Universal robot with vacuum gripper end effector

edit

I am fairly new to ros and am trying to setup a palletizing robot using ros/gazebo. I will spawn boxes in gazebo, then using moveit, stack them onto a pallet.

I am able to move the arm to an arbitrary location using the moveit python API and the movement successfully appears in gazebo.

I'm stuck at setting up the vacuum gripper end effector. I've added the following to ur_description/urdf/ur10.urdf.xacro

http://docs.ros.org/melodic/api/gazebo_plugins/html/group__GazeboRosVacuumGripper.html

I changed the parent link to ee_link in the joint definition and got rid of references to "left". However, when I start gazebo, I get the error

[ INFO] [1534117768.436336913]: Loaded gazebo_ros_control. 

[ INFO] [1534117768.441885800]: Loading gazebo_ros_vacuum_gripper   

[FATAL] [1534117768.441926563]: gazebo_ros_vacuum_gripper plugin error: link named: end_effector does not exist   

[FATAL] [1534117768.441936983]: gazebo_ros_vacuum_gripper plugin error: You should check it exists and is not connected with fixed joint 

[FATAL] [1534117768.441946112]: gazebo_ros_vacuum_gripper plugin error: Found links are:  base_link shoulder_link upper_arm_link forearm_link wrist_1_link wrist_2_link wrist_3_link

I also tried adding the link to ur.gazebo.xacro and the joint to ur_gazebo/controller/arm_controller_ur10.yaml with no luck.

Any ideas? Is there a complete example of attaching an end effector to a universal robot that I can analyze?