K-Touch Auto bed leveling

thingiverse

# Summary An Auto-bed leveling sensor made from a 12mm tactile switch and a 12v linear solenoid, it can be mounted instead of a BL-Touch directly , is compact, cheaper, and even more accurate ( Standard Deviation 0.0024 mm ) . https://youtu.be/XFoX_xrcobI ### Parts used : **JF-0826B DC 12V 2A Pull Type Linear Solenoid 12 mm Tactile switch Tip31c transistor ( you have to install heatsink ) 500 Ohm resistor 330 Ohm resistor #### Note: you will have to heat the M3 nut in button holder for it to be a perfect fit. # Software: **Edit configuration.h Make sure your head drives into the middle and up before homing Z-axis **#define Z_SAFE_HOMING** Disable MIN_SOFTWARE_ENDSTOPS so that you can adjust Nozzle/Probe Distance easily. However, once configured make sure you re-enable them to give you extra safety if you want. **#define MIN_SOFTWARE_ENDSTOPS** In our case we simply use the zMin Endstop Header that was used by the mechanical endstop **#define Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN** For the optical endstop sensor no pullup is needed, just for X and Y if you use mechanical endstops there: Disable **//#define ENDSTOPPULLUPS**** **Enable **#define ENDSTOPPULLUP_XMIN** and **#define ENDSTOPPULLUP_YMIN** **#define Z_MIN_ENDSTOP_INVERTING false**** #define Z_MIN_PROBE_ENDSTOP_INVERTING false** Tell Marlin you have a solenoid attached **// A probe that is deployed and stowed with a solenoid pin (SOL1_PIN)** **#define SOLENOID_PROBE** **#define SOL1_PIN 11 // this is the solenoid signal** Choose your leveling method, **#define AUTO_BED_LEVELING_BILINEAR** . Enable auto leveling, choose your leveling. Maybe start with Bilinear and if everything works check out UBLMesh Validation, **#define G26_MESH_VALIDATION**, enable to give you a good check if your leveling works!use M48 to check the accuracy of your probe, really handy to check the quality of your assembly. **#define Z_MIN_PROBE_REPEATABILITY_TEST** make sure the printhead is raised before homing **#define Z_HOMING_HEIGHT 5**ZProbe Offset to Nozzle (check the great documentation in marlin code): **#define X_PROBE_OFFSET_FROM_EXTRUDER -10 // X offset: -left +right [of the nozzle]**** #define Y_PROBE_OFFSET_FROM_EXTRUDER 30 // Y offset: -front +behind [the nozzle] #define Z_PROBE_OFFSET_FROM_EXTRUDER 0 // Z offset: -below +above [the nozzle] **For Z_PROBE_OFFSET_FROM_EXTRUDER start with **0**!!! Until you find out your exact distance. Otherwise you might ram your nozzle into your bed!!!For Z-Probe Clearance set those values for a start: **#define Z_CLEARANCE_DEPLOY_PROBE 7 // Z Clearance for Deploy/Stow #define Z_CLEARANCE_BETWEEN_PROBES 5 // Z Clearance between probe points **Additionally:** ** // Travel limits (mm) after homing, check this to make sure your head stays in range. E.g. if your endstop position of your head is in the lower left but the print area starts 20mm to the right and 20mm up than you need to set this: ** **#define X_MIN_POS -20 ** **#define Y_MIN_POS -20** **#define Z_MIN_POS 0** **Enable EEPROM settings** #define EEPROM_SETTINGS // Enable for M500 and M501 commands. ### ## Calibrate Z offset: **Refer to these videos both work well choose your preferred method** https://youtu.be/fN_ndWvXGBQ https://youtu.be/y_1Kg45APko **Enjoy not having to level your bed forever :)** **If you made this project please let us know :)**