Designing an enclosure for my Ender 3 and wanted to move the electronics box completely out of the enclosure to make it accessible and reduce the amount of heat the electronics were exposed to.
TeachingTech did an amazing job with their design so no need to reinvent the wheel. Remix kept most of the mounting holes (minus the buck connector and relay for the Raspberry Pi side since I don't need the holes). Other side is for the standard Ender 3 board with mounting holes for the smoothers.
Made a few dimensional changes to increase the height of the box to 50mm since it is not constrained by the Ender 3 frame, and closed off part of the back. Additionally modified the tops to not require the frame to stay in place. Added mounting brackets on the sides of each box to screw in place to the enclosure. recommend you raise it off the surface to provide enough clearance for the fan to push the hot air out.
Original files found here