printer.cfg modified - 04.10.2026 - 00:21:00

printer_data/config/printer.cfg

@@ -626,18 +626,27 @@ gcode:
    
 [gcode_macro PRINT_START]
 description: Heat, home, level, touch-calibrate, scan adaptively, and purge
+# Touch runs at 150 C, but the hotend grows as it heats further, which lowers
+# the nozzle at print temperature (most visible with ABS at 250-260 C).
+# Compensation = (EXTRUDER - touch_temp) * thermal_z_per_c, applied as a Z
+# gcode offset. Tune the base height only with TOUCH_SAVE_Z_OFFSET.
+variable_touch_temp: 150
+variable_thermal_z_per_c: 0.0004
+variable_thermal_z_comp: 0.0
 gcode:
     {% set bedtemp = params.BED|int %}
     {% set hotendtemp = params.EXTRUDER|int %}
+    {% set thermal_z_comp = ([hotendtemp - touch_temp, 0]|max * thermal_z_per_c)|round(3) %}
 
     SET_IDLE_TIMEOUT TIMEOUT={printer.configfile.settings.idle_timeout.timeout|int}
     G90
     SET_GCODE_OFFSET Z=0
+    SET_GCODE_VARIABLE MACRO=PRINT_START VARIABLE=thermal_z_comp VALUE=0.0
     SET_FAN_SPEED FAN=front SPEED=0.55
     STATUS_HOMING
     G28
     # Soften residue while the bed heats; Cartographer Touch uses at most 150 C.
-    M104 S150
+    M104 S{touch_temp}
     STATUS_HEATING
     M190 S{bedtemp}
     {% if bedtemp > 95 %}
@@ -647,7 +656,8 @@ gcode:
     {% endif %}
     STATUS_LEVELING
     QUAD_GANTRY_LEVEL
-    M109 S150
+    # The nozzle has been at touch_temp since homing, so tip residue is soft for the wipe.
+    M109 S{touch_temp}
     STATUS_CLEANING
     CLEAN_NOZZLE
     STATUS_CALIBRATING_Z
@@ -658,10 +668,23 @@ gcode:
     M107
     STATUS_HEATING
     M109 S{hotendtemp}
+    SET_GCODE_OFFSET Z={thermal_z_comp} MOVE=0
+    SET_GCODE_VARIABLE MACRO=PRINT_START VARIABLE=thermal_z_comp VALUE={thermal_z_comp}
+    { action_respond_info("PRINT_START: hot-nozzle Z compensation +%.3f mm for %d C" % (thermal_z_comp, hotendtemp)) }
     STATUS_CLEANING
     LINE_PURGE
     STATUS_PRINTING
 
+[gcode_macro TOUCH_SAVE_Z_OFFSET]
+description: Store baby-stepping into the Touch model without the hot-nozzle compensation; then run SAVE_CONFIG
+gcode:
+    {% set comp = printer["gcode_macro PRINT_START"].thermal_z_comp|float %}
+    {% set total = printer.gcode_move.homing_origin.z|float %}
+    { action_respond_info("TOUCH_SAVE_Z_OFFSET: gcode offset %.3f, of which hot-nozzle compensation %.3f; saving %.3f" % (total, comp, total - comp)) }
+    SET_GCODE_OFFSET Z_ADJUST={-comp} MOVE=0
+    Z_OFFSET_APPLY_PROBE
+    SET_GCODE_OFFSET Z_ADJUST={comp} MOVE=0
+
 [gcode_macro CARTOGRAPHER_MESH]
 description: Adaptive scan with a safe full-mesh fallback for unreachable edge-only objects
 gcode: