diff --git a/LuaLibs/MachiningLib.lua b/LuaLibs/MachiningLib.lua
index bfc88fe..17fee4b 100644
--- a/LuaLibs/MachiningLib.lua
+++ b/LuaLibs/MachiningLib.lua
@@ -320,6 +320,7 @@ local function Check2DBladeCollision( Edge, vtNFace, vtHead, Part, Tool, dDepthT
       ptMaxElev = ptMaxElev + vtNFace * Tool.dThickness
    end
    -- TODO qui sostituire con il valore reale letto dal SetupInfo
+   -- per Fast si dovrà aggiungere la lunghezza del massimo utensile utilizzabile con lama
    local dHeadDepth = 480
    local dHeadWidth = 480
    local ptOpposite = ptMaxElev + Edge.vtN * dHeadWidth
@@ -328,12 +329,19 @@ local function Check2DBladeCollision( Edge, vtNFace, vtHead, Part, Tool, dDepthT
    -- flat region dal rettangolo
    local idHeadSurfFr = EgtSurfFlatRegion( idTempGroup, idHeadRectangle)
 
-   -- intersezione
-   --local idTestSurfFr = EgtCopyGlob( idPartSurfFr, idTempGroup)
-   -- TODO ritornare correttamente
-   local bCollisionFound = EgtSurfFrIntersect( idPartSurfFr, idHeadSurfFr)
+   -- intersezione (se fallisce si inverte la flat region del motore, probabile normale opposta)
+   local bIntersectSuccess = EgtSurfFrIntersect( idPartSurfFr, idHeadSurfFr)
+   if not bIntersectSuccess then
+      EgtInvertSurf( idHeadSurfFr)
+      bIntersectSuccess = EgtSurfFrIntersect( idPartSurfFr, idHeadSurfFr)
+   end
+   if not bIntersectSuccess then
+      error( 'Check2DBladeCollision : intersect fail')
+   end
 
-   return false
+   local bCollisionFound = EgtExistsObj( idPartSurfFr)
+
+   return bCollisionFound
 end
 
 -------------------------------------------------------------------------------------------------------------
diff --git a/StrategyLibs/FACEBYBLADE.lua b/StrategyLibs/FACEBYBLADE.lua
index 7b78014..f1a762e 100644
--- a/StrategyLibs/FACEBYBLADE.lua
+++ b/StrategyLibs/FACEBYBLADE.lua
@@ -273,7 +273,7 @@ function FACEBYBLADE.Make( Proc, Part, FaceToMachine, EdgeToMachine, OptionalPar
    if nToolIndex then
 
       Cutting.nToolIndex = nToolIndex
-      Cutting.bIsApplicable, Cutting.sBladeEngagement = MachiningLib.GetBladeEngagement( FaceToMachine, EdgeToMachine, Part, TOOLS[nToolIndex], dDepthToMachine, bCollisionCheckForDownUpOnly)
+      Cutting.bIsApplicable, Cutting.sBladeEngagement = MachiningLib.GetBladeEngagement( FaceToMachine, EdgeToMachine, Part, TOOLS[Cutting.nToolIndex], dDepthToMachine, bCollisionCheckForDownUpOnly)
 
    -- utensile da cercare: si prende la lama migliore che può effettuare questo taglio, senza particolari analisi
    else
@@ -347,7 +347,7 @@ function FACEBYBLADE.Make( Proc, Part, FaceToMachine, EdgeToMachine, OptionalPar
    if OppositeToolDirectionMode ~= 'Disabled' then
 
       -- lavorando dalla direzione opposta si verifica come se si lavorasse il lato opposto
-      local bIsApplicableOpposite, sBladeEngagementOpposite = MachiningLib.GetBladeEngagement( FaceToMachine, EdgeToMachineOpposite, Part, TOOLS[nToolIndex], dDepthToMachine, bCollisionCheckForDownUpOnly)
+      local bIsApplicableOpposite, sBladeEngagementOpposite = MachiningLib.GetBladeEngagement( FaceToMachine, EdgeToMachineOpposite, Part, TOOLS[Cutting.nToolIndex], dDepthToMachine, bCollisionCheckForDownUpOnly)
 
       -- taglio opposto non fattibile
       if not bIsApplicableOpposite then
@@ -416,9 +416,9 @@ function FACEBYBLADE.Make( Proc, Part, FaceToMachine, EdgeToMachine, OptionalPar
          and FaceData.IsFaceRectangle( FaceToMachine) then
 
          -- TODO la lama sotto deve poter ridurre. Ghigliottina sì o no?
-         local bIsTopBlade = TOOLS[nToolIndex].SetupInfo.HeadType.bTop
-         Cutting.dMaxRadialOffset = TOOLS[nToolIndex].dMaxMaterial - Cutting.dDepthToMachine - BeamData.CUT_SIC
-         Cutting.dRadialOffsetGuillotine = FACEBYBLADE.GetRadialOffsetForGuillotine( nToolIndex, EdgeToMachine.dLength)
+         local bIsTopBlade = TOOLS[Cutting.nToolIndex].SetupInfo.HeadType.bTop
+         Cutting.dMaxRadialOffset = TOOLS[Cutting.nToolIndex].dMaxMaterial - Cutting.dDepthToMachine - BeamData.CUT_SIC
+         Cutting.dRadialOffsetGuillotine = FACEBYBLADE.GetRadialOffsetForGuillotine( Cutting.nToolIndex, EdgeToMachine.dLength)
          if Cutting.dMaxRadialOffset > 10 * GEO.EPS_SMALL then
             -- taglio a ghigliottina
             if bIsTopBlade and ( Cutting.dRadialOffsetGuillotine < Cutting.dMaxRadialOffset - 10 * GEO.EPS_SMALL) then
@@ -437,7 +437,7 @@ function FACEBYBLADE.Make( Proc, Part, FaceToMachine, EdgeToMachine, OptionalPar
       if OppositeToolDirectionMode == 'Enabled' then
          EdgeToMachineForEngagement = EdgeToMachineOpposite
       end
-      local bIsApplicable, sBladeEngagement = MachiningLib.GetBladeEngagement( FaceToMachine, EdgeToMachineForEngagement, Part, TOOLS[nToolIndex], dDepthToMachine)
+      local bIsApplicable, sBladeEngagement = MachiningLib.GetBladeEngagement( FaceToMachine, EdgeToMachineForEngagement, Part, TOOLS[Cutting.nToolIndex], dDepthToMachine)
       if bIsApplicable then
          Cutting.sBladeEngagement = sBladeEngagement
       else