This is an ABL mount I made for the Ender 3. My Ender has a bent / twisted Y extrusion. The X extrusion might also not be straight. As a result, my BLTouch was totally useless, no matter how "level" I made my bed, I would get extremely rough first layers.
It took a long time and a lot of effort to root-cause this. But then I ran into this which claimed to fix this for an Ender 3 S1 with Sprite Extruder that has a bent Y axis.
I was suprised to see that this fix didn't exist for original Ender 3's. This design is loosely based on this Ender 3 MAX CR Touch mount, but I did design this from scratch which is why this isn't a remix. Not that this is a very good design and it's probably very specific to my setup but it works for me!
This is only guaranteed to work with BLTouch. Not tested with CRTouch or 3DTouch or anything else.
This design has some extra spacing to work with dual 5015 blowers using a Minimus Shroud
The original X endstop will either not work or lose you a significant amount of bed space on the x axis. I used this X endstop mount, which (with the original endstop and with the screws on the actual switch removed) just fits behind the ABL mount and triggers off of the X carriage
Offsets are: -53X 0Y
_Note: Ender 3 has built in standoffs for the hot end to bolt on to. I had a tough time finding a consistent value for their length online so I measured mine to be 4.5mm and designed this around that. Online I saw 5mm, 4.5mm, 3.5mm. If you're using some 3rd party X carriage or Creality revisioned them at some point, your mileage may vary a tiny bit. I printed an older revision of this mount which was realistically more like +1mm offset on Y and it still worked great but going from 1mm to 0mm offset worked better. _