Update: improved version and now with the correct openSCAD-file! ;)

This is a mount for the 18mm distance sensor probe (e.g. LJC18A3-H-Z/BX).
The ones I found on Thingiverse all placed the probe very far outside the effector which limited the printing-radius.
I found that if you grind down a little of the lower threaded part of the sensor to the diameter of the plastic cap, it fits between the rods of the effector (not the parallel ones!!). This made it possible to get as close to the effector as possible. The mount is attached with the original screws on top of the hotend-assembly. You also don't need the giant 18mm nuts and washers!

After making some changes to the firmware like relative position to nozzle, maximum probe-radius and some others, you can enjoy ABL for low cost.
I will update this later.
I added the openSCAD-file if you want to alter something.

Enjoy.