I am writing a blog series about designing a partially 3d printed test machine and using it to analyze the mechanical properties of 3D printed materials. You can read about the project at the link at the bottom, any feedback or fresh ideas will be welcome! . The rectangle is a test specimen specifically designed for a 4 point bend loading on my machine. The part 'should' require 200 lbs to break when printed at 100% infill. . The test fixture design is also included here to reduce the size of later bom's. The fixture is designed so that the load path is 100% steel-to-steel rather than through any plastic, which keeps the frame stiff. . http://engineerdog.com/2015/03/24/introduction-to-3d-printing-materials-testing-series/Specimen Dimensions: 5.25" x .5" x .375" To be printed with various infills for the purpose of mechanical testing. *Four Point bend fixture parts list: (All parts are available at common big box hardware stores!) (4)- socket head cap screws (2)- 7" long slotted hole channel (13/16" × 1 5/8") (4)- standard strut channel nuts (4)- 1/2" NOT x 3" long pipe nipples (8)- rubber bands