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Hi all,
I have defined a custom joint similar to that of between Humerus(P) and Ulna radius hand(B) to the links of a manipulator, but thing is Joint as to perform like a hinge but it(B) rotating like following a circumference of the circle. So how to resolve this ?

Thanks and regards,
Pavan G

Joint as to perform like a hinge

It sounds like you should be using a pin joint instead (https://simtk.org/api_docs/opensim/api_ ... Joint.html).

Hi Thomas,
Thanks for your reply, If i use Pin Joint then," one coordinate about the common Z-axis of parent and child joint frames" will happens but i want about the x-axis, so using custom joint.

Thanks and regards,
Pavan G

Hi,
And below you can find image of my problem.

If i use Pin Joint then," one coordinate about the common Z-axis of parent and child joint frames" will happens but i want about the x-axis, so using custom joint.

You should still use a pin joint---just provide the orientationInParent and orientationInBody arguments. See the "Adding the Joint for the Platform Body" section on this page: https://simtk-confluence.stanford.edu/d ... lker+Model.

Hi Thomas,
Actually it solved co-ordinate issue, but the rotation of the part/body continues same as that of above, it's not acting like a hinge, Do i need to give any wrapObject/Constraint anything there? to remain part attached and only to swing ?

Thanks and regards,
Pavan G

Please upload your model file.

HI,
Here is the file .


Thanks and regards,
Pavan G

You have not provided the geometry files ("NAssem - Nlink1-1.STL" and "NAssem - Nlink2-1.STL") so I can't reproduce the issue. Note, however, that the multibody system is defined independently of the geometry you attach to the bodies for visualization, so you might try using existing geometry files first (e.g., from the arm26 model). Once the mechanism is defined, you could then replace the arm26 geometry with your own.

Hi Thomas,
Thanks a lot for your time. Sorry, forget to add the files. So here are the parts ,, since it was not allowing me to add .stl files , I just renamed at the end by .osim. Please rename it by .stl once you download.

Thanks and regards,
Pavan G