diff --git a/GeoCalc.cpp b/GeoCalc.cpp
index bfb6a12..4e23a58 100644
--- a/GeoCalc.cpp
+++ b/GeoCalc.cpp
@@ -94,7 +94,7 @@ GetRotationComponent( const Vector3d& vtDir1, double dComp, const Vector3d& vtDi
       if ( dDenom * dNumer > 0)
          dAng1Deg = dOffsAngRad * RADTODEG ;
       else
-         dAng1Deg = dOffsAngRad * RADTODEG + ANG_STRAIGHT ;
+         dAng1Deg = dOffsAngRad * RADTODEG + ( dOffsAngRad < 0 ? ANG_STRAIGHT : - ANG_STRAIGHT) ;
       bDet = true ;
       return 1 ;
    }
diff --git a/Machine.h b/Machine.h
index 2a86826..af2b356 100644
--- a/Machine.h
+++ b/Machine.h
@@ -187,6 +187,7 @@ class Machine
                         int nNumRotAx, const KinAxis& RotAx1, const KinAxis& RotAx2,
                         int& nStat, double& dAngA1, double& dAngB1, double& dAngA2, double& dAngB2) const ;
       bool GetDirection( const Vector3d& vtDir, const DBLVECTOR& vAng, Vector3d& vtNew) const ;
+      bool GetSccDir( int nSolCh, const Vector3d& vtDirA, Vector3d& vtDirScc) const ;
       bool VerifyScc( const Vector3d& vtDirI, const Vector3d& vtDirA, int nSolCh) const ;
       bool AdjustAngleInStroke( const STROKE& Stroke, double& dAng) const ;
       bool LuaInit( const std::string& sMachineName) ;
diff --git a/MachineCalc.cpp b/MachineCalc.cpp
index 6b65e5b..c074c7e 100644
--- a/MachineCalc.cpp
+++ b/MachineCalc.cpp
@@ -754,9 +754,11 @@ Machine::GetMyAngles( const Vector3d& vtDirT, const Vector3d& vtDirA,
         // se indeterminato, provo a determinarlo con la direzione ausiliaria
          if ( ! bDet2) {
             bool bDetX ;
-            vtDirI2.GetRotation( vtDirAn, vtAx1, dAngA2, bDetX) ;
+            Vector3d vtSccDir ;
+            bool bSccDir = GetSccDir( m_nCalcSolCh, vtDirAn, vtSccDir) ;
+            vtDirI2.GetRotation( vtSccDir, vtAx1, dAngA2, bDetX) ;
             if ( bDetX)
-               bDet2 = true ;
+               bDet2 = bSccDir ;
             else
                dAngA2 = 0 ;
          }
@@ -775,9 +777,11 @@ Machine::GetMyAngles( const Vector3d& vtDirT, const Vector3d& vtDirA,
         // se indeterminato, provo a determinarlo con la direzione ausiliaria
          if ( ! bDet1) {
             bool bDetX ;
-            vtDirI1.GetRotation( vtDirAn, vtAx1, dAngA1, bDetX) ;
+            Vector3d vtSccDir ;
+            bool bSccDir = GetSccDir( m_nCalcSolCh, vtDirAn, vtSccDir) ;
+            vtDirI1.GetRotation( vtSccDir, vtAx1, dAngA1, bDetX) ;
             if ( bDetX)
-               bDet1 = true ;
+               bDet1 = bSccDir ;
             else
                dAngA1 = 0 ;
          }
@@ -1012,6 +1016,24 @@ Machine::GetToolDirFromAngles( double dAngA, double dAngB, Vector3d& vtDir) cons
    return GetDirection( m_vtCalcDir, vAng, vtDir) ;
 }
 
+//----------------------------------------------------------------------------
+bool
+Machine::GetSccDir( int nSolCh, const Vector3d& vtDirA, Vector3d& vtDirScc) const
+{
+   switch ( nSolCh) {
+   case MCH_SCC_ADIR_XP : vtDirScc = X_AX ; return true ;
+   case MCH_SCC_ADIR_XM : vtDirScc = - X_AX ; return true ;
+   case MCH_SCC_ADIR_YP : vtDirScc = Y_AX ; return true ;
+   case MCH_SCC_ADIR_YM : vtDirScc = - Y_AX ; return true ;
+   case MCH_SCC_ADIR_ZP : vtDirScc = Z_AX ; return true ;
+   case MCH_SCC_ADIR_ZM : vtDirScc = - Z_AX ; return true ;
+   case MCH_SCC_ADIR_NEAR : vtDirScc = vtDirA ; return true ;
+   case MCH_SCC_ADIR_FAR : vtDirScc = - vtDirA ; return true ;
+   }
+   vtDirScc = vtDirA ;
+   return false ;
+}
+
 //----------------------------------------------------------------------------
 bool
 Machine::VerifyScc( const Vector3d& vtDirI, const Vector3d& vtDirA, int nSolCh) const
diff --git a/Operation.cpp b/Operation.cpp
index 2852c42..ef2edea 100644
--- a/Operation.cpp
+++ b/Operation.cpp
@@ -509,8 +509,6 @@ Operation::CalculateAxesValues( const string& sHint)
    DBLVECTOR vAxRotPrec( nRotAxes, 0.) ;
    DBLVECTOR vAxVal ;
   // se utensile non cambiato, uso gli angoli finali della lavorazione precedente
-  // ! ToolChangeNeeded( *pPrevOp, *this)
-  // GetToolName() == sPrevTool
    if ( ! sPrevTool.empty()  &&  ! ToolChangeNeeded( *pPrevOp, *this)  &&
         pPrevOp->GetFinalAxesValues( vAxVal)) {
       for ( int i = 0 ; i < nRotAxes ; ++ i)