KEYTouch ABL©

thingiverse

Hello 3D printing community! Here's my approach to implementing Auto Bed Leveling (ABL) on an Ender3. You'll need a NC microswitch and an Allen-Key, so no fancy or expensive gadgets are required. The accuracy is excellent - I've achieved a range of 0.012 on M48 with a standard deviation of 0.003. The idea came from Marlin's code, where the Allen-key was used in delta printers. Here's what I did: I connected a new micro-switch in series with the Z end-switch to work as a new input, eliminating the need for PIN27 or PIN29. No extra device is required to match the voltage or polarity. Here's a Fritzing drawing of the wiring connections. The wire should be connected to the pins that have continuity when the switch is not pressed - this is called NC or normally closed! You'll need to insert something between, so you can either cut the wire and connect it there or remove a pin from the plug. I recommend using a cable tie to secure it. Now, let's move on to the software: In slicer, after G28;, add a new line for ABL to work: G29; ABL VERY Important! Don't forget to park the key before starting the print! If you forget, it's not my fault - I've forgotten several times at the beginning. We move in front: G0 X150 Y0 Z40 F10000; MOVE IN FRONT Also, add some noise! M300 P200; G4 P400; M300 P200; G4 P400; M300 P200; G4 P400; M300 P200; G4 P400; Now we need a stop to have time to remove the key: M0 RETRACT KEY PROBE; PAUSE TO REMOVE KEY Also, move back to start point: G1 X0 Y0 Z30 F5000.0 ;Move to start position From here, everything remains as you have it set up in the slicer. If you want to modify less in slicer, you can add it in Marlin: #define Z_PROBE_END_SCRIPT And there, you can add what you want the machine to do. I hope you like my tutorial or at least the explanation. Happy 3D Printing with your newly made KEYTouch ABL! As recommended, here's the modification for Marlin 2.0: FYI, I was setting up this great addon following the tutorial on thingiverse. Using Marlin Bugfix 2.0.x, I found out that those three lines have been replaced by: #define NOZZLE_TO_PROBE_OFFSET { -45, -3, -10.93 } where the three numbers are X, Y, Z The Arduino IDE will tell you the errors and corrections, so it's not difficult to debug. Thanks @Jester_ITA! https://youtu.be/xnBpRn5ex0Q