The NASA 3D Resources website has posted hundreds of 3D models, images, textures and visualizations that you can download for free. As far as models, they've got everything from astronaut gloves and spacesuits to satellites and spacecraft:
There's also a Printable section where you can download .stl files for 3D printing (though some of them are fresh conversions that may require tweaking). In that section we found the Cassini probe, the Curiosity Rover, the Hubble Space Telescope, and even the first object designed on Earth, and e-mailed to space for manufacture: A wrench that was 3D printed on the ISS.
"The Multi-Purpose Precision Maintenance Tool has a number of important tools which allow an astronaut to complete tasks with comfort and ease. The different sized drives at the top allows the user to attach sockets. In the center are wrenches of varying sizes, allowing fewer wrenches to be carried to the job site. On the left is a precision measuring tool along with wire gauges and a single edged wire stripper. In the center is an outline for Velcro to be applied allowing an easy storage around the station. A circular hole in the bottom center allows for a clip to be used as well. On the right, and ergonomic grip is built into the tool with ridges for better grasp, lastly a pry bar is built into the ergonomic grip for ease of access."