On Facebook, I ran a poll to see where people download 3D models from. These are the most common sites for downloading 3D models for model railways.
Downloading files from these sites are downloaded for free or for a fee.
When looking for files for model railways these are the best sites to start with.
Sites like yeggi.com and stlfinder.com are search engines for 3D models.
60% of people download from Thingiverse.com
19% of people download from Cults3d.com
6% of people download from CGTrader.com
4% of people download from Thangs.com
2% of people download from Printables.com
2% of people download from TurboSquid.com
6% of people download from other sites not listed.
Remember files shared on these sites are from only people who are willing to share their designs, don’t expect to find everything you require.