diff --git a/LuaLibs/ProcessHeadCut.lua b/LuaLibs/ProcessHeadCut.lua
index d38e615..b6671f4 100644
--- a/LuaLibs/ProcessHeadCut.lua
+++ b/LuaLibs/ProcessHeadCut.lua
@@ -196,7 +196,11 @@ local function MakeHeadChamfer( idProc, nPartId)
    EgtSetGridFrame( Frame3d( 0,0,0, GDB_FR.RIGHT))
 
    local dQ09Value = EgtGetInfo( idProc, 'Q09', 'd')
+   if not dQ09Value then
+      dQ09Value = 0.1
+   end
    local bChamferedEdge = dQ09Value > 0
+   dQ09Value = EgtIf( bChamferedEdge, max( dQ09Value, 0.1), min( dQ09Value, -0.1))
 
    local nIdFirstEntity, nEntityCnt = EgtExplodeCurveCompo( nLoopId)
    local p3MidPoint = EgtMP( nIdFirstEntity, GDB_ID.GRID)
@@ -232,6 +236,9 @@ local function MakeHeadChamfer( idProc, nPartId)
    end
    EgtChangeClosedCurveStartPoint( idGeom, p3MidPoint, GDB_RT.GRID)
 
+   -- reimposto la griglia
+   EgtSetGridFrame()
+
    -- Inserisco la lavorazione del lato standard
    local dExtra = 2
    local sName1 = 'HeadCham_' .. ( EgtGetName( idProc) or tostring( idProc))
diff --git a/LuaLibs/ProcessSplit.lua b/LuaLibs/ProcessSplit.lua
index 62664c4..3a8792f 100644
--- a/LuaLibs/ProcessSplit.lua
+++ b/LuaLibs/ProcessSplit.lua
@@ -198,7 +198,13 @@ local function MakeTailChamfer( idProc, nPartId, dDepthTailChamfer)
    EgtSetGridFrame( Frame3d( 0,0,0, GDB_FR.LEFT))
 
    local dQ09Value = EgtGetInfo( idProc, 'Q09', 'd')
+   if not dQ09Value then
+      dQ09Value = 0.1
+   end
    local bChamferedEdge = dQ09Value > 0
+   dQ09Value = EgtIf( bChamferedEdge, max( dQ09Value, 0.1), min( dQ09Value, -0.1))
+
+   
 
    local nIdFirstEntity, nEntityCnt = EgtExplodeCurveCompo( nLoopId)
    local p3MidPoint = EgtMP( nIdFirstEntity, GDB_ID.GRID)
@@ -234,6 +240,9 @@ local function MakeTailChamfer( idProc, nPartId, dDepthTailChamfer)
    end
    EgtChangeClosedCurveStartPoint( idGeom, p3MidPoint, GDB_RT.GRID)
 
+   -- reimposto la griglia
+   EgtSetGridFrame()
+
    -- Inserisco la lavorazione del lato standard
    local dExtra = 2
    local sName1 = 'TailCham_' .. ( EgtGetName( idProc) or tostring( idProc))