How would I modify this URDF to make include the gripper arm? - ros

Question

I have this robot arm which came with a URDF file and some STL files. The URDF file includes all of the revolute joints but it does not include a joint for the gripper.
I'm trying to figure out how to add the gripper to the URDF so I can simulate it, but I am having a tough time since I've never done this before.
The last link/joint of the URDF look like this:
<link name="link5">
<visual>
<origin
xyz="0 0 -0.11"
rpy="0 0 0"/>
<geometry>
<mesh
filename="package://dofbot_info/meshes/link5.STL"/>
</geometry>
<material
name="">
<color
rgba="1 1 1 1"/>
</material>
</visual>
<collision>
<origin
xyz="0 0 0"
rpy="0 0 0"/>
<geometry>
<mesh
filename="package://dofbot_info/meshes/link5.STL"/>
</geometry>
</collision>
</link>
<joint name="joint5" type="revolute">
<origin
xyz="-0.18385 -0.00215 -0.000605"
rpy="0 -1.5708 0"/>
<parent
link="link4"/>
<child
link="link5"/>
<axis
xyz="0 0 1"/>
<limit
lower="-1.5708"
upper="3.1416"
effort="100"
velocity="1"/>
</joint>
If I want this gripper to open and close in RViz, could I do so with the current mesh/STL? If not, how would I re-build a moveable gripper with basic shapes like rectangles in the URDF?
Here is a closeup link-5 stl:

Answer 1

As I wrote in the comments, here is a way to create a simplified model, from that you would need to create a ROS Node to publish the joint_states in a way that would mimic the motion of your gripper
EDIT:
Seems that someone has already done it for you