An example of how to clean a non-manifold STL with blender. Can other tools fix it automatically? I bet. Is it good to understand how manifoldness works? I think so.
I use the free (beta) Netfabb cloud service - http://cloud.netfabb.com/
Seems most people do. But I like the open source aspect of reprap, and don’t want to be dependent on a closed source product. I also set out on this to understand what non-manifoldness was about, and learn blender. Useful for education, but I’d hate to have to fix all my parts manually like this.
This is also amazing because the netfabb cloud service doesn’t always fix files either. This more hands-on approach is more likely to get some of the more difficult files fixed.
@ThantiK I’ve fixed parts netfabb failed on. It’s annoying, and one would hope part creators would do better, but if it’s the only option then it’s good to know how.