I’m sure this is obvious to those that know, but I can’t think how to draw this. I’m crating a knob for an old radio. Around the edge it is knurled, and I can’t work out how to do this. Clearly, you start out with a circle, but what then. I don’t want to individually draw every indentation manually.
If I’ve done this correctly, here is a picture of the original knob.
Thank you for any suggestions on how to do this.