VSS Spring flexible regen error

[Zestje]

Hi,

I've been playing around with a VSS spring in WF4 (using the E-Cognition tutorial from Leo Greene as a basis) and want to try assembling it as a flexible component. So I made a very simple assembly and want to use the spring length (the first sketch feature in the
spring) for the flexibility and the distance between 2 planes in the assembly to set this length.

Somehow when I regenerate the assembly (e.g. after changing the distance between the planes) this resuls in an error in a spring feature, which I can't fix, just suppress. Then when I resume the same feature immediately after, the feature DOES work! Upon the next regen I get the error again.

When I change the length in the part instead of the assembly and regenerate just the part I do not get the regen error!?

I can't find what I'm doing wrong (I suspect a circular reference somewhere), so help is appreciated!

Here's the file...:


2009-09-29_041723_VSS_Spring_Flex_090929.zip

 

[tobbo]

another thing to add to your problem is that if you change the distance tothe "end plane" in the .asm , but only a small distance at the time , it works. So, It works if you change from 107-105. then from 105-102, from 102-98, 98-96, 96-95 . But i dont work if you change it from 107 direct to 95.


strange, and kind of funny.


dont know why tho... would be nice to know.


//Tobias

 

[Zestje]

Doesn't anyone have a clue?

I tried simplifying the graph and setting the VSS cross section to constant (which it actually is anyway), but it didn't help...

 

[Zestje]

I can't believe I've found it!

I use the length of a curve to define the pitch as a parameter by using a relation.
This parameter is later used in the graph for the VSS to calculate the bending points in the graph.

Now when I change the length of the curve (edit defenition, change it, click OK) and go to parameters, the value is NOT yet updated! Only when I regenerate the part again the parameter gets updated!

This is what causes the error, because the pitch defined high up in the model tree and used further down in the graph somehow is -not- updated the 1st time the part auto-regenerates after I changed the feature.

When I simply replace the pitch parameter in the relations for the graph by its formula, the problem no longer occurs!

This is very weird behaviour if you ask me. As soon as I change a feature which influences a paramter I expect the parameter to be updated immediately!

But I guess this behaviour is probably by design ...

 

[dr_gallup]

There are several things in Pro/E which can take two regens to fully update. It is because of the order that Pro/E evaluates things. Someplace this is spelled out but I can't find it at the moment. I do know that using sketcher relations that are also tied to part relations will take 2 regens. Sounds like you have a similar situation.