Joint Problem

[Anonymous]

Hi All -- I have a problem with this mechanism. I may not live long enough to solve it by myself --- need your help. I have attached a zip file. I am working in Inventor 2012 Product Design Suite Ultimate, with service pack 2. As you can see, the "Crank Example.iam" drags fine. But when I place it into the Dynamic environment, I have 2 redundancies. The goal here is to run the motion by rotation of  "Assembly 5".  I have tried using a point on plane, and point on line with zero success, with the point on the center of the roller shaft.

I have worked most of the examples in WasimYounis's book, "Up & Running ..... Part 2 -Dynamic Simulation". Having used Pro-E's Mechanism Dynamics for 3 years, Inventor seems much more difficult than necessary!  And I find explanation lacking for a thorough understanding of the logic in applying the proper joint.

Thanks in advance for any suggestions.

Beenthere

[Anonymous]

With some more trial & error, I find that if I delete my Tangent:1 constraint, and my Planer constraint between 1018 & "Angled Shaft"; and add a "Cyl in Cyl" joint, the dynamics works with zero redundancies. Where is the force transmitted?---Thru the Cyl in Cyl joint? What centers the "Angled Shaft"?

Beenthere

[JDMather]

Attach the new iam here (don't need the part files again).

Which shaft is the input shaft?

Edit the Properties of the Revolution Joint for the input shaft and click on the Imposed Motion icon to right.

Enable Imposed Motion and enter appropriate value.

[JDMather]

Also I noticed that some of your sketches are not constrained.

This is important in Pro/E or Inventor.

In this image see that the center of one circle is not at the origin concentric with the other origin.

Here is a getting started document.

http://home.pct.edu/~jmather/SkillsUSA%20University.pdf

[Anonymous]

Thank you JD --- As I stated, "Assembly 5" is the input.  I have attached the assembly that works, but I have yet to check it out for forces, to see if the cam roller force is in line with the roller shaft. 

Most of the parts were brought in from SolidWorkks. Is that an issue. I don't understand why the sketckes have to be properly constrained?  You seem to be familiar with Pro-E. can you give me an honest comparison? I'm learning IV along with Sim 360, to take advantage of the FEA, which I understand is a step-up from "Mechanica" -- thoughts?

Beenthere

[Anonymous]

I have been trying to figure out the best way to apply a joint that will attach the crank part to the angled shaft, so the assembly will rotate with zero redundancies. As shown, I have a "Rolling on Rolling", which runs. When I place a pure Torque load on the left shaft (see Diagram 1),  and drive it with the RH shaft, I get some weird loads. I can understand that the cam load would be on the contacting cam, but why not perp to the roller?

I would expect to see forces as shown on Digram 2, but I suppose for that to happen, I would have to connect the angled shaft to the crank in a different manner. I tried a Point on a Plane, but that didn't work for me. Why can't one get that option if you select "Automatically Convert Constraints to Standard Jonts" ?

Not obvious to me --- Is there a better solution?

Thanks --

Beenthere