This is V2 of a small rig I designed to test filaments for usability to print enclosures.

The harder it is to break the print along the layers, the closer you are to the optimal temperature and cooling for the filament. So it's a temperature calibration test after all.

Print the bar vertically with 100 % infill and not only perimeters but at least one line of diagonal infill for more rigidity. Use a brim of 10 lines or so. Should take only around 10 minutes to print.

Then insert it into the rig as shown in the photo, slightly fastening it with the screw. Measure with a caliper how far the screw head sticks out from the frame, should be about 25 mm.

Slowly tighten the screw until the bar breaks and measure again.

The difference is the result. The higher the number, the sturdier the layer adhesion is.

Vary the temperature and cooling settings to optimize.

Best result so far, with non-flexible filament: all the way in and not broken, just cracked: PETG at 240 °C nozzle temperature. See second photo (older version of this rig).

At the wrong temperatures / cooling settings it breaks as early as 3 mm in.

PS: Thanks go out to Uwe for the screw and nut that fit a lot better than on the first version.