marcio-ao

G425 - Perform auto-calibration

calibration Uses a calibration cube, washer or bolt for automatic calibration CALIBRATION_GCODE

Description

This command performs an automatic calibration of backlash, positional errors, and nozzle offset by touching the nozzle on the sides of a bed-mounted, electrically-conductive object (e.g., a cube, washer or bolt).

This command measures backlash but doesn’t enable backlash correction. Use M425 to enable backlash correction.

Notes

Requires CALIBRATION_GCODE and the following parameters:

  • CALIBRATION_MEASUREMENT_RESOLUTION determines the increments taken in mm when performing measurements.
  • CALIBRATION_FEEDRATE_SLOW, CALIBRATION_FEEDRATE_FAST and CALIBRATION_FEEDRATE_TRAVEL determine the speed of motion during the calibration.
  • CALIBRATION_NOZZLE_TIP_HEIGHT and CALIBRATION_NOZZLE_OUTER_DIAMETER refer to the conical part of the nozzle tip.
  • CALIBRATION_REPORTING enables G425 V for reporting of measurements.
  • CALIBRATION_OBJECT_CENTER and CALIBRATION_OBJECT_DIMENSIONS define the true location and dimensions of a cube/bolt/washer mounted on the bed.
  • CALIBRATION_MEASURE_RIGHT, CALIBRATION_MEASURE_FRONT, CALIBRATION_MEASURE_LEFT and CALIBRATION_MEASURE_BACK define the usable touch points. Comment out any sides which are unreachable by the probe. For best results, all four sides should be reachable.
  • CALIBRATION_PIN, CALIBRATION_PIN_INVERTING, CALIBRATION_PIN_PULLDOWN and CALIBRATION_PIN_PULLUP configure the pin used for calibration. For example, if the nozzle is grounded, the calibation cube would be connected to a digital input pin with a pull-up enabled.

Usage

G425 [B] [T < index >] [U < linear >] [V]

Parameters

[B]

Perform calibration of backlash only.

[T < index >]

Perform calibration of one toolhead only.

[U < linear >]

Uncertainty: how far to start probe away from the cube (mm)

[V]

Probe cube and print position, error, backlash and hotend offset. (Requires CALIBRATION_REPORTING)

Examples

Check positional accuracy before calibration (Requires CALIBRATION_REPORTING):

T1                  ; Switch to second nozzle 
G425 V              ; Showing positional report for T1 
T0                  ; Switch to second nozzle 
G425 V              ; Showing positional report for T0 

Perform automatic calibration:

G425                ; Perform full calibration sequence 
M425 F1 S0          ; Enable backlash compensation at 100% 

Check positional accuracy after calibration (Requires CALIBRATION_REPORTING):

T1                  ; Switch to second nozzle 
G425 V              ; Validate by showing report for T1 
T0                  ; Switch to second nozzle 
G425 V              ; Validate by showing report for T0