Assembly Help

[SteveFrey]

In this assembly I am trying to insert the spring up against the plunger which rides against the small bar. When the hinge pin turns, it pushes the bar down and forces the plunger to compress the spring between itself and the back plate. I am having trouble constraining the parts so that the spring will be adaptive to the actions described above. It seems that using the parts as a contact set in a lot of this assembly is better than using constraints.

The two things that are baffling me are 1) making the spring adapt to the changes and 2) making the plunger stay constrained to the hinge pin in all positions. It seems that this would be a transitional constraint. Is that correct? Am I on the right track or am I wandering down the wrong road on this one? Any assistance would be helpful. Thank you.

[JDMather]

I noticed in Sketch1 of PP4300 the sketch is placed at the origin but not constrained to the origin. Why would you not have Inventor automatically constrain this sketch?

[SteveFrey]

To tell you the truth, I made the part a long time ago so I have to answer, "I don't know why". I've slowly been learning more and more about Inventor and a lot of it is learning about what I've done wrong.

[JDMather]

Do you really need to have the spring compress - it would be much easier in Inventor Studio.

[SteveFrey]

I don't need to have it compress. I am just wondering how I would do this in the event I needed to show someone. My next question was should it be done in Studio but I think you answered that for me.

[JDMather]

I don't see where you state what version of Inventor you are using? The files indicate r2008.

[SteveFrey]

Yes, 2008

[SteveFrey]

I don't need the springs to move but for my own knowledge, I can't figure out how to constrain the bar to the shaft. I would like to have the bar fall into the groove in the shaft when it is rotated and then push out while still being constrained to the outside of the shaft. Transitional did not work and tangent only works on one surface at a time.

[JDMather]

I think if you add very small fillets to the edges (they are going to get rounded anyway during deburr or in the operation of this mechanism) the Transistional will work. Tangent would not be correct. Otherwise use Contact Sets with ONLY these two parts as part of the contact set. Use Tangent with the plunger and cylinder. Leave one end of the spring free unless you are going to animate spring in Studio. If they ever get the forum fixed so that I can post files again I will attach the solution.

[SteveFrey]

Great, and thanks. As always, you're a big help.