To extend the idea for a place to share CAD files, LMR now has this forum specifically for the purpose. Please keep your posts on-topic.
To attach a CAD library to a post, please wrap your files up in a .zip or .tar.gz archive. Rather than adding potentially dozens of file extensions to the "allowed" list, this will make it less likely to forget some.
This post will be updated with more intelligent information, because I don't have a clue what I'm talking about when it comes to CAD.