This design is loosely based on this https://www.thingiverse.com/thing:5824800 but my printer could not print that model at a large enough scale for me to use it, and I didn't like the wall in the middle.

This was designed in TinkerCAD.

I have not yet printed this exact version, but I printed the v2 which had an issue where I forgot to make the bottom flat and even, but this one has addressed that issue.

Updated to v5: makes the bottom completely flat as the previous one still had some extraneous parts that made it not completely flat on the bottom

Updated to V6: Made drain angle steeper and added wedges to corners to ensure all water makes it to the outlet ramp