hi . i have urdf file that i export from solidworks using swurdfexporter. but all joints are fixed !! i have fixed joint like this :

 <joint name="joint_U17_1"   type="fixed">
    <origin  xyz="0.07175 0 0"   rpy="1.57079642071591 -1.56033165440561E-10 -3.14159263868863" />
    <parent  link="link_U4_1" />
    <child   link="link_U17_1" />
    <axis  xyz="0 0 0" />
  </joint>

i want this joint to be revolute joint . i changed my urdf file like this :

<joint  name="joint_U17_1"  type="revolute">
    <origin    xyz="0.07175 0 0"   rpy="1.57079642071591 -1.56033165440561E-10 -3.14159263868863" />
    <parent   link="link_U4_1" />
    <child   link="link_U17_1" />
    <axis   xyz="0 0 0" />
 <limit effort="1.0" lower="-2.53" upper="2.53" velocity="1.571"/>
  </joint>

but i have this error and Rviz show links that connected to this joint in other place:

[ERROR] [1481959999.299028146]: Ignoring transform for child_frame_id "link_U17_1" from authority "unknown_publisher" because of a nan value in the transform (-nan -nan -nan) (-nan -nan -nan -nan)