Section relations won't update

Ok, here's my problem. I created some relations in a section of a variable
section sweep, and have some equations referencing parameters that were
created in the part. When I change some of the part parameters, my section
doesn't respond unless I open the relations editor, navigate to the
section's relations and click the button to execute/verify relations. I go
back to the regular part and do a regen and it works. What am I doing
wrong?

Thanks in advance,
Jason L

 

I created some relations in a section of a variable

Is you sayin' that if you change the parameters and regen the part the VSS
section isn't reflecting the changes? Is there a ref dim value being included
in the relations? (ref dims update post section regen)

(I have stumbled across similar situations, took two consecutive regens, etc.
Not sure if it was I or Pro/E that was confused.)

 

I would, but the trajpar relation that references part parameters needs to
be in the sketch or my wave washer won't have any waves to it. I am just
trying to create the perfect crest-to-crest stacked wave washer that is
available through Smalley Steel Ring Co., and I need it to be flexible in an
assembly.

If anyone has any regular or crest-to-crest wave washer models that are
easily made flexible, let me know, because I would like to compare models.

 

sorry Jeff, no ref dims used. I just can't figure it out.

 

Here is the link to my parts. Feel free to look at my relations and tell me
what I am doing wrong.
http://www.geocities.com/tectranbrake/wave_washers.zip

 

... and tell me what I am doing wrong.

Hi Jason,

I've seen this before and my fix was just to Edit Def, Ok the VSS. After
playin' with your file a bit I found a way to get the VSS to regen correctly:

In the VSS sketcher relations;
Insert "amplitude = free_ht" above your sd7 assignment.
Substitute "amplitude" for "free_ht" in your sd7 assignment.

The VSS will then update correctly when you change the part param FREE_HT and
regen.

I have no idea why. Forcing a param read before section regen? Normal or bug?
I've had no Pro/E training and never quite know when I'm (or anyone else is)
doing something "right". I've never assigned D values in Part Relations (vs
feature or section relations), for instance. Is that a common practice?

 

Thanks so much Jeff for getting back to me so soon. I am going on vacation
for a week, so I will have to try your fix when I get back. As far as your
other questions, I am in the dark as much as you. I had very little Pro/E
training a long time ago, so for the most part I am self-taught. We don't
even have maintenance here, so I rely on newsgroups and message boards to
find all my answers. So thanks again, I really appreciate it.

One more thing.....Pro/E understands "amplitude" the same way it reads
"trajpar" or is that like creating a parameter within the sketch?

Thanks,
Jason

 

"amplitude" is just a symbol, a name. Could be anything. The idea was just to
get FREE_HT to be read before assignment to sd7 and see if there was an effect.

 

... or is that like creating a parameter within the sketch?

Yes.
(My reading comprehension skills are a little dull sometimes.)

`;^)

 

I gather, from the extended converstation on this problem, that you are making a
variable section sweep, using a circular trajectory and, then, getting the wavy
feature with a trajpar formula. On top of this, you are trying to shortcut the
input process with a number of parameters, used, hopefully, to govern the
defining values of the wave and the washer profile.

You've already discovered the main drawback to this approach: Pro/e doesn't
recognize any feature change so doesn't regen the model when you change some
parameters. Many more difficulties exist with this procedure, especially when it
involves a VSS with trajpar. Let me suggest a more robust, elegant alternative: a
curve by equation.

With a curve by equation ('Insert>Curve>Equation'), you get a robust feature that
changes when parameters change. The neat thing about using a curve by equation for
your VSS trajectory is that Pro/e doesn't know if the feature has changed unless
it evaluates the equation. Thus, all changes to parameters used in curve equations
get evaluated immediately. So, your wavy trajectory for your VSS is capable of
supporting a wavy feature that is infinitely variable.

Here is a wavy washer I created using the following parameters and equation:

Parameters
waves=4
offset=2
height=.5
across=4

Equation (cylindrical csys)
r=across
theta=t*360
z=offset+(sin(t*360*waves))*height / offset just gives it a +/- distance from Z0

I could change any of these parameters with an immediate update of the curve
trajectory and, thus, of the feature itself.

 

David,
Is it z=offset +(sin(theta*waves)*height ?
1. I don't see theta used but it is defined.
2. The "/ offset" after height is confusing.
MNM

 

Yes, thanks for the correction. I should have just done copy and paste instead of
depending on memory.

Okay, this is copied from the equation input screen and it was as you suggested. I
know this one's okay because it produces the wavy curve and it does vary by
changing any of the parameters and regenerating the model. I did the VSS as a
surface and turned it into a solid with 'Edit>Thicken'. If you do the thickening
with the surface as midplane, the feature is almost indestructible.

If you want to make this really slick, do it all in a program ('Tools>Program'),
i.e., set up the paramters, take prompted input to the parameters and even add
relations to govern the width of the washer (or diameter of hole) and the
thickness. And, if you want to be super slick, give this a java gui.

/* For cylindrical coordinate system, enter parametric equation
/* in terms of t (which will vary from 0 to 1) for r, theta and z
/* For example: for a circle in x-y plane, centered at origin
/* and radius = 4, the parametric equations will be:
/* r = 4
/* theta = t * 360
/* z = 0
/*-------------------------------------------------------------------
r=across
theta=t*360
z=offset+(sin(theta*waves))*height