Passing Parameters to Lower Parts/Assemblies

[JM_10432119]

Hi I'm trying to streamline design without skeletons or notebooks.

I've been using relations referencing the GA. Ex: 

WO_NUM = WO_NUM:1

DIA = DIA:1

The :1 calls up parameter of session ID 1

I found out that model intent > program can do the same thing with more steps. Is there a reason to use program instead.

Do you have any ways to basically do top down design without access to skeletons or notebooks?

[tbraxton]

The main difference in using Pro/Program would be the ability to force user interaction to modify the state of the model using program functionality. With relations the user must modify the relations in the editor. If you want to use the Inputs function in program and the UI associated with it, then that may be a better option. If you elaborate on the design intent or an example that you need to manage that may lead to more relevant suggestions.

I would say that if your designs have much complexity and require changes often then managing a true top-down design can be quite laborious and error prone.

[JM_10432119]

I'm coming to understand the complicated things my previous employer did with Creo. It used Pro/Program > read file and always added another step to regen. I think it would add errors forcing my current coworkers to interact.

Right now I'm trying to do a couple of things. Send project details to subassemblies so when a design is copied drawing information has to be changed in one place. That's working out well with relations. Next is having the important overall dimensions someplace that can update relevant parts and maybe even add or subtract a part if the design requires it. Relations should be able to handle that too.

[tbraxton]

Pro/Program can replace components or suppress them in an assembly, I do not believe it can delete a component.

I have never used relations to suppress or replace components. I am not sure it is even possible using only relations. Somone else may know about this and respond.

If you need a design configuration manager there are some 3rd party apps available that use Excel as the front end to drive configurations within Creo.

[KenFarley · Accepted solution]

In case you haven't seen it, there was a discussion of top down design in the past:

https://community.ptc.com/t5/3D-Part-Assembly-Design/Top-Down-Design-Question/td-p/595149

Maybe it'll be helpful?

[JM_10432119]

Thanks, that's a way I haven't tried yet. I'm a bit worried about part stability without the master assembly open. But I'm guessing this is everything I would want from a skeleton.

[tbraxton]

I don't know how large your assemblies are but make sure you have the computer HW to support having the top-level assembly open to make a change on any component. You must push all changes from the top level "master" assembly down to the components which requires the top level to be in session to make any changes to a part driven by the assembly.

IMO that is a huge drawback and I would not use that technique over the top-down design tools in AAX given a choice. It is easy to justify the cost of AAX module price as a cost savings in this context if you use Creo every day to design products.

In the absence of AAX then a master assembly is better than nothing.

[KenFarley]

I haven't really had much trouble with slowness, but I'm usually dealing with about 20-30 parts of wildly varying complexity. I've had some designs that needed 100s of parts, but usually those were split up into maybe two or three large portions of the design. Oh well.

[tbraxton]

I was using Pro/E before the top-down design tools were available and we did manage designs without those tools. Master model merge technique was one of the first to be introduced (predates the Top-Down tools) and we used that extensively. We still had issues with regeneration times because we needed large data sets in session to manage design intent. Being able to break down design structure within Creo to limited data sets is essential in some environments as it is still not practical to load a top-level assembly into session to make changes.

Once the top-down design functions were released we did adopt them. I have never been without AAX functionality since it was released but I know there are some companies that will not pay for the add on functionality. 

[PBrulot]

Hi, using program instead does usually not replace the need for relations but adds more functionality. You can for example automatically suppress or replace components within an assembly. You can not delete parts using program. Be aware that using pro program at assembly level also requires the advanced assembly extension (aax).

If you want to control multiple parts / assemblies at multiple levels with a couple of parameters, I would personally choose the notebook functionality. It's a very clear and defined way of work and the dependencies are not as strict as with skeletons and easily broken. 

If you do not want to use skeletons nor notebooks, you will have to use the session ID in the relations as you showed in the example. Be aware that this ID changes for each session, depending on the order you open parts and assemblies in your Creo session.

There is one alternative that I would not really recommend but you might want to try. You can define the parameters in an empty part and use it as an inheritance feature. It is far-fetched, you still need to define relations and it still requires an AAX license but it does work without needing the session ID.

[JM_10432119]

Good to know "Be aware that using pro program at assembly level also requires the advanced assembly extension (aax)." I'm currently using creo 2 with AAX but moving to a newer version which doesn't have it. I didn't consider it wouldn't carry over.