For the 2WD robot kit "2WD Smart Robot Car Chassis Kit DIY" I needed a holder for the IR opto coupler speed sensor (MH-sensor compatible type).
This is the second version, which fits better onto the acrylic frame with one screw (per side).

Caution: as the parts are all "compatible" ones, you need to check, if it fits for your needs.

Creality

Ender 3

Doesn't Matter

No

0,2

20%

Glass plate needs to be heated to 50°C

Sketchup is free and easy to learn, but you need to be careful to get sollid structures.