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Deformed Part-HELP! Getting "No Such Rule" message.

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4mranch1

Aerospace
Jun 27, 2007
87
I am using NX3 on a DEll PC without TeamCenter. My intent is to create a Part Family of o-rings that can be deformed when added to an assembly. I created the Part Family file that consists of a sketch ellipse and revolve centerline (ID of o-ring.). The deformed part asks for Groove OD for the o-ring, width (Cross section) of the deformed o-ring, and height (Cross section) of the deformed o-ring. I am able to verify these parts in the Part Family and can add the initial component to my assembly. The "No such rule" message window appears after I have entered the deform data for the second o-ring and entered OK.

Any help would be greatly appreciated.
 
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Can deformable parts be used as part family components anyway?
 
Yes, they can... but it's been my experience that they're more trouble than it's worth. YMMV.

In my previous company (Aerospace engine OEM), we tried using the deformable parts for o-rings, showing the squeeze when in the assembled state. Getting the designers to consistently follow the same design standards, utilize the approved o-rings/suppliers, materials, backup rings, blah, blah, blah, ...made the assemblies a virtual nightmare. There were complaints of greately reduced times for updates, mating errors when mating conditions were applied, and a whole host of other issues. At the end of the day, we wound up just loading an empty ref set and 'faking' the 2-d xsections as req'd for layouts and dwgs.

This was in NX/NX2, so perhaps none of the above applies anymore. :)

Regards,
SS
CAD should pay for itself, shouldn't it?
 
I have an O-Ring part family that performs well, but I only use a circle and not an ellipse. The deformation is simply to control the OD and cross-section, so that pictorially, the assembly looks okay.

Specialty Engineered Automation (SEA)
a UGS Foundation Partner
 
I agree with phillpd. NX3 or NX4 does not handel ellipses well.
 
As an aside, an installed oring does not have an ellipse cross section, but an oval one.
 
I had a problem with NX3 deformable parts.
Can't remeber the error message but the work around was to add the part and just accept the default values. Once the part was added I then edited the deformable values to what I wanted.

Mark Benson
Aerodynamic Model Designer
 
I thought that the ellipse may be the problem so I recreated the model as two 180 degree arcs with two lines drawn between them. In addition to the model change I also tried the deformed part as a stand alone model not as a Part Family. I still get the "No such rule" error message and I cannot deform the second, third, etc... models. They all appear as deformable parts, but only the first part is actually deformable.

Gary Ashby
Designer
 
Does anyone know exactly what "No such rule" means so I can possibly track down my problem that way?

Gary Ashby
Designer
 
Gary,

When creating the deformable component, are you selecting ALL features ? I have seen that before, and can't remember whether it is an issue with NX evaluating the expressions.

Specialty Engineered Automation (SEA)
a UGS Foundation Partner
 
Yes, I am selecting all features when going thru the create deformable part procedure.

When I add the second part to my assembly it will add after the "No such rule" message, but in the undeformed state. If I try to edit the deform it is shown as requiring to be created. If I try and create it I just get the "No such rule" message again.

Gary Ashby
Designer
 
This problem is still haunting me and I sure would like to resolve it. I know this is a forum that some of the greatest minds using UG/NX today follow.

Thanks in advance for the input.

Gary Ashby
Designer
 
Would it be an option to create a reference set of the part in the deformed condition? I have had a similar problem trying to create a deformed seal for an assy I'm working on and I finally decided to just create a seperate reference set. The deformed part has become more trouble than it's worth.

Al Griego
 
Agriego,

Our initial thoughts were to do just that, but the part being an o-ring meant that one size could be used in several size applications. This would mean that we have several reference sets to accomodate each use with slightly different IDs, widths, and ODs. This could become cumbersome but it may be the direction we have to go since deform part is giving such problems.

I tried to create the model as simple as possible using a primitive cylinder first, then placing a hole feature thru it, and finally placing the blends. Now I can add the component and my deform part window appears and I can change the parameters, but when OK is entered I get: "Internal error: memory access violation"

I need HELP!

Gary Ashby
Designer
 
Could you just use sketch and expressions to control the o-ring? As for deforming, you could control it with expressions to update too.

So I assume you cannot show the interference of the o-ring in its application, it has to be deformed?

Justin Ackley
Designer
 
jackley,

We could show the interference (or even just fake it in the drawing view with manual arcs and lines.), but it would be preferable to show the o-ring in its istalled state so our drawing cross sections appear correctly.

I know UG/NX3 should be able do this, I just need to find out what myself or my machine set-up is doing to cause this.

Once again, thanks all for your continued help and suggestions in this matter.

Gary Ashby
Designer
 
Another problem I have had that this could be related to is the orientation of features and the WCS of the assy part you are adding the deformed part to.
If your deformable part relies on creating a feature using any reference to XC,YC or ZC or any operations like trim that may rely on the wcs to define intersect points you may run into problems. The deformed part (wrongly in my opinion) re-calcilates these features using the new WCS in the assy to define these features. Your problem doesn't sound the same but it's the only other thing I can think of.

Just had a bit of a thought. How are you defining the way that users input/select the values for your deformable part?
The error sounds like it has a problem with the rule/s that are controlling this. 3rd screen in the wizard. Lower radio selection. Have you tried defining a range or if that's what you are using have you tried a different option here yet?

Hope that helps.




Mark Benson
Aerodynamic Model Designer
 
MSPBenson,

Thanks for your insight, it sent me down the right road so I could get the deformable o-rings we were looking for. I did away with any solid that referenced a direction for creation. I also found that I could not use variables in my expressions (i.e. H=Height). I also was not able to create a Part Family out of these parts so we will just specify the individual model/size required in the assembly. Multiple adds of the same o-ring is allowable and each may be sized differently according to the groove.

The method used was two cylinders subtracting the smaller from the larger to get the initial ring solid (Hgt./Arc Method) and then adding a blend to each edge.

Once again, thank you everyone for inputting your ideas so we could get this done.


Gary Ashby
Designer
 
Is there any one have experience of drawing an Ellipse shape such as Ellipse type Cone paper.
 
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