# Error Create your first robot with ROS unit 3 simulation

**URL:** <https://get-help.theconstruct.ai/t/error-create-your-first-robot-with-ros-unit-3-simulation/9759>\
**Category:** Your First Robot With ROS\
**Tags:** error\
**Created:** [May 3, 2021, 4:18am UTC](https://get-help.theconstruct.ai/t/error-create-your-first-robot-with-ros-unit-3-simulation/9759 "2021-05-03T04:18:00Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![u1802520](https://get-help.theconstruct.ai/user_avatar/get-help.theconstruct.ai/u1802520/32/6826_2.png) [@u1802520](https://get-help.theconstruct.ai/u/u1802520)\
**Post date:** [May 3, 2021, 4:18am UTC](https://get-help.theconstruct.ai/t/error-create-your-first-robot-with-ros-unit-3-simulation/9759/1 "2021-05-03T04:18:00Z")

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Hi, i am creating my own robot for a personal project, i am taking as guide the course Create Your First Robot with ROS. but when making the simulation i have an error.

 ![image](https://get-help.robotigniteacademy.com/uploads/default/original/2X/b/b4825cc3cd793f3d88400ef1e95c6b7f8031b3f1.jpeg)  
i think is a conflict with the transformations. seems like gazebo disconect the two wheels from the transformation.  
 ![image](https://get-help.robotigniteacademy.com/uploads/default/original/2X/4/486a4f493f6103a97cac8a6d9f758eb53daeb07a.jpeg)  
Does anyone knows why this happen and how to solve it?  
(perhaps something about the differential drive gazebo plugin)?

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**Author:** ![duckfrost2](https://get-help.theconstruct.ai/user_avatar/get-help.theconstruct.ai/duckfrost2/32/9365_2.png) [@duckfrost2](https://get-help.theconstruct.ai/u/duckfrost2)\
**Post date:** [May 3, 2021, 7:46am UTC](https://get-help.theconstruct.ai/t/error-create-your-first-robot-with-ros-unit-3-simulation/9759/2 "2021-05-03T07:46:49Z")

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Hi,

This is related to the differential drive that doesn’t connect the TFs, Its not a big deal as for the course, but if you want to fix it you will have to check the differential drive ruling configuration or just publish a static transform that connects the Base\_footprint link with the base\_link.

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**Author:** ![Stevethehalfb](https://get-help.theconstruct.ai/letter_avatar_proxy/v4/letter/s/c5a1d2/32.png) [@Stevethehalfb](https://get-help.theconstruct.ai/u/Stevethehalfb)\
**Post date:** [May 9, 2021, 5:26pm UTC](https://get-help.theconstruct.ai/t/error-create-your-first-robot-with-ros-unit-3-simulation/9759/3 "2021-05-09T17:26:10Z")

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Hi,  
I can’t see what is wrong with the differential drive setup in the rosbots.gazebo.xacro. It uses the base\_link as the robotBaseFrame so I don’t see why as in the above screenshot gazebo is publish the transform between the base\_footprint and the wheels rather than the base\_link and the wheels.

As I look at it the base\_footprint & base\_joint just provide a ‘z’ offset to the base\_link. So as a simple ‘fix’ I removed the base\_footprint & base\_joint from the main .xacro and everything linked up correctly.