Print Strength Test Rig

thingiverse

This is a compact rig I created to evaluate filaments for usability in printing enclosures. It's used to determine how difficult it is to break the print along its layers. Print the bar vertically with 100 percent infill and not just perimeters but at least one line of diagonal infill for increased rigidity. Use a brim of ten lines or so. This should take only around ten minutes to print. Then insert it into the rig as shown in the first photo, tightening it slightly with the screw. Measure with a caliper how far the screw head sticks out from the frame; this should be about 22.5 mm. Slowly tighten the screw until the bar breaks, holding the screw in place and measuring again. The difference is the result. The higher the number, the sturdier the layer adhesion is. Best results so far, with non-flexible filament: all the way in (22.5 mm) and not broken, just cracked: PETG at 240 degrees Celsius nozzle temperature. See second photo. At wrong temperatures / cooling settings it breaks as early as three mm in. Last photo: PP filament, can be bent back without leaving any traces of stress. Edit January 22, 2019: If you had problems with the screw not fitting, please download all files again. Edit January 23, 2019: There's a new enhanced version two available here: https://www.thingiverse.com/thing:3376700 Uses nut and bolt from here: https://www.thingiverse.com/thing:193647