I have basically taken the design from lrpena (https://www.thingiverse.com/lrpena/about) and flipped it up on its side as I didn't like the Raspberry Pi hanging off of the side of the printer.
Printed on my Flashforge Creator Pro as I was still setting up my Ender 3.
Everything should line up nicely. I think I got a bit heavy handed with my sanding, so that why the end cap looks a little off in the photo.
Feedback always welcome!