From 29a494aa9e8f1c1458d587d8331adee6e8d44a5b Mon Sep 17 00:00:00 2001 From: Timofey Titovets Date: Sun, 1 Feb 2026 17:00:07 +0100 Subject: [PATCH] docs: eddy homing correction macro Signed-off-by: Timofey Titovets --- docs/Eddy_Probe.md | 34 ++++++++++++++++++++++++++++++++-- 1 file changed, 32 insertions(+), 2 deletions(-) diff --git a/docs/Eddy_Probe.md b/docs/Eddy_Probe.md index 812df992e..8b229545e 100644 --- a/docs/Eddy_Probe.md +++ b/docs/Eddy_Probe.md @@ -4,8 +4,10 @@ This document describes how to use an [eddy current](https://en.wikipedia.org/wiki/Eddy_current) inductive probe in Klipper. -Currently, an eddy current probe can not be used for Z homing. The -sensor can only be used for Z probing. +Currently, an eddy current probe can not precisely home Z (i.e., `G28 Z`). +The sensor can precisely do Z probing (i.e., `PROBE ...`). +Look at the [homing correction](Eddy_Probe.md#homing-correction-macros) +for further details. Start by declaring a [probe_eddy_current config section](Config_Reference.md#probe_eddy_current) @@ -66,6 +68,34 @@ surface temperature or sensor hardware temperature can skew the results. It is important that calibration and probing is only done when the printer is at a stable temperature. +## Homing correction macros + +Because of current limitations, homing and probing +are implemented differently for the eddy sensors. +As a result, homing suffers from an offset error, +while probing handles this correctly. + +To correct the homing offset. +One can use the suggested macro inside the homing override or +inside the starting G-Code. + +[Force move](Config_Reference.md#force_move) section +have to be defined in the config. + +``` +[gcode_macro _RELOAD_Z_OFFSET_FROM_PROBE] +gcode: + {% set Z = printer.toolhead.position.z %} + SET_KINEMATIC_POSITION Z={Z - printer.probe.last_probe_position.z} + +[gcode_macro SET_Z_FROM_PROBE] +gcode: + {% set METHOD = params.METHOD | default("automatic") %} + PROBE METHOD={METHOD} + _RELOAD_Z_OFFSET_FROM_PROBE + G0 Z5 +``` + ## Tap calibration The Eddy probe measures the resonance frequency of the coil.