diff --git a/LuaLibs/WProcessFreeContour.lua b/LuaLibs/WProcessFreeContour.lua
index d06c4e4..114cfa8 100644
--- a/LuaLibs/WProcessFreeContour.lua
+++ b/LuaLibs/WProcessFreeContour.lua
@@ -1913,9 +1913,9 @@ local function MakeByNail( Proc, nRawId, b3Raw)
    if Proc.Double == 2 then
       dExtraDelta = 0.45 * dCntPar
       if Proc.Delta > 0 then
-         EgtSetMachiningParam( MCH_MP.ENDADDLEN, -abs( Proc.Delta) - dExtraDelta)
+         EgtSetMachiningParam( MCH_MP.ENDADDLEN, -Proc.DblAcc - dExtraDelta)
       else
-         EgtSetMachiningParam( MCH_MP.STARTADDLEN, -abs( Proc.Delta) - dExtraDelta)
+         EgtSetMachiningParam( MCH_MP.STARTADDLEN, -Proc.DblAcc - dExtraDelta)
       end
    end
    -- assegno parametri a note utente