For those with arthritis, lamps that come with tiny knurled switches that must be pressed down and then turned are just painful to use. This easy to print knob has matching knurls to press-fit over a ~5.5mm diameter lamp rotary switch. The size and shape of the knob makes it much easier to press the switch down and turn it smoothly.

Print upside down and no supports are needed. If your lamp rotary switch is a little larger or smaller, scaling the model ought to be enough. The knurled recess is meant to be not as deep as the switch is tall, because there needs to be room to press the switch down (see the picture).

This is a remix of thehans Smooth n' Curvy Star Knob (https://www.thingiverse.com/thing:1562501). All I did was to add the knurls.