At FYSEC2017A last week, we heard about a site called sketchfab. Sessions like this are an invitation to get sidetracked, & my friend Terry & I set up an account & went in for a look. There are some truly amazing 3D models there that I think could have real utility in science teaching (& an enormous amount of other material (classical sculpture, anyone?), from complete organisms down to the level of macromolecular structure.
There are some seriously talented people out there! (And many thanks to Andy Todd, who's happy to have his work shared here.)
A #FYSEC2017 if you're a twitterer :)