Hi did you ever solve this issue? I am currently facing this problem and I am looking for a solution.
Did you every figure out the answer to this problem?
Hi, I want to run SLAM on robot only have two motor without encoders. me no odometry so how i can run SLAM on my robot. what type of changes i need to made in slamtoolbox having no odometry just rplidar ?
Hi Josh. First of all thank you for the tutorials they have been a great introduction to using ROS. I seem to have a problem with loading the slam map in rviz, itdoesnāt show up at all. Under Map, Message it says No map recieved and under Transfor it ays could not transform from [] to [map]. I have tried everything, from checking the publishing of the topics /map, /map to /odom, also the tf tree looks correct. I do not know what the problem may be. Thanks in advance.
did it solved? i also got this error
Hey Josh and everybody,
I donāt know if you ever read this or not 
but first thank you for the nice content. And second, I have 2 problems. I have searched for days and checked many underlying things, but couldnāt realize the solution.
-
When I run the robot around, the whole map (obstacles detected by Lidar) turns around. It seems like the speed of the robot in Rviz is simply twice as in Gazebo. Later I realized that in Rviz, the
odom frameandmap frameare stuck together. And I think this might be the reason (?). I have followed your tutorial and I donāt know how to solve it. -
When I add the
maptopic in Rviz, I get a status warning, saying āNo map receivedā. When I echo the /map topic, nothing shows up. I donāt know why this topic is not being published.
@JoshNewans Your help, is much is greatly appreciated.
Anyone who can help is appreciated as well 
Hello
Iāve been trying to put together what your video says with the official rplidar repository (GitHub - Slamtec/rplidar_ros), but Iāve had a problem when trying to run Slam_toolbox, this because when I try to generate a map I keep getting that there is no map itself.
I want to make SLAM to be able to register a track in real time, thatās why I never tried anything with gazebo or anything like that, however, I donāt know how to fix the problem.
The codes Iām using to start things up are as follows:
Start lidar (once I run slam_toolbox it doesnāt generate me map):
"sudo chmod 666 /dev/ttyUSB0
source install/setup.bash
ros2 launch rplidar_ros view_rplidar_a1_lauch.py"
Run map (it generates the folders but I donāt get the lidar):
ros2 run rviz2 rviz2 -d /opt/ros/humble/share/nav2_bringup/rviz/nav2_default_view.rviz
Iām getting this issue with my robot. Iām not using a RPLidar though. My Lidar model is Litra-LTME02
Please take a look at the image