Contact Set Behavior

[ThinAirDesigns]

Noob here.  Much appreciate the effort y'all put into this valuable resource.

So my usual method of learning software like this (it's not my first cattle drive) is to put together silly little projects that utilze different features and just see how successful I am. Attached are  two simple slabs with grooves and a ball, constrained such that the movement of one slab forces relative motion in the other slab.  

The way I understand contact sets (which could very well be wrong), the closed nature of the grooves should act as a stop for the entire mechanism and would not require any additional constraint range limits (which I know how to apply).  The current behavior however is not what I expected.  When mousing the slabs, there IS a bit of a hitch or detent effect when the ball reaches the end of the groove, but then it blows right on past and out the end of the slab.

Suggestions?

(As as aside, this is the first time I have ever attached a zip file with an .iam and the .ipt files.  When I do such for questions like this, do I also include the project file in the zip or does that just complicate things like (file) path issues for others to open?)

Thanks.
JB

[CCarreiras · Accepted solution]

HI!

First, you can always send the Project File, the paths will redefine when we unzip in other folder. But, it's better if you use Save as Pack and Go in Inventor, or directly  in the folder, hover the mouse in assembly file, RMButton and select Pack and go. This way you guarantee that all parts belonging to the assembly are Zipped.

The behavior you're seeing is normal. If you move the system slowly, it behaves naturally, as you expected. If you shake or move a bit faster, it will pass "physically" the borders, and you are ready to inspect the next collision. And this is the objective , is why it behaves like that. Imagine one rail, full of barriers... you can go passing thru the rail and inspect not only one collision, but all collisions on all the route.

If you want to have realistic behavior, just pass to the "Dynamic Module" and try your assembly there (Only in Inventor Pro).

Did you find this reply helpful ? If so, use the    Accept as Solution or Kudos - Thank you!

[ThinAirDesigns]

Thanks Carlos.  Exactly what I needed to know (on both counts).   

JB

[JDMather · Accepted solution]

Sometimes the computer cannot keep up with the calculations detecting collision when using mouse movement.

If you Drive Constraint instead - the behavior should be as expected.

It advisable to do your collision detection and then turn off the solver so that you do not slow down everything you are doing.

[ThinAirDesigns]

So now I know why it was suddenly slow. Thanks, good info.

JB