diff --git a/FrameCutPageUC.xaml.vb b/FrameCutPageUC.xaml.vb
index b936f51..84c018b 100644
--- a/FrameCutPageUC.xaml.vb
+++ b/FrameCutPageUC.xaml.vb
@@ -797,6 +797,9 @@ Public Class FrameCutPageUC
       ' Recupero ingombro locale della sezione
       Dim b3Sect As New BBox3d
       EgtGetBBox(nSectId, GDB_BB.STANDARD, b3Sect)
+      ' Differenza in Y sezione tra start e minimo della sezione
+      Dim ptTmp As Point3d : EgtStartPoint(nSectId, nSectLayId, ptTmp)
+      Dim dDiffY = ptTmp.y - b3Sect.Min().y
       ' Porto la sezione nel piano YZ
       EgtChangeGroupFrame(nSectLayId, New Frame3d(Point3d.ORIG(), Frame3d.TYPE.LEFT))
       ' Recupero o creo layer per la linea guida
@@ -810,6 +813,7 @@ Public Class FrameCutPageUC
       EgtSetColor(nGuideLayId, COL_FRAME())
       ' Creo la curva guida (per ora arco)
       Dim ptStart As Point3d : EgtStartPoint(nSectId, nGuideLayId, ptStart)
+      ptStart.z -= dDiffY
       Dim dExtRad As Double = 0 : StringToLen(ArcRadTxBx.Text, dExtRad)
       Dim dRad As Double = dExtRad - b3Sect.DimX()
       If dRad < 10 * EPS_SMALL Then
@@ -820,7 +824,7 @@ Public Class FrameCutPageUC
       If dAngCenDeg > 360 Then dAngCenDeg = 360
       Dim dAngIniDeg As Double = If(dAngCenDeg < 180, -90 - dAngCenDeg / 2, -dAngCenDeg)
       Dim ptCen As Point3d = ptStart - Vector3d.FromPolar(dRad, dAngIniDeg)
-      Dim nGuideId As Integer = EgtCreateArc(nGuideLayId, ptCen, dRad, dAngIniDeg, dAngCenDeg, 0)
+      Dim nGuideId As Integer = EgtCreateArc(nGuideLayId, ptCen, dExtRad, dAngIniDeg, dAngCenDeg, 0)
       ' Recupero o creo layer per la superficie
       Dim nSurfLayId As Integer = EgtGetFirstNameInGroup(nPartId, NAME_SURF)
       If nSurfLayId = GDB_ID.NULL Then