I remixed the Fan & Sensor Holder by Leo_N, which I found had a fan tray that was too narrow and put too much pressure on the fan housing - and which was also too small to hold a Noctua 40mm fan. I also shortened the edges of the fan supports, which were too tall in my opinion. Just like Leo_N's original design, this is meant to work without the heatsink on your printer, so remove that and then use two M3x25 screws to put this in place. This bracket will hold an 18mm sensor perfectly, I recommend the LJ18A3-8-Z/BX which functions well with the 5V the Anet A8 board natively supplies (no need for a voltage booster).
Now the bracket holds a Noctua 40mm fan, with the rubber vibration dampers in place, and holds your auto-bed leveling sensor!
PRINT IN ABS OR PETG! Any softer of a material and it will warp over time. See notes in Leo_N's original design.
SUPPORTS: Print with "touching build plate" supports turned on only, not the "everywhere" option.
Print in PETG or ABS. PLA will allow warping over time.