Assembly STEP import - position/placement of items

[btimmerman]

Hi all!

I'm trying to figure out how Creo knows the position (or placement/location) of items within an imported STEP assembly.

After importing the step you obviously are left with an assembly where all the single parts and sub-asm. are in the right spot, but how is that location determined and stored? When deleting the Import Feature Id ## of a imported part, the complete geometry is deleted. Do the same in an assembly and all parts are still there .. in the right place.

And then the catch: When I replace one of the single parts with a non-imported part (native Creo from my Workspace) it still is valid and not packaged. While adding that same part seperately (forgotten by supplier) I need to provide constraints to prevent it from being Packaged ..

[James62]

Creo simply reads position of each assembly component from the STEP file. Each of the component's own origin can be placed elsewhere than the origin of the assembly itself.

Components of an imported assembly might just become packaged once they go through edit definition.

[btimmerman]

One would expect packaged items while repositioning through Edit Def or moving etc. Thing is that this does not happen at all. Even when rearranging items to and from other assemblies, positions are fine while I just deleted any reference to the imported step by deleting the Import Feature(s). So the question remains where these positions are stored without having constraints in any way?

[James62 · Accepted solution]

These positions come from the STEP file. The imported feature at the assembly level contains no information if all the components come in as solids, and there are no assembly level curves, surfaces or anything defined inside the STEP assembly file as assembly level entities.

STEP file contains no references. no constraints, it contains just the geometry and the information about absolute coord systems of each component. All Creo does is not turn the components into packaged states, unless the user edits the definition of a component, but the components aren't really assembled or referenced anyhow after coming in on import.

[wbottis]

Hello,

I am attempting to import a step assembly as a single part (in order to simplify the model tree).  Our organization forces us to adhere to strict naming conventions for all parts and assemblies, so in order to prevent ourselves from going out of business by spending money to do this for hundreds of parts, it would be more cost effective to import certain assembles as a singe part.  Is there a way to do this successfully so that all the parts in the assembly adhere to their correct positions when importing the step assembly as a single part?  I have not been able to do this successfully in years, but I figured Creo 5 would have figured it out.

Alternatively, I have tried shrink wrapping the assembly with zero success no matter how low I assign the accuracy of the shrinkwrap.  This takes several minutes of waiting/computing followed by Creo aborting at the very end.  I have tried several iterations of this with zero success.  Thank you.

[StephenW]

Add the hidden config.pro option:

intf3d_in_as_part YES.

[wbottis]

Thanks, Stephen.  Can you provide quick instructions for doing that properly?  Thank you.

[StephenW]

Go to FILE - OPTIONS - CONFIGURATION EDITOR - ADD.

It's a hidden option so you can't use find, you have to type in the values

Type intf3d_in_as_part  in the option name 

Type YES in the option value

Then OK.

You should be able to select part in the import dialog and the STEP parts should import in their correct positions.

[wbottis]

Thanks, Steve.  2nd attempt to import step assembly as a part file in process.  First attempt, Creo is not responding after over 1 hour.  Keep you posted.

[Pettersson]

This hidden option usually does the trick, but I've seen it fail once or twice. The backup solution is to import as assembly, export as IGES, then import back as STEP. It's a hassle, but gets the job done.

[wbottis]

OK, I'll give that a try.  When importing back as a STEP file from an IGES file, do you import as a part?  If so, is this without turning the hidden config.pro option to YES?

[Pettersson]

If you do it via IGES, you import the STEP as assembly and the IGES as part. The hidden setting doesn't matter in this case.