diff --git a/stretch_description/urdf/stretch_aruco.xacro b/stretch_description/urdf/stretch_aruco.xacro
index 602f60c..8902d2a 100644
--- a/stretch_description/urdf/stretch_aruco.xacro
+++ b/stretch_description/urdf/stretch_aruco.xacro
@@ -119,7 +119,7 @@
         xyz="-2.77555756156289E-17 2.56739074444567E-16 -0.000125000000000042"
         rpy="0 0 0" />
       <mass
-        value="0.000399141592653546" />
+        value="0" />
       <inertia
         ixx="0"
         ixy="0"
@@ -174,7 +174,7 @@
         xyz="1.11022302462516E-16 3.05311331771918E-16 -0.00012499999999821"
         rpy="0 0 0" />
       <mass
-        value="0.000224999999999975" />
+        value="0" />
       <inertia
         ixx="0"
         ixy="0"
@@ -229,7 +229,7 @@
         xyz="8.32667268468867E-17 1.77635683940025E-15 -0.000125000000000264"
         rpy="0 0 0" />
       <mass
-        value="0.000225" />
+        value="0" />
       <inertia
         ixx="0"
         ixy="0"
diff --git a/stretch_description/urdf/stretch_d435i.xacro b/stretch_description/urdf/stretch_d435i.xacro
index ff85f30..ea8d71c 100644
--- a/stretch_description/urdf/stretch_d435i.xacro
+++ b/stretch_description/urdf/stretch_d435i.xacro
@@ -3,18 +3,18 @@
 
   <xacro:arg name="use_nominal_extrinsics" default="true"/>
   <xacro:arg name="add_plug" default="false"/>
-  <xacro:include filename="$(find realsense2_description)/urdf/_d435.urdf.xacro"/>
+  <xacro:include filename="$(find realsense2_description)/urdf/_d435i.urdf.xacro"/>
 
   <!-- xyz = "
        depth (- recessed into head / + protruding from front)
        up and down (- down / + up)
        sideways (- right / + left)
        " -->
-  <xacro:sensor_d435 parent="link_head_tilt" use_nominal_extrinsics="$(arg use_nominal_extrinsics)">
+  <xacro:sensor_d435i parent="link_head_tilt" use_nominal_extrinsics="$(arg use_nominal_extrinsics)">
     <origin
       xyz="0.03 -0.0122 0.0182"
       rpy="0.0 0.0 0.0" />
-  </xacro:sensor_d435>
+  </xacro:sensor_d435i>
   
 </robot>
 
diff --git a/stretch_description/urdf/stretch_gripper.xacro b/stretch_description/urdf/stretch_gripper.xacro
index 14615d8..03acc68 100644
--- a/stretch_description/urdf/stretch_gripper.xacro
+++ b/stretch_description/urdf/stretch_gripper.xacro
@@ -12,12 +12,12 @@
       <mass
         value="0.101902711393094" />
       <inertia
-        ixx="2.79241618017607E-05"
-        ixy="-1.10819247449605E-05"
-        ixz="-1.50343284036654E-05"
-        iyy="3.67945130513069E-05"
-        iyz="-4.33280448535579E-06"
-        izz="4.14524691955231E-05" />
+        ixx="0.001"
+        ixy="0"
+        ixz="0"
+        iyy="0.001"
+        iyz="0"
+        izz="0.001" />
     </inertial>
     <visual>
       <origin
@@ -69,12 +69,12 @@
       <mass
         value="0.0476207785199474" />
       <inertia
-        ixx="0"
+        ixx="0.001"
         ixy="0"
         ixz="0"
-        iyy="0"
+        iyy="0.001"
         iyz="0"
-        izz="0" />
+        izz="0.001" />
     </inertial>
     <visual>
       <origin
@@ -125,12 +125,12 @@
       <mass
         value="0.00382159917455729" />
       <inertia
-        ixx="0"
+        ixx="0.001"
         ixy="0"
         ixz="0"
-        iyy="0"
+        iyy="0.001"
         iyz="0"
-        izz="0" />
+        izz="0.001" />
     </inertial>
     <visual>
       <origin
@@ -180,12 +180,12 @@
       <mass
         value="0.0476207785199481" />
       <inertia
-        ixx="0"
+        ixx="0.001"
         ixy="0"
         ixz="0"
-        iyy="0"
+        iyy="0.001"
         iyz="0"
-        izz="0" />
+        izz="0.001" />
     </inertial>
     <visual>
       <origin
@@ -236,12 +236,12 @@
       <mass
         value="0.00382160037319545" />
       <inertia
-        ixx="0"
+        ixx="0.001"
         ixy="0"
         ixz="0"
-        iyy="0"
+        iyy="0.001"
         iyz="0"
-        izz="0" />
+        izz="0.001" />
     </inertial>
     <visual>
       <origin
@@ -300,6 +300,3 @@
   </joint>
   
 </robot>
-
-  
-
diff --git a/stretch_description/urdf/stretch_laser_range_finder.xacro b/stretch_description/urdf/stretch_laser_range_finder.xacro
index af62fb6..3632a66 100644
--- a/stretch_description/urdf/stretch_laser_range_finder.xacro
+++ b/stretch_description/urdf/stretch_laser_range_finder.xacro
@@ -57,6 +57,3 @@
   </joint>
 
 </robot>
-
-  
-
diff --git a/stretch_description/urdf/stretch_main.xacro b/stretch_description/urdf/stretch_main.xacro
index 7d878f2..6309cde 100644
--- a/stretch_description/urdf/stretch_main.xacro
+++ b/stretch_description/urdf/stretch_main.xacro
@@ -1,6 +1,11 @@
 <?xml version="1.0"?>
 <robot xmlns:xacro="http://www.ros.org/wiki/xacro" name="stretch_main">
-  
+  <xacro:property name="M_PI" value="3.1415926535897931" /> 
+  <xacro:property name="joint_damping" value="21.75"/>
+  <xacro:property name="joint_friction" value="10.48"/>
+  <xacro:property name="joint_spring_stiffness" value="0"/>
+  <xacro:property name="joint_spring_reference" value="0"/>
+
   <link
     name="base_link">
     <inertial>
@@ -49,14 +54,14 @@
         xyz="1.25554620866719E-07 3.54748938447003E-07 0.0239581106165018"
         rpy="0 0 0" />
       <mass
-        value="0.00356714564938475" />
+        value="0.01" />
       <inertia
-        ixx="0"
+        ixx="0.001"
         ixy="0"
         ixz="0"
-        iyy="0"
+        iyy="0.001"
         iyz="0"
-        izz="0" />
+        izz="0.001" />
     </inertial>
     <visual>
       <origin
@@ -95,6 +100,7 @@
       link="link_right_wheel" />
     <axis
       xyz="0 0 1" />
+    <dynamics damping="${joint_damping}" friction="${joint_friction}" spring_reference="${joint_spring_reference}" spring_stiffness="{joint_spring_stiffness}"/>
   </joint>
   
   <link
@@ -104,14 +110,14 @@
         xyz="1.2555462092223E-07 -3.54748938502514E-07 -0.0239581106165035"
         rpy="0 0 0" />
       <mass
-        value="0.00356714564938459" />
+        value="0.01" />
       <inertia
-        ixx="0"
+        ixx="0.001"
         ixy="0"
         ixz="0"
-        iyy="0"
+        iyy="0.001"
         iyz="0"
-        izz="0" />
+        izz="0.001" />
     </inertial>
     <visual>
       <origin
@@ -150,8 +156,60 @@
       link="link_left_wheel" />
     <axis
       xyz="0 0 1" />
+    <dynamics damping="${joint_damping}" friction="${joint_friction}" spring_reference="${joint_spring_reference}" spring_stiffness="{joint_spring_stiffness}"/>
   </joint>
-  
+
+  <link name="caster_link">
+    <collision>
+      <geometry>
+        <sphere radius="0.032"/>
+      </geometry>
+      <origin rpy="0 0 0" xyz="0 0 0"/>
+      <surface>
+        <friction>
+          <ode>
+            <mu>0</mu>
+            <mu2>0</mu2>
+            <slip1>1.0</slip1>
+            <slip2>1.0</slip2>
+          </ode>
+        </friction>
+      </surface>
+    </collision>
+    <visual>
+      <origin
+        xyz="0 0 0"
+        rpy="0 0 0" />
+      <geometry>
+        <mesh
+          filename="package://stretch_description/meshes/omni_wheel_m.STL" />
+      </geometry>
+      <material
+        name="">
+        <color
+          rgba="0.792156862745098 0.819607843137255 0.933333333333333 1" />
+      </material>
+    </visual>
+    <inertial>
+      <mass value="0.01" />
+      <origin xyz="0 0 0" />
+      <inertia
+        ixx="0.001"
+        ixy="0"
+        ixz="0"
+        iyy="0.001"
+        iyz="0"
+        izz="0.001" />
+    </inertial>
+  </link>
+
+  <joint name="caster_joint" type="fixed">
+    <parent link="base_link"/>
+    <child link="caster_link"/>
+    <origin xyz="-0.245 0.0 0.032" rpy="${-M_PI/2} 0 0"/>
+    <axis xyz="0 0 1" />
+  </joint>
+
   <link
     name="link_mast">
     <inertial>
@@ -330,12 +388,12 @@
       <mass
         value="0.0626921047058405" />
       <inertia
-        ixx="0.000115246639451415"
-        ixy="4.42139679831176E-14"
-        ixz="1.89711279909763E-09"
-        iyy="0.000115246639420046"
-        iyz="-2.68592949587539E-09"
-        izz="9.38270676408352E-14" />
+        ixx="0.001"
+        ixy="0"
+        ixz="0"
+        iyy="0.001"
+        iyz="0"
+        izz="0.001" />
     </inertial>
     <visual>
       <origin
@@ -387,12 +445,12 @@
       <mass
         value="0.0569074368576238" />
       <inertia
-        ixx="0.000105206697151872"
-        ixy="2.59896259031046E-14"
-        ixz="1.69941454517918E-09"
-        iyy="0.000105206697154717"
-        iyz="-1.60895568923743E-09"
-        izz="5.20570301686304E-14" />
+        ixx="0.001"
+        ixy="0"
+        ixz="0"
+        iyy="0.001"
+        iyz="0"
+        izz="0.001" />
     </inertial>
     <visual>
       <origin
@@ -444,12 +502,12 @@
       <mass
         value="0.0511763619538321" />
       <inertia
-        ixx="9.58490021274768E-05"
-        ixy="2.27446667584309E-14"
-        ixz="1.54951672295709E-09"
-        iyy="9.5849002131875E-05"
-        iyz="-1.40692486873422E-09"
-        izz="4.57014633924348E-14" />
+        ixx="0.001"
+        ixy="0"
+        ixz="0"
+        iyy="0.001"
+        iyz="0"
+        izz="0.001" />
     </inertial>
     <visual>
       <origin
@@ -501,12 +559,12 @@
       <mass
         value="0.101241250325294" />
       <inertia
-        ixx="0.000227156999010352"
-        ixy="8.90680620109423E-06"
-        ixz="-7.91132210985695E-05"
-        iyy="0.000300732790537324"
-        iyz="7.21771824540896E-06"
-        izz="9.35784422621597E-05" />
+        ixx="0.001"
+        ixy="0"
+        ixz="0"
+        iyy="0.001"
+        iyz="0"
+        izz="0.001" />
     </inertial>
     <visual>
       <origin
@@ -558,12 +616,12 @@
       <mass
         value="0.0405398981326229" />
       <inertia
-        ixx="2.20062857967227E-09"
-        ixy="1.15494401227051E-13"
-        ixz="1.02598056874346E-11"
-        iyy="2.20039759185237E-09"
-        iyz="-2.47692875363392E-11"
-        izz="3.26666802416509E-13" />
+        ixx="0.001"
+        ixy="0"
+        ixz="0"
+        iyy="0.001"
+        iyz="0"
+        izz="0.001" />
     </inertial>
     <visual>
       <origin
@@ -576,7 +634,7 @@
       <material
         name="">
         <color
-	  rgba="0.792156862745098 0.819607843137255 0.933333333333333 1" />
+	        rgba="0.792156862745098 0.819607843137255 0.933333333333333 1" />
       </material>
     </visual>
     <collision>
@@ -603,10 +661,10 @@
     <axis
       xyz="0 0 -1" />
     <!--
-	stowed to front ~225 deg: 3.15159 x 1.25 = 3.9395
-	using 4.0
-	stowed to back ~100 deg:  100 / 180 x 3.14159 = 1.7453
-	using -1.75
+      stowed to front ~225 deg: 3.15159 x 1.25 = 3.9395
+      using 4.0
+      stowed to back ~100 deg:  100 / 180 x 3.14159 = 1.7453
+      using -1.75
     -->
     <limit effort="100" lower="-1.75" upper="4.0" velocity="1.0"/>
   </joint>
@@ -620,12 +678,12 @@
       <mass
         value="0.129454717596498" />
       <inertia
-        ixx="2.9340596231093E-05"
-        ixy="-7.89638931853666E-07"
-        ixz="-4.74678128515878E-06"
-        iyy="2.68283736177377E-05"
-        iyz="1.80251508621876E-06"
-        izz="1.4617291423745E-05" />
+        ixx="0.001"
+        ixy="0"
+        ixz="0"
+        iyy="0.001"
+        iyz="0"
+        izz="0.001" />
     </inertial>
     <visual>
       <origin
@@ -675,12 +733,12 @@
       <mass
         value="0.035858341182617" />
       <inertia
-        ixx="2.75847937559827E-05"
-        ixy="5.25762707913649E-07"
-        ixz="-9.28796751052893E-07"
-        iyy="2.08815921106858E-05"
-        iyz="1.17265055331737E-05"
-        izz="6.78612505435872E-06" />
+        ixx="0.001"
+        ixy="0"
+        ixz="0"
+        iyy="0.001"
+        iyz="0"
+        izz="0.001" />
     </inertial>
     <visual>
       <origin
@@ -732,12 +790,12 @@
       <mass
         value="0.0701242408063442" />
       <inertia
-        ixx="1.73265934767466E-05"
-        ixy="2.38363792824069E-07"
-        ixz="7.96430204321056E-08"
-        iyy="4.11044416077217E-05"
-        iyz="-9.41955638215997E-07"
-        izz="2.38851808140542E-05" />
+        ixx="0.001"
+        ixy="0"
+        ixz="0"
+        iyy="0.001"
+        iyz="0"
+        izz="0.001" />
     </inertial>
     <visual>
       <origin
@@ -781,6 +839,3 @@
   </joint>
 
 </robot>
-
-  
-