# Gazebo Vacuum Plugin grabbing the center of object

HI guys,

I am trying to utilize the Gazebo Vacuum plugin and I am almost 100% there. I am just having a minor issue where the plugin grabs the center of the object not the limits of it.

I followed the ROS Answer here .

And the crucial thing for this plugin is the distance between the object link and gripper one (currently the plugin does not compute the distance between the collisions of gripper and the object), so in most cases you need to add another link to the robot to use this gripper.

I do not fully understand what it means to add another link to the robot to use this gripper.

Only in the on state will the 'gripper' exert a force on any other links that are close to it (see these lines that calculate the force).

Forgive me if my question does not make sense but is there a way to mimic the limits of the object so that the vacuum sees it as a link?

<robot xmlns:xacro="http://wiki.ros.org/xacro"
name="ur5" >

<xacro:arg name="transmission_hw_interface" default="hardware_interface/PositionJointInterface"/>

<!-- common stuff -->
<xacro:include filename="$(find ur_description)/urdf/common.gazebo.xacro" /> <!-- ur5 --> <xacro:include filename="$(find ur_description)/urdf/ur5.urdf.xacro" />

<!-- arm -->
<xacro:ur5_robot prefix="" joint_limited="false"
transmission_hw_interface="\$(arg transmission_hw_interface)"  />
<joint name="world_joint" type="fixed">
<origin xyz="0.0 0.0 1.273" rpy="3.141 0.0 0.0" />
</joint>
<gravity>0</gravity>
<visual>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
<box size="0.03 0.30 0.03"/>
</geometry>
<material name="transparent">
<color rgba="0 0 0 0"/>
</material>
</visual>
<inertial>
<origin rpy="0 0 0" xyz="0.000000 0.000000 0.000000"/>
<mass value="0.0001"/>
<inertia ixx="1e-08" ixy="0" ixz="0" iyy="1e-08" iyz="0" izz="1e-08"/>
</inertial>
<joint name="gripper_joint_stick" type="revolute">
<axis xyz="1 0 0" />
<origin rpy="0 0 0" xyz="0.0 0.24 0.00" />
<limit effort="50" velocity="50" lower="0" upper="0" />
<dynamics damping="0.0" friction="10"/>
</joint>

<gravity>0</gravity>
<visual>
<origin rpy="0 0 0" xyz="0 0 0"/>
<geometry>
</geometry>
<material name="transparent">
<color rgba="0 0 0 0"/>
</material>
</visual>
<inertial>
<origin rpy="0 0 0" xyz="0 0 0"/>
<mass value="0.0001"/>
<inertia ixx="1e-08" ixy="0" ixz="0" iyy="1e-08" iyz="0" izz="1e-08"/>
</inertial>
<origin rpy=" -1.5708 0  0 ...