMALL, false, false)) ;
-      if ( ! IsNull( pSfrRemoved)  &&  pSfrRemoved->IsValid())
-         pSfrNoRemoved->Subtract( *pSfrNoRemoved) ;
-   }
-   if ( pSfrNoRemoved->IsValid()  &&  pSfrNoRemoved->GetChunkCount() > 0)
-      return true ;
-
    /*
       Casi gestiti :
       1) La curva esterna e mista e non ho isole ( ho già il percorso)
@@ -1777,8 +1767,10 @@ GetPocketCurvesByClosedEdges( const ISurfFlatRegion* pSfrChunk, const PocketPara
           PtrOwner<ISurfFlatRegion> pSrfIslands( CreateSurfFlatRegion()) ;
          if ( IsNull( pSrfIslands))
             return false ;
-         for ( int i = 1 ; i < pSfrChunk->GetLoopCount( 0) ; ++ i)
+         for ( int i = 1 ; i < pSfrChunk->GetLoopCount( 0) ; ++ i) {
             pSrfIslands->AddExtLoop( pSfrChunk->GetLoop( 0, i)) ;
+            vpCrvs.emplace_back( ConvertCurveToComposite( pSfrChunk->GetLoop( 0, i))) ;
+         }
          pSrfIslands->Offset( PockParams.dRad + PockParams.dRadialOffset, ICurve::OFF_FILLET) ;
          for ( int nC = 0 ; nC < pSrfIslands->GetChunkCount() ; ++ nC)
             for ( int nL = 0 ; nL < pSrfIslands->GetLoopCount( nL) ; ++ nL)
@@ -1790,6 +1782,31 @@ GetPocketCurvesByClosedEdges( const ISurfFlatRegion* pSfrChunk, const PocketPara
    if ( vCrvCompoRes_tmp.empty())
       return true ;
 
+  // controllo che effettivamente l'utensile svuoti la regione
+   PtrOwner<ISurfFlatRegion> pSfrNoRemoved( CloneSurfFlatRegion( pSfrChunk)) ;
+   if ( IsNull( pSfrNoRemoved)  ||  ! pSfrNoRemoved->IsValid())
+      return false ;
+   for ( int i = 0 ; i < int( vCrvCompoRes_tmp.size()) ; ++ i) {
+      PtrOwner<ISurfFlatRegion> pSfrRemoved( GetSurfFlatRegionFromFatCurve( CloneCurveComposite( vCrvCompoRes_tmp[i]), PockParams.dRad + PockParams.dRadialOffset + 50 * EPS_SMALL, false, false)) ;
+      if ( ! IsNull( pSfrRemoved)  &&  pSfrRemoved->IsValid()) {
+         if ( AreOppositeVectorEpsilon( pSfrRemoved->GetNormVersor(), pSfrNoRemoved->GetNormVersor(), 25. * EPS_SMALL))
+            pSfrRemoved->Invert() ;
+         pSfrNoRemoved->Subtract( *pSfrRemoved) ;
+      }
+   }
+   for ( int i = 0 ; i < int( vpCrvs.size()) ; ++ i) {
+      if ( vpCrvs[i]->GetTempProp( 0) == TEMP_PROP_CLOSE_EDGE) {
+         PtrOwner<ISurfFlatRegion> pSfrRemoved( GetSurfFlatRegionFromFatCurve( CloneCurveComposite( vpCrvs[i]), PockParams.dRad + PockParams.dRadialOffset + 50 * EPS_SMALL, false, false)) ;
+         if ( ! IsNull( pSfrRemoved)  &&  pSfrRemoved->IsValid()) {
+            if ( AreOppositeVectorEpsilon( pSfrRemoved->GetNormVersor(), pSfrNoRemoved->GetNormVersor(), 25. * EPS_SMALL))
+               pSfrRemoved->Invert() ;
+            pSfrNoRemoved->Subtract( *pSfrRemoved) ;
+         }
+      }
+   }
+   if ( pSfrNoRemoved->IsValid()  &&  pSfrNoRemoved->GetChunkCount() > 0)
+      return true ;
+
    bAllRemoved = true ;
 
    // recupero la superficie limite ( se esiste ed è valida)