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What's wrong ?


New member
Hello there,

I am connecting a rotating arm with the frame(base) using a pin. I use the axis of the pin and the axis of the bracket on the frame, and a plane to create this connection.

When I am done I click OK (the message Connection Definition Complete is there) In the three the arm has a little square which tells me that is not a true pin connection .

What am I doing wrong?

Of course, I get that pesky message (Microsoft Visual C++ Runtime Library) Assertion Failed! which, as recomended, I select to Ignore it.

Any clues?




Active member

May be you will not be interested in this answer but I suggest say good bye to Pro/Mechanica Motion, if you are using Wildfire and have license for MDO.



New member
The little square next to the components in the model tree means that the component is underconstrained-- which is exactly what you want for connections.

With regular constraints, a fully constrained component has 6 DOF, 3 translational and 3 rotational, fully restrained. If you package a component, or leave it underconstrained, or use connections, you'll have less than 6 DOF eliminated. Pro indicates that with the empty box next to the component in the model tree.