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Hello

I'm working on an OpenSim laboratory session for a sports biomechanics course and wanted to utilise the cycling model available on the Simtk website. It was working in the version 4 beta but now I've upgraded to the new release of version 4.0 the model doesn't load. I'm now getting this error:
Failed to connect Socket 'child_frame' of type PhysicalFrame (details: Component 'bb' could not find '../crank' of type PhysicalFrame. Make sure a component exists at this path and that it is of the correct type.
Thrown at component.h:764 in getComponent().).
In Object 'bb' of type CustomJoint.
Thrown at component.cpp:312 in finalizeConnections().

I'm at a loss why it isn't loading in the new version. When I look at the model XML file there is a "crank" body and the custom joint doesn't appear to have any errors that would stop the model form being loaded.

<CustomJoint name="bb">
<!--Path to a Component that satisfies the Socket 'parent_frame' of type PhysicalFrame (description: The parent frame for the joint.).-->
<socket_parent_frame_connectee_name>ground_offset</socket_parent_frame_connectee_name>
<!--Path to a Component that satisfies the Socket 'child_frame' of type PhysicalFrame (description: The child frame for the joint.).-->
<socket_child_frame_connectee_name>../crank</socket_child_frame_connectee_name>
<!--List containing the generalized coordinates (q's) that parameterize this joint.-->
<coordinates>

Any thoughts would be much appreciated,
Scott

I am running into the same issue.

Did you ever get a solution to this problem, I am running into the same issue.
Thanks in advance.

Seems I fix the problem....

here the model!

Andrea

Great Information was very useful for me.

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Thanks Andrea for fixing the .osim file for version 4, may I ask what did you do exactly ? I now have problems running the forward analysis *from the project files, since I get the hip moving instead of being fixed. How can I correct this problem?

In order to lock the hip movement, it seems that line 914 in the simplified_cycling_modelV4.osim file needs to be changed as follows: