diff --git a/urdf/diffbot_description.urdf.xacro b/urdf/diffbot_description.urdf.xacro
index abadfe1..d86e4e0 100644
--- a/urdf/diffbot_description.urdf.xacro
+++ b/urdf/diffbot_description.urdf.xacro
@@ -2,196 +2,227 @@
 <robot xmlns:xacro="http://www.ros.org/wiki/xacro">
 
   <xacro:macro name="diffbot" params="prefix">
+    <xacro:include filename="inertial_macros.xacro"/>
 
     <!-- Constants for robot dimensions -->
     <xacro:property name="PI" value="3.1415926535897931"/>
-    <xacro:property name="base_mass" value="0.3" />
-    <!-- arbitrary value for base mass -->
-    <xacro:property name="base_width" value="0.26" />
-    <!-- Updated wheel spacing to 25cm -->
-    <xacro:property name="base_length" value="0.34" />
-    <xacro:property name="base_height" value="0.123" />
-    <xacro:property name="wheel_mass" value="0.3" />
-    <!-- arbitrary value for wheel mass -->
-    <xacro:property name="wheel_len" value="0.020" />
-    <xacro:property name="wheel_radius" value="0.0625" />
-    <xacro:property name="caster_wheel_mass" value="0.1" />
-    <!-- arbitrary value for caster wheel mass -->
-    <xacro:property name="caster_wheel_radius" value="0.04" />
-    <xacro:property name="z_offset" value="-${base_height/2}" />
-    <!-- Offset of main Axis to center of base body (Axis of rotation for steering) -->
-    <xacro:property name="base_offset" value="0.11" />
+
+    <!-- new properties -->
+    <xacro:property name="chassis_length" value="0.34"/>
+    <xacro:property name="chassis_width" value="0.26"/>
+    <xacro:property name="chassis_height" value="0.123"/>
+    <xacro:property name="chassis_mass" value="3.0"/>
+    <xacro:property name="wheel_radius" value="0.0625"/>
+    <xacro:property name="wheel_thickness" value="0.020"/>
+    <xacro:property name="wheel_mass" value="0.02"/>
+    <xacro:property name="wheel_offset_x" value="0.285748"/>
+    <xacro:property name="wheel_offset_y" value="0.33675"/>
+    <xacro:property name="wheel_offset_z" value="-0.035"/>
+    <xacro:property name="caster_wheel_radius" value="0.04"/>
+    <xacro:property name="caster_wheel_mass" value="0.01"/>
+    <xacro:property name="caster_wheel_offset_x" value="0.075"/>
+    <xacro:property name="caster_wheel_offset_z" value="${wheel_offset_z - wheel_radius + caster_wheel_radius}"/>
+
+    <!-- Materials -->
+    <material name="white">
+        <color rgba="1 1 1 1" />
+    </material>
+
+    <material name="orange">
+        <color rgba="1 0.3 0.1 1"/>
+    </material>
+
+    <material name="blue">
+        <color rgba="0.2 0.2 1 1"/>
+    </material>
+
+    <material name="black">
+        <color rgba="0 0 0 1"/>
+    </material>
+
+    <material name="red">
+        <color rgba="1 0 0 1"/>
+    </material>
+    
+    <material name="green">
+        <color rgba="0.0 0.8 0.0 1.0"/>
+    </material>
+    
+    <material name="grey">
+        <color rgba="0.6 0.6 0.6 1.0"/>
+    </material>
+    
+    <material name="grey2">
+        <color rgba="0.9 0.9 0.9 1.0"/>
+    </material>
+
+    <material name="lightGrey">
+        <color rgba="0.6 0.6 0.6 1.0"/>
+    </material>
     
     <!-- Base Link -->
     <link name="${prefix}base_link">
-      <visual>
-        <origin xyz="0 0 0" rpy="0 0 0" />
-        <geometry>
-          <mesh filename="package://cps_loki_description/mesh/base_link_visual.stl"/>
-        </geometry>
-        <material name="base_link_material">
-          <color rgba="0.80032179626883115375 0.81301836741632160788 0.83346199892499306383 1.0"/>
-        </material>
-      </visual>
-      <collision>
-        <origin xyz="0 0 0" rpy="0 -0 0" />
-        <geometry>
-          <mesh filename="package://cps_loki_description/mesh/base_link_collision.stl"/>
-        </geometry>
-      </collision>
-      <inertial>
-        <origin xyz="0 0 0" rpy="0 0 0"/>
-        <mass value="8.4123950268139715547" />
-        <inertia ixx="0.090166990291185383777" ixy="4.7429179749238352248e-18" ixz="1.4209310488728267579e-18" iyy="0.055481261106946747064" iyz="-0.01112159061226025876" izz="0.13051099377067149065" />
-      </inertial>
     </link>
 
     <!-- Adding base_footprint for mapping (Needed by slam toolbox) -->
-    <link name="${prefix}base_footprint">
-    </link>
-
     <joint name="${prefix}base_footprint_joint" type="fixed">
       <parent link="${prefix}base_link" />
       <child link="${prefix}base_footprint" />
-      <origin xyz="0 0 ${z_offset}" rpy="0 0 0" />
+      <origin xyz="0 0 0" rpy="0 0 0" />
     </joint>
 
-    <!-- right wheel joint -->
+     <link name="${prefix}base_footprint">
+    </link>
+
+    <!-- CHASSIS LINK -->
+
+    <joint name="${prefix}chassis_joint" type="fixed">
+        <parent link="${prefix}base_link"/>
+        <child link="${prefix}chassis"/>
+        <origin xyz="${-chassis_length/2 + 0.065} 0 ${wheel_radius - wheel_offset_z}"/>
+    </joint>
+
+    <link name="${prefix}chassis">
+        <visual>
+            <origin xyz="0 0 0"/>
+            <geometry>
+                <box size="${chassis_length} ${chassis_width} ${chassis_height}"/>
+            </geometry>
+            <material name="orange"/>
+        </visual>
+        <collision>
+            <origin xyz="0 0 0"/>
+            <geometry>
+                <box size="${chassis_length} ${chassis_width} ${chassis_height}"/>
+            </geometry>
+        </collision>
+        <xacro:inertial_box mass="0.5" x="${chassis_length}" y="${chassis_width}" z="${chassis_height}">
+            <origin xyz="0 0 0" rpy="0 0 0"/>
+        </xacro:inertial_box>
+    </link>
+
+    <gazebo reference="chassis">
+        <material>Gazebo/Orange</material>
+    </gazebo>
+
+    <!-- RIGHT WHEEL -->
     <joint name="${prefix}right_wheel_joint" type="continuous">
-      <origin xyz="0 ${-0.125 - wheel_len /2} ${z_offset}" rpy="${PI / 2} 0 0" />
-      <parent link="${prefix}base_link" />
-      <child link="${prefix}right_wheel" />
-      <axis xyz="0 0 -1"/>
-      <limit effort="1" velocity="20" />
-      <joint_properties friction="0.0"/>
+        <parent link="${prefix}chassis"/>
+        <child link="${prefix}right_wheel"/>
+        <origin xyz="${chassis_length/2 - 0.075} -${wheel_offset_y/2 + wheel_thickness/2 + 0.01} ${wheel_offset_z}" rpy="${pi/2} 0 0" />
+        <axis xyz="0 0 -1"/>
+        <limit effort="1" velocity="20" />
+        <joint_properties friction="0.0"/>
     </joint>
 
-    <!-- right wheel Link -->
     <link name="${prefix}right_wheel">
-      <visual>
-        <origin xyz="0 0 ${wheel_len}" rpy="0 -0 0" />
-        <geometry>
-          <mesh filename="package://cps_loki_description/mesh/wheel_link_visual.stl"/>
-        </geometry>
-        <material name="wheel_link_material">
-          <color rgba="0.50196078431372548323 0.50196078431372548323 0.50196078431372548323 1.0"/>
-        </material>
-      </visual>
-      <collision>
-        <origin xyz="0 0 ${wheel_len}" rpy="0 -0 0" />
-        <geometry>
-          <mesh filename="package://cps_loki_description/mesh/wheel_link_collision.stl"/>
-        </geometry>
-      </collision>
-      <inertial>
-        <origin xyz="-1.3877787807814456755e-17 -6.9388939039072283776e-18 -0.017500000000000029421" rpy="0 0 0"/>
-        <mass value="0.43298678305638949038" />
-        <inertia ixx="0.00043196650576949035269" ixy="0" ixz="1.8666117243005040269e-36" iyy="0.00043196650576949029848" iyz="0" izz="0.00078373880522818965139" />
-      </inertial>
+        <visual>
+            <geometry>
+                <cylinder radius="${wheel_radius}" length="${wheel_thickness}"/>
+            </geometry>
+            <material name="blue"/>
+        </visual>
+        <collision>
+            <geometry>
+                <sphere radius="${wheel_radius}"/>
+            </geometry>
+        </collision>
+        <xacro:inertial_cylinder mass="${wheel_mass}" length="${wheel_thickness}" radius="${wheel_radius}">
+            <origin xyz="0 0 0" rpy="0 0 0"/>
+        </xacro:inertial_cylinder>
     </link>
 
-    <!-- left wheel joint -->
+    <gazebo reference="right_wheel">
+        <material>Gazebo/Blue</material>
+    </gazebo>
+
+    <!-- LEFT WHEEL -->
     <joint name="${prefix}left_wheel_joint" type="continuous">
-      <origin xyz="0 ${0.125 + wheel_len /2} ${z_offset}" rpy="${PI / 2} 0 0" />
-      <parent link="${prefix}base_link" />
-      <child link="${prefix}left_wheel" />
-      <axis xyz="0 0 1" />
-      <limit effort="1" velocity="20" />
-      <joint_properties friction="0.0" />
+        <parent link="${prefix}chassis"/>
+        <child link="${prefix}left_wheel"/>
+        <origin xyz="${chassis_length/2 - 0.075} ${wheel_offset_y/2 + wheel_thickness/2 + 0.01} ${wheel_offset_z}" rpy="-${pi/2} 0 0" />
+        <axis xyz="0 0 1"/>
     </joint>
 
-    <!-- left wheel Link -->
     <link name="${prefix}left_wheel">
-      <visual>
-        <origin xyz="0 0 ${wheel_len}" rpy="0 -0 0" />
-        <geometry>
-          <mesh filename="package://cps_loki_description/mesh/wheel_link_2_visual.stl"/>
-        </geometry>
-        <material name="wheel_link_2_material">
-          <color rgba="0.50196078431372548323 0.50196078431372548323 0.50196078431372548323 1.0"/>
-        </material>
-      </visual>
-      <collision>
-        <origin xyz="0 0 ${wheel_len}" rpy="0 -0 0" />
-        <geometry>
-          <mesh filename="package://cps_loki_description/mesh/wheel_link_2_collision.stl"/>
-        </geometry>
-      </collision>
-      <inertial>
-        <origin xyz="-2.7755575615628913511e-17 0 -0.017500000000000015543" rpy="0 0 0"/>
-        <mass value="0.43298678305638949038" />
-        <inertia ixx="0.00043196650576949035269" ixy="1.4778173856800390343e-52" ixz="-4.8081924471597460774e-36" iyy="0.00043196650576949029848" iyz="0" izz="0.00078373880522818965139" />
-      </inertial>
+        <visual>
+            <geometry>
+                <cylinder radius="${wheel_radius}" length="${wheel_thickness}"/>
+            </geometry>
+            <material name="blue"/>
+        </visual>
+        <collision>
+            <geometry>
+                <sphere radius="${wheel_radius}"/>
+            </geometry>
+        </collision>
+        <xacro:inertial_cylinder mass="${wheel_mass}" length="${wheel_thickness}" radius="${wheel_radius}">
+            <origin xyz="0 0 0" rpy="0 0 0"/>
+        </xacro:inertial_cylinder>
     </link>
 
-    <!-- caster wheel joint -->
+    <gazebo reference="left_wheel">
+        <material>Gazebo/Blue</material>
+    </gazebo>
+
+    <!-- CASTER WHEEL -->
     <joint name="${prefix}caster_wheel_joint" type="fixed">
-      <origin xyz="-${base_length / 2 + base_offset} 0 -0.02" rpy="0 0 ${PI}" />
-      <parent link="${prefix}base_link" />
-      <child link="${prefix}caster_wheel" />
-      <axis xyz="0 0 1"/>
-      <limit effort="1" velocity="20" />
-      <joint_properties friction="0.0"/>
+        <parent link="${prefix}chassis"/>
+        <child link="${prefix}caster_wheel"/>
+        <origin xyz="-${caster_wheel_offset_x*2} 0 ${caster_wheel_offset_z}"/>
     </joint>
 
-    <!-- caster wheel Link -->
     <link name="${prefix}caster_wheel">
-      <visual>
-        <origin xyz="0 0 0" rpy="0 -0 0" />
-        <geometry>
-          <mesh filename="package://cps_loki_description/mesh/caster_link_visual.stl"/>
-        </geometry>
-        <material name="caster_link_material">
-          <color rgba="0.69513764518117548974 0.69513764518117548974 0.69513764518117548974 1.0"/>
-        </material>
-      </visual>
-      <collision>
-        <origin xyz="0 0 0" rpy="0 -0 0" />
-        <geometry>
-          <mesh filename="package://cps_loki_description/mesh/caster_link_collision.stl"/>
-        </geometry>
-      </collision>
-      <inertial>
-        <origin xyz="-0.0043392325658342043027 -0.026018163063004008662 -0.040087257391101506487" rpy="0 0 0"/>
-        <mass value="0.4365196214157913146" />
-        <inertia ixx="0.00065232223366267665706" ixy="-2.2812456870885095374e-05" ixz="-2.819328031928647945e-05" iyy="0.00051934268155350092177" iyz="-0.00016904771834628737077" izz="0.00028021186492738437085" />
-      </inertial>
+        <visual>
+            <geometry>
+                <sphere radius="${caster_wheel_radius}"/>
+            </geometry>
+            <material name="white"/>
+        </visual>
+        <collision>
+            <geometry>
+                <sphere radius="${caster_wheel_radius}"/>
+            </geometry>
+        </collision>
+        <xacro:inertial_sphere mass="${caster_wheel_mass}" radius="${caster_wheel_radius}">
+            <origin xyz="0 0 0" rpy="0 0 0"/>
+        </xacro:inertial_sphere>
     </link>
 
-    <!-- laser_link -->
-    <link name="${prefix}laser_link">
-      <visual>
-        <origin xyz="0 0 0" rpy="${PI} -0 0" />
-        <geometry>
-          <mesh filename="package://cps_loki_description/mesh/laser_link_visual.stl"/>
-        </geometry>
-        <material name="laser_link_material">
-          <color rgba="0.49803921568627451677 0.49803921568627451677 0.49803921568627451677 1.0"/>
-        </material>
-      </visual>
-      <collision>
-        <origin xyz="0 0 0" rpy="${PI} -0 0" />
-        <geometry>
-          <mesh filename="package://cps_loki_description/mesh/laser_link_collision.stl"/>
-        </geometry>
-      </collision>
-      <inertial>
-        <origin xyz="8.0502568807622093404e-21 2.7755575615628913511e-17 -0.01526549883836261258" rpy="${PI} 0 0"/>
-        <mass value="0.065307030550339775776" />
-        <inertia ixx="1.578111853789072904e-05" ixy="-4.8590457654361857326e-53" ixz="1.0816309858643350309e-52" iyy="1.5781118537890654501e-05" iyz="9.8088682514084147142e-38" izz="1.9760068210357054465e-05" />
-      </inertial>
-    </link>
+    <gazebo reference="caster_wheel">
+        <material>Gazebo/White</material>
+        <mu1 value="0.001"/>
+        <mu2 value="0.001"/>
+    </gazebo>
 
-    <!-- laser_joint -->
+    <!-- LASER -->
     <joint name="${prefix}laser_joint" type="fixed">
-      <origin xyz="-0.015 0 0.09" rpy="0 0 0"/>
-      <parent link="${prefix}base_link" />
-      <child link="${prefix}laser_link" />
-      <axis xyz="0 0 1"/>
-      <limit effort="1" velocity="20" />
-      <joint_properties friction="0.0"/>
+        <parent link="${prefix}chassis"/>
+        <child link="${prefix}laser_frame"/>
+        <origin xyz="${chassis_length/2 - 0.15285} 0 ${chassis_height/2 + 0.030}" rpy="0 0 ${pi}"/>
     </joint>
 
+    <link name="${prefix}laser_frame">
+        <visual>
+            <geometry>
+                <cylinder radius="0.04" length="0.05"/>
+            </geometry>
+            <material name="black"/>
+        </visual>
+        <collision>
+            <geometry>
+                <sphere radius="${caster_wheel_radius}"/>
+            </geometry>
+        </collision>
+        <xacro:inertial_sphere mass="${caster_wheel_mass}" radius="${caster_wheel_radius}">
+            <origin xyz="0 0 0" rpy="0 0 0"/>
+        </xacro:inertial_sphere>
+    </link>
+
+    <gazebo reference="laser_frame">
+        <material>Gazebo/White</material>
+    </gazebo>
+
     <!-- camera_link -->
     <link name="${prefix}camera_link">
       <visual>