Transpositor - a tool that makes song transposition easier.
The tool consists of two concentric Circles of fifths, which can be rotated with respect to each other.

If you want to transpose a song from C to G, for example, simply rotate the outer disc such that C and G are aligned and all other pitches become aligned appropriately as well.

See a demo gif here.

The transpositor comes in two notation variants: Western (aka Dutch) and German.

The thing is about 10cm in diameter.

It is printed in two parts: Inner and outer. The outer disc is then pressed and 'clicked' into the inner. Print precision and printer setup needs to be relatively good in order for the outer disc to fit and rotate well. If the outer disc fits but tends to jam, consider giving it a bit of sandpaper on the inside.

I used colorprint (M600 manual filament exchange) to print the letters with different color.

When rendering from the OpenSCAD source file, you need the same font that I used installed: DejaVu Math TeX Gyre
If this font is not installed, the pitch labels are unlikely to render correctly.

Prusa

i3 MK3

No

No

0.10

The outer ring might need a bit of sanding on the inner edge to rotate without jamming. The way the outer ring fits and 'clicks' onto the inner base is quite dependant on the 3D printer and material used.rn