# URDF Importer - Mimic support in 2023.1.0 **URL:** \ **Category:** Isaac Sim\ **Created:** [October 24, 2023, 10:38pm UTC](https://forums.developer.nvidia.com/t/urdf-importer-mimic-support-in-2023-1-0/270575 "2023-10-24T22:38:14Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![bren1](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@bren1](https://forums.developer.nvidia.com/u/bren1)\ **Post date:** [October 24, 2023, 10:38pm UTC](https://forums.developer.nvidia.com/t/urdf-importer-mimic-support-in-2023-1-0/270575/1 "2023-10-24T22:38:14Z")
I’m currently attempting to import a new robot into Isaac SIM, featuring a 2x4 bar linkage mechanism. This mechanism works flawlessly in RVIZ. However, when imported into SIM, all the extracted mimic joints are added as independent joints. To make these joints act as 2 Degrees of Freedom (DoF), would I need to develop a custom “controller”? If so, what would be the most effective approach to achieve this? For a better understanding of the robot, I’ve attached a picture of the RVIZ import. The primary challenge lies in maintaining the upper body parallel to the ground plane. ![Screenshot from 2023-10-24 15-37-05](https://global.discourse-cdn.com/nvidia/original/4X/e/0/8/e083dda3a0839ee1a01cd231d77aae791b6e73cd.png) ---
**Author:** ![rthaker](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/rthaker/32/171374_2.png) [@rthaker](https://forums.developer.nvidia.com/u/rthaker)\ **Post date:** [October 30, 2023, 11:07pm UTC](https://forums.developer.nvidia.com/t/urdf-importer-mimic-support-in-2023-1-0/270575/3 "2023-10-30T23:07:34Z")
Attaching the doc for your review while the right PIC can look at your question: [5.1. Import URDF — Omniverse IsaacSim latest documentation](https://docs.omniverse.nvidia.com/isaacsim/latest/advanced_tutorials/tutorial_advanced_import_urdf.html) ---
**Author:** ![bishwajit.kr](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@bishwajit.kr](https://forums.developer.nvidia.com/u/bishwajit.kr)\ **Post date:** [May 13, 2024, 2:13pm UTC](https://forums.developer.nvidia.com/t/urdf-importer-mimic-support-in-2023-1-0/270575/4 "2024-05-13T14:13:29Z")
for me also mimic is not working, after commenting out mimic the error is gone and I am able to control the robot, but for robotiq gripper you might see a bad movement animation. ---
**Author:** ![hslktestmail](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@hslktestmail](https://forums.developer.nvidia.com/u/hslktestmail)\ **Post date:** [June 12, 2024, 3:01am UTC](https://forums.developer.nvidia.com/t/urdf-importer-mimic-support-in-2023-1-0/270575/5 "2024-06-12T03:01:16Z")
Sorry if this will not help. I did not work on 4 bar linkages but I saw these videos. These are about a 4 bar linkage gripper. [![](https://global.discourse-cdn.com/nvidia/original/4X/b/f/0/bf0c87cbf0396ed0a746cd845352f02f367649be.jpeg "[isaac sim] Robotiq 2F85 gripper assembly") ](https://www.youtube.com/watch?v=oBOD2yJv-a0) [![](https://global.discourse-cdn.com/nvidia/original/4X/6/b/f/6bffd3af1e8f3ce93b18ae9da16bad431a7b5e83.jpeg "How to Set Up Closed-Loop Gripper with Robotiq 2F-85") ](https://www.youtube.com/watch?v=UpGgq-BR0Gg) ---
**Author:** ![rthaker](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/rthaker/32/171374_2.png) [@rthaker](https://forums.developer.nvidia.com/u/rthaker)\ **Post date:** [June 13, 2024, 2:08pm UTC](https://forums.developer.nvidia.com/t/urdf-importer-mimic-support-in-2023-1-0/270575/6 "2024-06-13T14:08:18Z")
Hi @bren1 / @bishwajit.kr / @hslktestmail - Mimic Joint support is available in Isaac Sim 4.0 ---
**Author:** ![rgasoto](https://sea2.discourse-cdn.com/nvidia/user_avatar/forums.developer.nvidia.com/rgasoto/32/21824_2.png) [@rgasoto](https://forums.developer.nvidia.com/u/rgasoto)\ **Post date:** [June 13, 2024, 2:42pm UTC](https://forums.developer.nvidia.com/t/urdf-importer-mimic-support-in-2023-1-0/270575/7 "2024-06-13T14:42:04Z")
Also Check this [https://docs.omniverse.nvidia.com/isaacsim/latest/advanced\_tutorials/tutorial\_advanced\_rigging\_complex\_structures.html](https://docs.omniverse.nvidia.com/isaacsim/latest/advanced_tutorials/tutorial_advanced_rigging_complex_structures.html)