KlackEnder-Probe for Ender 2

It was very difficult to squish a KlackEnder probe in to my Ender-2 but it turned out really good in the end. I have been using this for almost two years know and it helps a lot. I doubt that anybody else will make this for an old printer so I will not put so much effort in the description.

It should be possible to modify this to fit Ender 3 or any other Ender that uses the same x-plate.

I typically get the following accuracy:
M48 V4 X50 Y50: Range 0.003 and SD 0.001000 or less
M48 L8 V4 X50 Y50: Range 0.005 and SD 0.001250 or less

Kevinakasam instruction for the original KlackEnder is extremely well made and most of it applies to this version as well:
https://github.com/kevinakasam/KlackEnder-Probe?tab=readme-ov-file

Here are some pos and cons compare to the original:
++ Fits Ender 2
++ Probe offset 0, 15 (or 0, 0**) instead of 4, 21 (15mm instead of 21.4mm from nozzle)
++ Easier to connect wires to magnets
++ “Probe dock” removed, no longer needed
++ No damage to the X-plate because of Probe mount screw.
-- Probe is always attached/removed when homing
-- PROBE_OFFSET_WIZARD do not work because of Marlin bugg (?). Use a multimeter instead.
https://github.com/MarlinFirmware/Marlin/issues/25550
https://github.com/MarlinFirmware/Marlin/issues/25222

** Zero Probe for full bed meshing. It’s not quite as accurate as the standard version.

BOM - Parts you need:
Better motherboard than original (I use BTT E3 SKR MINI v3.0 + BTT TFT35-E3 V3.0)
https://www.thingiverse.com/thing:6793509
Marlin (I haven’t tested Klipper).

Probe:
1x OMRON D2F-F or similar switch (2x if you also use the full bed probe)
2x Magnet 3x3mm
2x M2x12mm screw (or glue)

Probe Retainer:
3x 1.4x25mm nails or similar
2x M4x8mm screw
2x M4 t-nut
2x M4 washer

Probe mount:
2x Magnet 3x3mm
1x M3x8mm screw

Small cable tie and some cable (you may also need a connector to connect the probe to the mainboard e.g JST XH)

Firmware:
I use Marlin 2.1.2.4 (with no bugg fixes) from Ender 3 and E3 SKR MINI v3.0.
Included config files may not work for you. Search for “–MEABL-“ in files for ABL changes.
I use the following since I don’t want to probe at the screws holding the bed (164x164 BED_SIZE)
MESH_INSET 4 and GRID_MAX_POINTS_X 7 that’s takes 3min 20sec (grid 7x7 points) or
MESH_INSET 4 and GRID_MAX_POINTS_X 14 that’s takes 9min 30sec (grid 14x14 points)