There are a number of websites that provide 3D designs for free or for a fee. Here are a few examples:

1. Instructables is a well-known “how-to” website, which gives you instructions for making projects using your 3D printer.

2. Cults is one of the fastest-growing 3D model communities. It also hosts a 3D printer file marketplace where makers can share or sell their designs.

3. CGTrader is a large platform intended for more professional or advanced 3D models, most of which are not directly intended for 3D printing.

4. MyMiniFactory is another great site for downloading 3D models that also has a big community behind the scenes.

5. Printables is another 3D model database created by Prusa Research.

6. Thingiverse is the biggest, easy-to-use site where you can download free 3D models.