DrScoles, I’m using ScketchUp because I want an app that is free and will always remain free (at least the last full download and installation file I had) because I drew/draw an entire new airplane/plan for my current project and want to be sure I will always be able to open the plan. I was using Autocad long time ago and was looking to buy a new licence or use the Fuzion one, but as Sketchup is free and do all I need and mostly the last downloaded setup file will remain free, I choose it.