How to simulate ball bearings in isaac sim

Omniverse Isaac Sim
1

Note: For any Isaac Lab topics, please submit your topic to its GitHub repo ( GitHub - isaac-sim/IsaacLab: Unified framework for robot learning built on NVIDIA Isaac Sim ) following the instructions provided on Isaac Lab’s Contributing Guidelines ( Contribution Guidelines — Isaac Lab Documentation ).

Please provide all relevant details below before submitting your post. This will help the community provide more accurate and timely assistance. After submitting, you can check the appropriate boxes. Remember, you can always edit your post later to include additional information if needed.

Isaac Sim Version

5.1.0
[x ] 5.0.0
4.5.0
4.2.0
4.1.0
4.0.0
4.5.0
2023.1.1
2023.1.0-hotfix.1
Other (please specify):

Operating System

Ubuntu 24.04
Ubuntu 22.04
Ubuntu 20.04
Windows 11
[x ] Windows 10
Other (please specify):

GPU Information

  • Model: 5060 TI 16GB
  • Driver Version:

Topic Description

How to simulate ball bearings in isaac sim

Detailed Description

I’m trying to use autodesk fusion to combine the parts into the base link and limbs. But the limbs are made up of interconnecting limbs which are connected by ball bearings.
I’m struggling to figure out how to combine(simplify) the components and simulate the balll bearing joints in isaac sim

https://github.com/MuShibo/Micro-Wheeled_leg-Robot/blob/master/1.RobotModel/OriginalRobotModel.stp

The ball bearings are circled. The yellow piece is hinged on 2 different leg segments.

Untitled
Untitled1110×816 301 KB

3

To simulate ball bearings in Isaac Sim, use rigid body spheres with proper collider and joint configuration, as Isaac Sim supports physically accurate simulation of contacts and jointed constraints suitable for representing bearing-like mechanisms.

Basic Steps

  • Model the bearing components (inner race, outer race, and balls) as separate rigid bodies in your CAD tool, then import the assembly into Isaac Sim as a USD file.
  • Assign physics materials to the balls and races to control friction and restitution using the Physics > Physics Material tool in Isaac Sim. Choose sphere primitives for the ball elements for computational efficiency.
  • Set up colliders for each part. For ball bearings, ensure the balls have sphere colliders and use primitive geometry for best performance.
  • Use appropriate joints:
    • The balls can be left as free-moving rigid bodies constrained between the inner and outer races by collision boundaries.
    • For the housing and shaft, use fixed or revolute joints depending on the assembly, but do not constrain the balls directly - they should roll due to contact forces between the two races.

Key Details

  • Verify the contacts and friction parameters in the assigned physics material to tune the bearing’s rolling behavior, minimizing friction for the balls and races.
  • For bearings that support compliance (spring-damper behavior), adjust compliant contact parameters in the advanced settings of the physics material.
  • Use the Stage panel to inspect and tune collision bounds, ensuring no interpenetration at the start of the simulation.
  • For debugging, use the contact sensor capability to monitor contact forces on the balls if required.