Simple knobs that are easy to print.
Just print the body of the knob, the small central cap and add a bolt and you're done.
I thought of making colored caps to make the size easily identifiable and at the same time improve its aesthetic appearance.
I used bolts with a length of 20mm and I obtained a useful threaded part of 13mm, if you need a longer thread use suitable bolts.
If you need the exact dimensions, please refer to the table included in the assembly sheet.