Which joint?

[peterbrown77]

View attachment 4762It's been so long since I took the Mechanisms class..... I
can't remember which connection to use. I have a lever
with a spherical pocket in it. Into this pocket is a pin
with a fully rounded tip, much smaller than the pocket's
sphere. I can't make a ball connection and can't seem to
figure out how to use the tangent of it (which is what it
really is) as the translation constraint.

Any ideas?

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Edited by: peterbrown77

 

[peterbrown77]

Wow, so many views and no responses?

 

[jimshaw]

Peter,


I, for one, amhaving a tough time answering you because I'm not sure how to help you. What exactly are you trying to simulate with this model?


Jim
http://www.linkedin.com/in/shawengineering

 

[peterbrown77]

If you look at the image, the lever pivots on the hole and
pushes the conical pin back against a spring. So, the tip
of the pin is rounded and the hole in which the tip is
sitting is a spherical pocket. The pin is in a hole so it
can only move in one axis, but the spherical pocket is
moving through an arc - therefore the rounded tip of the
pin moves across the face of the spherical pocket.

 

[jimshaw]

That's what I thought, so what's the spherical pocket for?


If you remove the pocket, and just had a flat surface on the lever, then a slider constraint would work out well.


Jim
http://www.linkedin.com/in/shawengineering

 

[peterbrown77]

Right - except that the pin has a spring on it and it wants
to wobble in the hole because of the slack between the
spring, the pin, and the hole. The pocket keeps the pin
more or less aligned in the hole.

A Ball connection would work? But I guess I have to
construct curves or something for it to track? Obviously a
CSYS won't work because of the sliding motion.

 

[jimshaw]

So if the pin is designed to wobble in it's hole, how are you going to simulate this wobblein your analysis?


Jim
http://www.linkedin.com/in/shawengineering