These shims were design to go under the original feet from my Creality Ender 5 to level the printer on an otherwise uneven surface. With the Customizer this should be useful to level many other devices with round feet.
The parametric OpenSCAD design allows for any custom height and changes to all other critical dimensions. Shims from 1 to 10 mm have been uploaded for convenience as STL files.
The back story starts with trying to diagnose a rather elusive problem with my printer. I was reminded of a comment from a senior millwright that I worked with that went something like this: "You know how the first you to do solve any computer problem is to restart the machine? For any mechanical equipment problem the first thing you should do is level the base and square the joints. It can fix many things that are otherwise almost impossible to find."
When printing I suggest slicing with 3-walls and concentric infill to increase the bearing strength.