diff --git a/examples/NeedleInsertion.py b/examples/NeedleInsertion.py
index c813262..d832c17 100644
--- a/examples/NeedleInsertion.py
+++ b/examples/NeedleInsertion.py
@@ -194,7 +194,7 @@ def createScene(root):
     )
     root.addObject("DistanceFilter",algo="@InsertionAlgo",distance=0.01)
     root.addObject("SecondDirection",name="punctureDirection",handler="@Volume/collision/SurfaceTriangles")
-    root.addObject("ConstraintUnilateral",input="@InsertionAlgo.collisionOutput",directions="@punctureDirection",draw_scale=0.001)
+    root.addObject("ConstraintUnilateral",input="@InsertionAlgo.collisionOutput",directions="@punctureDirection", contactDistance=0, draw_scale=0.001)
 
     root.addObject("FirstDirection",name="bindDirection", handler="@Needle/bodyCollision/NeedleBeams")
     root.addObject("ConstraintInsertion",input="@InsertionAlgo.insertionOutput", directions="@bindDirection",draw_scale=0.002, frictionCoeff=0.002)
diff --git a/examples/NeedleInsertionCycles.py b/examples/NeedleInsertionCycles.py
index 2b3cb85..7a64803 100644
--- a/examples/NeedleInsertionCycles.py
+++ b/examples/NeedleInsertionCycles.py
@@ -211,7 +211,7 @@ def createScene(root):
     )
     root.addObject("DistanceFilter",algo="@InsertionAlgo",distance=0.01)
     root.addObject("SecondDirection",name="punctureDirection",handler="@Volume/collision/SurfaceTriangles")
-    root.addObject("ConstraintUnilateral",input="@InsertionAlgo.collisionOutput",directions="@punctureDirection",draw_scale=0.001, mu=0.001)
+    root.addObject("ConstraintUnilateral",input="@InsertionAlgo.collisionOutput",directions="@punctureDirection", contactDistance=0,draw_scale=0.001, mu=0.001)
 
     root.addObject("FirstDirection",name="bindDirection", handler="@Needle/bodyCollision/NeedleBeams")
     root.addObject("ConstraintInsertion",input="@InsertionAlgo.insertionOutput", directions="@bindDirection",draw_scale=0.002, frictionCoeff=0.00)#23)
diff --git a/examples/NeedleInsertionHaptics.py b/examples/NeedleInsertionHaptics.py
index e0a43da..eef1219 100644
--- a/examples/NeedleInsertionHaptics.py
+++ b/examples/NeedleInsertionHaptics.py
@@ -219,7 +219,7 @@ def createScene(root):
     )
     root.addObject("DistanceFilter",algo="@InsertionAlgo",distance=0.02)
     root.addObject("SecondDirection",name="punctureDirection",handler="@Volume/collision/SurfaceTriangles")
-    root.addObject("ConstraintUnilateral",input="@InsertionAlgo.collisionOutput",directions="@punctureDirection",draw_scale=0.001, mu=0.001)
+    root.addObject("ConstraintUnilateral",input="@InsertionAlgo.collisionOutput",directions="@punctureDirection", contactDistance=0,draw_scale=0.001, mu=0.001)
 
     root.addObject("FirstDirection",name="bindDirection", handler="@Needle/bodyCollision/NeedleBeams")
     root.addObject("ConstraintInsertion",input="@InsertionAlgo.insertionOutput", directions="@bindDirection",draw_scale="0.01", frictionCoeff=0.000)