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4-Participant
November 13, 2023
Question

Cero external merge fails when merged file made with different units

  • November 13, 2023
  • 1 reply
  • 3143 views

When unsung Merge/Inheritance to merge a part file (raw material file) into another file (machined part file) I am getting failures with the scaling of the parts. This only happens when the files are made using different units of measurement i.e. the part file being merged is mm and the part file that is being worked on is inches. 

 

What seems to be happening is a part made in metric being merged into an inch file has a scale that is 25.4 times the intended size because Creo isn't making the unit conversion and instead bring in the mm units unscaled into the inch file and vice-versa. 

This issue can somewhat go away when toggling between Merge/Inheritance but that will bring in the design tree which isn't ideal. 

 

We cant make them the same units of measure since the prints need to be in there respective units for documentation/customer reasons. 

 

Edit: using Creo 9

Edit 2: When changing the units in either model to match the part end up working fine, so there is something not connecting when scaling the units from a part file to a merge file.

 

 

1 reply

tbraxton
22-Sapphire II
22-Sapphire II
November 13, 2023

I suspect this is an accuracy issue and not a unit issue. When using data sharing features the absolute accuracy of source and target models should be matched. Do you have the absolute accuracy set for both parts and if so, what are the values?

 

What version of Creo are you using?

 

Are you using start parts for either part?

4-Participant
November 13, 2023

I am using is Creo 9. When I changed the accuracy from relative to Absolute on both models the issue did not go away.  When setting the absolute accuracy equal to each other that did not change anything, 

Edit: This issue was also present on Creo 7 and we are using start parts when making these.

tbraxton
22-Sapphire II
22-Sapphire II
November 13, 2023

"When setting the absolute accuracy equal to each other that did not change anything, "

 

This may seem an odd question, but it is important here.

Absolute accuracy has units of length so .001 mm is not equivalent to .001 inches. Can you verify the actual values of each model are equal?