diff --git a/LuaLibs/ProcessLapJoint.lua b/LuaLibs/ProcessLapJoint.lua
index 6a5921e..3589adb 100644
--- a/LuaLibs/ProcessLapJoint.lua
+++ b/LuaLibs/ProcessLapJoint.lua
@@ -2551,7 +2551,7 @@ end
 ---------------------------------------------------------------------
 local function MakeChamfer( Proc, bIs3Faces, nAddGrpId, vtOrtho, b3Solid, nSurfInt, dDepthCham)
 
-   -- Se variabile globale indica che lo smusso è gi stato fatto, esco
+   -- Se variabile globale indica che lo smusso è già stato fatto, esco
    if bMadeChamfer then
       return 0
    end
@@ -2565,6 +2565,7 @@ local function MakeChamfer( Proc, bIs3Faces, nAddGrpId, vtOrtho, b3Solid, nSurfI
    end
    -- ottengo le curve di contorno libero
    local nAuxId1, nAuxId2, nNumIdAux
+   local bIsOpenPath = false
    if bIs3Faces then
       -- estraggo i percorsi
       nAuxId1, nNumIdAux = EgtExtractSurfTmLoops( Proc.Id, nAddGrpId)
@@ -2575,6 +2576,36 @@ local function MakeChamfer( Proc, bIs3Faces, nAddGrpId, vtOrtho, b3Solid, nSurfI
    else
       nAuxId1, nNumIdAux = EgtExtractSurfTmLoops( Proc.Id, nAddGrpId)
       if not nNumIdAux then nNumIdAux = 0 end
+      -- se non è una curva chiusa bisogna estrarre le sole curve da lavorare
+      if Proc.TopologyLongName == 'Groove-Blind-RightAngles-Parallel-4' then
+         local IdsToMachine = {}
+         bIsOpenPath = true
+         local nFirstId, nIdCount = EgtExplodeCurveCompo( nAuxId1)
+         for i = nFirstId, nFirstId + nIdCount - 1, 1 do
+            -- se segmento di retta
+            if EgtGetType( i) == GDB_TY.CRV_LINE then
+               local _, nEntitiesCount = EgtCurveDomain(i)
+               for j = 0, nEntitiesCount - 1 do
+                  local ptStart = EgtUP( i, j, GDB_RT.GLOB)
+                  local ptEnd = EgtUP( i, j + 1, GDB_RT.GLOB)
+                  if ( AreSameVectorApprox( vtOrtho, X_AX()) and ( abs( ptStart:getX() - b3Solid:getMax():getX()) < 100 * GEO.EPS_SMALL and abs( ptEnd:getX() - b3Solid:getMax():getX()) < 100 * GEO.EPS_SMALL) or
+                       AreSameVectorApprox( vtOrtho, -X_AX()) and ( abs( ptStart:getX() - b3Solid:getMin():getX()) < 100 * GEO.EPS_SMALL and abs( ptEnd:getX() - b3Solid:getMin():getX()) < 100 * GEO.EPS_SMALL) or
+                       AreSameVectorApprox( vtOrtho, Y_AX()) and ( abs( ptStart:getY() - b3Solid:getMax():getY()) < 100 * GEO.EPS_SMALL and abs( ptEnd:getY() - b3Solid:getMax():getY()) < 100 * GEO.EPS_SMALL) or
+                       AreSameVectorApprox( vtOrtho, -Y_AX()) and ( abs( ptStart:getY() - b3Solid:getMin():getY()) < 100 * GEO.EPS_SMALL and abs( ptEnd:getY() - b3Solid:getMin():getY()) < 100 * GEO.EPS_SMALL) or
+                       AreSameVectorApprox( vtOrtho, Z_AX()) and ( abs( ptStart:getZ() - b3Solid:getMax():getZ()) < 100 * GEO.EPS_SMALL and abs( ptEnd:getZ() - b3Solid:getMax():getZ()) < 100 * GEO.EPS_SMALL) or
+                       AreSameVectorApprox( vtOrtho, -Z_AX()) and ( abs( ptStart:getZ() - b3Solid:getMin():getZ()) < 100 * GEO.EPS_SMALL and abs( ptEnd:getZ() - b3Solid:getMin():getZ()) < 100 * GEO.EPS_SMALL)
+                     ) then
+                     table.insert( IdsToMachine, i)
+                  end
+               end
+            else
+               return 0
+            end
+         end
+         local ptNear = EgtSurfTmFacetCenter(Proc.Id, 0, GDB_ID.ROOT)
+         nAuxId1 = EgtCurveCompoByReorder( nAddGrpId, IdsToMachine, ptNear, true, GDB_ID.ROOT)
+         nNumIdAux = 1
+      end
    end
 
    local dExtra = 2
@@ -2594,13 +2625,20 @@ local function MakeChamfer( Proc, bIs3Faces, nAddGrpId, vtOrtho, b3Solid, nSurfI
          end
       else
          AuxId = nAuxId1 + i - 1
-         vtExtr, _, _ = EgtCurveArea( AuxId)
-      end
-      if vtExtr then
-         if not bIs3Faces then
+         if bIsOpenPath then
+            _, vtExtr = EgtCurveIsFlat( AuxId)
+         else
+            vtExtr, _, _ = EgtCurveArea( AuxId)
+         end
+         if vtExtr then
             local fFrCurve = EgtGetGlobFrame( AuxId)
             vtExtr:toGlob( fFrCurve)
+            if bIsOpenPath and vtExtr * vtOrtho < GEO.EPS_SMALL then
+               vtExtr = -vtExtr
+            end
          end
+      end
+      if vtExtr then
 --         if bIs3Faces and i == nNumIdAux then
 --            vtExtr = -vtExtr
 --         end
@@ -2844,6 +2882,12 @@ local function MakeByChainOrSaw( Proc, nPhase, nRawId, nPartId, nFacInd,
          local nOk, sErr = MakeChamfer( Proc, bIs3Faces, nAddGrpId, vtOrtho, b3Solid, nSurfInt, dDepthCham)
          if nOk < 0 then return false, sErr end
       end
+   -- slot aperta su due lati
+   elseif Proc.TopologyLongName == 'Groove-Blind-RightAngles-Parallel-4' then
+      if nChamfer > 0 then
+         local nOk, sErr = MakeChamfer( Proc, false, nAddGrpId, rfFac:getVersZ(), b3Solid, nil, dDepthCham)
+         if nOk < 0 then return false, sErr end
+      end
    end
    if not dDepth then dDepth = dElev end
    -- Recupero le facce adiacenti alla principale