This thing was inspired by Thomas Sanladerer's excellent (and fun!) video on the strength of various materials. While it is true you can build anything with a 3D printer, you need to understand the material properties if you're going to print parts as structural members. This part is used to determine tensile (and potentially compression) strength of a 3D printed material. Print this thing in the material of your choice and then put a drill bit or hex wrench (as shown in the photos) through one end (to hang it from a vice). You can use the hole in the other end to attach weights and to apply force. The cross section is nominally 10 x 10mm (or 100mm^2) in imperial units that is .155 sq inch. You can divide the force applied in pounds by .155 and get PSI or pounds per square inch. The measurement wil be "nominal" as most 3D printers aren't that accurate. In my case one side was 9.93mm and the other 10.15mm making the area nominally .158 square inchs, roughly 2% bigger than spec. If you're trying to be really accurate you can use a caliper to measure to get exact numbers to work from. The thing prints one vertical and one horizontal. It does this because the slicer lays now plastic which, from a tensile strength point of view, favors horizontal (long runs) prints rather than layers. In Testing keep the two identified (when not printing with a raft the 'smooth' side will tell you.) so that you can get both the 'vertical' printed tensile strength and the 'horizontal' printed tensile strength. Finally, infill has a big impact here, high infill will put more plastic in the cross section, lower infill will do the opposite. At the end of the day it is the total cross sectional area of plastic, and its homogeneity that determines how 'strong' the piece will be in tension (and how crushable in compression).