When I�m working on a big model in SketchUp, I like to save a new copy of my file every few hours. Doing so lets me easily go back to a previous version in case I�ve accidentally deleted something I need � this happens more often than I care to admit. It also provides a measure of protection against file corruption, which isn�t common, but can be devastating.
For the last eight years, I�ve been choosing File > Save As� and creating a numbered copy in the folder that contains my project. The result is a long, long list of sequentially numbered files. The most recent is the one with the highest number appended to the end, as you can see in the screenshot below. Simple, no?
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There are two problems with this system (as I�ve come to find out the hard way): First, when I come back to a project after a hiatus, I�m never 100% sure that I�m working on the latest version of my file. Maybe I saved a newer version somewhere else? Second, when I�m working on a set of drawings in LayOut, the linked SketchUp file always needs to be the most recent one. Every time I change the name of the SketchUp file (three or four times a day), I need to manually re-link the new model to my LayOut file. Yech.
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Using the Save A Copy As� command (instead of Save As�) takes care of both these issues. It lets you save a version of your model as a new file without renaming the one you�re working on. The saved versions can be numbered and archived, but the �master� version is always called the same thing. There�s no confusion about which is the latest, and working with LayOut is twenty times easier. Presto.
Choosing Save A Copy As... allows you to save "snapshots" of your model while continuing to work on the same file. I like to keep an archive of old versions in a separate folder, just to keep things tidy.
I love it when answers to complicated problems are so simple. Thanks Mitchel!