After calibrating my filaments by printing numerous temperature towers, I wanted a tower to adjust the fan speed and created this tool. 

It provides a stringing test using the peak in the centre of each level, bridging and overhang performance tests and a layer adhesion test using the thin pole on the side of the model.

The following G-code makes the adjustment in SuperSlicer or PrusaSlicer straightforward and can be easily inserted as Before Layer Change G-code.

; Fan Tower with 11 levels at 10mm
M106 S{0 + (25.5 * - int(((1.6 - layer_z) / 10)))}

Hope you will enjoy using it. Uploading makes would be highly appreciated. 

EDIT 2024_05_28

v2 offers a wider overhang part.