When designing STL and other files it can be very handy to keep older versions of the design. This is a common issue for software development where it is not sensible to delete older versions of the source code.
Version Control software provides the solution because whilst you want to use the latest design it's nice to be able to pull back an older version of a design.
Sourcegear Vault is a great solution and offers a free single user license. That might sound like a complex solution however it's much easier than maintaining older copies of updated designs when you have hundreds of different designs.
https://sourcegear.com/vault/
Version Control of design files
Moderator: CrazyIvan