flexi-bot/docs/marlin/_gcode/M425.md

tag	title	brief	author	experimental	requires	group	codes	notes	parameters	examples
m0425	Backlash compensation	Enable and tune backlash compensation	marcio-ao	true	BACKLASH_COMPENSATION,BACKLASH_GCODE	calibration	M425	Requires `BACKLASH_COMPENSATION`, `BACKLASH_GCODE` and the following parameters: - `BACKLASH_DISTANCE_MM` specifies the default backlash on the X, Y and Z axis. - `BACKLASH_CORRECTION` specifies the default backlash correction (0.0 = none; 1.0 = 100%). - `BACKLASH_SMOOTHING_MM` enables backlash smoothing over a specified distance. - `BACKLASH_GCODE` enables [`M425`](/docs/gcode/M425.html) for run-time tuning of backlash. - `MEASURE_BACKLASH_WHEN_PROBING` turns on Z backlash measurement when probing with [`G29`](/docs/gcode/G029.html). - Use `BACKLASH_MEASUREMENT_LIMIT`, `BACKLASH_MEASUREMENT_RESOLUTION` and `BACKLASH_MEASUREMENT_FEEDRATE` to configure [`G29`](/docs/gcode/G029.html) backlash measurement.	tag optional description values F true Enable or disables backlash correction, or sets an intermediate fade-out (0.0 = none; 1.0 = 100%) tag type value float tag optional description values S true Distance over which backlash correction is spread tag type linear float tag optional description values X true Set the backlash distance on X (mm; 0 to disable) tag type linear float tag optional description values Y true Set the backlash distance on Y (mm; 0 to disable) tag type linear float tag optional description values Z true Set the backlash distance on Z (mm; 0 to disable) tag type linear float tag optional description Z true When `MEASURE_BACKLASH_WHEN_PROBING` is enabled, loads the measured backlash into the backlash distance parameter	pre code Manually configure backlash compensation: M425 X0.1 Y0.2 Z0.3 ; Set backlash to specific values for all axis M425 F1 ; Enable backlash compensation at 100% pre code Use smoothing for best print surface quality: M425 F1 S3 pre code Use no smoothing for best dimensional accuracy: M425 F1 S0 pre code post Automatically measure X, Y, and Z backlash using [`G425`](/docs/gcode/G425.html): G425 ; Perform a full calibration M425 F1 ; Use full measured value of backlash on X, Y and Z G425 automatically loads the measured backlash into the backlash distance, but will not enable backlash compensation. pre code post To automatically measure Z backlash when probing with `MEASURE_BACKLASH_WHEN_PROBING`: G29 ; Perform probe and measure backlash on Z M425 F1 Z ; Use full measured value of backlash on Z `MEASURE_BACKLASH_WHEN_PROBING` measures backlash, but does not update the configured backlash distance. The measured value should be activated by using the `Z` argument without a value. This differs from the behavior of [`G425`](/docs/gcode/G425.html). pre code Report the current backlash configuration: M425

Backlash compensation will add extra steps to one or more segments whenever a motor reverses direction.

By default, steps are added to the first segment after a direction change. This gives the best dimensional accuracy but may cause marks to appear in the print. Smoothing spreads the added steps over multiple consecutive segments to prevent blemishes in the print, at the expense of dimensional accuracy.

Backlash compensation can be configured at either compile-time or run-time. Enable BACKLASH_GCODE to turn on M425 and a "Backlash" menu item.

Backlash can be measured automatically on all axes with G425 or on Z only with G29 when MEASURE_BACKLASH_WHEN_PROBING is enabled.