Required Hardware: 

• a pair of specific hinges such as: https://www.amazon.de/-/en/Rev-Shelf-LD-0220-50SC-Close-Hinges/dp/B018A36II6
• 6mm thick board for the back and bottom of the tray

There are 2 different sizes:

• the small one: 15cm tall / 8cm deep
• the big one: 15cm tall / 12cm deep

FreeCAD file is also attached so that you can adjust to your cabinet/sink/panel sizes.

The mounting system is rather sub-optimal; screwing the second side is really painful and requires some 90° angle-drill adapter or manual screwing… for me this was too late, do not hesitate to remix.

Print settings: white PLA, 0,2mm, infill 20%, no support.

[EDIT 29 Apr. 2024]: After 18 months of daily use the bottom of the big drawer broke. Adding a v2 for the big drawer with more robust bottom and additional brackets.