Mirrored feature not updating

Annoying, huh   I avoid mirrors because, like you, I can't get the hang of it either.  I need reliable associativity.  If a rotational pattern will do the same, it is the go-to feature.

edit: old history pretty much asking the same... Mirror Feature Issue

‌Hello Kaleb,

I do not like mirror. I think it is best to just draw all of the parts. It does take longer sometimes to sketch everything, but it does save time regenerating and failing. That is my take on it. It seems pattern and mirror messEs up when regenerating.

Peace, Billy

The Mirror feature is very limited in functionality unless you mirror the whole feature tree, i.e Mirror Merge. Unfortunately not out until maybe mid 2017, but from Creo 4.0 M020 I believe it will behave as you and all of us Creo users want.

I was just trying to resolve this same issue and stumbled upon a fix that worked at the time.  If you right click on the Mirrored Merge id in the model tree, click on Edit Definition, then click ok it regenerates the mirror from the updated file. There is a place to choose the file it is mirroring, it would not let me change it but by editing the definition it does seem to regenerate from the updated file.  

When modifying a mirrored feature, be sure to modify the original and not the mirror.  Modifying the mirror may break the mirror link.  Also I have found that mirroring modifying features, such as rounds and chamfers, can cause problems.

It's funny, Creo is billed as high end, yet it can't mirror?  I'm fighting this right now.

I complain about this stuff and then the Creo apologists come and attack me.  "We just use some crazy workaround and are happy that way.  And, besides, why would we need it when Creo can do trajpar??"

I tried editing the mirror and then using a different plane and then re-editing and using the desired plane and it DIDN'T UPDATE!  You would think this would force a rebuild.

News Flash:  SolidQuirks can handle mirrors anywhere from simple to complex with half it's code tied behind it's back.

Being able to leverage symmetry is a fundamental solid-modeling technique.

Just loaded version 4 and am really liking the improvements.  Starting to feel a lot more like SolidQuirks, without the mirroring capabilities that is.

Yeah, mirroring has always been a real weak spot for Creo. It's been somewhat improved in creo 5, where there's a "reapply mirror" checkbox that somewhat fixes this issue. It still has the issue of not being able to add or remove references, though.

I use a workaround (yes, it's a workaround, but it has some good advantages compared to the regular mirror). Here's what I do:

1. Select the surfaces you want to mirror, instead of the features. In most cases, this can be done with a Seed and Boundary selection. Try to use a smart selection method (S&B, loop surface, intent surface, etc.) and not just selecting all the surfaces one by one.
2. Copy and paste the surfaces (Ctrl+C, Ctrl+V).
3. Now select the quilt (not the feature) and mirror that.
4. Solidify the mirror.

A bit messy, but you'll never have problems with the mirror not updating, you can add or remove references in the original features, it's easy to add or remove features from the mirror and it's also computationally lighter. The main downside is that if it crashes, someone with low skills in Creo might not be able to fix it because they don't understand how it was done.