Kitchen Aid Lock/Speed Knob

thingiverse

When a mixer gets dropped and a knob breaks, you look at it and exclaim, "That's basically a scaled sphere, three cylinders, and two cubes in OpenSCAD." The hole is slightly undersized on purpose. It's meant to be heated with a lighter or small torch just hot enough to allow you to press fit the knob onto the stem for maximum grip. A stock picture of a green knob was used from the web to illustrate the original design, while the white one shows the repaired version.