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Assembly dosen't regenerate properly (Assembly cut)

Daniel
12-Amethyst

Assembly dosen't regenerate properly (Assembly cut)

It's a general problem, but to explain it, I made this assembly ("ASM_A"):

In sub-assembly B, there are two Flanges (Placement: "Flange-2 on Flange-1")

In assembly A, there is a assembly cut (It dosen't really matter what you cut).

Now go to Flange-2 and change the distance between the holes ("mod dim Flange-2")

 

You can regenerate the model, but it won't fail (even if you can see that it doesn't fit anymore).

Now close the assemblys and erase them. If you open up ASM-A, it will still regenerate. Only if you open ASM-B before ASM-A, regeneration will fail.

 

This is a problem, i can't be sure if my assembly is clean if it doesn't regenerate.

 

Can anyone reproduce this? And do you know what one can do against it?

 

Thx

 

Edit: My problem is the regeneration of the placement of the flanges. Because of the assembly cut in A.asm, it seems that Creo doesn't regenerate the Placement properly. 

--> I can make the Placement undoable (changing distance between holes / deleting refs / etc.) and Creo still won't show me a fail when regenerating the model.

1 ACCEPTED SOLUTION

Accepted Solutions
Mahesh_Sharma
22-Sapphire I
(To:Daniel)

@Daniel @TomU 

 

I worked with development about the fix for this issue. Development reviewed this in detail and tried fixing this issue however fixing it is extremely risky for other features, because of high risk in nature fix for this cannot implement in released versions. Development will plan to make changes in upcoming versions. 

 

Reference Article: CS331239

View solution in original post

28 REPLIES 28
TomU
23-Emerald II
(To:Daniel)

Can you upload your assembly?  You will need to zip it first...

Daniel
12-Amethyst
(To:TomU)

two assemblys, before and after dim change. Made in education version of Creo 5 because I can't upload from the company (same problem nevertheless)

Mahesh_Sharma
22-Sapphire I
(To:Daniel)

@Daniel 

 

I reviewed the sample data and If I am getting this correctly, issue according to you is that when editing the holes on one flange, holes on other flange are not updating (Please correct me if I am wrong). And if this is correct, I don't see a problem here, two circular cutouts on flange 1 and flange 2 are part of extrude feature and both of these are independent, not referencing to other. So changing the distance between two holes on one flange will not change other. 

Not exactly. My problem is that the Assembly doesn't fail.

As you can see in the model i made...

  • hole 1 of Flange-1 coincident with hole 1 of Flange-2 and
  • hole 2 of Flange-1 coincident with hole 2 of Flange-2

If now someone changes the distance between hole 1 and 2 of Flange-2 (but not of Flange-1) i expect the Assembly to fail. The placement can't be fulfilled any longer. If the assembly now tells me as expected that it failed, i can start to search for the mistake.

 

And that is my Problem. If your Creo works as mine (btw which version do you use?) you can open A.asm after you changed the dim of flange-2 and nothing will fail --> Therefore i won't realise that the Flange-2 doesn't fit on Flange-1. Imagine the whole thing in a bigger assembly where multiple people work with

 

I know for sure, that the "not failed part even if it should fail" occures because of the assembly cut in the upper assembly

 

I know its a strange problem

 

Mahesh_Sharma
22-Sapphire I
(To:Daniel)

@Daniel 

 

OK, thanks for clarification... 

Couple of points.. 

1. Hole features are part of extrude feature only. So not any additional hole feature.

2. These are appearing coincident but none of them are referring to each other. 

3. Assembly cut id's in Flange1 and 2 are of Extrude cut feature at assembly level (A.asm). 

 

Both of the Flange 1&2 are independent to each other and circular cuts are not referring to each other. If you would like to maintain the same distance .. you can refer establish the reference in circles in flange1 or 2. Once done it will follow the changes made in flange.  

Thx for trying to help, I really appreciate that, but we’re still talking about two different topics.

 

I know the difference between holes and extrudes but it doesn't matter for this regeneration fail (if I’m not terribly wrong). I call them holes so you know what I mean, I could also call them round extrudes.

 

If you open A.asm from the attached files it should look like this: P1

Two of the "holes" don't fit: P2

Open B.asm (without erasing A.asm😞 P3

Regenerate as many times you like, the assembly won't fail

Open "edit definition" of Flange-2: P4

Creo will now tell you that the Constraints are Invalid, which is something it didn't do before.

If you now exit the Component Placement without editing anything it should look like this: P5

Regenerate as many times you like, the assembly won't fail.

 

What this means is that the assembly won't show it failed, even though we saw from P4 that it actually did.

 

My Problem with this is, that if I have a big assembly, where I won't control every connection, the assembly won't tell me if some parts/connections/whatever failed

 

PS: Instead of the "holes" you could build whatever constrain you like in B.asm. Change one of the parts so that the connection isn't possible anymore. Delete the references if you like. As long as you open A.asm first, the model won't fail. In P6 for example I deleted the "holes" in Flange-2 and the assembly still doesn't show a fail.

 

 

StephenWilliams
22-Sapphire III
(To:Daniel)

Check config.pro option:

Do you have ALLOW_FREEZE_FAILED_ASSY_COMP YES (default is NO) will let components stay in place without failure

 

You could try REGEN_FAILURE_HANDLING RESOLVE_MODE.  This will go back to the old way Creo used to fail and go in to resolve mode, I'm not sure this will get the assembly to fail though. If you have new users who have never seen resolve mode, they will freak!

We normaly have ALLOW_FREEZE_FAILED_ASSY_COMP on YES, but i tried both options and they don't help.

Yes, I know more or less how resolve mode works, but it doesn't help either

@StephenWilliams @Mahesh_Sharma @TomU What does it show in your CAD when you open my files? Does Creo realise that the placement is wrong?

TomU
23-Emerald II
(To:Daniel)

I didn't try since you said it was made in the educational version of Creo.  Those of us with normal 'commercial' licenses can't open anything made in the educational versions.

TomU
23-Emerald II
(To:Daniel)

I've had issues similar to this in the past where placement constraints don't fail when they should.  Could you please post a picture of each of the placement constraints between the two blocks?  I will try to recreate this on my system.  I think the key is going to be exactly replicating your placement constraints...

StephenWilliams
22-Sapphire III
(To:Daniel)

Same here. I can't open educational versions.

I work on large assemblies. I have failures up and down my model tree all day, every day. Some of which I have control over, some I don't (based on whose model it is within my company).

I do agree that placement failures don't seem to stand out very well.

 

Mahesh_Sharma
22-Sapphire I
(To:Daniel)

@Daniel 

 

Apologies for overlooking this..  New images clarify that. I see what you mean It is same in Creo 7.0. too.

 

@TomU @kdirth @StephenWilliams 

 

I will check this internally update accordingly. 

kdirth
18-Opal
(To:TomU)

I was able to recreated the issue in CREO 4.0.  Without the assembly cut, the model fails as expected.  With an assembly cut, changing the hole does not cause a regeneration failure.  In fact, the blocks will not not change position to follow either hole alignment.

 

Attached is my test files.  Open test_assy-2.asm, edit the dimension between holes in test_block-1 and regenerate as many times as you like.  Delete the assembly cut, change the holes, regenerate, and it will fail.

 

I would suggest starting a support case with PTC.


There is always more to learn in Creo.
TomU
23-Emerald II
(To:kdirth)

Yep, reproducible in Creo 6.0 as well.  @kdirth, thanks for making this.  @Daniel, do you have active maintenance?  If not, let me know and I'll open a case.  This is clearly a problem.

Mahesh_Sharma
22-Sapphire I
(To:Daniel)

@Daniel @TomU @kdirth @StephenWilliams 

 

Reworked with new dateset in Creo 7.0... got a regeneration failure. 

 

Check attached video from Creo 7.0. 

 

I hope this time I am not missing something 🙂

TomU
23-Emerald II
(To:Mahesh_Sharma)

@Mahesh_Sharma,

The placement fails because you don't have an assembly cut.  Add an assembly cut at the top level, then move the holes and regenerate.  Most likely nothing will fail... which is the problem being highlighted here.

Mahesh_Sharma
22-Sapphire I
(To:TomU)

Thanks @TomU I will revisit this and take it further. 

Are there any updates on the topic?

Mahesh_Sharma
22-Sapphire I
(To:Daniel)

Not yet.  I will keep you posted. 

Daniel
12-Amethyst
(To:TomU)

exactly

Daniel
12-Amethyst
(To:Daniel)

Thx to all of you for replying 😊

 

@TomU  That would be great if you could open a case. We don't have direct maintenance, everything must go over the company CAD-Help and they aren't particularly fast. Could you update us in this thread or should I give you my mail?

I can’t upload any files from the normal Creo Version, since we do have Digital Guardian (every CAD-file is tracked), but in the meantime there should be enough working files in this thread.

 

@StephenWilliams  “I have failures up and down my model tree all day, every day» Yes, we do have too, but since I’m aware of that regen problem I realized that quite some of our ASM-fails can be related to it. I might be a little bit paranoid, but I think it’s a big issue.

 

A bit more information to the regen problem:

It seems it does always show a Fail if Creo can’t regen a feature in a part (see “Featur-Fail_on_part_lvl”, I created a fail-Extrude on part-lvl and the asm failed)

It won’t fail if the placement in a “lower than ASM-Cut” is corrupt except if the placement is needed in Top-level. For example, if you referred a bolt to it or if you used it as ref for the ASM-Cut

C1: proper asm without bolt

C2: corrupt asm without bolt

D1: proper asm with bolt

D2: corrupt asm with bolt (failed, but just the placement of the bolt, sub-asm still doesn’t fail

(files from @kdirth used)

 

For me it seems like the whole thing starts with the way creo handles assembly-cuts. 

I’m “glad” it seems to “work” up to the latest version of Creo.

I don't think it's related to the config-file, since we could all reproduce it.

TomU
23-Emerald II
(To:Daniel)

@Daniel,

@Mahesh_Sharma is part of the tech support team.  He has agreed to pursue this internally for now, so no case is necessary.  I'll let you know if I hear anything back.

Daniel
12-Amethyst
(To:TomU)

👍

Mahesh_Sharma
22-Sapphire I
(To:Daniel)

@Daniel @TomU 

 

I worked with development about the fix for this issue. Development reviewed this in detail and tried fixing this issue however fixing it is extremely risky for other features, because of high risk in nature fix for this cannot implement in released versions. Development will plan to make changes in upcoming versions. 

 

Reference Article: CS331239

View solution in original post

TomU
23-Emerald II
(To:Mahesh_Sharma)

@Mahesh_Sharma,

 

Thanks for the update.  This seems like a pretty serious bug.  Do you have an article number and/or SPR number that we can use to track it?  Do you have any idea which version it is expected to be fixed in?  8?  9?

 

Thanks!

Mahesh_Sharma
22-Sapphire I
(To:TomU)

@TomU 

 

Article CS331239 

 

No commit release as of now. 

I had the fear it would somehow end this way. Thanks for the help anyway. Could you insert the Article number in your post that I accepted as solution, so that one doesn’t have to search for it?

 

And perhaps it would make sense to change "Applies to" form "Creo 4" to "Creo 3 - Creo 7"

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