Good morning,
I am trying to build the urdf of a robot. When I declare the kinematic model inserting for example one joint between two link, the child one does not rotate on the joint axes.

This is the code

<link name="upper_arm_link">
    <visual>
      <geometry>
        <mesh filename="package://omni_base_robot_model_tom/meshes/STL_Comau/AA_Racer5_2.stl" />
      </geometry>
    </visual>
</link>

 <joint name="elbow_joint" type="revolute">
    <parent link="upper_arm_link" />
    <child link = "forearm_link" />
    <origin xyz="0.27 0 0.2" rpy="0.0 0.0 0.0" />
    <axis xyz="1 0 0"/>
    <limit lower="-6.24" upper="6.24" effort="10.0" velocity="3.14"/>
    <dynamics damping="10" friction="0.1"/>
  </joint>

<link name="forearm_link">
    <visual>
      <geometry>
        <mesh filename="package://omni_base_robot_model_tom/meshes/STL_Comau/AA_Racer5_3.stl" />
      </geometry>
    </visual>
</link>

According to the code the "forearm_link" should rotate on the x axes of the joint; but it rotates on the x axes of the global frame. How can i fix this problem?

---

Edit: Hi @bhavyadoshi26 and thanks for your interest, here is the full code I am using:

<!--kinematic chain-->

<link name="base_footprint" >
      <origin xyz="0.0 0.0 0.0" rpy="0.0 0.0 0" />
</link>


<link name="base_link">
    <visual>
      <geometry>
        <mesh filename="package://omni_base_robot_model_tom/meshes/STL_Comau/AA_Racer5_1.stl" />
      </geometry>
     <material name="gray"/>
    </visual>
</link>

<joint name="base_footprint_joint" type="fixed">
    <origin xyz="0 0 0.051" rpy="0 0 0" />
    <parent link="base_footprint"/>
    <child link="base_link"/>
</joint>

<link name="upper_arm_link">
    <visual>
      <geometry>
        <mesh filename="package://omni_base_robot_model_tom/meshes/STL_Comau/AA_Racer5_2.stl" />
      </geometry>
     <material name="gray"/>
     <origin rpy="0 0 0" xyz="0.05 0 0.3650"/>
    </visual>
</link>

<joint name="shoulder_lift_joint" type="revolute">
    <axis xyz="0 0 1" rpy="-1.57 0 0"/>
    <parent link="base_link" />
    <child link = "upper_arm_link" />
    <limit lower="-6.28" upper="6.28" effort="10.0" velocity="3.14"/>
    <dynamics damping="10" friction="0.1"/>
</joint>

<link name="forearm_link">
    <visual>
      <geometry>
        <mesh filename="package://omni_base_robot_model_tom/meshes/STL_Comau/AA_Racer5_3.stl" />
      </geometry>
      <origin rpy="0 0 0" xyz="0.027 0 0.0"/>
     <material name="gray"/>
    </visual>
</link>

<joint name="elbow_joint" type="revolute">
    <axis xyz="1 0 0" rpy="0 0 0"/>
    <parent link="upper_arm_link" />
    <child link = "forearm_link" />
    <limit lower="-6.28" upper="6.28" effort="10.0" velocity="3.14"/>
    <dynamics damping="10" friction="0.1"/>
</joint>

Unfortunately I cannot upload the image because of the rate (<5), anyway the problem seems to be the same discussed on the question you linked, but the solution does not seems to be helpfull.