I am having some trouble with creo. I am working in Creo 2.0 and I want to make a modell with the exact measures as another object that is a stp file. Think of it as if I imported a turtle into cad as a stp file and then wanted to make a shell for it that is formfitted perfectly. I have tried importing it into creo and using sections to make curves on the section, which works until I want to remove the imported stp model. Then everything is deleted since it is all connected to the modell. And I can't make changes to the curves either. Is there perhaps a way to get the curves in to a sketch and make it independent. Or is there another and better way to do this?