ROSbot XL wheel swap
Overview
ROSbot XL is a 4x4 drive autonomous mobile robot platform powered by ROS what allows to change the set of multi-directional mecanum wheels to the set of off-road, high grip, puncture resistant rubber wheels.
Change from Regular Wheels to Mecanum Wheels
- Remove M4x6 with a flat head (ISO 7380) (2.5mm allen key) holding each wheel. Bolts are placed axially inside the counterbore hole.
![](/assets/images/XL_wheel_swap_mecanum_bolts-7b8837052f5949396cf0ad892546cf51.png)
![](/assets/images/XL_wheel_swap_mecanum_bolts_inv-47f7b04db6e998d7637550493987da6c.png)
- Slide wheel of the coupler.
![](/assets/images/XL_wheel_swap_none-c60ad3f2e9069754257f494e600d5ee4.png)
![](/assets/images/XL_wheel_swap_none_inv-79e56dda4ad00992285538960e9362f1.png)
- Place the rubber wheels on couplers and fix them using M4x6 bolts with a flat head (2.5mm allen key). Tighten the bolts with a torque of 1.5Nm.
![](/assets/images/XL_wheel_swap_regular_bolts-d398b8b857e9fb3ce86b5dc96b1b2857.png)
![](/assets/images/XL_wheel_swap_regular_bolts_inv-dea9d6f6c858ee39735bff262cebcb99.png)
Change from Mecanum Wheels to Regular Wheels
- Remove M4x6 with a flat head (ISO 7380) (2.5mm allen key) holding each wheel.
![](/assets/images/XL_wheel_swap_regular_bolts-d398b8b857e9fb3ce86b5dc96b1b2857.png)
![](/assets/images/XL_wheel_swap_regular_bolts_inv-dea9d6f6c858ee39735bff262cebcb99.png)
- Slide wheel of the coupler.
- Place the Mecanum Wheels on couplers. The order in which the wheels are placed is extremely important, as there are left-handed and right-handed wheels.
![](/assets/images/XL_wheel_swap_mecanum_order-ee6d06de7156cc19d37387278811a658.png)
![](/assets/images/XL_wheel_swap_mecanum_order_inv-1b559229fa1d0938e71ffd67edda1f0f.png)
- Place M4x6 bolts with a flat head (2.5mm allen key) inside the counterbore hole. Tighten the bolts with a torque of 1.5Nm.
![](/assets/images/XL_wheel_swap_mecanum_bolts-7b8837052f5949396cf0ad892546cf51.png)
![](/assets/images/XL_wheel_swap_mecanum_bolts_inv-47f7b04db6e998d7637550493987da6c.png)
Software
After changing the wheels on the ROSbot XL, you must let know the ROS driver about it.
In ROSbot XL by default, ROS drivers in the SBC run within a Docker container and assume that mecanum wheels are mounted. Follow the steps to make the required changes in the software:
-
Login via SSH into SBC (just like in the tutorial)
-
Edit the Docker Compose file with:
sudo nano compose.yaml
-
Edit
mecanum
parameter in theros2 launch
command inrosbot-xl
service:command: ros2 launch rosbot_xl_bringup bringup.launch.py mecanum:=${MECANUM:-False}
- For standard wheels:
mecanum:=${MECANUM:-False}
- For mecanum wheels:
mecanum:=${MECANUM:-True}
- For standard wheels:
-
If they are already running, restart Docker Containers:
docker compose up -d --force-recreate
-
Test the results by running the ROSbot's ROS drivers and then sending a message to the
cmd_vel
topic with a non-zero value of sideways movement (linear.y
) or usingros2 run teleop_twist_keyboard teleop_twist_keyboard
and then controlling with Shift pressed.