Parallel Robot similar to Stewart platform physx issue

Isaac Sim Version
4.2.0
Windows 11
RTX 4070 Ti

Hi everyone,

I’m experiencing issues importing my first robot model from OnShape into NVIDIA Isaac Sim. While the model functions correctly in OnShape, it’s not behaving as expected in the simulation environment. Has anyone encountered similar problems or can suggest solutions for proper model integration between OnShape and Isaac Sim? Specific details about import settings or workflows would be especially helpful.

regards
Yuuki

I’m not an expert in this specific area, but could you check if Breaking the Articulation Loop is helpful?

Thank you for the link. While it didn’t fully address my issue, it provided some valuable insights. I learned that the articulation needs to be structured as a kinematic tree, which isn’t possible in my specific case. Therefore, I’ll need to develop a workaround solution.

For reference, I’ve attached a video of my previous simulation in Webots along with a diagram illustrating my kinematic flow.

Adding to my previous message: When I first started with Isaac Sim a few weeks ago, I experimented without following any tutorials and managed to correctly build the kinematics. The simulation worked in principle, though the joints were very unstable, as shown in the two attached videos.

This makes me think that a solution to my current problem exists.

Here a follow up, I’m getting closer to the solution. This following Post on the Forum helped me to get the Sim working.

[Support Parallel Robots? - Omniverse / Isaac Sim - NVIDIA Developer Forums]
(Support Parallel Robots?)

Unfortunately the Ball Joints are getting dislocated and it not accurate at all. You can see that in the Video.