Online 3D model repositories

These websites host collections of 3D models that other users have uploaded. There are dozens of these sites, some with free models and some with models you pay to download. In the following subsections, we will discuss what to expect from the three most popular sites.

Thingiverse

Thingiverse (http://www.thingiverse.com/), owned by 3D printer manufacturer Makerbot, is by far the most popular 3D printing model site. Most models are free, but even on free models the uploader may choose to set restrictions on usage, for example, not for commercial use.

Most of the models are in .stl format, ready to download and print. Models can be uploaded in nearly any format, including .skp.

3D Warehouse

The 3D Warehouse (http://3dwarehouse.sketchup.com) is SketchUp's very own repository of models. It's astonishingly extensive—everything from Star Wars X-Wing models and people in various uniforms and poses, to architectural models and useful household objects, and nearly everything...