Rotary encoder knob. 

30mm x 30mm x 16.3mm
For 6mm rotary encoder
Very easy and fun to print. You can print in one color or, like I did, use two, as shown in the attached photos.
Supports disabled. They are not necessary, I printed without them.

Choose your favorite textured plate, like I did.

Besides the black color, I used silk filaments. They look great in my opinion.

 

0.16mm first layer
0.12mm all other layers
File painted with Fuzzy Skin, do not change anything.

 

Bonus file, on the second plate, with a small recess, looks best in a solid color, but here you can test it yourself.