Might have to rotate to make it fit. Will need supports if you want the overhang around the edge.

STL file in IMPERIAL units!!!

I have included a basic "footprint" of the opening so you can add whatever you would want.

I am also including the custom one I am making for myself. It is for holding a Spotify car thing and a radio shack HTX-202 ham radio. I'm assuming I may be the only one in the world needing both of these, but if you can make use of both, then here you go!

I would be happy to help you modify this to what you may need. If you have dimensions, comment and let me know.

Creality

Ender 3

Yes

Fast print settings seem to work fine. Infill over 20% is pointless. I used regular amazon PLA so I'm sure almost anything will work fine!