Creo .dwg model imports in inches, but Save As converts to mm, won't rescale.

[FieldEng]

I am using Creo 12.4.2.0.  I have an engine model that was created in Autocad.  The base units are in inches.  When I import the .dwg, the units are correct.  As soon as I save the file with a new name (File --> Save As Copy), it always re-scales the model to mm.  It's not converting the units. it's multiplying all the inch dimensions by 25.4, and then saving the file as inches.  I have tried rescaling (Model --> Operations --> Rescale), but no matter what I try, the dimensions don't change or convert.  I have also tried to change the units from IPS to MKS, but I don't have the option to convert or interpret.  These options are grayed out.

I misspoke in my initial post.  It's a .dwg file, not .dxf.  The forum will not allow me up upload this type of file.

[tbraxton]

You are not providing enough information to address the problem.  So many things could cause this issue, we don't know what you are working with. What version of Creo? Importing DXF with 3D ACIS data structures or a 2D drawing?

Post the .dxf file here for evaluation.

[FieldEng]

I don't know what ACIS data structures are.  It's a 3D model in .dwg format that I got from a colleague.  It imports fine.

I have found that if I create a new assembly and insert the imported model into it, the model retains the properties of the assembly, rather than trying to save the imported model as a new part.  

That seems to have solved the problem, but I would like to know if there's another way around this issue.

[tbraxton]

If you are importing 3D data then the DXF file has ACIS data within it that is read by Creo upon import. I suspect that your issue is on the Creo side, Creo is likely doing exactly what it is supposed to do based on your actions. i am not able to debug it without the data set and clear instructions on how to replicate your actions and environment.

Embedded ACIS geometry can only be imported as a new assembly or an assembly component. Immediately after doing this, save (do not use save as) the model and then check the units. If the units are as you want them then you can rename the Creo file with the import feature.

Look here for details on how the 3D data is handled by Creo.

https://support.ptc.com/help/creo/creo_pma/r11.0/usascii/index.html#page/data_exchange/interface/About_Importing_DXF_Files_with_3D_Data.html 

[anursingh]

Hi @FieldEng,

I wanted to see if you got the help you needed.

If so, please mark the appropriate reply as the Accepted Solution. It will help other members who may have the same question.
Please note that industry experts also review the replies and may eventually accept one of them as solution on your behalf.
Of course, if you have more to share on your issue, please pursue the conversation. 

Thanks,
Anurag 

[FieldEng]

Hello,

No, unfortunately, I didn’t receive any satisfactory responses. References to the documentation didn’t explain the unit conversion.