Made this bracket to offset display on my Ender3 (will work on any 20x20 extrusion), as the bullseye fanduct kept bumping against it when using the entire width of the print bed. Also, gave me the opportunity to recess the display towards the back some.
Nothing hugely difficult on this one, print using at least 3 perimeters and >30% infill, just to ensure it's sturdy enough. the M5 nuts are a tight fit on purpose, so use a small hammer to tap them in; I used nylon locknut just to be sure nothing would come loose. On the extrusion, use the typical t-nut and M5 screws and you're good to go.