diff --git a/newton-4.00/applications/ndSandbox/ndDemoEntityManager.cpp b/newton-4.00/applications/ndSandbox/ndDemoEntityManager.cpp
index 102dd2e76..fb3f653a5 100644
--- a/newton-4.00/applications/ndSandbox/ndDemoEntityManager.cpp
+++ b/newton-4.00/applications/ndSandbox/ndDemoEntityManager.cpp
@@ -41,7 +41,7 @@
 //#define DEFAULT_SCENE	1		// gpu basic rigidbody
 //#define DEFAULT_SCENE	2		// friction ramp
 //#define DEFAULT_SCENE	3		// basic compound shapes
-#define DEFAULT_SCENE	4		// conservation of momentum 
+//#define DEFAULT_SCENE	4		// conservation of momentum 
 //#define DEFAULT_SCENE	5		// basic Stacks
 //#define DEFAULT_SCENE	6		// basic Trigger
 //#define DEFAULT_SCENE	7		// object Placement
@@ -57,7 +57,7 @@
 //#define DEFAULT_SCENE	17		// cart pole discrete controller
 //#define DEFAULT_SCENE	18		// cart pole continue controller
 //#define DEFAULT_SCENE	19		// unit cycle controller
-//#define DEFAULT_SCENE	20		// simple industrial robot
+#define DEFAULT_SCENE	20		// simple industrial robot
 //#define DEFAULT_SCENE	21		// advanced industrial robot
 //#define DEFAULT_SCENE	22		// quadruped test 1
 //#define DEFAULT_SCENE	23		// quadruped test 2
diff --git a/newton-4.00/sdk/dNewton/dIkSolver/ndIk6DofEffector.cpp b/newton-4.00/sdk/dNewton/dIkSolver/ndIk6DofEffector.cpp
index 08d8a4c42..100992954 100644
--- a/newton-4.00/sdk/dNewton/dIkSolver/ndIk6DofEffector.cpp
+++ b/newton-4.00/sdk/dNewton/dIkSolver/ndIk6DofEffector.cpp
@@ -21,12 +21,10 @@ ndIk6DofEffector::ndIk6DofEffector()
 	,m_angularDamper(ndFloat32(50.0f))
 	,m_angularMaxTorque(D_LCP_MAX_VALUE)
 	,m_angularRegularizer(ndFloat32(5.0e-3f))
-	,m_angularMaxSpringRamp(ndFloat32(1.0e10f))
 	,m_linearSpring(ndFloat32(1000.0f))
 	,m_linearDamper(ndFloat32(50.0f))
 	,m_linearMaxForce(D_LCP_MAX_VALUE)
 	,m_linearRegularizer(ndFloat32(5.0e-3f))
-	,m_linearMaxSpringRamp(ndFloat32(1.0e10f))
 	,m_rotationType(m_disabled)
 	,m_controlDofOptions(0xff)
 {
@@ -40,12 +38,10 @@ ndIk6DofEffector::ndIk6DofEffector(const ndMatrix& pinAndPivotChild, const ndMat
 	,m_angularDamper(ndFloat32(50.0f))
 	,m_angularMaxTorque(D_LCP_MAX_VALUE)
 	,m_angularRegularizer(ndFloat32(5.0e-3f))
-	,m_angularMaxSpringRamp(ndFloat32(1.0e10f))
 	,m_linearSpring(ndFloat32(1000.0f))
 	,m_linearDamper(ndFloat32(50.0f))
 	,m_linearMaxForce(D_LCP_MAX_VALUE)
 	,m_linearRegularizer(ndFloat32(5.0e-3f))
-	,m_linearMaxSpringRamp(ndFloat32(1.0e10f))
 	,m_rotationType(m_disabled)
 	,m_controlDofOptions(0xff)
 {
diff --git a/newton-4.00/sdk/dNewton/dIkSolver/ndIk6DofEffector.h b/newton-4.00/sdk/dNewton/dIkSolver/ndIk6DofEffector.h
index 6934ee43b..1f97897a5 100644
--- a/newton-4.00/sdk/dNewton/dIkSolver/ndIk6DofEffector.h
+++ b/newton-4.00/sdk/dNewton/dIkSolver/ndIk6DofEffector.h
@@ -72,13 +72,11 @@ class ndIk6DofEffector: public ndJointBilateralConstraint
 	ndFloat32 m_angularDamper;
 	ndFloat32 m_angularMaxTorque;
 	ndFloat32 m_angularRegularizer;
-	ndFloat32 m_angularMaxSpringRamp;
 	
 	ndFloat32 m_linearSpring;
 	ndFloat32 m_linearDamper;
 	ndFloat32 m_linearMaxForce;
 	ndFloat32 m_linearRegularizer;
-	ndFloat32 m_linearMaxSpringRamp;
 
 	ndRotationType m_rotationType;
 	union