diff --git a/LuaLibs/RunMachParamFromSWCalc.lua b/LuaLibs/RunMachParamFromSWCalc.lua
index 15c2b6c..eec4539 100644
--- a/LuaLibs/RunMachParamFromSWCalc.lua
+++ b/LuaLibs/RunMachParamFromSWCalc.lua
@@ -1,4 +1,4 @@
--- RunMachParamFromSWCalc.lua by Egaltech s.r.l. 2022/09/15
+-- RunMachParamFromSWCalc.lua by Egaltech s.r.l. 2022/11/22
 -- Calcolo dei parametri di stampa
 
 -- Tabella per definizione modulo
@@ -82,12 +82,14 @@ function RunMachParamFromSWCalc.Exec()
             dTotLayerLength = dTotLayerLength + dTotCrvLength
             -- recupero area
             local nOuterCrvId = EgtGetFirstNameInGroup( nCrvId, OUTER_CRV)
-            local _, _, dTotCrvArea = EgtCurveArea( nOuterCrvId)
-            local dOuterLength = EgtCurveLength( nOuterCrvId)
-            -- recupero offset del part per aggiungerlo all'area interna
-            local dOffset = EgtGetInfo( nPartId, KEY_OFFSET_SLICE, 'd')
-            dTotCrvArea = dTotCrvArea + ( dOffset * dOuterLength)
-            dTotLayerArea = dTotLayerArea + dTotCrvArea
+            if nOuterCrvId and dStrandCount > 0.5 then
+               local _, _, dTotCrvArea = EgtCurveArea( nOuterCrvId)
+               local dOuterLength = EgtCurveLength( nOuterCrvId)
+               -- recupero offset del part per aggiungerlo all'area interna
+               local dOffset = EgtGetInfo( nPartId, KEY_OFFSET_SLICE, 'd')
+               dTotCrvArea = dTotCrvArea + ( dOffset * dOuterLength)
+               dTotLayerArea = dTotLayerArea + dTotCrvArea
+            end
             nCrvId = EgtGetNextName( nCrvId, CONTOUR_GRP .. '*')
          end
          -- recupero feed del layer
@@ -114,11 +116,16 @@ function RunMachParamFromSWCalc.Exec()
          end
          EgtSetInfo( nLayerResultId, KEY_SLICEID, nOrigLayers)
          -- calcolo costante MF
-         local dMF = dTotLayerLength * dStrand / dTotLayerArea * 100
+         local dMF = 1
+         local dSC = 1
+         if dTotLayerArea > 1 then
+            dMF = dTotLayerLength * dStrand / dTotLayerArea * 100
+            dSC = dStrandCount
+         end
          -- calcolo tempi stimati del layer
-         local dTMin = ( dMF + MATERIAL.AMin) / MATERIAL.BMin * pow( 0.25 * dStrand, MATERIAL.KW) * pow( dSliceStep, MATERIAL.KZ) * pow( dStrandCount, MATERIAL.KN)
-         local dTTrg = ( dMF + MATERIAL.ATrg) / MATERIAL.BTrg * pow( 0.25 * dStrand, MATERIAL.KW) * pow( dSliceStep, MATERIAL.KZ) * pow( dStrandCount, MATERIAL.KN)
-         local dTMax = ( dMF + MATERIAL.AMax) / MATERIAL.BMax * pow( 0.25 * dStrand, MATERIAL.KW) * pow( dSliceStep, MATERIAL.KZ) * pow( dStrandCount, MATERIAL.KN)
+         local dTMin = ( dMF + MATERIAL.AMin) / MATERIAL.BMin * pow( 0.25 * dStrand, MATERIAL.KW) * pow( dSliceStep, MATERIAL.KZ) * pow( dSC, MATERIAL.KN)
+         local dTTrg = ( dMF + MATERIAL.ATrg) / MATERIAL.BTrg * pow( 0.25 * dStrand, MATERIAL.KW) * pow( dSliceStep, MATERIAL.KZ) * pow( dSC, MATERIAL.KN)
+         local dTMax = ( dMF + MATERIAL.AMax) / MATERIAL.BMax * pow( 0.25 * dStrand, MATERIAL.KW) * pow( dSliceStep, MATERIAL.KZ) * pow( dSC, MATERIAL.KN)
          local dFMin = dTotLayerLength / dTMax * 60
          local dFTrg = dTotLayerLength / dTTrg * 60
          local dFMax = dTotLayerLength / dTMin * 60