Thingiverse and other online resources for STL's

Not usually the best option!

While it seems like someone has done the job for you already, be careful. Look for STL files which show actual pictures of printed attempts. If the only images availible are from renders, there is a good chance it will not work. Additionally, if you are trying to print a specific size object you will still need to edit the STL before attempting to slice it.

Thingiverse - Digital Designs for Physical Objectsthingiverse

Printables