This is the prototype printed version of the mechanical load frame I am building. It has been provided as a single assembly just so you can view the model.
There is not a set of printable parts because I cannot yet recommend that anyone else build it as shown. I need to figure out how to better adhere steel to abs and how to add the steel plates without doing so much preparation work.

The technique of gluing the metal sheets to printed parts is called composite sandwich. You can read more about this specific design and my plan for mechanically testing 3d printed specimens here:

http://engineerdog.com/2015/03/26/3d-printing-materials-testing-series-part-1-the-problem-the-plan-and-the-prototype/

EDIT: The final version of this machine can be found here:
http://www.instructables.com/id/TestrBot-The-300-Universal-Test-Machine/

More parts to come when I get the chance to adjust the model to fit a new actuator design and reevaluate methods of strengthening the printed beams.
It took way too much time to cut out the steel sheets, there's got to be a better off-the-shelf solution.