Ender 3 ( or any 40 x 40 extrusion) cable chain mount adapter.

thingiverse

This is a bit niche, but thought I'd upload it anyway. It's an add-on for the excellent Ender 3 cable chain system (https://www.thingiverse.com/thing:2920060) by johnniewhiskey Having printed off a rear mounted electronics case (https://www.thingiverse.com/thing:3688967) by TeachingTech, the cable chain mount for the bed had nowhere to attach. This thing allows you to use the original mount that slides into the slots on the 40 x 40 extrusion - it bolts to the back of said extrusion and the original mount just slides on. You'll need to tap two M5 threads in the extrusion though. Easy enough with a tap (obvs) or if you happen to have a sturdy M5 cap head, that'll work too, just don't get it jammed in there ;) You'll also need a couple of M5 bolts, about 6-10mm long. Shorter the better if you haven't tapped the holes very deep.