This is my first trial to correct the problem of not having automatic leveling. I tried to make it tough, but still not enough for a very precise leveling. It works, but I was dreaming I would be able to keep the calibration even after removing the bed because I had the extra nuts (the thin ones) to lock it...
Another side effect is the shrunk printing area. With the new adaptors I had to setup Cura with 150mm instead of the original 180mm (but I really don't think this printer would be capable of printing something close to 180mm of diameter).
Hint: if your printer is not very precise, scale up the nuts inside Cura (or Slic3r) before generating the g-code. I suggest scaling only X and Y dimensions by 101% (or scale factor 1.01).
How to assemble it
The Nut_counter is the first nut (from bottom to top). If you look at the first photograph, you may see it. It is supposed to lock the big, tough, nut.
1) Attach the Base to your printer (you should center it in relation to each triangle vertice).
2) Add the Nut_counter and put it all the way down to free the way.
3) Add the Nut.
4) Add your printer bed.
5) Add the Nut_small_new.
6) Level the bed using the Nut and the Nut_small_new.
7) Use the Nut_counter to lock the Nut.
8) Print the AnycubicTestRing140 to verify if it's working. I also paused the printer to correct the bed level during the very first layers.
Be careful, depending on your setup for brim/skirt, your printer may hit the bed levelers when printing the AnycubicTestRing140 test file. I've changed my Machine settings to a bed with diameter of 150mm to avoid surprises.
This bed leveler is not a very good solution because it's quite hard to get the leveling right and if you remove the bed plate you will need to redo it. In the future, I will design something better that allows me to attach an extra removable bed plate or, even better, remove the one I have without ruining the leveling.
Here I'm explaining how I did it:
If you liked this thing, don't forget to visit my personal website: ricardodeazambuja.com
DISCLAIMER: use it at your own risk ;)