It always bothered me how a calibration cube is the standard for stepper motor calibrations — it takes long time to print, uses bunch of filament, and doesn't even calibrate your printer well. Calibration will be more accurate the bigger your test print is, and 20mm is just way too small.
It's a calibration print. It doesn't need to be a neat, symmetrical cube. It just needs to have a 100x100x100mm size and be rigid enough that you can put calipers around it.
With that in mind, I made a model that prints 5-10 times faster than just a regular calibration cube, using minimal amount of materials, while still retaining enough rigidity to not bend under pressure.
On a Ender 3 machine at default speed, your print time should be around:
On the same machine, a 20 x 20 x 20mm Calibration Cube takes about 40~50 minutes.
This was originally uploaded on Thingiverse, and therefore I made this using OpenSCAD so that people could customize the length, nozzle width etc. using the Thingiverse web interface. I don't think Printables.com has something like that, so I'm also including the original OpenSCAD file as well. You can change the values of the model as you wish, provided you have OpenSCAD installed.
(Step 1–4 are optional and will only make the print slightly faster.)
(You can just download .stl files.)
The author hasn't provided the model origin yet.