diff --git a/LuaLibs/CalcToolPath.lua b/LuaLibs/CalcToolPath.lua
index d812767..e4cfb3d 100644
--- a/LuaLibs/CalcToolPath.lua
+++ b/LuaLibs/CalcToolPath.lua
@@ -353,6 +353,7 @@ local function AddLeadIn( nCrvId, LayerParams, nGrpId)
       EgtModifyCurveExtrusion( nLeadInCrv, LayerParams.vtSlicing, GDB_RT.GLOB)
       EgtSetInfo( nLeadInCrv, KEY_TYPE, TYPE.LINK)
       EgtSetName( nLeadInCrv, LEAD_IN_CRV)
+      EgtSetColor( nLeadInCrv, EgtStdColor('GRAY'))
       local dStrand = EgtGetInfo( nCrvId, KEY_CRV_STRAND, 'd')
       EgtSetInfo( nLeadInCrv, KEY_CRV_STRAND, dStrand)
    end
@@ -387,6 +388,7 @@ local function AddLeadOut( nCrvId, LayerParams, nGrpId)
       EgtModifyCurveExtrusion( nLeadOutCrv, LayerParams.vtSlicing, GDB_RT.GLOB)
       EgtSetInfo( nLeadOutCrv, KEY_TYPE, TYPE.LINK)
       EgtSetName( nLeadOutCrv, LEAD_OUT_CRV)
+      EgtSetColor( nLeadOutCrv, EgtStdColor('GRAY'))
       local dStrand = EgtGetInfo( nCrvId, KEY_CRV_STRAND, 'd')
       EgtSetInfo( nLeadOutCrv, KEY_CRV_STRAND, dStrand)
    end
diff --git a/LuaLibs/RunCalcSolids.lua b/LuaLibs/RunCalcSolids.lua
index 5488fca..15b87d6 100644
--- a/LuaLibs/RunCalcSolids.lua
+++ b/LuaLibs/RunCalcSolids.lua
@@ -436,41 +436,52 @@ function RunCalcSolids.Exec()
                      nSolidGrpId = EgtGroup( nCrvGrpId)
                      EgtSetName( nSolidGrpId, SOLID_GRP)
                      EgtSetLevel( nSolidGrpId, GDB_LV.TEMP)
-                     -- scorro le curve del percorso utensile per creare i solidi
                      local vIds = EgtGetAllInGroup( nTPathGrpId)
                      
-                     if LayerParams.bSpiralVase and #vIds > 2 and EgtGetName( vIds[#vIds]) ~= WIPE_CRV then
-                         -- nel caso a spirale gestione speciale per unire i tratti dei primi layers che sono stati spezzati per feed variabile
-                        local bHasDelta = EgtExistsInfo( vIds[#vIds], KEY_FEED_COEFF)
-                        if bHasDelta then
-                           -- prima curva è a quota costante
-                           CreateSolidFromCurve( vIds[1], nSolidGrpId, LayerParams, nLayer)
-                           -- le rimanenti curve possono essere unite
-                           local vNewIds = EgtTableFill( vIds[2], #vIds-1)
-                           local nNewCrv = EgtCurveCompo( nSolidGrpId, vNewIds, false)
-                           local dStrand = EgtGetInfo( vIds[2], KEY_CRV_STRAND, 'd') or LayerParams.dStrand
-                           EgtSetInfo( nNewCrv, KEY_CRV_STRAND, dStrand)
-                           EgtSetInfo( nNewCrv, KEY_TYPE, TYPE.OUTER_SHELL)
-                           CreateSolidFromCurve( nNewCrv, nSolidGrpId, LayerParams, nLayer)
-                           EgtErase( nNewCrv)
-                        else
-                           local vNewIds = EgtTableFill( vIds[1], #vIds-1)
-                           local nNewCrv = EgtCurveCompo( nSolidGrpId, vNewIds, false)
-                           local dStrand = EgtGetInfo( vIds[2], KEY_CRV_STRAND, 'd') or LayerParams.dStrand
-                           EgtSetInfo( nNewCrv, KEY_CRV_STRAND, dStrand)
-                           EgtSetInfo( nNewCrv, KEY_TYPE, TYPE.OUTER_SHELL)
-                           CreateSolidFromCurve( nNewCrv, nSolidGrpId, LayerParams, nLayer)
-                           EgtErase( nNewCrv)
-                           CreateSolidFromCurve( vIds[#vIds], nSolidGrpId, LayerParams, nLayer)
+                     -- spiral vase
+                     if LayerParams.bSpiralVase then
+                        -- i tratti di ingresso, uscita e quelli a quota costante vanno gestiti singolarmente, quelli a quota variabile vanno concatenati
+                        local vChainedIds = {}
+                        local vTmpIds = {}
+                        for i = 1, #vIds do
+                           local sName = EgtGetName( vIds[i])
+                           local dDelta = ( EgtEP( vIds[i], GDB_ID.ROOT) - EgtSP( vIds[i], GDB_ID.ROOT)) * LayerParams.vtSlicing
+                           if abs( dDelta) < GEO.EPS_SMALL or sName == LEAD_IN_CRV or sName == LEAD_OUT_CRV or sName == COASTING_CRV or sName == WIPE_CRV then
+                              -- inserisco il gruppo di tratti da concatenare e lo resetto
+                              if #vTmpIds > 0 then 
+                                 table.insert( vChainedIds, vTmpIds)
+                                 vTmpIds = {}
+                              end
+                              -- inserisco la curva singola corrente
+                              table.insert( vChainedIds, { vIds[i]})
+                           else
+                              table.insert( vTmpIds, vIds[i])
+                           end
+                        end
+                        -- inserisco ultimo gruppo
+                        if #vTmpIds > 0 then
+                           table.insert( vChainedIds, vTmpIds)
                         end
                         
+                        for i = 1, #vChainedIds do
+                           if #vChainedIds[i] == 1 then
+                              CreateSolidFromCurve( vChainedIds[i][1], nSolidGrpId, LayerParams, nLayer)
+                           else
+                              local nNewCrv = EgtCurveCompo( nSolidGrpId, vChainedIds[i], false)
+                              local dStrand = EgtGetInfo( vChainedIds[i][1], KEY_CRV_STRAND, 'd') or LayerParams.dStrand
+                              EgtSetInfo( nNewCrv, KEY_CRV_STRAND, dStrand)
+                              EgtSetInfo( nNewCrv, KEY_TYPE, TYPE.OUTER_SHELL)
+                              CreateSolidFromCurve( nNewCrv, nSolidGrpId, LayerParams, nLayer)
+                              EgtErase( nNewCrv)
+                           end
+                        end
+                        
+                     -- caso standard
                      else
-                        -- caso standard
                         for i = 1, #vIds do
                            CreateSolidFromCurve( vIds[i], nSolidGrpId, LayerParams, nLayer)
                         end
                      end
-                     
                   else
                      bSolidsOk = true
                      break