diff --git a/src/Interaction/sphereInteraction/sphereInteractionsLinearModels.cpp b/src/Interaction/sphereInteraction/sphereInteractionsLinearModels.cpp
index 1c45936b..6a361789 100644
--- a/src/Interaction/sphereInteraction/sphereInteractionsLinearModels.cpp
+++ b/src/Interaction/sphereInteraction/sphereInteractionsLinearModels.cpp
@@ -58,6 +58,6 @@ createInteraction(pFlow::cfModels::limitedLinearNormalRolling, pFlow::conveyorBe
 createInteraction(pFlow::cfModels::nonLimitedLinearNormalRolling,pFlow::conveyorBeltMotionGeometry);
 
 // multiRotationAxisMotionGeometry
-//createInteraction(pFlow::cfModels::limitedLinearNormalRolling, pFlow::multiRotationAxisMotionGeometry);
-//createInteraction(pFlow::cfModels::nonLimitedLinearNormalRolling,pFlow::multiRotationAxisMotionGeometry);
+createInteraction(pFlow::cfModels::limitedLinearNormalRolling, pFlow::multiRotationAxisMotionGeometry);
+createInteraction(pFlow::cfModels::nonLimitedLinearNormalRolling,pFlow::multiRotationAxisMotionGeometry);
 
diff --git a/src/Interaction/sphereInteraction/sphereInteractionsNonLinearModels.cpp b/src/Interaction/sphereInteraction/sphereInteractionsNonLinearModels.cpp
index c13ec77e..f7700209 100644
--- a/src/Interaction/sphereInteraction/sphereInteractionsNonLinearModels.cpp
+++ b/src/Interaction/sphereInteraction/sphereInteractionsNonLinearModels.cpp
@@ -58,5 +58,5 @@ createInteraction(pFlow::cfModels::limitedNonLinearNormalRolling, pFlow::conveyo
 createInteraction(pFlow::cfModels::nonLimitedNonLinearNormalRolling,pFlow::conveyorBeltMotionGeometry);
 
 // multiRotationAxisMotionGeometry
-//createInteraction(pFlow::cfModels::limitedNonLinearNormalRolling, pFlow::multiRotationAxisMotionGeometry);
-//createInteraction(pFlow::cfModels::nonLimitedNonLinearNormalRolling,pFlow::multiRotationAxisMotionGeometry);
+createInteraction(pFlow::cfModels::limitedNonLinearNormalRolling, pFlow::multiRotationAxisMotionGeometry);
+createInteraction(pFlow::cfModels::nonLimitedNonLinearNormalRolling,pFlow::multiRotationAxisMotionGeometry);
diff --git a/src/phasicFlow/structuredData/line/line.hpp b/src/phasicFlow/structuredData/line/line.hpp
index 375588a4..62cf9271 100755
--- a/src/phasicFlow/structuredData/line/line.hpp
+++ b/src/phasicFlow/structuredData/line/line.hpp
@@ -50,6 +50,7 @@ public:
 	//// - Constructors 
 		FUNCTION_HD
 		line()
+		: v21_(1, 0, 0), p1_(0, 0, 0)
 		{}
 
 		FUNCTION_HD
@@ -86,6 +87,10 @@ public:
 		void set(const realx3 &lp1, const realx3 &lp2)
 		{
 			v21_ = lp2 - lp1;
+			if(v21_.length() < verySmallValue)
+			{
+				v21_ = realx3(1, 0, 0);
+			}
 			p1_ = lp1;
 		}
 
@@ -121,7 +126,7 @@ public:
 		real projectNormalizedLength(realx3 p) const 
 		{
 			realx3 w = p - p1_;
-			return dot(w,v21_) / dot(v21_,v21_);
+			return dot(w, v21_) / dot(v21_, v21_);
 		}
 
 	//// - IO operation