So I am trying to find the best way to do what I need to do and to avoid problems. Right now I have modelled a pneumatic cylinder, this is a full assembly with roughly 30 parts, 3 sub assemblies, and about 20 drawings. This is the "43" model and has been completely finished and approved. Now I am required to model the "32" model. These two models use very similar, if not identical parts, except for the overall length of the parts has been changed. I am unsure how to start this project. I was thinking originally that I would simply copy and paste a version of the "43" model and then modify it as needed but am worried about the actual files in the 43 being changed by accident or by file association between the two different models, the 43 and the 32. I guess my question is how would people on here go about doing this project? I want to avoid any editing of the 43 because I was very happy to not have to deal it with that any more. Also is there a way to see all the file associations with each file? Thanks in advance people.