MarlinFirmware · 12oclocker · Sep 3, 2025 · Sep 3, 2025 · Sep 3, 2025 · Sep 3, 2025
diff --git a/Marlin/Configuration.h b/Marlin/Configuration.h
@@ -1415,6 +1415,15 @@
 // Force the use of the probe for Z-axis homing
 //#define USE_PROBE_FOR_Z_HOMING
 
+/**
+ * For machines with Z endstop(s) and a reliable Z probe this option will
+ * cause Z to home first using Z endstop and then re-home with the probe
+ * to establish a more ideal Z0 position for probing the bed. This can be
+ * useful when Z must home to MAX but you want to establish a better Z0
+ * based on bed height. Requires a  probe and calibrated probe Z offset.
+ */
+//#define REHOME_Z_WITH_PROBE
+
 /**
  * Z_MIN_PROBE_PIN
  *

diff --git a/Marlin/src/feature/powerloss.cpp b/Marlin/src/feature/powerloss.cpp
@@ -62,7 +62,7 @@ uint32_t PrintJobRecovery::cmd_sdpos, // = 0
 #include "../module/printcounter.h"
 #include "../module/temperature.h"
 
-#if HOMING_Z_WITH_PROBE
+#if Z_CAN_HOME_WITH_PROBE
   #include "../module/probe.h"
 #endif
 
@@ -470,7 +470,7 @@ void PrintJobRecovery::resume() {
 
   #if HOMING_Z_DOWN
     // Move to a safe XY position and home Z while avoiding the print.
-    const xy_pos_t p = xy_pos_t(POWER_LOSS_ZHOME_POS) TERN_(HOMING_Z_WITH_PROBE, - probe.offset_xy);
+    const xy_pos_t p = xy_pos_t(POWER_LOSS_ZHOME_POS) TERN_(Z_CAN_HOME_WITH_PROBE, - probe.offset_xy);
     PROCESS_SUBCOMMANDS_NOW(TS(F("G1F1000X"), p_float_t(p.x, 3), 'Y', p_float_t(p.y, 3), F("\nG28HZ")));
   #endif
 

diff --git a/Marlin/src/gcode/calibrate/G28.cpp b/Marlin/src/gcode/calibrate/G28.cpp
@@ -147,7 +147,7 @@
     constexpr xy_float_t safe_homing_xy = { Z_SAFE_HOMING_X_POINT, Z_SAFE_HOMING_Y_POINT };
     destination.set(safe_homing_xy, current_position.z);
 
-    TERN_(HOMING_Z_WITH_PROBE, destination -= probe.offset_xy);
+    TERN_(Z_CAN_HOME_WITH_PROBE, destination -= probe.offset_xy);
 
     if (position_is_reachable(destination)) {
 
@@ -384,7 +384,7 @@ void GcodeSuite::G28() {
           if (DEBUGGING(LEVELING)) DEBUG_ECHOLNPGM("R0 = No Z raise");
         }
         else {
-          bool with_probe = ENABLED(HOMING_Z_WITH_PROBE);
+          bool with_probe = ENABLED(Z_CAN_HOME_WITH_PROBE);
           // Raise above the current Z (which should be synced in the planner)
           // The "height" for Z is a coordinate. But if Z is not trusted/homed make it relative.
           if (seenR || !(z_min_trusted || axis_should_home(Z_AXIS))) {
@@ -473,7 +473,9 @@ void GcodeSuite::G28() {
               stepper.set_separate_multi_axis(false);
             #endif
 
-            #if ENABLED(Z_SAFE_HOMING)
+            // Use Safe Homing for Z unless re-homing with probe.
+            // Assume that it only applies to the probe-homing step.
+            #if ENABLED(Z_SAFE_HOMING) && DISABLED(REHOME_Z_WITH_PROBE)
               // H means hold the current X/Y position when probing.
               // Otherwise move to the define safe X/Y position before homing Z.
               if (!parser.seen_test('H'))

diff --git a/Marlin/src/inc/Conditionals-3-etc.h b/Marlin/src/inc/Conditionals-3-etc.h
@@ -432,7 +432,14 @@
     #define NEED_Z_MIN_PROBE_PIN 1
   #endif
   #if Z_HOME_TO_MIN && (!NEED_Z_MIN_PROBE_PIN || ENABLED(USE_PROBE_FOR_Z_HOMING))
-    #define HOMING_Z_WITH_PROBE 1
+    #define HOMING_Z_WITH_PROBE 1     // Always home Z with probe
+  #endif
+  #if ANY(HOMING_Z_WITH_PROBE, REHOME_Z_WITH_PROBE)
+    #define Z_CAN_HOME_WITH_PROBE 1   // Can home Z with probe or endstop
+  #endif
+  #ifdef REHOME_Z_WITH_PROBE
+    #undef REHOME_Z_WITH_PROBE
+    #define REHOME_Z_WITH_PROBE 1 // ensure a value of 1 so we can use with #elif and TERN
   #endif
   #if DISABLED(NOZZLE_AS_PROBE)
     #define HAS_PROBE_XY_OFFSET 1

diff --git a/Marlin/src/inc/Conditionals-4-adv.h b/Marlin/src/inc/Conditionals-4-adv.h
@@ -160,6 +160,7 @@
   #undef ENABLE_LEVELING_FADE_HEIGHT
   #undef HOME_Z_FIRST
   #undef HOMING_Z_WITH_PROBE
+  #undef REHOME_Z_WITH_PROBE
   #undef INPUT_SHAPING_Z
   #undef NUM_Z_STEPPERS
   #undef SAFE_BED_LEVELING_START_Z

diff --git a/Marlin/src/inc/Conditionals-5-post.h b/Marlin/src/inc/Conditionals-5-post.h
@@ -1467,7 +1467,7 @@
   #endif
 
   // Disable Z axis sensorless homing if a probe is used to home the Z axis
-  #if HOMING_Z_WITH_PROBE
+  #if Z_CAN_HOME_WITH_PROBE
     #undef Z_STALL_SENSITIVITY
     #undef Z2_STALL_SENSITIVITY
     #undef Z3_STALL_SENSITIVITY

diff --git a/Marlin/src/inc/SanityCheck.h b/Marlin/src/inc/SanityCheck.h
@@ -2557,6 +2557,8 @@ static_assert(NUM_SERVOS <= NUM_SERVO_PLUGS, "NUM_SERVOS (or some servo index) i
   #error "Z_HOME_DIR must be -1 when homing Z with the probe."
 #elif ALL(USE_PROBE_FOR_Z_HOMING, HOME_Z_FIRST)
   #error "HOME_Z_FIRST can't be used when homing Z with a probe."
+#elif ALL(HOMING_Z_WITH_PROBE, REHOME_Z_WITH_PROBE)
+  #error "HOMING_Z_WITH_PROBE and REHOME_Z_WITH_PROBE are mutually-exclusive."
 #endif
 
 #if Z_HOME_TO_MAX && defined(Z_AFTER_HOMING) && DISABLED(ALLOW_Z_AFTER_HOMING)

diff --git a/Marlin/src/inc/Warnings.cpp b/Marlin/src/inc/Warnings.cpp
@@ -716,6 +716,10 @@
   #error "Z_SAFE_HOMING is recommended when homing with a probe. (Enable Z_SAFE_HOMING or define NO_Z_SAFE_HOMING_WARNING to suppress this warning.)"
 #endif
 
+#if REHOME_Z_WITH_PROBE && IS_CARTESIAN && NONE(Z_SAFE_HOMING, NO_Z_SAFE_HOMING_WARNING)
+  #error "Z_SAFE_HOMING is recommended when re-homing with a probe. (Enable Z_SAFE_HOMING or define NO_Z_SAFE_HOMING_WARNING to suppress this warning.)"
+#endif
+
 #if HAS_TRINAMIC_CONFIG && NONE(EDGE_STEPPING, NO_EDGE_STEPPING_WARNING)
   #error "EDGE_STEPPING is strongly recommended with Trinamic stepper drivers. (Enable EDGE_STEPPING or define NO_EDGE_STEPPING_WARNING to suppress this warning.)"
 #endif

diff --git a/Marlin/src/lcd/extui/mks_ui/draw_z_offset_wizard.cpp b/Marlin/src/lcd/extui/mks_ui/draw_z_offset_wizard.cpp
@@ -109,7 +109,7 @@ static void event_handler(lv_obj_t *obj, lv_event_t event) {
       SET_SOFT_ENDSTOP_LOOSE(false);
       TERN_(HAS_LEVELING, set_bed_leveling_enabled(mks_leveling_was_active));
       // On cancel the Z position needs correction
-      #if HOMING_Z_WITH_PROBE && defined(PROBE_OFFSET_WIZARD_START_Z)
+      #if Z_CAN_HOME_WITH_PROBE && defined(PROBE_OFFSET_WIZARD_START_Z)
         set_axis_never_homed(Z_AXIS);
         queue.inject_P(PSTR("G28Z"));
       #else

diff --git a/Marlin/src/lcd/menu/menu_probe_offset.cpp b/Marlin/src/lcd/menu/menu_probe_offset.cpp
@@ -82,7 +82,7 @@ void probe_offset_wizard_menu() {
   ACTION_ITEM(MSG_BUTTON_CANCEL, []{
     set_offset_and_go_back(z_offset_backup);
     // On cancel the Z position needs correction
-    #if HOMING_Z_WITH_PROBE && defined(PROBE_OFFSET_WIZARD_START_Z)
+    #if Z_CAN_HOME_WITH_PROBE && defined(PROBE_OFFSET_WIZARD_START_Z)
       set_axis_never_homed(Z_AXIS);
       queue.inject(F("G28Z"));
     #else
@@ -104,7 +104,7 @@ void probe_offset_wizard_menu() {
  *   3. Go to the probe_offset_wizard_menu() screen for Z position adjustment to acquire Z0.
  */
 void prepare_for_probe_offset_wizard() {
-  #if defined(PROBE_OFFSET_WIZARD_XY_POS) || !HOMING_Z_WITH_PROBE
+  #if defined(PROBE_OFFSET_WIZARD_XY_POS) || !Z_CAN_HOME_WITH_PROBE
     if (ui.should_draw()) MenuItem_static::draw(1, GET_TEXT_F(MSG_PROBE_WIZARD_PROBING));
 
     if (ui.wait_for_move) return;