*Update* I have four beautilfl new knobs (FREE) and they look great, Thank you Elecraft.
What all the fuss is about. Some versions of the K3 Elecraft radio were shipped with some vendor supplied knobs that were defective. Here is an example. Note the small cracks originating at the set screw. Note the pyramid crack on the end and the less obvious crack on the right side of the set screw.
It works fine. I have requested replacement as Elecrafters is well aware of the issue and in my view has done an excellent job of finding and replacing the product.