A simple knob for a rotary encoder.

I suggest 0.1 layer height and put a modifier on the first layer to make it walls only so that the infill doesn't ruin the looks of it. 

I also suggest using scarf joint seam around the entire wall without wiping. 

And outer/inner wall printing order.

Fit is a little tight so I uploaded a version with 0.2mm extra for the inner hole.