# Joint between different namespace/models

Hello,

I'm working on a project where I have to connect two quads on a bar. On the images below you can see what I have achieved so far.

https://ibb.co/fm511Q

https://ibb.co/khbVvk

I'd like to know if there's a way to create joints between the models on the image. The models have to be independent because I have to be able to fly the quads, and to do that they have to have different namespaces.

My launch file looks like this:

<?xml version="1.0"?>

<launch>

<include file="$(find hector_gazebo_worlds)/launch/start.launch"/> <group ns="uav1"> <include file="$(find hector_quadrotor_gazebo)/launch/spawn_quadrotor.launch">
<arg name="name" value="uav1" />
<arg name="tf_prefix" value="uav1" />
<arg name="model" value="$(find hector_quadrotor_description)/urdf/quadrotor.gazebo.xacro" /> <arg name="y" value="-1.0" /> <arg name="controllers" value=" controller/attitude controller/velocity controller/position "/> </include> <include file="$(find hector_quadrotor_teleop)/launch/taranis.launch" >
<arg name="control_mode" value="velocity"/>
</include>

</group>

<group ns="uav2">
<include file="$(find hector_quadrotor_gazebo)/launch/spawn_quadrotor.launch"> <arg name="name" value="uav2" /> <arg name="tf_prefix" value="uav2" /> <arg name="model" value="$(find hector_quadrotor_description)/urdf/quadrotor.gazebo.xacro" />
<arg name="y" value="1.0" />
<arg name="controllers" value="
controller/attitude
controller/velocity
controller/position
"/>
</include>
<include file="$(find hector_quadrotor_teleop)/launch/taranis.launch" > <arg name="control_mode" value="velocity"/> </include> </group> <group ns="barra"> <include file="$(find hector_quadrotor_gazebo)/launch/spawn_barra.launch">
<arg name="name" value="barra" />
<arg name="y" value="0" />
</include>

</group>
</launch>