Auto Bed Leveling, adding to existing working printer

HI

my printer was working as normal with Z-endstop switch. I would like to add auto-bed leveling to this, for that i purchased PNP inductive sensor, which is connected to RAMPS1.5 with resistor voltage drop circuit,

i measured the voltage using a multimeter when it triggered, the voltage goes to zero and in normal conditions, 4.8 volts

Here is my major changes in firmware,

#define Z_MIN_PROBE_USES_Z_MIN_ENDSTOP_PIN
#define FIX_MOUNTED_PROBE

#define Z_CLEARANCE_DEPLOY_PROBE   2 // Z Clearance for Deploy/Stow
#define Z_CLEARANCE_BETWEEN_PROBES  2 // Z Clearance between probe points

#define AUTO_BED_LEVELING_BILINEAR

  #define LEFT_PROBE_BED_POSITION 20
  #define RIGHT_PROBE_BED_POSITION 160
  #define FRONT_PROBE_BED_POSITION 20
  #define BACK_PROBE_BED_POSITION 195

#define Z_SAFE_HOMING

G29 is working and probing on 9 points within the boundaries which i mentioned. The issue is i added G29 into my slicer and when i start printing, it's not on bed level. lets say 2mm above the bed(air print). this 2mm is the clearance changed in the firmware(before it was 10)

how to configure auto bed leveling properly?

Also, i need a recommendation for the Best auto-leveling sensor,: Inductive sensor, Bltouch or IR based

auto bed leveling is kind of working,

But when I start printing, it's not in the level of bed, While G1 F60 Z0 is torching(approx) the bed, but when i start print, it is calculated based on first layer height and z offset i think.

please help me

34 views, no response

You can find a comparison of different types of Z probe at [duet3d.dozuki.com].

btw what you are talking about is auto bed compensation, not auto bed levelling. Sadly bed compensation is frequently called bed levelling. Auto bed levelling does what it says: it makes the bed level automatically, for example by probing the bed to find out how much it is off-level, then adjusting multiple leadscrews independently to make it level (or to make the gantry level with the bed). Whereas auto bed compensation means probing the bed to determine how much off-level and/or not flat it is, then adjusting the Z height during printing depending on the XY position of the nozzle.

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Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].