# Revision history [back]

### Best practice with tf transforms

Hey,

I've got a small problem: I have three laser scanners mounted at my robot with -> frames:

(name -> tf frame)

• Hokuyo 1 -> hokuyo1_frame
• Hokuyo 2 -> hokuyo2_frame
• Another 4 layer Laser scanner -> Scanner_frame1

these laserscanners are translational and rotational shifted together. Which leads to me to use some tf transformations. So I flew over the tutorials and just gut confused which would be the best practice to convert them all do a static frame at the robot. Also i dont have a baselink at my robot for now so how do i create one in the origin of my robot? If I print the current frames with rosrun tf view_frames I just see the Scanner_frame1 and not the two hokuyo frames, however I can watch the data in rviz by hand typing the fixed frame as hokuyo1/2_frame.