Creo 11 - Does changing a start part effect existing parts?

[pmuewi]

I have a huge library of existing parts and assemblies that were all created with the same start part and start assembly files. If I make a change to the start part or start assembly templates, will that have any effect on existing parts and assemblies, or will it only be applied to new parts or assemblies created after the template change?

[BenLoosli · Accepted solution]

Only new parts and assemblies created with the new templates.

The start part is 'copied' to your new file name when you create a new object.

[pmuewi]

Thanks!

[Patriot_1776]

It WOULD be cool if there was a way to automatically update parts/dwgs using updated start models and dwg templates at the users option.  I suppose that could be done running model check, but it would be cool for people without that optional package to be able to hit "Y" or "N" to update using the latest.

One thing I DID learn (Ouch!), is that if you have library parts that have defined constraints, and you CHANGE them, they very well may (probably will) fail in all the assemblies they're used in, requiring reconstraining them EVERYWHERE.  THAT was a not very pleasant surprise.  So, if you've got a big library of fasteners etc., be VERY careful to make the constraints EXACTLY the way you want them the first time, then leave them alone.

[tbraxton]

You raise an important issue if one were to update legacy data sets using new templates/start parts. For each legacy file you should determine all external references before you attempt to use new templates. I would save a backup copy before any changes and then gain a complete understanding of the ramifications of altering the external references as a result of reducing to practice the use of a new start part.

The start part is saved to the model when newly created using a start part so it is self contained within the part or assembly model. There is no external reference to a start part when using a start model to create a new model.

In theory you could copy all features of a legacy model into a new template and it could be automated but I would do a lot of testing before automating something like this. Unless you need new features added to legacy models there are some other tools that can deal with things like adding/deleting layers, parameters and some other data types within existing models.

[Patriot_1776]

I can't imagine wanting start parts to have any reference to external geometry, that sounds like an exceedingly bad idea.  I've never even heard of doing something like that.  So, I can't imagine that if you were able to update legacy parts to use the new start parts (for things like layers, relations, parameters, etc.) that it could cause issues.  Like I said, I've read/heard that Modelcheck can be set up to automatically update legacy models to all the latest stuff in the start part.  I think we really need to do that here, since when we do update models/dwgs we have to do it manually.  Yes, we can cut&paste relations and parameters, and do the "extend rules" thing for the layers, but it would be nice to do it automatically.

[pmuewi]

I did some testing, and depending on what you change in the start part, loading a new version into an old file can have pretty serious ramifications. Minor things like references breaking can happen, but I also saw whole sets of features fail. Again, depends on what you've changed. 

We have a legacy start part that still uses relative accuracy, and switching to absolute creates a whole host of issues with the files in our library.

[tbraxton]

The accuracy issues are independent of the external references. It is unfortunate that the old start parts were using relative accuracy. If you need to update all models to use absolute accuracy, then that is going to be a lot of effort for any models of even moderate complexity.

I would suggest that you deal with the accuracy conversion without involving the new start part first. Before converting to absolute accuracy, you should decide if a single value for absolute accuracy is appropriate. Setting the accuracy smaller than required will increase regeneration time which may or may not matter to you.

I occasionally get called to update models including a conversion to absolute accuracy and it has always been a pretty tedious exercise. If there are any data sharing references involved with the model being updated, then all of the parent/child models should also be updated to use the same accuracy.

If you run a compare model report in Creo between the old and new start parts that might be useful. That report results could be used to potentially re-map references during conversion to the new start part. If your new start part does not include features or an analog to features in the legacy start part, then that will be problematic from the first step.

[pmuewi]

Yes, totally understand that those are separate issues.

Luckily we're not looking to update accuracy across our existing library, we have a lot of very complex models of parts with existing tooling, so fixing any issues with older models would be difficult to say the least.

I'm currently using an updated start part in a silo'd off area of our network to vet any potential issues and will be rolling out new start parts and start assemblies to users once testing is complete.