I designed this adapter to add lock nuts to the Creality metal leveling nuts. I've tried, and remixed, other bed leveling solutions and this one remains level the longest (I miss the clicks from the Ultimate Ender 3 Bed Leveling Knob though).
The Creality knob has 6 spokes with a maximum with of 2.75mm and requires a M4 lock nut with a face width of 7mm. The Fusion 360 source file is include and all dimensions/values are all parameterized so you should be able to easily adapt this design to your specific knob.
The STL should be printed nut side down and does not require any support. I printed at 0.20mm layer height for a clean print.
The bed leveling screws on my Ender 3 V2 were loose in the bed plate so I also had to add nuts between the bed and the spring otherwise the screw would just spin. The extra nut caused the springs to bottom out with the stock bolt. This additional hardware will be required if you are in the same situation:
The author marked this model as their own original creation.